// src/services/db/flyerLocation.db.ts
/**
 * Repository for managing flyer_locations (many-to-many relationship between flyers and store_locations).
 */
import type { Logger } from 'pino';
import type { PoolClient, Pool } from 'pg';
import { handleDbError } from './errors.db';
import type { FlyerLocation } from '../../types';
import { getPool } from './connection.db';

export class FlyerLocationRepository {
  private db: Pool | PoolClient;

  constructor(dbClient?: PoolClient) {
    this.db = dbClient || getPool();
  }

  /**
   * Links a flyer to one or more store locations.
   * @param flyerId The ID of the flyer
   * @param storeLocationIds Array of store_location_ids to associate with this flyer
   * @param logger Logger instance
   * @returns Promise that resolves when all links are created
   */
  async linkFlyerToLocations(
    flyerId: number,
    storeLocationIds: number[],
    logger: Logger,
  ): Promise<void> {
    try {
      if (storeLocationIds.length === 0) {
        logger.warn({ flyerId }, 'No store locations provided for flyer linkage');
        return;
      }

      // Use VALUES with multiple rows for efficient bulk insert
      const values = storeLocationIds.map((_, index) => `($1, $${index + 2})`).join(', ');

      const query = `
        INSERT INTO public.flyer_locations (flyer_id, store_location_id)
        VALUES ${values}
        ON CONFLICT (flyer_id, store_location_id) DO NOTHING
      `;

      await this.db.query(query, [flyerId, ...storeLocationIds]);

      logger.info(
        { flyerId, locationCount: storeLocationIds.length },
        'Linked flyer to store locations',
      );
    } catch (error) {
      handleDbError(
        error,
        logger,
        'Database error in linkFlyerToLocations',
        { flyerId, storeLocationIds },
        {
          defaultMessage: 'Failed to link flyer to store locations.',
        },
      );
    }
  }

  /**
   * Links a flyer to all locations of a given store.
   * This is a convenience method for the common case where a flyer is valid at all store locations.
   * @param flyerId The ID of the flyer
   * @param storeId The ID of the store
   * @param logger Logger instance
   * @returns Promise that resolves to the number of locations linked
   */
  async linkFlyerToAllStoreLocations(
    flyerId: number,
    storeId: number,
    logger: Logger,
  ): Promise<number> {
    try {
      const query = `
        INSERT INTO public.flyer_locations (flyer_id, store_location_id)
        SELECT $1, store_location_id
        FROM public.store_locations
        WHERE store_id = $2
        ON CONFLICT (flyer_id, store_location_id) DO NOTHING
        RETURNING store_location_id
      `;

      const res = await this.db.query(query, [flyerId, storeId]);
      const linkedCount = res.rowCount || 0;

      logger.info({ flyerId, storeId, linkedCount }, 'Linked flyer to all store locations');

      return linkedCount;
    } catch (error) {
      handleDbError(
        error,
        logger,
        'Database error in linkFlyerToAllStoreLocations',
        { flyerId, storeId },
        {
          defaultMessage: 'Failed to link flyer to all store locations.',
        },
      );
    }
  }

  /**
   * Removes all location links for a flyer.
   * @param flyerId The ID of the flyer
   * @param logger Logger instance
   */
  async unlinkAllLocations(flyerId: number, logger: Logger): Promise<void> {
    try {
      await this.db.query('DELETE FROM public.flyer_locations WHERE flyer_id = $1', [flyerId]);

      logger.info({ flyerId }, 'Unlinked all locations from flyer');
    } catch (error) {
      handleDbError(
        error,
        logger,
        'Database error in unlinkAllLocations',
        { flyerId },
        {
          defaultMessage: 'Failed to unlink locations from flyer.',
        },
      );
    }
  }

  /**
   * Removes a specific location link from a flyer.
   * @param flyerId The ID of the flyer
   * @param storeLocationId The ID of the store location to unlink
   * @param logger Logger instance
   */
  async unlinkLocation(flyerId: number, storeLocationId: number, logger: Logger): Promise<void> {
    try {
      await this.db.query(
        'DELETE FROM public.flyer_locations WHERE flyer_id = $1 AND store_location_id = $2',
        [flyerId, storeLocationId],
      );

      logger.info({ flyerId, storeLocationId }, 'Unlinked location from flyer');
    } catch (error) {
      handleDbError(
        error,
        logger,
        'Database error in unlinkLocation',
        { flyerId, storeLocationId },
        {
          defaultMessage: 'Failed to unlink location from flyer.',
        },
      );
    }
  }

  /**
   * Gets all location IDs associated with a flyer.
   * @param flyerId The ID of the flyer
   * @param logger Logger instance
   * @returns Promise that resolves to an array of store_location_ids
   */
  async getLocationIdsByFlyerId(flyerId: number, logger: Logger): Promise<number[]> {
    try {
      const res = await this.db.query<{ store_location_id: number }>(
        'SELECT store_location_id FROM public.flyer_locations WHERE flyer_id = $1',
        [flyerId],
      );

      return res.rows.map((row) => row.store_location_id);
    } catch (error) {
      handleDbError(
        error,
        logger,
        'Database error in getLocationIdsByFlyerId',
        { flyerId },
        {
          defaultMessage: 'Failed to get location IDs for flyer.',
        },
      );
    }
  }

  /**
   * Gets all flyer_location records for a flyer.
   * @param flyerId The ID of the flyer
   * @param logger Logger instance
   * @returns Promise that resolves to an array of FlyerLocation objects
   */
  async getFlyerLocationsByFlyerId(flyerId: number, logger: Logger): Promise<FlyerLocation[]> {
    try {
      const res = await this.db.query<FlyerLocation>(
        'SELECT * FROM public.flyer_locations WHERE flyer_id = $1',
        [flyerId],
      );

      return res.rows;
    } catch (error) {
      handleDbError(
        error,
        logger,
        'Database error in getFlyerLocationsByFlyerId',
        { flyerId },
        {
          defaultMessage: 'Failed to get flyer locations.',
        },
      );
    }
  }
}