.機能追加、DBバグ修正

config.ini.example

@@ -51,5 +51,10 @@ rate_limit_enabled = true
 rate_limit_requests = 100
 # Window size in seconds
 rate_limit_window = 60
-# Trusted proxies (comma separated IP addresses or CIDR)
+#; Trusted proxies (comma separated IP addresses or CIDR)
-# trusted_proxies = 127.0.0.1, 10.0.0.0/8
+; trusted_proxies = 127.0.0.1, 10.0.0.0/8
+
+[notification]
+; Telegram Bot Token (@BotFatherで取得)
+; ユーザーはプロフィール画面でChat IDを設定します
+telegram_bot_token =

docs/API.md

@@ -45,6 +45,7 @@ X-API-Key: hm_XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 | PUT | `/api/v1/assignments/:id` | 課題更新 |
 | DELETE | `/api/v1/assignments/:id` | 課題削除 |
 | PATCH | `/api/v1/assignments/:id/toggle` | 完了状態トグル |
+| GET | `/api/v1/statistics` | 統計情報取得 |
 
 ---
 
@@ -369,6 +370,94 @@ curl -X PATCH \
 
 ---
 
+## 統計情報取得
+
+ユーザーの課題統計を取得します。科目、日付範囲でフィルタリング可能です。
+
+```
+GET /api/v1/statistics
+```
+
+### クエリパラメータ
+
+| パラメータ | 型 | 説明 |
+|------------|------|------|
+| `subject` | string | 科目で絞り込み（省略時: 全科目） |
+| `from` | string | 課題登録日の開始日（YYYY-MM-DD形式） |
+| `to` | string | 課題登録日の終了日（YYYY-MM-DD形式） |
+
+### レスポンス
+
+**200 OK**
+
+```json
+{
+  "total_assignments": 45,
+  "completed_assignments": 30,
+  "pending_assignments": 12,
+  "overdue_assignments": 3,
+  "on_time_completion_rate": 86.7,
+  "filter": {
+    "subject": null,
+    "from": "2025-01-01",
+    "to": "2025-12-31"
+  },
+  "subjects": [
+    {
+      "subject": "数学",
+      "total": 15,
+      "completed": 12,
+      "pending": 2,
+      "overdue": 1,
+      "on_time_completion_rate": 91.7
+    },
+    {
+      "subject": "英語",
+      "total": 10,
+      "completed": 8,
+      "pending": 2,
+      "overdue": 0,
+      "on_time_completion_rate": 87.5
+    }
+  ]
+}
+```
+
+### 科目別統計 (特定科目のみ)
+
+```json
+{
+  "total_assignments": 15,
+  "completed_assignments": 12,
+  "pending_assignments": 2,
+  "overdue_assignments": 1,
+  "on_time_completion_rate": 91.7,
+  "filter": {
+    "subject": "数学",
+    "from": null,
+    "to": null
+  }
+}
+```
+
+### 例
+
+```bash
+# 全体統計
+curl -H "X-API-Key: hm_xxx" http://localhost:8080/api/v1/statistics
+
+# 科目で絞り込み
+curl -H "X-API-Key: hm_xxx" "http://localhost:8080/api/v1/statistics?subject=数学"
+
+# 日付範囲で絞り込み
+curl -H "X-API-Key: hm_xxx" "http://localhost:8080/api/v1/statistics?from=2025-01-01&to=2025-03-31"
+
+# 科目と日付範囲の組み合わせ
+curl -H "X-API-Key: hm_xxx" "http://localhost:8080/api/v1/statistics?subject=数学&from=2025-01-01&to=2025-03-31"
+```
+
+---
+
 ## エラーレスポンス
 
 すべてのエラーレスポンスは以下の形式で返されます：

docs/SPECIFICATION.md

@@ -65,14 +65,37 @@ homework-manager/
 | Title | string | 課題タイトル | Not Null |
 | Description | string | 説明 | - |
 | Subject | string | 教科・科目 | - |
+| Priority | string | 重要度 (`low`, `medium`, `high`) | Default: `medium` |
 | DueDate | time.Time | 提出期限 | Not Null |
 | IsCompleted | bool | 完了フラグ | Default: false |
+| IsArchived | bool | アーカイブフラグ | Default: false |
 | CompletedAt | *time.Time | 完了日時 | Nullable |
+| ReminderEnabled | bool | 1回リマインダー有効 | Default: false |
+| ReminderAt | *time.Time | リマインダー通知日時 | Nullable |
+| ReminderSent | bool | リマインダー送信済み | Default: false |
+| UrgentReminderEnabled | bool | 督促通知有効 | Default: true |
+| LastUrgentReminderSent | *time.Time | 最終督促通知日時 | Nullable |
 | CreatedAt | time.Time | 作成日時 | 自動設定 |
 | UpdatedAt | time.Time | 更新日時 | 自動更新 |
 | DeletedAt | gorm.DeletedAt | 論理削除日時 | ソフトデリート |
 
-### 2.3 APIKey（APIキー）
+### 2.3 UserNotificationSettings（通知設定）
+
+ユーザーの通知設定を管理するモデル。
+
+| フィールド | 型 | 説明 | 制約 |
+|------------|------|------|------|
+| ID | uint | 設定ID | Primary Key |
+| UserID | uint | ユーザーID | Unique, Not Null |
+| TelegramEnabled | bool | Telegram通知 | Default: false |
+| TelegramChatID | string | Telegram Chat ID | - |
+| LineEnabled | bool | LINE通知 | Default: false |
+| LineNotifyToken | string | LINE Notifyトークン | - |
+| CreatedAt | time.Time | 作成日時 | 自動設定 |
+| UpdatedAt | time.Time | 更新日時 | 自動更新 |
+| DeletedAt | gorm.DeletedAt | 論理削除日時 | ソフトデリート |
+
+### 2.4 APIKey（APIキー）
 
 REST API認証用のAPIキーを管理するモデル。
 
@@ -130,18 +153,50 @@ REST API認証用のAPIキーを管理するモデル。
 |------|------|
 | ダッシュボード | 課題の統計情報、本日期限の課題、期限切れ課題、今週期限の課題を表示 |
 | 課題一覧 | フィルタ付き（未完了/完了済み/期限切れ）で課題を一覧表示 |
-| 課題登録 | タイトル、説明、教科、提出期限を入力して新規登録 |
+| 課題登録 | タイトル、説明、教科、重要度、提出期限、通知設定を入力して新規登録 |
 | 課題編集 | 既存の課題情報を編集 |
 | 課題削除 | 課題を論理削除 |
 | 完了トグル | 課題の完了/未完了状態を切り替え |
+| 統計 | 科目別の完了率、期限内完了率等を表示 |
 
-### 4.3 プロフィール機能
+### 4.3 通知機能
+
+#### 4.3.1 1回リマインダー
+
+指定した日時に1回だけ通知を送信する機能。
+
+| 項目 | 説明 |
+|------|------|
+| 設定 | 課題登録・編集画面で通知日時を指定 |
+| 送信 | 指定日時にTelegram/LINEで通知 |
+
+#### 4.3.2 督促通知
+
+課題を完了するまで繰り返し通知を送信する機能。デフォルトで有効。
+
+| 項目 | 説明 |
+|------|------|
+| 開始タイミング | 期限の **3時間前** |
+| 重要度「大」 | **10分**ごとに通知 |
+| 重要度「中」 | **30分**ごとに通知 |
+| 重要度「小」 | **60分**ごとに通知 |
+| 停止条件 | 課題の完了ボタンを押すまで継続 |
+
+#### 4.3.3 通知チャンネル
+
+| チャンネル | 設定方法 |
+|------------|----------|
+| Telegram | config.iniでBot Token設定、プロフィールでChat ID入力 |
+| LINE Notify | プロフィールでアクセストークン入力 |
+
+### 4.4 プロフィール機能
 
 | 機能 | 説明 |
 |------|------|
 | プロフィール表示 | ユーザー情報を表示 |
 | プロフィール更新 | 表示名を変更 |
 | パスワード変更 | 現在のパスワードを確認後、新しいパスワードに変更 |
+| 通知設定 | Telegram/LINE通知の有効化とトークン設定 |
 
