/**
 * Click Analytics API Routes
 *
 * Aggregates product click events by brand and campaign for analytics dashboards.
 *
 * Endpoints:
 *   GET /api/analytics/clicks/brands - Top brands by click engagement
 *   GET /api/analytics/clicks/campaigns - Top campaigns/specials by engagement
 *   GET /api/analytics/clicks/stores/:storeId/brands - Per-store brand engagement
 *   GET /api/analytics/clicks/summary - Overall click summary stats
 */

import { Router, Request, Response } from 'express';
import { pool } from '../db/pool';
import { authMiddleware } from '../auth/middleware';

const router = Router();

// All click analytics endpoints require authentication
router.use(authMiddleware);

/**
 * GET /api/analytics/clicks/brands
 * Get top brands by click engagement
 *
 * Query params:
 *   - state: Filter by store state (e.g., 'AZ')
 *   - store_id: Filter by specific store
 *   - brand_id: Filter by specific brand
 *   - days: Lookback window (default 30)
 *   - limit: Max results (default 25)
 */
router.get('/brands', async (req: Request, res: Response) => {
  try {
    const {
      state,
      store_id,
      brand_id,
      days = '30',
      limit = '25'
    } = req.query;

    const daysNum = parseInt(days as string, 10) || 30;
    const limitNum = Math.min(parseInt(limit as string, 10) || 25, 100);

    // Build conditions and params
    const conditions: string[] = [
      'e.brand_id IS NOT NULL',
      `e.occurred_at >= NOW() - INTERVAL '${daysNum} days'`
    ];
    const params: any[] = [];
    let paramIdx = 1;

    if (state) {
      conditions.push(`d.state = $${paramIdx++}`);
      params.push(state);
    }

    if (store_id) {
      conditions.push(`e.store_id = $${paramIdx++}`);
      params.push(store_id);
    }

    if (brand_id) {
      conditions.push(`e.brand_id = $${paramIdx++}`);
      params.push(brand_id);
    }

    const whereClause = conditions.length > 0 ? `WHERE ${conditions.join(' AND ')}` : '';

    // Query for brand engagement
    const result = await pool.query(`
      SELECT
        e.brand_id,
        e.brand_id as brand_name,
        COUNT(*) as clicks,
        COUNT(DISTINCT e.product_id) as unique_products,
        COUNT(DISTINCT e.store_id) as unique_stores,
        MIN(e.occurred_at) as first_click_at,
        MAX(e.occurred_at) as last_click_at
      FROM product_click_events e
      LEFT JOIN dispensaries d ON e.store_id::int = d.id
      ${whereClause}
      GROUP BY e.brand_id
      ORDER BY clicks DESC
      LIMIT ${limitNum}
    `, params);

    // Try to get actual brand names from products
    const brandIds = result.rows.map(r => r.brand_id).filter(Boolean);
    let brandNamesMap: Record<string, string> = {};

    if (brandIds.length > 0) {
      const brandNamesResult = await pool.query(`
        SELECT DISTINCT brand_name_raw as brand_name
        FROM store_products
        WHERE brand_name_raw = ANY($1)
      `, [brandIds]);

      brandNamesResult.rows.forEach(r => {
        brandNamesMap[r.brand_name] = r.brand_name;
      });
    }

    const brands = result.rows.map(row => ({
      brand_id: row.brand_id,
      brand_name: brandNamesMap[row.brand_id] || row.brand_id,
      clicks: parseInt(row.clicks, 10),
      unique_products: parseInt(row.unique_products, 10),
      unique_stores: parseInt(row.unique_stores, 10),
      first_click_at: row.first_click_at,
      last_click_at: row.last_click_at
    }));

    res.json({
      filters: {
        state: state || null,
        store_id: store_id || null,
        brand_id: brand_id || null,
        days: daysNum
      },
      brands
    });
  } catch (error: any) {
    console.error('[ClickAnalytics] Error fetching brand analytics:', error.message);
    res.status(500).json({ error: 'Failed to fetch brand analytics' });
  }
});

