Implement admin api handlers

backend/internal/db/admin.go

@@ -0,0 +1,80 @@
+// Package db provides the database access layer for the application. It contains methods for interacting with the database, such as creating, updating, and deleting records.
+package db
+
+import "novamd/internal/models"
+
+// SystemStats represents system-wide statistics
+type SystemStats struct {
+	TotalUsers      int `json:"totalUsers"`
+	TotalWorkspaces int `json:"totalWorkspaces"`
+	ActiveUsers     int `json:"activeUsers"` // Users with activity in last 30 days
+	StorageUsed     int `json:"storageUsed"` // Total storage used in bytes
+	TotalFiles      int `json:"totalFiles"`  // Total number of files across all workspaces
+}
+
+// GetAllUsers returns a list of all users in the system
+func (db *DB) GetAllUsers() ([]*models.User, error) {
+	rows, err := db.Query(`
+		SELECT 
+			id, email, display_name, role, created_at,
+			last_workspace_id
+		FROM users
+		ORDER BY id ASC`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var users []*models.User
+	for rows.Next() {
+		user := &models.User{}
+		err := rows.Scan(
+			&user.ID, &user.Email, &user.DisplayName, &user.Role,
+			&user.CreatedAt, &user.LastWorkspaceID,
+		)
+		if err != nil {
+			return nil, err
+		}
+		users = append(users, user)
+	}
+	return users, nil
+}
+
+// GetSystemStats returns system-wide statistics
+func (db *DB) GetSystemStats() (*SystemStats, error) {
+	stats := &SystemStats{}
+
+	// Get total users
+	err := db.QueryRow("SELECT COUNT(*) FROM users").Scan(&stats.TotalUsers)
+	if err != nil {
+		return nil, err
+	}
+
+	// Get total workspaces
+	err = db.QueryRow("SELECT COUNT(*) FROM workspaces").Scan(&stats.TotalWorkspaces)
+	if err != nil {
+		return nil, err
+	}
+
+	// Get active users (users with activity in last 30 days)
+	err = db.QueryRow(`
+		SELECT COUNT(DISTINCT user_id) 
+		FROM sessions 
+		WHERE created_at > datetime('now', '-30 days')`).
+		Scan(&stats.ActiveUsers)
+	if err != nil {
+		return nil, err
+	}
+
+	// Get total files and storage used
+	// Note: This assumes you're tracking file sizes in your filesystem
+	err = db.QueryRow(`
+		SELECT COUNT(*), COALESCE(SUM(size), 0) 
+		FROM files`).
+		Scan(&stats.TotalFiles, &stats.StorageUsed)
+	if err != nil {
+		return nil, err
+	}
+
+	return stats, nil
+}