 ### 4.4 管理者機能
 
@@ -183,6 +238,9 @@ csrf_secret = your-secure-csrf-secret
 rate_limit_enabled = true
 rate_limit_requests = 100
 rate_limit_window = 60
+
+[notification]
+ telegram_bot_token = your-telegram-bot-token
 ```
 
 ### 5.2 設定項目
@@ -200,6 +258,7 @@ rate_limit_window = 60
 | `security` | `rate_limit_enabled` | レート制限有効化 | `true` |
 | `security` | `rate_limit_requests` | 期間あたりの最大リクエスト数 | `100` |
 | `security` | `rate_limit_window` | 期間（秒） | `60` |
+| `notification` | `telegram_bot_token` | Telegram Bot Token | - |
 
 ### 5.3 環境変数
 
@@ -216,6 +275,7 @@ rate_limit_window = 60
 | `ALLOW_REGISTRATION` | 新規登録許可 (true/false) |
 | `HTTPS` | HTTPSモード (true/false) |
 | `TRUSTED_PROXIES` | 信頼するプロキシのリスト |
+| `TELEGRAM_BOT_TOKEN` | Telegram Bot Token |
 
 ### 5.4 設定の優先順位
 

internal/config/config.go

@@ -17,6 +17,10 @@ type DatabaseConfig struct {
 	Name     string
 }
 
+type NotificationConfig struct {
+	TelegramBotToken string
+}
+
 type Config struct {
 	Port              string
 	SessionSecret     string
@@ -29,6 +33,7 @@ type Config struct {
 	RateLimitWindow   int
 	TrustedProxies    []string
 	Database          DatabaseConfig
+	Notification      NotificationConfig
 }
 
 func Load(configPath string) *Config {
@@ -123,6 +128,12 @@ func Load(configPath string) *Config {
 				cfg.TrustedProxies = []string{proxies}
 			}
 		}
+
+		// Notification section
+		section = iniFile.Section("notification")
+		if section.HasKey("telegram_bot_token") {
+			cfg.Notification.TelegramBotToken = section.Key("telegram_bot_token").String()
+		}
 	} else {
 		log.Println("config.ini not found, using environment variables or defaults")
 	}
@@ -169,6 +180,9 @@ func Load(configPath string) *Config {
 	if trustedProxies := os.Getenv("TRUSTED_PROXIES"); trustedProxies != "" {
 		cfg.TrustedProxies = []string{trustedProxies}
 	}
+	if telegramToken := os.Getenv("TELEGRAM_BOT_TOKEN"); telegramToken != "" {
+		cfg.Notification.TelegramBotToken = telegramToken
+	}
 
 	if cfg.SessionSecret == "" {
 		log.Fatal("FATAL: Session secret is not set. Please set it in config.ini ([session] secret) or via SESSION_SECRET environment variable.")

internal/database/database.go

@@ -2,6 +2,7 @@ package database
 
 import (
 	"fmt"
+	"time"
 
 	"homework-manager/internal/config"
 	"homework-manager/internal/models"
@@ -61,6 +62,21 @@ func Connect(dbConfig config.DatabaseConfig, debug bool) error {
 		return err
 	}
 
+	// Set connection pool settings
+	sqlDB, err := db.DB()
+	if err != nil {
+		return err
+	}
+
+	// SetMaxIdleConns sets the maximum number of connections in the idle connection pool.
+	sqlDB.SetMaxIdleConns(10)
+
+	// SetMaxOpenConns sets the maximum number of open connections to the database.
+	sqlDB.SetMaxOpenConns(100)
+
+	// SetConnMaxLifetime sets the maximum amount of time a connection may be reused.
+	sqlDB.SetConnMaxLifetime(time.Hour)
+
 	DB = db
 	return nil
 }
@@ -70,10 +86,10 @@ func Migrate() error {
 		&models.User{},
 		&models.Assignment{},
 		&models.APIKey{},
+		&models.UserNotificationSettings{},
 	)
 }
 
 func GetDB() *gorm.DB {
 	return DB
 }
-

internal/handler/api_handler.go

@@ -285,7 +285,7 @@ func (h *APIHandler) CreateAssignment(c *gin.Context) {
 		}
 	}
 
-	assignment, err := h.assignmentService.Create(userID, input.Title, input.Description, input.Subject, input.Priority, dueDate)
+	assignment, err := h.assignmentService.Create(userID, input.Title, input.Description, input.Subject, input.Priority, dueDate, false, nil, true)
 	if err != nil {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create assignment"})
 		return
@@ -351,7 +351,8 @@ func (h *APIHandler) UpdateAssignment(c *gin.Context) {
 		}
 	}
 
-	assignment, err := h.assignmentService.Update(userID, uint(id), title, description, subject, priority, dueDate)
+	// Preserve existing reminder settings for API updates
+	assignment, err := h.assignmentService.Update(userID, uint(id), title, description, subject, priority, dueDate, existing.ReminderEnabled, existing.ReminderAt, existing.UrgentReminderEnabled)
 	if err != nil {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to update assignment"})
 		return
@@ -396,3 +397,44 @@ func (h *APIHandler) ToggleAssignment(c *gin.Context) {
 
 	c.JSON(http.StatusOK, assignment)
 }
+
+// GetStatistics returns statistics for the authenticated user
+// GET /api/v1/statistics?subject=数学&from=2025-01-01&to=2025-12-31&include_archived=true
+func (h *APIHandler) GetStatistics(c *gin.Context) {
+	userID := h.getUserID(c)
+
+	// Parse filter parameters
+	filter := service.StatisticsFilter{
+		Subject:         c.Query("subject"),
+		IncludeArchived: c.Query("include_archived") == "true",
+	}
+
+	// Parse from date
+	if fromStr := c.Query("from"); fromStr != "" {
+		fromDate, err := time.ParseInLocation("2006-01-02", fromStr, time.Local)
+		if err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid 'from' date format. Use YYYY-MM-DD"})
+			return
+		}
+		filter.From = &fromDate
+	}
+
+	// Parse to date
+	if toStr := c.Query("to"); toStr != "" {
+		toDate, err := time.ParseInLocation("2006-01-02", toStr, time.Local)
+		if err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid 'to' date format. Use YYYY-MM-DD"})
+			return
+		}
+		filter.To = &toDate
+	}
+
+	stats, err := h.assignmentService.GetStatistics(userID, filter)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to fetch statistics"})
+		return
+	}
+
+	c.JSON(http.StatusOK, stats)
+}
+

internal/handler/assignment_handler.go

@@ -119,6 +119,17 @@ func (h *AssignmentHandler) Create(c *gin.Context) {
 	priority := c.PostForm("priority")
 	dueDateStr := c.PostForm("due_date")
 
+	// Parse reminder settings
+	reminderEnabled := c.PostForm("reminder_enabled") == "on"
+	reminderAtStr := c.PostForm("reminder_at")
+	var reminderAt *time.Time
+	if reminderEnabled && reminderAtStr != "" {
+		if parsed, err := time.ParseInLocation("2006-01-02T15:04", reminderAtStr, time.Local); err == nil {
+			reminderAt = &parsed
+		}
+	}
+	urgentReminderEnabled := c.PostForm("urgent_reminder_enabled") == "on"
+
 	dueDate, err := time.ParseInLocation("2006-01-02T15:04", dueDateStr, time.Local)
 	if err != nil {
 		dueDate, err = time.ParseInLocation("2006-01-02", dueDateStr, time.Local)
@@ -140,7 +151,7 @@ func (h *AssignmentHandler) Create(c *gin.Context) {
 		dueDate = dueDate.Add(23*time.Hour + 59*time.Minute)
 	}
 
-	_, err = h.assignmentService.Create(userID, title, description, subject, priority, dueDate)
+	_, err = h.assignmentService.Create(userID, title, description, subject, priority, dueDate, reminderEnabled, reminderAt, urgentReminderEnabled)
 	if err != nil {
 		role, _ := c.Get(middleware.UserRoleKey)
 		name, _ := c.Get(middleware.UserNameKey)
@@ -191,6 +202,17 @@ func (h *AssignmentHandler) Update(c *gin.Context) {
 	priority := c.PostForm("priority")
 	dueDateStr := c.PostForm("due_date")
 
+	// Parse reminder settings
+	reminderEnabled := c.PostForm("reminder_enabled") == "on"
+	reminderAtStr := c.PostForm("reminder_at")
+	var reminderAt *time.Time
+	if reminderEnabled && reminderAtStr != "" {
+		if parsed, err := time.ParseInLocation("2006-01-02T15:04", reminderAtStr, time.Local); err == nil {
+			reminderAt = &parsed
+		}
+	}
+	urgentReminderEnabled := c.PostForm("urgent_reminder_enabled") == "on"
+
 	dueDate, err := time.ParseInLocation("2006-01-02T15:04", dueDateStr, time.Local)
 	if err != nil {
 		dueDate, err = time.ParseInLocation("2006-01-02", dueDateStr, time.Local)
@@ -201,7 +223,7 @@ func (h *AssignmentHandler) Update(c *gin.Context) {
 		dueDate = dueDate.Add(23*time.Hour + 59*time.Minute)
 	}
 
-	_, err = h.assignmentService.Update(userID, uint(id), title, description, subject, priority, dueDate)
+	_, err = h.assignmentService.Update(userID, uint(id), title, description, subject, priority, dueDate, reminderEnabled, reminderAt, urgentReminderEnabled)
 	if err != nil {
 		c.Redirect(http.StatusFound, "/assignments")
 		return
@@ -231,3 +253,90 @@ func (h *AssignmentHandler) Delete(c *gin.Context) {
 
 	c.Redirect(http.StatusFound, "/assignments")
 }
+
+func (h *AssignmentHandler) Statistics(c *gin.Context) {
+	userID := h.getUserID(c)
+	role, _ := c.Get(middleware.UserRoleKey)
+	name, _ := c.Get(middleware.UserNameKey)
+
+	// Parse filter parameters
+	filter := service.StatisticsFilter{
+		Subject:         c.Query("subject"),
+		IncludeArchived: c.Query("include_archived") == "true",
+	}
+
+	fromStr := c.Query("from")
+	toStr := c.Query("to")
+
+	// Parse from date
+	if fromStr != "" {
+		fromDate, err := time.ParseInLocation("2006-01-02", fromStr, time.Local)
+		if err == nil {
+			filter.From = &fromDate
+		}
+	}
+
+	// Parse to date
+	if toStr != "" {
+		toDate, err := time.ParseInLocation("2006-01-02", toStr, time.Local)
+		if err == nil {
+			filter.To = &toDate
+		}
+	}
+
+	stats, err := h.assignmentService.GetStatistics(userID, filter)
+	if err != nil {
+		RenderHTML(c, http.StatusInternalServerError, "error.html", gin.H{
+			"title":   "エラー",
+			"message": "統計情報の取得に失敗しました",
+		})
+		return
+	}
+
+	// Get available subjects for filter dropdown (exclude archived)
+	subjects, _ := h.assignmentService.GetSubjectsWithArchived(userID, false)
+	archivedSubjects, _ := h.assignmentService.GetArchivedSubjects(userID)
+
+	// Create a map for quick lookup of archived subjects
+	archivedMap := make(map[string]bool)
+	for _, s := range archivedSubjects {
+		archivedMap[s] = true
+	}
+
+	RenderHTML(c, http.StatusOK, "assignments/statistics.html", gin.H{
+		"title":            "統計",
+		"stats":            stats,
+		"subjects":         subjects,
+		"archivedSubjects": archivedMap,
+		"selectedSubject":  filter.Subject,
+		"fromDate":         fromStr,
+		"toDate":           toStr,
+		"includeArchived":  filter.IncludeArchived,
+		"isAdmin":          role == "admin",
+		"userName":         name,
+	})
+}
+
+func (h *AssignmentHandler) ArchiveSubject(c *gin.Context) {
+	userID := h.getUserID(c)
+	subject := c.PostForm("subject")