/**
 * GET /api/analytics/clicks/products
 * Get top products by click engagement
 *
 * Query params:
 *   - state: Filter by store state (e.g., 'AZ')
 *   - store_id: Filter by specific store
 *   - brand_id: Filter by specific brand
 *   - days: Lookback window (default 30)
 *   - limit: Max results (default 25)
 */
router.get('/products', async (req: Request, res: Response) => {
  try {
    const {
      state,
      store_id,
      brand_id,
      days = '30',
      limit = '25'
    } = req.query;

    const daysNum = parseInt(days as string, 10) || 30;
    const limitNum = Math.min(parseInt(limit as string, 10) || 25, 100);

    // Build conditions and params
    const conditions: string[] = [
      'e.product_id IS NOT NULL',
      `e.occurred_at >= NOW() - INTERVAL '${daysNum} days'`
    ];
    const params: any[] = [];
    let paramIdx = 1;

    if (state) {
      conditions.push(`d.state = $${paramIdx++}`);
      params.push(state);
    }

    if (store_id) {
      conditions.push(`e.store_id = $${paramIdx++}`);
      params.push(store_id);
    }

    if (brand_id) {
      conditions.push(`e.brand_id = $${paramIdx++}`);
      params.push(brand_id);
    }

    const whereClause = conditions.length > 0 ? `WHERE ${conditions.join(' AND ')}` : '';

    // Query for product engagement with product details from dutchie_products
    const result = await pool.query(`
      SELECT
        e.product_id,
        e.brand_id,
        COUNT(*) as clicks,
        COUNT(DISTINCT e.store_id) as unique_stores,
        MIN(e.occurred_at) as first_click_at,
        MAX(e.occurred_at) as last_click_at
      FROM product_click_events e
      LEFT JOIN dispensaries d ON e.store_id::int = d.id
      ${whereClause}
      GROUP BY e.product_id, e.brand_id
      ORDER BY clicks DESC
      LIMIT ${limitNum}
    `, params);

    // Try to get product details from dutchie_products
    const productIds = result.rows.map(r => r.product_id).filter(Boolean);
    let productDetailsMap: Record<string, { name: string; brand: string; type: string; subcategory: string }> = {};

    if (productIds.length > 0) {
      // Try to match by external_id or id
      const productDetailsResult = await pool.query(`
        SELECT
          provider_product_id as external_id,
          id::text as product_id,
          name_raw as name,
          brand_name_raw as brand_name,
          category_raw as type,
          subcategory_raw as subcategory
        FROM store_products
        WHERE provider_product_id = ANY($1) OR id::text = ANY($1)
      `, [productIds]);

      productDetailsResult.rows.forEach(r => {
        productDetailsMap[r.external_id] = {
          name: r.name,
          brand: r.brand_name,
          type: r.type,
          subcategory: r.subcategory
        };
        productDetailsMap[r.product_id] = {
          name: r.name,
          brand: r.brand_name,
          type: r.type,
          subcategory: r.subcategory
        };
      });
    }

    const products = result.rows.map(row => {
      const details = productDetailsMap[row.product_id];
      return {
        product_id: row.product_id,
        product_name: details?.name || `Product ${row.product_id}`,
        brand_id: row.brand_id,
        brand_name: details?.brand || row.brand_id || 'Unknown',
        category: details?.type || null,
        subcategory: details?.subcategory || null,
        clicks: parseInt(row.clicks, 10),
        unique_stores: parseInt(row.unique_stores, 10),
        first_click_at: row.first_click_at,
        last_click_at: row.last_click_at
      };
    });

    res.json({
      filters: {
        state: state || null,
        store_id: store_id || null,
        brand_id: brand_id || null,
        days: daysNum
      },
      products
    });
  } catch (error: any) {
    console.error('[ClickAnalytics] Error fetching product analytics:', error.message);
    res.status(500).json({ error: 'Failed to fetch product analytics' });
  }
});

