/**
 * Geofence Database Layer
 * CRUD operations for Geofence, GeofenceEvent, and GeofenceStatus
 */

import Database from 'better-sqlite3';
import path from 'path';
import type {
  Geofence,
  GeofenceEvent,
  GeofenceStatus,
  CreateGeofenceInput,
  CreateGeofenceEventInput,
} from './types';

const dbPath = path.join(process.cwd(), 'data', 'database.sqlite');

function getDb() {
  return new Database(dbPath);
}

export const geofenceDb = {
  /**
   * Create a new geofence
   */
  create(data: CreateGeofenceInput): Geofence {
    const db = getDb();
    try {
      const stmt = db.prepare(`
        INSERT INTO Geofence (
          id, name, description, shape_type,
          center_latitude, center_longitude, radius_meters,
          owner_id, device_id, color
        ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
      `);

      stmt.run(
        data.id,
        data.name,
        data.description || null,
        'circle',
        data.center_latitude,
        data.center_longitude,
        data.radius_meters,
        data.owner_id,
        data.device_id,
        data.color || '#3b82f6'
      );

      return this.findById(data.id)!;
    } finally {
      db.close();
    }
  },

  /**
   * Find geofence by ID
   */
  findById(id: string): Geofence | null {
    const db = getDb();
    try {
      const stmt = db.prepare('SELECT * FROM Geofence WHERE id = ?');
      return stmt.get(id) as Geofence | null;
    } finally {
      db.close();
    }
  },

  /**
   * Find all geofences for an owner
   */
  findByOwner(ownerId: string): Geofence[] {
    const db = getDb();
    try {
      const stmt = db.prepare('SELECT * FROM Geofence WHERE owner_id = ? ORDER BY created_at DESC');
      return stmt.all(ownerId) as Geofence[];
    } finally {
      db.close();
    }
  },

  /**
   * Find all active geofences for a specific device
   */
  findActiveForDevice(deviceId: string): Geofence[] {
    const db = getDb();
    try {
      const stmt = db.prepare(`
        SELECT * FROM Geofence
        WHERE device_id = ? AND is_active = 1
        ORDER BY created_at DESC
      `);
      return stmt.all(deviceId) as Geofence[];
    } finally {
      db.close();
    }
  },

  /**
   * Delete a geofence
   */
  delete(id: string): boolean {
    const db = getDb();
    try {
      const stmt = db.prepare('DELETE FROM Geofence WHERE id = ?');
      const result = stmt.run(id);
      return result.changes > 0;
    } finally {
      db.close();
    }
  },

  /**
   * Get current status for device/geofence pair
   */
  getStatus(deviceId: string, geofenceId: string): GeofenceStatus | null {
    const db = getDb();
    try {
      const stmt = db.prepare(`
        SELECT * FROM GeofenceStatus
        WHERE device_id = ? AND geofence_id = ?
      `);
      return stmt.get(deviceId, geofenceId) as GeofenceStatus | null;
    } finally {
      db.close();
    }
  },

  /**
   * Update or create status for device/geofence pair
   */
  updateStatus(deviceId: string, geofenceId: string, isInside: boolean): void {
    const db = getDb();
    try {
      const now = new Date().toISOString();
      const isInsideInt = isInside ? 1 : 0;

      // Try to update existing status
      const updateStmt = db.prepare(`
        UPDATE GeofenceStatus
        SET is_inside = ?,
            last_enter_time = CASE WHEN ? = 1 AND is_inside = 0 THEN ? ELSE last_enter_time END,
            last_exit_time = CASE WHEN ? = 0 AND is_inside = 1 THEN ? ELSE last_exit_time END,
            last_checked_at = ?,
            updated_at = ?
        WHERE device_id = ? AND geofence_id = ?
      `);

      const result = updateStmt.run(
        isInsideInt,
        isInsideInt, now, // for enter
        isInsideInt, now, // for exit
        now,
        now,
        deviceId,
        geofenceId
      );

      // If no rows updated, insert new status
      if (result.changes === 0) {
        const insertStmt = db.prepare(`
          INSERT INTO GeofenceStatus (
            device_id, geofence_id, is_inside,
            last_enter_time, last_exit_time, last_checked_at
          ) VALUES (?, ?, ?, ?, ?, ?)
        `);

        insertStmt.run(
          deviceId,
          geofenceId,
          isInsideInt,
          isInside ? now : null,
          !isInside ? now : null,
          now
        );
      }
    } finally {
      db.close();
    }
  },

  /**
   * Create a new geofence event
   */
  createEvent(event: CreateGeofenceEventInput): GeofenceEvent {
    const db = getDb();
    try {
      const stmt = db.prepare(`
        INSERT INTO GeofenceEvent (
          geofence_id, device_id, location_id,
          event_type, latitude, longitude,
          distance_from_center, timestamp
        ) VALUES (?, ?, ?, ?, ?, ?, ?, ?)
      `);

      const result = stmt.run(
        event.geofence_id,
        event.device_id,
        event.location_id,
        event.event_type,
        event.latitude,
        event.longitude,
        event.distance_from_center,
        event.timestamp
      );

      // Return the created event
      const selectStmt = db.prepare('SELECT * FROM GeofenceEvent WHERE id = ?');
      return selectStmt.get(result.lastInsertRowid) as GeofenceEvent;
    } finally {
      db.close();
    }
  },

  /**
   * Find events for a specific device or geofence
   */
  findEvents(filters: {
    deviceId?: string;
    geofenceId?: string;
    limit?: number;
  }): GeofenceEvent[] {
    const db = getDb();
    try {
      let query = 'SELECT * FROM GeofenceEvent WHERE 1=1';
      const params: any[] = [];

      if (filters.deviceId) {
        query += ' AND device_id = ?';
        params.push(filters.deviceId);
      }

      if (filters.geofenceId) {
        query += ' AND geofence_id = ?';
        params.push(filters.geofenceId);
      }

      query += ' ORDER BY timestamp DESC';

      if (filters.limit) {
        query += ' LIMIT ?';
        params.push(filters.limit);
      }

      const stmt = db.prepare(query);
      return stmt.all(...params) as GeofenceEvent[];
    } finally {
      db.close();
    }
  },

  /**
   * Mark notification as sent or failed
   */
  markNotificationSent(eventId: number, success: boolean, error?: string): void {
    const db = getDb();
    try {
      const stmt = db.prepare(`
        UPDATE GeofenceEvent
        SET notification_sent = ?,
            notification_error = ?
        WHERE id = ?
      `);

      stmt.run(
        success ? 1 : 2, // 1 = sent, 2 = failed
        error || null,
        eventId
      );
    } finally {
      db.close();
    }
  },
};