+
+	if subject != "" {
+		h.assignmentService.ArchiveSubject(userID, subject)
+	}
+
+	c.Redirect(http.StatusFound, "/statistics")
+}
+
+func (h *AssignmentHandler) UnarchiveSubject(c *gin.Context) {
+	userID := h.getUserID(c)
+	subject := c.PostForm("subject")
+
+	if subject != "" {
+		h.assignmentService.UnarchiveSubject(userID, subject)
+	}
+
+	c.Redirect(http.StatusFound, "/statistics?include_archived=true")
+}
+
+

internal/handler/profile_handler.go

@@ -4,18 +4,21 @@ import (
 	"net/http"
 
 	"homework-manager/internal/middleware"
+	"homework-manager/internal/models"
 	"homework-manager/internal/service"
 
 	"github.com/gin-gonic/gin"
 )
 
 type ProfileHandler struct {
-	authService *service.AuthService
+	authService         *service.AuthService
+	notificationService *service.NotificationService
 }
 
-func NewProfileHandler() *ProfileHandler {
+func NewProfileHandler(notificationService *service.NotificationService) *ProfileHandler {
 	return &ProfileHandler{
-		authService: service.NewAuthService(),
+		authService:         service.NewAuthService(),
+		notificationService: notificationService,
 	}
 }
 
@@ -27,15 +30,17 @@ func (h *ProfileHandler) getUserID(c *gin.Context) uint {
 func (h *ProfileHandler) Show(c *gin.Context) {
 	userID := h.getUserID(c)
 	user, _ := h.authService.GetUserByID(userID)
+	notifySettings, _ := h.notificationService.GetUserSettings(userID)
 
 	role, _ := c.Get(middleware.UserRoleKey)
 	name, _ := c.Get(middleware.UserNameKey)
 
 	RenderHTML(c, http.StatusOK, "profile.html", gin.H{
-		"title":    "プロフィール",
+		"title":          "プロフィール",
-		"user":     user,
+		"user":           user,
-		"isAdmin":  role == "admin",
+		"isAdmin":        role == "admin",
-		"userName": name,
+		"userName":       name,
+		"notifySettings": notifySettings,
 	})
 }
 
@@ -47,24 +52,27 @@ func (h *ProfileHandler) Update(c *gin.Context) {
 
 	role, _ := c.Get(middleware.UserRoleKey)
 	user, _ := h.authService.GetUserByID(userID)
+	notifySettings, _ := h.notificationService.GetUserSettings(userID)
 
 	if err != nil {
 		RenderHTML(c, http.StatusOK, "profile.html", gin.H{
-			"title":    "プロフィール",
+			"title":          "プロフィール",
-			"user":     user,
+			"user":           user,
-			"error":    "プロフィールの更新に失敗しました",
+			"error":          "プロフィールの更新に失敗しました",
-			"isAdmin":  role == "admin",
+			"isAdmin":        role == "admin",
-			"userName": name,
+			"userName":       name,
+			"notifySettings": notifySettings,
 		})
 		return
 	}
 
 	RenderHTML(c, http.StatusOK, "profile.html", gin.H{
-		"title":    "プロフィール",
+		"title":          "プロフィール",
-		"user":     user,
+		"user":           user,
-		"success":  "プロフィールを更新しました",
+		"success":        "プロフィールを更新しました",
-		"isAdmin":  role == "admin",
+		"isAdmin":        role == "admin",
-		"userName": user.Name,
+		"userName":       user.Name,
+		"notifySettings": notifySettings,
 	})
 }
 
@@ -77,25 +85,28 @@ func (h *ProfileHandler) ChangePassword(c *gin.Context) {
 	role, _ := c.Get(middleware.UserRoleKey)
 	name, _ := c.Get(middleware.UserNameKey)
 	user, _ := h.authService.GetUserByID(userID)
+	notifySettings, _ := h.notificationService.GetUserSettings(userID)
 
 	if newPassword != confirmPassword {
 		RenderHTML(c, http.StatusOK, "profile.html", gin.H{
-			"title":         "プロフィール",
+			"title":          "プロフィール",
-			"user":          user,
+			"user":           user,
-			"passwordError": "新しいパスワードが一致しません",
+			"passwordError":  "新しいパスワードが一致しません",
-			"isAdmin":       role == "admin",
+			"isAdmin":        role == "admin",
-			"userName":      name,
+			"userName":       name,
+			"notifySettings": notifySettings,
 		})
 		return
 	}
 
 	if len(newPassword) < 8 {
 		RenderHTML(c, http.StatusOK, "profile.html", gin.H{
-			"title":         "プロフィール",
+			"title":          "プロフィール",
-			"user":          user,
+			"user":           user,
-			"passwordError": "パスワードは8文字以上で入力してください",
+			"passwordError":  "パスワードは8文字以上で入力してください",
-			"isAdmin":       role == "admin",
+			"isAdmin":        role == "admin",
-			"userName":      name,
+			"userName":       name,
+			"notifySettings": notifySettings,
 		})
 		return
 	}
@@ -103,11 +114,12 @@ func (h *ProfileHandler) ChangePassword(c *gin.Context) {
 	err := h.authService.ChangePassword(userID, oldPassword, newPassword)
 	if err != nil {
 		RenderHTML(c, http.StatusOK, "profile.html", gin.H{
-			"title":         "プロフィール",
+			"title":          "プロフィール",
-			"user":          user,
+			"user":           user,
-			"passwordError": "現在のパスワードが正しくありません",
+			"passwordError":  "現在のパスワードが正しくありません",
-			"isAdmin":       role == "admin",
+			"isAdmin":        role == "admin",
-			"userName":      name,
+			"userName":       name,
+			"notifySettings": notifySettings,
 		})
 		return
 	}
@@ -118,5 +130,46 @@ func (h *ProfileHandler) ChangePassword(c *gin.Context) {
 		"passwordSuccess": "パスワードを変更しました",
 		"isAdmin":         role == "admin",
 		"userName":        name,
+		"notifySettings":  notifySettings,
 	})
 }
+
+func (h *ProfileHandler) UpdateNotificationSettings(c *gin.Context) {
+	userID := h.getUserID(c)
+	role, _ := c.Get(middleware.UserRoleKey)
+	name, _ := c.Get(middleware.UserNameKey)
+	user, _ := h.authService.GetUserByID(userID)
+
+	settings := &models.UserNotificationSettings{
+		TelegramEnabled: c.PostForm("telegram_enabled") == "on",
+		TelegramChatID:  c.PostForm("telegram_chat_id"),
+		LineEnabled:     c.PostForm("line_enabled") == "on",
+		LineNotifyToken: c.PostForm("line_token"),
+	}
+
+	err := h.notificationService.UpdateUserSettings(userID, settings)
+
+	notifySettings, _ := h.notificationService.GetUserSettings(userID)
+
+	if err != nil {
+		RenderHTML(c, http.StatusOK, "profile.html", gin.H{
+			"title":          "プロフィール",
+			"user":           user,
+			"notifyError":    "通知設定の更新に失敗しました",
+			"isAdmin":        role == "admin",
+			"userName":       name,
+			"notifySettings": notifySettings,
+		})
+		return
+	}
+
+	RenderHTML(c, http.StatusOK, "profile.html", gin.H{
+		"title":          "プロフィール",
+		"user":           user,
+		"notifySuccess":  "通知設定を更新しました",
+		"isAdmin":        role == "admin",
+		"userName":       name,
+		"notifySettings": notifySettings,
+	})
+}
+

internal/models/assignment.go

@@ -15,10 +15,18 @@ type Assignment struct {
 	Priority    string         `gorm:"not null;default:medium" json:"priority"` // low, medium, high
 	DueDate     time.Time      `gorm:"not null" json:"due_date"`
 	IsCompleted bool           `gorm:"default:false" json:"is_completed"`
+	IsArchived  bool           `gorm:"default:false;index" json:"is_archived"`
 	CompletedAt *time.Time     `json:"completed_at,omitempty"`
-	CreatedAt   time.Time      `json:"created_at"`
+	// Reminder notification settings (one-time)
-	UpdatedAt   time.Time      `json:"updated_at"`
+	ReminderEnabled bool       `gorm:"default:false" json:"reminder_enabled"`
-	DeletedAt   gorm.DeletedAt `gorm:"index" json:"-"`
+	ReminderAt      *time.Time `json:"reminder_at,omitempty"`
+	ReminderSent    bool       `gorm:"default:false;index" json:"reminder_sent"`
+	// Urgent reminder settings (repeating until completed)
+	UrgentReminderEnabled   bool       `gorm:"default:true" json:"urgent_reminder_enabled"`
+	LastUrgentReminderSent  *time.Time `json:"last_urgent_reminder_sent,omitempty"`
+	CreatedAt               time.Time  `json:"created_at"`
+	UpdatedAt               time.Time  `json:"updated_at"`
+	DeletedAt               gorm.DeletedAt `gorm:"index" json:"-"`
 
 	User *User `gorm:"foreignKey:UserID" json:"user,omitempty"`
 }

internal/models/notification_settings.go

@@ -0,0 +1,22 @@
+package models
+
+import (
+	"time"
+
+	"gorm.io/gorm"
+)
+
+// UserNotificationSettings stores user's notification preferences
+type UserNotificationSettings struct {
+	ID              uint           `gorm:"primarykey" json:"id"`
+	UserID          uint           `gorm:"uniqueIndex;not null" json:"user_id"`
+	TelegramEnabled bool           `gorm:"default:false" json:"telegram_enabled"`
+	TelegramChatID  string         `json:"telegram_chat_id"`
+	LineEnabled     bool           `gorm:"default:false" json:"line_enabled"`
+	LineNotifyToken string         `json:"-"` // Hide token from JSON
+	CreatedAt       time.Time      `json:"created_at"`
+	UpdatedAt       time.Time      `json:"updated_at"`
+	DeletedAt       gorm.DeletedAt `gorm:"index" json:"-"`
+
+	User *User `gorm:"foreignKey:UserID" json:"-"`
+}

internal/repository/assignment_repository.go

@@ -186,3 +186,181 @@ func (r *AssignmentRepository) CountOverdueByUserID(userID uint) (int64, error)
 		Where("user_id = ? AND is_completed = ? AND due_date < ?", userID, false, now).Count(&count).Error
 	return count, err
 }
+
+// StatisticsFilter holds filter parameters for statistics queries
+type StatisticsFilter struct {
+	Subject         string
+	From            *time.Time
+	To              *time.Time
+	IncludeArchived bool
+}
+
+// AssignmentStatistics holds statistics data
+type AssignmentStatistics struct {
+	Total                  int64
+	Completed              int64
+	Pending                int64
+	Overdue                int64
+	CompletedOnTime        int64
+	OnTimeCompletionRate   float64
+}
+
+// SubjectStatistics holds statistics for a specific subject
+type SubjectStatistics struct {
+	Subject              string
+	Total                int64
+	Completed            int64
+	Pending              int64
+	Overdue              int64
+	CompletedOnTime      int64
+	OnTimeCompletionRate float64
+}
+
+// GetStatistics returns statistics for a user with optional filters
+func (r *AssignmentRepository) GetStatistics(userID uint, filter StatisticsFilter) (*AssignmentStatistics, error) {
+	now := time.Now()
+	stats := &AssignmentStatistics{}
+
+	// Base query
+	baseQuery := r.db.Model(&models.Assignment{}).Where("user_id = ?", userID)
+	
+	// Apply subject filter
+	if filter.Subject != "" {
+		baseQuery = baseQuery.Where("subject = ?", filter.Subject)
+	}
+	