/**
 * GET /api/analytics/clicks/campaigns
 * Get top campaigns/specials by click engagement
 *
 * Query params:
 *   - state: Filter by store state
 *   - store_id: Filter by specific store
 *   - days: Lookback window (default 30)
 *   - limit: Max results (default 25)
 */
router.get('/campaigns', async (req: Request, res: Response) => {
  try {
    const {
      state,
      store_id,
      days = '30',
      limit = '25'
    } = req.query;

    const daysNum = parseInt(days as string, 10) || 30;
    const limitNum = Math.min(parseInt(limit as string, 10) || 25, 100);

    // Build conditions
    const conditions: string[] = [
      'e.campaign_id IS NOT NULL',
      `e.occurred_at >= NOW() - INTERVAL '${daysNum} days'`
    ];
    const params: any[] = [];
    let paramIdx = 1;

    if (state) {
      conditions.push(`d.state = $${paramIdx++}`);
      params.push(state);
    }

    if (store_id) {
      conditions.push(`e.store_id = $${paramIdx++}`);
      params.push(store_id);
    }

    const whereClause = `WHERE ${conditions.join(' AND ')}`;

    // Query for campaign engagement with campaign details
    const result = await pool.query(`
      SELECT
        e.campaign_id,
        c.name as campaign_name,
        c.slug as campaign_slug,
        c.description as campaign_description,
        c.active as is_active,
        c.start_date,
        c.end_date,
        COUNT(*) as clicks,
        COUNT(DISTINCT e.product_id) as unique_products,
        COUNT(DISTINCT e.store_id) as unique_stores,
        MIN(e.occurred_at) as first_event_at,
        MAX(e.occurred_at) as last_event_at
      FROM product_click_events e
      LEFT JOIN dispensaries d ON e.store_id::int = d.id
      LEFT JOIN campaigns c ON e.campaign_id = c.id
      ${whereClause}
      GROUP BY e.campaign_id, c.name, c.slug, c.description, c.active, c.start_date, c.end_date
      ORDER BY clicks DESC
      LIMIT ${limitNum}
    `, params);

    const campaigns = result.rows.map(row => ({
      campaign_id: row.campaign_id,
      campaign_name: row.campaign_name || `Campaign ${row.campaign_id}`,
      campaign_slug: row.campaign_slug,
      campaign_description: row.campaign_description,
      is_active: row.is_active,
      start_date: row.start_date,
      end_date: row.end_date,
      clicks: parseInt(row.clicks, 10),
      unique_products: parseInt(row.unique_products, 10),
      unique_stores: parseInt(row.unique_stores, 10),
      first_event_at: row.first_event_at,
      last_event_at: row.last_event_at
    }));

    res.json({
      filters: {
        state: state || null,
        store_id: store_id || null,
        days: daysNum
      },
      campaigns
    });
  } catch (error: any) {
    console.error('[ClickAnalytics] Error fetching campaign analytics:', error.message);
    res.status(500).json({ error: 'Failed to fetch campaign analytics' });
  }
});

/**
 * GET /api/analytics/clicks/stores/:storeId/brands
 * Get brand engagement for a specific store
 *
 * Query params:
 *   - days: Lookback window (default 30)
 *   - limit: Max results (default 25)
 */
router.get('/stores/:storeId/brands', async (req: Request, res: Response) => {
  try {
    const { storeId } = req.params;
    const { days = '30', limit = '25' } = req.query;

    const daysNum = parseInt(days as string, 10) || 30;
    const limitNum = Math.min(parseInt(limit as string, 10) || 25, 100);

    // Get store info
    const storeResult = await pool.query(
      'SELECT id, name, dba_name, city, state FROM dispensaries WHERE id = $1',
      [storeId]
    );

    if (storeResult.rows.length === 0) {
      return res.status(404).json({ error: 'Store not found' });
    }

    const store = storeResult.rows[0];