+	// Apply date range filter (by created_at)
+	if filter.From != nil {
+		baseQuery = baseQuery.Where("created_at >= ?", *filter.From)
+	}
+	if filter.To != nil {
+		// Add 1 day to include the entire "to" date
+		toEnd := filter.To.AddDate(0, 0, 1)
+		baseQuery = baseQuery.Where("created_at < ?", toEnd)
+	}
+
+	// Apply archived filter
+	if !filter.IncludeArchived {
+		baseQuery = baseQuery.Where("is_archived = ?", false)
+	}
+
+	// Total count
+	if err := baseQuery.Count(&stats.Total).Error; err != nil {
+		return nil, err
+	}
+
+	// Completed count
+	completedQuery := baseQuery.Session(&gorm.Session{})
+	if err := completedQuery.Where("is_completed = ?", true).Count(&stats.Completed).Error; err != nil {
+		return nil, err
+	}
+
+	// Pending count
+	pendingQuery := baseQuery.Session(&gorm.Session{})
+	if err := pendingQuery.Where("is_completed = ?", false).Count(&stats.Pending).Error; err != nil {
+		return nil, err
+	}
+
+	// Overdue count
+	overdueQuery := baseQuery.Session(&gorm.Session{})
+	if err := overdueQuery.Where("is_completed = ? AND due_date < ?", false, now).Count(&stats.Overdue).Error; err != nil {
+		return nil, err
+	}
+
+	// Completed on time count (completed_at <= due_date)
+	onTimeQuery := baseQuery.Session(&gorm.Session{})
+	if err := onTimeQuery.Where("is_completed = ? AND completed_at <= due_date", true).Count(&stats.CompletedOnTime).Error; err != nil {
+		return nil, err
+	}
+
+	// Calculate on-time completion rate
+	if stats.Completed > 0 {
+		stats.OnTimeCompletionRate = float64(stats.CompletedOnTime) / float64(stats.Completed) * 100
+	}
+
+	return stats, nil
+}
+
+// GetStatisticsBySubjects returns statistics grouped by subject
+func (r *AssignmentRepository) GetStatisticsBySubjects(userID uint, filter StatisticsFilter) ([]SubjectStatistics, error) {
+	now := time.Now()
+	subjects, err := r.GetSubjectsByUserID(userID)
+	if err != nil {
+		return nil, err
+	}
+
+	var results []SubjectStatistics
+	for _, subject := range subjects {
+		subjectFilter := StatisticsFilter{
+			Subject: subject,
+			From:    filter.From,
+			To:      filter.To,
+		}
+		stats, err := r.GetStatistics(userID, subjectFilter)
+		if err != nil {
+			return nil, err
+		}
+
+		// Count overdue for this subject
+		overdueQuery := r.db.Model(&models.Assignment{}).
+			Where("user_id = ? AND subject = ? AND is_completed = ? AND due_date < ?", userID, subject, false, now)
+		if filter.From != nil {
+			overdueQuery = overdueQuery.Where("created_at >= ?", *filter.From)
+		}
+		if filter.To != nil {
+			toEnd := filter.To.AddDate(0, 0, 1)
+			overdueQuery = overdueQuery.Where("created_at < ?", toEnd)
+		}
+		var overdueCount int64
+		overdueQuery.Count(&overdueCount)
+
+		results = append(results, SubjectStatistics{
+			Subject:              subject,
+			Total:                stats.Total,
+			Completed:            stats.Completed,
+			Pending:              stats.Pending,
+			Overdue:              overdueCount,
+			CompletedOnTime:      stats.CompletedOnTime,
+			OnTimeCompletionRate: stats.OnTimeCompletionRate,
+		})
+	}
+
+	return results, nil
+}
+
+// ArchiveBySubject archives all assignments for a subject
+func (r *AssignmentRepository) ArchiveBySubject(userID uint, subject string) error {
+	return r.db.Model(&models.Assignment{}).
+		Where("user_id = ? AND subject = ?", userID, subject).
+		Update("is_archived", true).Error
+}
+
+// UnarchiveBySubject unarchives all assignments for a subject
+func (r *AssignmentRepository) UnarchiveBySubject(userID uint, subject string) error {
+	return r.db.Model(&models.Assignment{}).
+		Where("user_id = ? AND subject = ?", userID, subject).
+		Update("is_archived", false).Error
+}
+
+// GetArchivedSubjects returns a list of archived subjects for a user
+func (r *AssignmentRepository) GetArchivedSubjects(userID uint) ([]string, error) {
+	var subjects []string
+	err := r.db.Model(&models.Assignment{}).
+		Where("user_id = ? AND is_archived = ? AND subject != ''", userID, true).
+		Distinct("subject").
+		Pluck("subject", &subjects).Error
+	return subjects, err
+}
+
+// GetSubjectsByUserIDWithArchived returns subjects optionally including archived
+func (r *AssignmentRepository) GetSubjectsByUserIDWithArchived(userID uint, includeArchived bool) ([]string, error) {
+	var subjects []string
+	query := r.db.Model(&models.Assignment{}).
+		Where("user_id = ? AND subject != ''", userID)
+	if !includeArchived {
+		query = query.Where("is_archived = ?", false)
+	}
+	err := query.Distinct("subject").Pluck("subject", &subjects).Error
+	return subjects, err
+}
+

internal/router/router.go

@@ -36,6 +36,15 @@ func getFuncMap() template.FuncMap {
 		"daysUntil": func(t time.Time) int {
 			return int(time.Until(t).Hours() / 24)
 		},
+		"divideFloat": func(a, b int64) float64 {
+			if b == 0 {
+				return 0
+			}
+			return float64(a) / float64(b)
+		},
+		"multiplyFloat": func(a float64, b float64) float64 {
+			return a * b
+		},
 	}
 }
 
@@ -164,11 +173,15 @@ func Setup(cfg *config.Config) *gin.Engine {
 
 	authService := service.NewAuthService()
 	apiKeyService := service.NewAPIKeyService()
+	notificationService := service.NewNotificationService(cfg.Notification.TelegramBotToken)
+
+	// Start notification reminder scheduler
+	notificationService.StartReminderScheduler()
 
 	authHandler := handler.NewAuthHandler()
 	assignmentHandler := handler.NewAssignmentHandler()
 	adminHandler := handler.NewAdminHandler()
-	profileHandler := handler.NewProfileHandler()
+	profileHandler := handler.NewProfileHandler(notificationService)
 	apiHandler := handler.NewAPIHandler()
 
 	guest := r.Group("/")
@@ -205,9 +218,15 @@ func Setup(cfg *config.Config) *gin.Engine {
 		auth.POST("/assignments/:id/toggle", assignmentHandler.Toggle)
 		auth.POST("/assignments/:id/delete", assignmentHandler.Delete)
 
+		auth.GET("/statistics", assignmentHandler.Statistics)
+		auth.POST("/statistics/archive-subject", assignmentHandler.ArchiveSubject)
+		auth.POST("/statistics/unarchive-subject", assignmentHandler.UnarchiveSubject)
+
 		auth.GET("/profile", profileHandler.Show)
 		auth.POST("/profile", profileHandler.Update)
 		auth.POST("/profile/password", profileHandler.ChangePassword)
+		auth.POST("/profile/notifications", profileHandler.UpdateNotificationSettings)
+
 		admin := auth.Group("/admin")
 		admin.Use(middleware.AdminRequired())
 		{
@@ -235,6 +254,7 @@ func Setup(cfg *config.Config) *gin.Engine {
 		api.PUT("/assignments/:id", apiHandler.UpdateAssignment)
 		api.DELETE("/assignments/:id", apiHandler.DeleteAssignment)
 		api.PATCH("/assignments/:id/toggle", apiHandler.ToggleAssignment)
+		api.GET("/statistics", apiHandler.GetStatistics)
 	}
 
 	return r

internal/service/assignment_service.go

@@ -31,18 +31,22 @@ func NewAssignmentService() *AssignmentService {
 	}
 }
 
-func (s *AssignmentService) Create(userID uint, title, description, subject, priority string, dueDate time.Time) (*models.Assignment, error) {
+func (s *AssignmentService) Create(userID uint, title, description, subject, priority string, dueDate time.Time, reminderEnabled bool, reminderAt *time.Time, urgentReminderEnabled bool) (*models.Assignment, error) {
 	if priority == "" {
 		priority = "medium"
 	}
 	assignment := &models.Assignment{
-		UserID:      userID,
+		UserID:                userID,
-		Title:       title,
+		Title:                 title,
-		Description: description,
+		Description:           description,
-		Subject:     subject,
+		Subject:               subject,
-		Priority:    priority,
+		Priority:              priority,
-		DueDate:     dueDate,
+		DueDate:               dueDate,
-		IsCompleted: false,
+		IsCompleted:           false,
+		ReminderEnabled:       reminderEnabled,
+		ReminderAt:            reminderAt,
+		ReminderSent:          false,
+		UrgentReminderEnabled: urgentReminderEnabled,
 	}
 
 	if err := s.assignmentRepo.Create(assignment); err != nil {
@@ -191,7 +195,7 @@ func (s *AssignmentService) SearchAssignments(userID uint, query, priority, filt
 	}, nil
 }
 
-func (s *AssignmentService) Update(userID, assignmentID uint, title, description, subject, priority string, dueDate time.Time) (*models.Assignment, error) {
+func (s *AssignmentService) Update(userID, assignmentID uint, title, description, subject, priority string, dueDate time.Time, reminderEnabled bool, reminderAt *time.Time, urgentReminderEnabled bool) (*models.Assignment, error) {
 	assignment, err := s.GetByID(userID, assignmentID)
 	if err != nil {
 		return nil, err
@@ -202,6 +206,13 @@ func (s *AssignmentService) Update(userID, assignmentID uint, title, description
 	assignment.Subject = subject
 	assignment.Priority = priority
 	assignment.DueDate = dueDate
+	assignment.ReminderEnabled = reminderEnabled
+	assignment.ReminderAt = reminderAt
+	assignment.UrgentReminderEnabled = urgentReminderEnabled
+	// Reset reminder sent flag if reminder settings changed
+	if reminderEnabled && reminderAt != nil {
+		assignment.ReminderSent = false
+	}
 
 	if err := s.assignmentRepo.Update(assignment); err != nil {
 		return nil, err
@@ -267,3 +278,133 @@ func (s *AssignmentService) GetDashboardStats(userID uint) (*DashboardStats, err
 		Subjects:      subjects,
 	}, nil
 }
+
+// StatisticsFilter holds filter parameters for statistics
+type StatisticsFilter struct {
+	Subject         string
+	From            *time.Time
+	To              *time.Time
+	IncludeArchived bool
+}
+
+// SubjectStats holds statistics for a subject
+type SubjectStats struct {
+	Subject              string  `json:"subject"`
+	Total                int64   `json:"total"`
+	Completed            int64   `json:"completed"`
+	Pending              int64   `json:"pending"`
+	Overdue              int64   `json:"overdue"`
+	OnTimeCompletionRate float64 `json:"on_time_completion_rate"`
+	IsArchived           bool    `json:"is_archived,omitempty"`
+}
+
+// StatisticsSummary holds overall statistics
+type StatisticsSummary struct {
+	TotalAssignments     int64          `json:"total_assignments"`
+	CompletedAssignments int64          `json:"completed_assignments"`
+	PendingAssignments   int64          `json:"pending_assignments"`
+	OverdueAssignments   int64          `json:"overdue_assignments"`
+	OnTimeCompletionRate float64        `json:"on_time_completion_rate"`
+	Filter               *FilterInfo    `json:"filter,omitempty"`
+	Subjects             []SubjectStats `json:"subjects,omitempty"`
+}
+
+// FilterInfo shows applied filters in response
+type FilterInfo struct {
+	Subject         *string `json:"subject"`
+	From            *string `json:"from"`
+	To              *string `json:"to"`
+	IncludeArchived bool    `json:"include_archived"`
+}
+
+// GetStatistics returns statistics for a user with optional filters
+func (s *AssignmentService) GetStatistics(userID uint, filter StatisticsFilter) (*StatisticsSummary, error) {
+	// Convert filter to repository filter
+	repoFilter := repository.StatisticsFilter{
+		Subject:         filter.Subject,
+		From:            filter.From,
+		To:              filter.To,
+		IncludeArchived: filter.IncludeArchived,
+	}
+
+	// Get overall statistics
+	stats, err := s.assignmentRepo.GetStatistics(userID, repoFilter)
+	if err != nil {
+		return nil, err
+	}
+
+	summary := &StatisticsSummary{
+		TotalAssignments:     stats.Total,
+		CompletedAssignments: stats.Completed,
+		PendingAssignments:   stats.Pending,
+		OverdueAssignments:   stats.Overdue,
+		OnTimeCompletionRate: stats.OnTimeCompletionRate,
+	}
+
+	// Build filter info
+	filterInfo := &FilterInfo{}
+	hasFilter := false
+	if filter.Subject != "" {
+		filterInfo.Subject = &filter.Subject
+		hasFilter = true
+	}
+	if filter.From != nil {
+		fromStr := filter.From.Format("2006-01-02")
+		filterInfo.From = &fromStr
+		hasFilter = true
+	}
+	if filter.To != nil {
+		toStr := filter.To.Format("2006-01-02")
+		filterInfo.To = &toStr
+		hasFilter = true
+	}
+	filterInfo.IncludeArchived = filter.IncludeArchived
+	if filter.IncludeArchived {
+		hasFilter = true
+	}
+	if hasFilter {
+		summary.Filter = filterInfo
+	}
+
+	// If no specific subject filter, get per-subject statistics
+	if filter.Subject == "" {
+		subjectStats, err := s.assignmentRepo.GetStatisticsBySubjects(userID, repoFilter)
+		if err != nil {
+			return nil, err
+		}
+
+		for _, ss := range subjectStats {
+			summary.Subjects = append(summary.Subjects, SubjectStats{
+				Subject:              ss.Subject,
+				Total:                ss.Total,
+				Completed:            ss.Completed,
+				Pending:              ss.Pending,
+				Overdue:              ss.Overdue,
+				OnTimeCompletionRate: ss.OnTimeCompletionRate,
+			})
+		}
+	}
+
+	return summary, nil
+}
+
+// ArchiveSubject archives all assignments for a subject
+func (s *AssignmentService) ArchiveSubject(userID uint, subject string) error {
+	return s.assignmentRepo.ArchiveBySubject(userID, subject)
+}
+
+// UnarchiveSubject unarchives all assignments for a subject
+func (s *AssignmentService) UnarchiveSubject(userID uint, subject string) error {
+	return s.assignmentRepo.UnarchiveBySubject(userID, subject)
+}
+
+// GetSubjectsWithArchived returns subjects optionally including archived
+func (s *AssignmentService) GetSubjectsWithArchived(userID uint, includeArchived bool) ([]string, error) {
+	return s.assignmentRepo.GetSubjectsByUserIDWithArchived(userID, includeArchived)
+}
+
+// GetArchivedSubjects returns archived subjects only
+func (s *AssignmentService) GetArchivedSubjects(userID uint) ([]string, error) {
+	return s.assignmentRepo.GetArchivedSubjects(userID)
+}
+

internal/service/notification_service.go

@@ -0,0 +1,330 @@
+package service
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"homework-manager/internal/database"
+	"homework-manager/internal/models"
+)
+
+// NotificationService handles Telegram and LINE notifications
+type NotificationService struct {
+	telegramBotToken string
+}
+
+// NewNotificationService creates a new notification service
+func NewNotificationService(telegramBotToken string) *NotificationService {
+	return &NotificationService{
+		telegramBotToken: telegramBotToken,
+	}
+}
+
+// GetUserSettings retrieves notification settings for a user
+func (s *NotificationService) GetUserSettings(userID uint) (*models.UserNotificationSettings, error) {
+	var settings models.UserNotificationSettings
+	result := database.GetDB().Where("user_id = ?", userID).First(&settings)
+	if result.Error != nil {
+		// If not found, return a new empty settings object
+		if result.RowsAffected == 0 {
+			return &models.UserNotificationSettings{
+				UserID: userID,
+			}, nil
+		}
+		return nil, result.Error
+	}
+	return &settings, nil
+}
+
+// UpdateUserSettings updates notification settings for a user
+func (s *NotificationService) UpdateUserSettings(userID uint, settings *models.UserNotificationSettings) error {
+	settings.UserID = userID
+	
+	var existing models.UserNotificationSettings
+	result := database.GetDB().Where("user_id = ?", userID).First(&existing)
+	
+	if result.RowsAffected == 0 {
+		// Create new
+		return database.GetDB().Create(settings).Error
+	}
+	
+	// Update existing
+	settings.ID = existing.ID
+	return database.GetDB().Save(settings).Error
+}
+
+// SendTelegramNotification sends a message via Telegram Bot API
+func (s *NotificationService) SendTelegramNotification(chatID, message string) error {
+	if s.telegramBotToken == "" {
+		return fmt.Errorf("telegram bot token is not configured")
+	}
+	if chatID == "" {
+		return fmt.Errorf("telegram chat ID is empty")
+	}
+
+	apiURL := fmt.Sprintf("https://api.telegram.org/bot%s/sendMessage", s.telegramBotToken)
+	
+	payload := map[string]string{
+		"chat_id":    chatID,
+		"text":       message,
+		"parse_mode": "HTML",
+	}
+	
+	jsonPayload, err := json.Marshal(payload)
+	if err != nil {
+		return err
+	}
+	
+	resp, err := http.Post(apiURL, "application/json", bytes.NewBuffer(jsonPayload))
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("telegram API returned status %d", resp.StatusCode)
+	}
+	
+	return nil
+}
+
+// SendLineNotification sends a message via LINE Notify API
+func (s *NotificationService) SendLineNotification(token, message string) error {
+	if token == "" {
+		return fmt.Errorf("LINE Notify token is empty")
+	}
+
+	apiURL := "https://notify-api.line.me/api/notify"
+	
+	data := url.Values{}
+	data.Set("message", message)
+	
+	req, err := http.NewRequest("POST", apiURL, strings.NewReader(data.Encode()))
+	if err != nil {
+		return err
+	}
+	
+	req.Header.Set("Authorization", "Bearer "+token)
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	
+	client := &http.Client{Timeout: 10 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("LINE Notify API returned status %d", resp.StatusCode)
+	}
+	
+	return nil
+}
+
+// SendAssignmentReminder sends a reminder notification for an assignment
+func (s *NotificationService) SendAssignmentReminder(userID uint, assignment *models.Assignment) error {
+	settings, err := s.GetUserSettings(userID)
+	if err != nil {
+		return err
+	}
+
+	message := fmt.Sprintf(
+		"📚 課題リマインダー\n\n【%s】\n科目: %s\n期限: %s\n\n%s",
+		assignment.Title,
+		assignment.Subject,
+		assignment.DueDate.Format("2006/01/02 15:04"),
+		assignment.Description,
+	)
+
+	var errors []string
+
+	// Send to Telegram if enabled
+	if settings.TelegramEnabled && settings.TelegramChatID != "" {
+		if err := s.SendTelegramNotification(settings.TelegramChatID, message); err != nil {
+			errors = append(errors, fmt.Sprintf("Telegram: %v", err))
+		}
+	}
+
+	// Send to LINE if enabled
+	if settings.LineEnabled && settings.LineNotifyToken != "" {
+		if err := s.SendLineNotification(settings.LineNotifyToken, message); err != nil {
+			errors = append(errors, fmt.Sprintf("LINE: %v", err))
+		}
+	}
+
+	if len(errors) > 0 {
+		return fmt.Errorf("notification errors: %s", strings.Join(errors, "; "))
+	}
+
+	return nil
+}
+
+// SendUrgentReminder sends an urgent reminder notification for an assignment
+func (s *NotificationService) SendUrgentReminder(userID uint, assignment *models.Assignment) error {
+	settings, err := s.GetUserSettings(userID)
+	if err != nil {
+		return err
+	}
+
+	timeRemaining := time.Until(assignment.DueDate)
+	var timeStr string
+	if timeRemaining < 0 {
+		timeStr = "期限切れ！"
+	} else if timeRemaining < time.Hour {
+		timeStr = fmt.Sprintf("あと%d分", int(timeRemaining.Minutes()))
+	} else {
+		timeStr = fmt.Sprintf("あと%d時間%d分", int(timeRemaining.Hours()), int(timeRemaining.Minutes())%60)
+	}
+
+	priorityEmoji := "📌"
+	switch assignment.Priority {
+	case "high":
+		priorityEmoji = "🚨"
+	case "medium":
+		priorityEmoji = "⚠️"
+	case "low":
+		priorityEmoji = "📌"
+	}
+
+	message := fmt.Sprintf(
+		"%s 督促通知！\n\n【%s】\n科目: %s\n期限: %s (%s)\n\n完了したらアプリで完了ボタンを押してください！",
+		priorityEmoji,
+		assignment.Title,
+		assignment.Subject,
+		assignment.DueDate.Format("2006/01/02 15:04"),
+		timeStr,
+	)
+
+	var errors []string
+
+	// Send to Telegram if enabled
+	if settings.TelegramEnabled && settings.TelegramChatID != "" {
+		if err := s.SendTelegramNotification(settings.TelegramChatID, message); err != nil {
+			errors = append(errors, fmt.Sprintf("Telegram: %v", err))
+		}
+	}
+
+	// Send to LINE if enabled
+	if settings.LineEnabled && settings.LineNotifyToken != "" {
+		if err := s.SendLineNotification(settings.LineNotifyToken, message); err != nil {
+			errors = append(errors, fmt.Sprintf("LINE: %v", err))
+		}
+	}
+
+	if len(errors) > 0 {
+		return fmt.Errorf("notification errors: %s", strings.Join(errors, "; "))
+	}
+
+	return nil
+}
+
+// getUrgentReminderInterval returns the reminder interval based on priority
+// high=10min, medium=30min, low=60min
+func getUrgentReminderInterval(priority string) time.Duration {
+	switch priority {
+	case "high":
+		return 10 * time.Minute
+	case "medium":
+		return 30 * time.Minute
+	case "low":
+		return 60 * time.Minute
+	default:
+		return 30 * time.Minute
+	}
+}
+