    // Query brand engagement for this store
    const result = await pool.query(`
      SELECT
        e.brand_id,
        COUNT(*) as clicks,
        COUNT(DISTINCT e.product_id) as unique_products,
        MIN(e.occurred_at) as first_click_at,
        MAX(e.occurred_at) as last_click_at
      FROM product_click_events e
      WHERE e.store_id = $1
        AND e.brand_id IS NOT NULL
        AND e.occurred_at >= NOW() - INTERVAL '${daysNum} days'
      GROUP BY e.brand_id
      ORDER BY clicks DESC
      LIMIT ${limitNum}
    `, [storeId]);

    const brands = result.rows.map(row => ({
      brand_id: row.brand_id,
      brand_name: row.brand_id, // Use brand_id as name for now
      clicks: parseInt(row.clicks, 10),
      unique_products: parseInt(row.unique_products, 10),
      first_click_at: row.first_click_at,
      last_click_at: row.last_click_at
    }));

    res.json({
      store: {
        id: store.id,
        name: store.dba_name || store.name,
        city: store.city,
        state: store.state
      },
      filters: {
        days: daysNum
      },
      brands
    });
  } catch (error: any) {
    console.error('[ClickAnalytics] Error fetching store brand analytics:', error.message);
    res.status(500).json({ error: 'Failed to fetch store brand analytics' });
  }
});

/**
 * GET /api/analytics/clicks/summary
 * Get overall click summary stats
 *
 * Query params:
 *   - state: Filter by store state
 *   - days: Lookback window (default 30)
 */
router.get('/summary', async (req: Request, res: Response) => {
  try {
    const { state, days = '30' } = req.query;
    const daysNum = parseInt(days as string, 10) || 30;

    const conditions: string[] = [`e.occurred_at >= NOW() - INTERVAL '${daysNum} days'`];
    const params: any[] = [];
    let paramIdx = 1;

    if (state) {
      conditions.push(`d.state = $${paramIdx++}`);
      params.push(state);
    }

    const whereClause = `WHERE ${conditions.join(' AND ')}`;

    // Get overall stats
    const statsResult = await pool.query(`
      SELECT
        COUNT(*) as total_clicks,
        COUNT(DISTINCT e.product_id) as unique_products,
        COUNT(DISTINCT e.store_id) as unique_stores,
        COUNT(DISTINCT e.brand_id) FILTER (WHERE e.brand_id IS NOT NULL) as unique_brands,
        COUNT(*) FILTER (WHERE e.campaign_id IS NOT NULL) as campaign_clicks,
        COUNT(DISTINCT e.campaign_id) FILTER (WHERE e.campaign_id IS NOT NULL) as unique_campaigns
      FROM product_click_events e
      LEFT JOIN dispensaries d ON e.store_id::int = d.id
      ${whereClause}
    `, params);

    // Get clicks by action
    const actionResult = await pool.query(`
      SELECT
        action,
        COUNT(*) as count
      FROM product_click_events e
      LEFT JOIN dispensaries d ON e.store_id::int = d.id
      ${whereClause}
      GROUP BY action
      ORDER BY count DESC
    `, params);

    // Get clicks by day (last 14 days for chart)
    const dailyResult = await pool.query(`
      SELECT
        DATE(occurred_at) as date,
        COUNT(*) as clicks
      FROM product_click_events e
      LEFT JOIN dispensaries d ON e.store_id::int = d.id
      ${whereClause}
      GROUP BY DATE(occurred_at)
      ORDER BY date DESC
      LIMIT 14
    `, params);

    const stats = statsResult.rows[0];

    res.json({
      filters: {
        state: state || null,
        days: daysNum
      },
      summary: {
        total_clicks: parseInt(stats.total_clicks, 10),
        unique_products: parseInt(stats.unique_products, 10),
        unique_stores: parseInt(stats.unique_stores, 10),
        unique_brands: parseInt(stats.unique_brands, 10),
        campaign_clicks: parseInt(stats.campaign_clicks, 10),
        unique_campaigns: parseInt(stats.unique_campaigns, 10)
      },
      by_action: actionResult.rows.map(row => ({
        action: row.action,
        count: parseInt(row.count, 10)
      })),
      daily: dailyResult.rows.map(row => ({
        date: row.date,
        clicks: parseInt(row.clicks, 10)
      })).reverse()
    });
  } catch (error: any) {
    console.error('[ClickAnalytics] Error fetching click summary:', error.message);
    res.status(500).json({ error: 'Failed to fetch click summary' });
  }
});

export default router;