+// ProcessPendingReminders checks and sends pending one-time reminders
+func (s *NotificationService) ProcessPendingReminders() {
+	now := time.Now()
+	
+	var assignments []models.Assignment
+	result := database.GetDB().Where(
+		"reminder_enabled = ? AND reminder_sent = ? AND reminder_at <= ? AND is_completed = ?",
+		true, false, now, false,
+	).Find(&assignments)
+	
+	if result.Error != nil {
+		log.Printf("Error fetching pending reminders: %v", result.Error)
+		return
+	}
+	
+	for _, assignment := range assignments {
+		if err := s.SendAssignmentReminder(assignment.UserID, &assignment); err != nil {
+			log.Printf("Error sending reminder for assignment %d: %v", assignment.ID, err)
+			continue
+		}
+		
+		// Mark as sent
+		database.GetDB().Model(&assignment).Update("reminder_sent", true)
+		log.Printf("Sent reminder for assignment %d to user %d", assignment.ID, assignment.UserID)
+	}
+}
+
+// ProcessUrgentReminders checks and sends urgent (repeating) reminders
+// Starts 3 hours before deadline, repeats at interval based on priority
+func (s *NotificationService) ProcessUrgentReminders() {
+	now := time.Now()
+	urgentStartTime := 3 * time.Hour // Start 3 hours before deadline
+	
+	var assignments []models.Assignment
+	result := database.GetDB().Where(
+		"urgent_reminder_enabled = ? AND is_completed = ? AND due_date > ?",
+		true, false, now,
+	).Find(&assignments)
+	
+	if result.Error != nil {
+		log.Printf("Error fetching urgent reminders: %v", result.Error)
+		return
+	}
+	
+	for _, assignment := range assignments {
+		timeUntilDue := assignment.DueDate.Sub(now)
+		
+		// Only send if within 3 hours of deadline
+		if timeUntilDue > urgentStartTime {
+			continue
+		}
+		
+		// Check if enough time has passed since last urgent reminder
+		interval := getUrgentReminderInterval(assignment.Priority)
+		
+		if assignment.LastUrgentReminderSent != nil {
+			timeSinceLastReminder := now.Sub(*assignment.LastUrgentReminderSent)
+			if timeSinceLastReminder < interval {
+				continue
+			}
+		}
+		
+		// Send urgent reminder
+		if err := s.SendUrgentReminder(assignment.UserID, &assignment); err != nil {
+			log.Printf("Error sending urgent reminder for assignment %d: %v", assignment.ID, err)
+			continue
+		}
+		
+		// Update last sent time
+		database.GetDB().Model(&assignment).Update("last_urgent_reminder_sent", now)
+		log.Printf("Sent urgent reminder for assignment %d (priority: %s) to user %d", 
+			assignment.ID, assignment.Priority, assignment.UserID)
+	}
+}
+
+// StartReminderScheduler starts a background goroutine to process reminders
+func (s *NotificationService) StartReminderScheduler() {
+	go func() {
+		ticker := time.NewTicker(1 * time.Minute)
+		defer ticker.Stop()
+		
+		for range ticker.C {
+			s.ProcessPendingReminders()
+			s.ProcessUrgentReminders()
+		}
+	}()
+	log.Println("Reminder scheduler started (one-time + urgent reminders)")
+}
+

web/templates/assignments/edit.html

@@ -39,6 +39,44 @@
                         <textarea class="form-control" id="description" name="description"
                             rows="3">{{.assignment.Description}}</textarea>
                     </div>
+                    <!-- 通知設定 -->
+                    <div class="card bg-light mb-3">
+                        <div class="card-body py-2">
+                            <h6 class="mb-2"><i class="bi bi-bell me-1"></i>通知設定</h6>
+                            <!-- 督促通知 -->
+                            <div class="form-check form-switch mb-2">
+                                <input class="form-check-input" type="checkbox" id="urgent_reminder_enabled"
+                                    name="urgent_reminder_enabled" {{if
+                                    .assignment.UrgentReminderEnabled}}checked{{end}}>
+                                <label class="form-check-label" for="urgent_reminder_enabled">
+                                    督促通知（期限3時間前から繰り返し通知）
+                                </label>
+                            </div>
+                            <div class="form-text small mb-2">
+                                重要度により間隔が変わります：大=10分、中=30分、小=1時間
+                            </div>
+                            <hr class="my-2">
+                            <!-- 1回リマインダー -->
+                            <div class="form-check form-switch">
+                                <input class="form-check-input" type="checkbox" id="reminder_enabled"
+                                    name="reminder_enabled" {{if .assignment.ReminderEnabled}}checked{{end}}
+                                    onchange="toggleReminderDate(this)">
+                                <label class="form-check-label" for="reminder_enabled">
+                                    1回リマインダー（指定日時に1回通知）
+                                </label>
+                            </div>
+                            <div class="mt-2" id="reminder_at_group"
+                                style="display: {{if .assignment.ReminderEnabled}}block{{else}}none{{end}};">
+                                <label for="reminder_at" class="form-label small">通知日時</label>
+                                <input type="datetime-local" class="form-control form-control-sm" id="reminder_at"
+                                    name="reminder_at"
+                                    value="{{if .assignment.ReminderAt}}{{formatDateInput .assignment.ReminderAt}}{{end}}">
+                                {{if .assignment.ReminderSent}}
+                                <div class="text-success small mt-1"><i class="bi bi-check-circle me-1"></i>通知送信済み</div>
+                                {{end}}
+                            </div>
+                        </div>
+                    </div>
                     <div class="d-flex gap-2">
                         <button type="submit" class="btn btn-primary"><i class="bi bi-check-lg me-1"></i>更新</button>
                         <a href="/assignments" class="btn btn-outline-secondary">キャンセル</a>
@@ -48,4 +86,9 @@
         </div>
     </div>
 </div>
+<script>
+    function toggleReminderDate(checkbox) {
+        document.getElementById('reminder_at_group').style.display = checkbox.checked ? 'block' : 'none';
+    }
+</script>
 {{end}}

web/templates/assignments/new.html

@@ -39,6 +39,37 @@
                         <textarea class="form-control" id="description" name="description"
                             rows="3">{{.description}}</textarea>
                     </div>
+                    <!-- 通知設定 -->
+                    <div class="card bg-light mb-3">
+                        <div class="card-body py-2">
+                            <h6 class="mb-2"><i class="bi bi-bell me-1"></i>通知設定</h6>
+                            <!-- 督促通知 -->
+                            <div class="form-check form-switch mb-2">
+                                <input class="form-check-input" type="checkbox" id="urgent_reminder_enabled"
+                                    name="urgent_reminder_enabled" checked>
+                                <label class="form-check-label" for="urgent_reminder_enabled">
+                                    督促通知（期限3時間前から繰り返し通知）
+                                </label>
+                            </div>
+                            <div class="form-text small mb-2">
+                                重要度により間隔が変わります：大=10分、中=30分、小=1時間
+                            </div>
+                            <hr class="my-2">
+                            <!-- 1回リマインダー -->
+                            <div class="form-check form-switch">
+                                <input class="form-check-input" type="checkbox" id="reminder_enabled"
+                                    name="reminder_enabled" onchange="toggleReminderDate(this)">
+                                <label class="form-check-label" for="reminder_enabled">
+                                    1回リマインダー（指定日時に1回通知）
+                                </label>
+                            </div>
+                            <div class="mt-2" id="reminder_at_group" style="display: none;">
+                                <label for="reminder_at" class="form-label small">通知日時</label>
+                                <input type="datetime-local" class="form-control form-control-sm" id="reminder_at"
+                                    name="reminder_at">
+                            </div>
+                        </div>
+                    </div>
                     <div class="d-flex gap-2">
                         <button type="submit" class="btn btn-primary"><i class="bi bi-check-lg me-1"></i>登録</button>
                         <a href="/assignments" class="btn btn-outline-secondary">キャンセル</a>
@@ -48,4 +79,9 @@
         </div>
     </div>
 </div>
+<script>
+    function toggleReminderDate(checkbox) {
+        document.getElementById('reminder_at_group').style.display = checkbox.checked ? 'block' : 'none';
+    }
+</script>
 {{end}}

web/templates/assignments/statistics.html

@@ -0,0 +1,344 @@
+{{template "base" .}}
+
+{{define "head"}}
+<style>
+    .stat-card {
+        transition: transform 0.2s ease-in-out;
+    }
+
+    .stat-card:hover {
+        transform: translateY(-5px);
+    }
+
+    .progress {
+        height: 25px;
+    }
+
+    .progress-bar {
+        font-size: 0.9rem;
+        font-weight: 500;
+    }
+
+    .subject-row:hover {
+        background-color: rgba(0, 0, 0, 0.02);
+    }
+
+    .table-progress {
+        height: 20px;
+    }
+
+    .pagination-info {
+        font-size: 0.875rem;
+    }
+</style>
+{{end}}
+
+{{define "content"}}
+<div class="d-flex justify-content-between align-items-center mb-4">
+    <h1><i class="bi bi-bar-chart me-2"></i>統計</h1>
+    <a href="/assignments" class="btn btn-outline-secondary">
+        <i class="bi bi-arrow-left me-1"></i>課題一覧に戻る
+    </a>
+</div>
+
+<div class="card mb-4">
+    <div class="card-body">
+        <form method="GET" action="/statistics" class="row g-3">
+            <div class="col-md-4">
+                <label class="form-label">科目</label>
+                <select name="subject" class="form-select">
+                    <option value="">すべての科目</option>
+                    {{range .subjects}}
+                    <option value="{{.}}" {{if eq . $.selectedSubject}}selected{{end}}>{{.}}{{if index
+                        $.archivedSubjects .}} (アーカイブ済){{end}}</option>
+                    {{end}}
+                </select>
+            </div>
+            <div class="col-md-2">
+                <label class="form-label">登録日（開始）</label>
+                <input type="date" name="from" class="form-control" value="{{.fromDate}}">
+            </div>
+            <div class="col-md-2">
+                <label class="form-label">登録日（終了）</label>
+                <input type="date" name="to" class="form-control" value="{{.toDate}}">
+            </div>
+            <div class="col-md-4 d-flex align-items-end">
+                <button type="submit" class="btn btn-primary me-2">
+                    <i class="bi bi-filter me-1"></i>絞り込み
+                </button>
+                <a href="/statistics" class="btn btn-outline-secondary">
+                    <i class="bi bi-x-lg me-1"></i>リセット
+                </a>
+            </div>
+        </form>
+    </div>
+</div>
+
+<div class="row g-4 mb-4">
+    <div class="col-6 col-lg-3">
+        <div class="card stat-card bg-primary text-white h-100">
+            <div class="card-body">
+                <div class="d-flex justify-content-between align-items-center">
+                    <div>
+                        <h6 class="text-white-50 mb-1">総課題数</h6>
+                        <h2 class="mb-0">{{.stats.TotalAssignments}}</h2>
+                    </div>
+                    <i class="bi bi-list-task display-4 opacity-50"></i>
+                </div>
+            </div>
+        </div>
+    </div>
+    <div class="col-6 col-lg-3">
+        <div class="card stat-card bg-success text-white h-100">
+            <div class="card-body">
+                <div class="d-flex justify-content-between align-items-center">
+                    <div>
+                        <h6 class="text-white-50 mb-1">完了</h6>
+                        <h2 class="mb-0">{{.stats.CompletedAssignments}}</h2>
+                    </div>
+                    <i class="bi bi-check-circle display-4 opacity-50"></i>
+                </div>
+            </div>
+        </div>
+    </div>
+    <div class="col-6 col-lg-3">
+        <div class="card stat-card bg-warning text-dark h-100">
+            <div class="card-body">
+                <div class="d-flex justify-content-between align-items-center">
+                    <div>
+                        <h6 class="text-dark-50 mb-1">未完了</h6>
+                        <h2 class="mb-0">{{.stats.PendingAssignments}}</h2>
+                    </div>
+                    <i class="bi bi-hourglass-split display-4 opacity-50"></i>
+                </div>
+            </div>
+        </div>
+    </div>
+    <div class="col-6 col-lg-3">
+        <div class="card stat-card bg-danger text-white h-100">
+            <div class="card-body">
+                <div class="d-flex justify-content-between align-items-center">
+                    <div>
+                        <h6 class="text-white-50 mb-1">期限切れ</h6>
+                        <h2 class="mb-0">{{.stats.OverdueAssignments}}</h2>
+                    </div>
+                    <i class="bi bi-exclamation-triangle display-4 opacity-50"></i>
+                </div>
+            </div>
+        </div>
+    </div>
+</div>
+
+<div class="card mb-4">
+    <div class="card-header">
+        <i class="bi bi-clock-history me-2"></i>期限内完了率
+    </div>
+    <div class="card-body">
+        <div class="row align-items-center">
+            <div class="col-md-3 text-center mb-3 mb-md-0">
+                <h1
+                    class="display-3 mb-0 {{if ge .stats.OnTimeCompletionRate 80.0}}text-success{{else if ge .stats.OnTimeCompletionRate 50.0}}text-warning{{else}}text-danger{{end}}">
+                    {{printf "%.1f" .stats.OnTimeCompletionRate}}%
+                </h1>
+                <small class="text-muted">期限内完了率</small>
+            </div>
+            <div class="col-md-9">
+                <div class="progress">
+                    {{if ge .stats.OnTimeCompletionRate 80.0}}
+                    <div class="progress-bar bg-success" role="progressbar"
+                        style="width: {{.stats.OnTimeCompletionRate}}%">
+                        {{printf "%.1f" .stats.OnTimeCompletionRate}}% 期限内に完了
+                    </div>
+                    {{else if ge .stats.OnTimeCompletionRate 50.0}}
+                    <div class="progress-bar bg-warning" role="progressbar"
+                        style="width: {{.stats.OnTimeCompletionRate}}%">
+                        {{printf "%.1f" .stats.OnTimeCompletionRate}}% 期限内に完了
+                    </div>
+                    {{else}}
+                    <div class="progress-bar bg-danger" role="progressbar"
+                        style="width: {{.stats.OnTimeCompletionRate}}%">
+                        {{printf "%.1f" .stats.OnTimeCompletionRate}}% 期限内に完了
+                    </div>
+                    {{end}}
+                </div>
+                <small class="text-muted mt-2 d-block">完了した課題のうち、期限内に完了した割合を表示しています。</small>
+            </div>
+        </div>
+    </div>
+</div>
+
+<div class="card mb-4" id="activeSubjectsCard">
+    <div class="card-header d-flex justify-content-between align-items-center">
+        <span><i class="bi bi-collection me-2"></i>アクティブ科目</span>
+        <span class="badge bg-primary" id="activeCount">0</span>
+    </div>
+    <div class="card-body p-0">
+        <div class="table-responsive">
+            <table class="table table-hover mb-0">
+                <thead class="table-light">
+                    <tr>
+                        <th>科目</th>
+                        <th class="text-center">総数</th>
+                        <th class="text-center">完了</th>
+                        <th class="text-center">未完了</th>
+                        <th class="text-center">期限切れ</th>
+                        <th class="text-center">完了率</th>
+                        <th style="width: 150px;">進捗</th>
+                        <th class="text-center">操作</th>
+                    </tr>
+                </thead>
+                <tbody id="activeSubjectsBody"></tbody>
+            </table>
+        </div>
+    </div>
+    <div class="card-footer d-flex justify-content-between align-items-center">
+        <span class="pagination-info" id="activePageInfo"></span>
+        <nav>
+            <ul class="pagination pagination-sm mb-0" id="activePagination"></ul>
+        </nav>
+    </div>
+</div>
+
+<div class="card" id="archivedSubjectsCard">
+    <div class="card-header d-flex justify-content-between align-items-center">
+        <span><i class="bi bi-archive me-2"></i>アーカイブ済み科目</span>
+        <span class="badge bg-secondary" id="archivedCount">0</span>
+    </div>
+    <div class="card-body p-0">
+        <div class="table-responsive">
+            <table class="table table-hover mb-0">
+                <thead class="table-light">
+                    <tr>
+                        <th>科目</th>
+                        <th class="text-center">総数</th>
+                        <th class="text-center">完了</th>
+                        <th class="text-center">未完了</th>
+                        <th class="text-center">期限切れ</th>
+                        <th class="text-center">完了率</th>
+                        <th style="width: 150px;">進捗</th>
+                        <th class="text-center">操作</th>
+                    </tr>
+                </thead>
+                <tbody id="archivedSubjectsBody"></tbody>
+            </table>
+        </div>
+    </div>
+    <div class="card-footer d-flex justify-content-between align-items-center">
+        <span class="pagination-info" id="archivedPageInfo"></span>
+        <nav>
+            <ul class="pagination pagination-sm mb-0" id="archivedPagination"></ul>
+        </nav>
+    </div>
+</div>
+
+<div class="card d-none" id="noSubjectsCard">
+    <div class="card-body text-center py-5">
+        <i class="bi bi-inbox display-1 text-muted"></i>
+        <h4 class="mt-3">科目別の統計データがありません</h4>
+        <p class="text-muted">課題を登録して科目を設定すると、ここに統計が表示されます。</p>
+    </div>
+</div>
+{{end}}
+
+{{define "scripts"}}
+<script id="subjectsData" type="application/json">
+{"csrfToken":"{{.csrfToken}}","subjects":[{{range $i, $s := .stats.Subjects}}{{if $i}},{{end}}{"subject":"{{$s.Subject}}","total":{{$s.Total}},"completed":{{$s.Completed}},"pending":{{$s.Pending}},"overdue":{{$s.Overdue}},"rate":{{$s.OnTimeCompletionRate}},"isArchived":{{if index $.archivedSubjects $s.Subject}}true{{else}}false{{end}}}{{end}}]}
+</script>
+<script>
+    (function () {
+        var data = JSON.parse(document.getElementById('subjectsData').textContent);
+        var csrfToken = data.csrfToken;
+        var subjects = data.subjects;
+        var PAGE_SIZE = 10;
+        var activeSubjects = subjects.filter(function (s) { return !s.isArchived; });
+        var archivedSubjects = subjects.filter(function (s) { return s.isArchived; });
+        var activePage = 1;
+        var archivedPage = 1;
+
+        function getRateClass(rate) {
+            if (rate >= 80) return 'text-success';
+            if (rate >= 50) return 'text-warning';
+            return 'text-danger';
+        }
+
+        function renderProgress(completed, pending, overdue, total) {
+            if (total === 0) return '<div class="progress table-progress"></div>';
+            var cP = (completed / total * 100).toFixed(1);
+            var pP = (pending / total * 100).toFixed(1);
+            var oP = (overdue / total * 100).toFixed(1);
+            return '<div class="progress table-progress">' +
+                '<div class="progress-bar bg-success" style="width:' + cP + '%" title="完了: ' + completed + '"></div>' +
+                '<div class="progress-bar bg-warning" style="width:' + pP + '%" title="未完了: ' + pending + '"></div>' +
+                '<div class="progress-bar bg-danger" style="width:' + oP + '%" title="期限切れ: ' + overdue + '"></div></div>';
+        }
+
+        function renderRow(s, isArchived) {
+            var action = isArchived ?
+                '<form action="/statistics/unarchive-subject" method="POST" class="d-inline"><input type="hidden" name="_csrf" value="' + csrfToken + '"><input type="hidden" name="subject" value="' + s.subject + '"><button type="submit" class="btn btn-sm btn-outline-success" title="復元"><i class="bi bi-arrow-counterclockwise"></i></button></form>' :
+                '<form action="/statistics/archive-subject" method="POST" class="d-inline"><input type="hidden" name="_csrf" value="' + csrfToken + '"><input type="hidden" name="subject" value="' + s.subject + '"><button type="submit" class="btn btn-sm btn-outline-secondary" title="アーカイブ"><i class="bi bi-archive"></i></button></form>';
+            return '<tr class="subject-row">' +
+                '<td><a href="/statistics?subject=' + encodeURIComponent(s.subject) + '" class="text-decoration-none"><i class="bi bi-folder me-1"></i>' + s.subject + '</a></td>' +
+                '<td class="text-center">' + s.total + '</td>' +
+                '<td class="text-center text-success">' + s.completed + '</td>' +
+                '<td class="text-center text-warning">' + s.pending + '</td>' +
+                '<td class="text-center text-danger">' + s.overdue + '</td>' +
+                '<td class="text-center"><span class="' + getRateClass(s.rate) + '">' + s.rate.toFixed(1) + '%</span></td>' +
+                '<td>' + renderProgress(s.completed, s.pending, s.overdue, s.total) + '</td>' +
+                '<td class="text-center">' + action + '</td></tr>';
+        }
+
+        function renderPagination(id, page, total, cb) {
+            var el = document.getElementById(id);
+            el.innerHTML = '';
+            if (total <= 1) return;
+            var prev = document.createElement('li');
+            prev.className = 'page-item' + (page === 1 ? ' disabled' : '');
+            prev.innerHTML = '<a class="page-link" href="#">&laquo;</a>';
+            if (page > 1) prev.onclick = function (e) { e.preventDefault(); cb(page - 1); };
+            el.appendChild(prev);
+            for (var i = 1; i <= total; i++) {
+                var li = document.createElement('li');
+                li.className = 'page-item' + (i === page ? ' active' : '');
+                li.innerHTML = '<a class="page-link" href="#">' + i + '</a>';
+                (function (p) { li.onclick = function (e) { e.preventDefault(); cb(p); }; })(i);
+                el.appendChild(li);
+            }
+            var next = document.createElement('li');
+            next.className = 'page-item' + (page === total ? ' disabled' : '');
+            next.innerHTML = '<a class="page-link" href="#">&raquo;</a>';
+            if (page < total) next.onclick = function (e) { e.preventDefault(); cb(page + 1); };
+            el.appendChild(next);
+        }
+
+        function renderActiveSubjects() {
+            var start = (activePage - 1) * PAGE_SIZE;
+            var end = Math.min(start + PAGE_SIZE, activeSubjects.length);
+            var totalPages = Math.ceil(activeSubjects.length / PAGE_SIZE);
+            document.getElementById('activeSubjectsBody').innerHTML = activeSubjects.slice(start, end).map(function (s) { return renderRow(s, false); }).join('');
+            document.getElementById('activeCount').textContent = activeSubjects.length;
+            document.getElementById('activePageInfo').textContent = activeSubjects.length > 0 ? (start + 1) + '-' + end + ' / ' + activeSubjects.length + ' 件' : '0 件';
+            renderPagination('activePagination', activePage, totalPages, function (p) { activePage = p; renderActiveSubjects(); });
+            document.getElementById('activeSubjectsCard').style.display = activeSubjects.length > 0 ? 'block' : 'none';
+        }
+
+        function renderArchivedSubjects() {
+            var start = (archivedPage - 1) * PAGE_SIZE;
+            var end = Math.min(start + PAGE_SIZE, archivedSubjects.length);
+            var totalPages = Math.ceil(archivedSubjects.length / PAGE_SIZE);
+            document.getElementById('archivedSubjectsBody').innerHTML = archivedSubjects.slice(start, end).map(function (s) { return renderRow(s, true); }).join('');
+            document.getElementById('archivedCount').textContent = archivedSubjects.length;
+            document.getElementById('archivedPageInfo').textContent = archivedSubjects.length > 0 ? (start + 1) + '-' + end + ' / ' + archivedSubjects.length + ' 件' : '0 件';
+            renderPagination('archivedPagination', archivedPage, totalPages, function (p) { archivedPage = p; renderArchivedSubjects(); });
+            document.getElementById('archivedSubjectsCard').style.display = archivedSubjects.length > 0 ? 'block' : 'none';
+        }
+
+        renderActiveSubjects();
+        renderArchivedSubjects();
+        if (activeSubjects.length === 0 && archivedSubjects.length === 0) {
+            document.getElementById('noSubjectsCard').classList.remove('d-none');
+            document.getElementById('activeSubjectsCard').style.display = 'none';
+            document.getElementById('archivedSubjectsCard').style.display = 'none';
+        }
+    })();
+</script>
+{{end}}

web/templates/layouts/base.html

@@ -45,6 +45,9 @@
                     <li class="nav-item">
                         <a class="nav-link" href="/assignments/new"><i class="bi bi-plus-circle me-1"></i>課題登録</a>
                     </li>
+                    <li class="nav-item">
+                        <a class="nav-link" href="/statistics"><i class="bi bi-bar-chart me-1"></i>統計</a>
+                    </li>
                     {{if .isAdmin}}
                     <li class="nav-item">
                         <a class="nav-link" href="/admin/users"><i class="bi bi-people me-1"></i>ユーザー管理</a>

web/templates/pages/profile.html

@@ -2,7 +2,7 @@
 
 {{define "content"}}
 <div class="row justify-content-center">
-    <div class="col-lg-8">
+    <div class="col-lg-10">
         <h1 class="mb-4"><i class="bi bi-person me-2"></i>プロフィール</h1>
         <div class="row g-4">
             <div class="col-md-6">
@@ -66,6 +66,56 @@
                 </div>
             </div>
         </div>
+
+        <!-- 通知設定 -->
+        <div class="card mt-4">
+            <div class="card-header">
+                <h5 class="mb-0"><i class="bi bi-bell me-2"></i>通知設定</h5>
+            </div>
+            <div class="card-body">
+                {{if .notifyError}}<div class="alert alert-danger">{{.notifyError}}</div>{{end}}
+                {{if .notifySuccess}}<div class="alert alert-success">{{.notifySuccess}}</div>{{end}}
+                <form method="POST" action="/profile/notifications">
+                    {{.csrfField}}
+                    <div class="row">
+                        <div class="col-md-6">
+                            <h6 class="mb-3"><i class="bi bi-telegram me-1"></i>Telegram</h6>
+                            <div class="form-check form-switch mb-2">
+                                <input class="form-check-input" type="checkbox" id="telegram_enabled"
+                                    name="telegram_enabled" {{if .notifySettings.TelegramEnabled}}checked{{end}}>
+                                <label class="form-check-label" for="telegram_enabled">Telegram通知を有効化</label>
+                            </div>
+                            <div class="mb-3">
+                                <label for="telegram_chat_id" class="form-label">Chat ID</label>
+                                <input type="text" class="form-control" id="telegram_chat_id" name="telegram_chat_id"
+                                    value="{{.notifySettings.TelegramChatID}}" placeholder="例: 123456789">
+                                <div class="form-text">
+                                    Botに<code>/start</code>を送信後、<a href="https://t.me/userinfobot"
+                                        target="_blank">@userinfobot</a>でIDを確認
+                                </div>
+                            </div>
+                        </div>
+                        <div class="col-md-6">
+                            <h6 class="mb-3"><i class="bi bi-chat-dots me-1"></i>LINE Notify</h6>
+                            <div class="form-check form-switch mb-2">
+                                <input class="form-check-input" type="checkbox" id="line_enabled" name="line_enabled"
+                                    {{if .notifySettings.LineEnabled}}checked{{end}}>
+                                <label class="form-check-label" for="line_enabled">LINE通知を有効化</label>
+                            </div>
+                            <div class="mb-3">
+                                <label for="line_token" class="form-label">アクセストークン</label>
+                                <input type="password" class="form-control" id="line_token" name="line_token"
+                                    value="{{.notifySettings.LineNotifyToken}}" placeholder="トークンを入力">
+                                <div class="form-text">
+                                    <a href="https://notify-bot.line.me/my/" target="_blank">LINE Notify</a>でトークンを発行
+                                </div>
+                            </div>
+                        </div>
+                    </div>
+                    <button type="submit" class="btn btn-primary"><i class="bi bi-check-lg me-1"></i>通知設定を保存</button>
+                </form>
+            </div>
+        </div>
     </div>
 </div>
 {{end}}