const express = require('express');
const { prisma } = require('../utils/db');
const { authenticate } = require('../middleware/auth');
const { requireAdmin } = require('../middleware/admin');
const matchingService = require('../services/matching');
const { SUGGESTION_STATUS } = require('../constants');
const { ACTIONS, log: activityLog, queryLogs, getActionTypes, getStats } = require('../services/activityLog');
const { getClientIP } = require('../utils/request');

const router = express.Router();

// POST /api/admin/events/:slug/run-now - Trigger matching immediately for an event
router.post('/events/:slug/run-now', authenticate, requireAdmin, async (req, res, next) => {
  try {
    const { slug } = req.params;

    const event = await prisma.event.findUnique({
      where: { slug },
      select: { id: true, slug: true },
    });

    if (!event) {
      return res.status(404).json({ success: false, error: 'Event not found' });
    }

    const startedAt = new Date();
    const runRow = await prisma.matchingRun.create({
      data: {
        eventId: event.id,
        trigger: 'manual',
        status: 'running',
        startedAt,
      },
    });

    try {
      const suggestions = await matchingService.runMatching(event.id);
      await matchingService.saveMatchingResults(event.id, suggestions, runRow.id);

      const notFoundCount = suggestions.filter(s => s.status === SUGGESTION_STATUS.NOT_FOUND).length;
      const matchedCount = suggestions.filter(s => s.status === SUGGESTION_STATUS.PENDING).length;

      await prisma.matchingRun.update({
        where: { id: runRow.id },
        data: {
          status: 'success',
          endedAt: new Date(),
          matchedCount,
          notFoundCount,
        },
      });

      // Log admin matching run activity
      activityLog({
        userId: req.user.id,
        username: req.user.username,
        ipAddress: getClientIP(req),
        action: ACTIONS.ADMIN_MATCHING_RUN,
        resource: `event:${event.id}`,
        method: req.method,
        path: req.path,
        metadata: {
          eventSlug: event.slug,
          runId: runRow.id,
          matchedCount,
          notFoundCount,
        },
      });

      return res.json({
        success: true,
        data: {
          eventSlug: event.slug,
          startedAt,
          endedAt: new Date(),
          matched: matchedCount,
          notFound: notFoundCount,
        },
      });
    } catch (err) {
      await prisma.matchingRun.update({
        where: { id: runRow.id },
        data: {
          status: 'error',
          endedAt: new Date(),
          error: String(err?.message || err),
        },
      });
      return res.status(500).json({ success: false, error: 'Matching failed', details: String(err?.message || err) });
    }
  } catch (error) {
    next(error);
  }
});

// GET /api/admin/events/:slug/matching-runs?limit=20 - List recent runs
router.get('/events/:slug/matching-runs', authenticate, requireAdmin, async (req, res, next) => {
  try {
    const { slug } = req.params;
    const limit = Math.min(parseInt(req.query.limit || '20', 10), 100);

    const event = await prisma.event.findUnique({
      where: { slug },
      select: { id: true },
    });

    if (!event) {
      return res.status(404).json({ success: false, error: 'Event not found' });
    }

    const runs = await prisma.matchingRun.findMany({
      where: { eventId: event.id },
      orderBy: { startedAt: 'desc' },
      take: limit,
      select: {
        id: true,
        trigger: true,
        status: true,
        startedAt: true,
        endedAt: true,
        matchedCount: true,
        notFoundCount: true,
        error: true,
      },
    });

    // Aggregate fresh stats per run from recording_suggestions (origin_run_id)
    // Cheap and valuable: shows actual created pairs in this run.
    if (runs.length > 0) {
      const runIds = runs.map(r => r.id);
      // Single SQL query for all listed runs (using parameterized query to prevent SQL injection)
      const aggRows = await prisma.$queryRaw`
        SELECT origin_run_id AS "originRunId",
               COUNT(*)::int AS "totalSuggestions",
               COUNT(*) FILTER (WHERE recorder_id IS NOT NULL)::int AS "assignedCount",
               COUNT(*) FILTER (WHERE status = 'not_found')::int AS "notFoundCount"
        FROM recording_suggestions
        WHERE event_id = ${event.id} AND origin_run_id = ANY(${runIds})
        GROUP BY origin_run_id
      `;
      const aggByRun = new Map(aggRows.map(r => [r.originRunId, r]));
      for (const r of runs) {
        const agg = aggByRun.get(r.id) || { totalSuggestions: 0, assignedCount: 0, notFoundCount: 0 };
        r.totalSuggestions = agg.totalSuggestions;
        r.assignedCount = agg.assignedCount;
        r.aggregatedNotFoundCount = agg.notFoundCount; // keep original notFoundCount for backward compat
      }
    }

    res.json({ success: true, count: runs.length, data: runs });
  } catch (error) {
    next(error);
  }
});

module.exports = router;

// GET /api/admin/events/:slug/matching-runs/:runId/suggestions - List suggestions created in this run
router.get('/events/:slug/matching-runs/:runId/suggestions', authenticate, requireAdmin, async (req, res, next) => {
  try {
    const { slug, runId } = req.params;
    const onlyAssigned = String(req.query.onlyAssigned || 'true') === 'true';
    const includeNotFound = String(req.query.includeNotFound || 'false') === 'true';
    const limit = Math.min(parseInt(req.query.limit || '100', 10), 200);

    const event = await prisma.event.findUnique({ where: { slug }, select: { id: true } });
    if (!event) {
      return res.status(404).json({ success: false, error: 'Event not found' });
    }

    const run = await prisma.matchingRun.findFirst({
      where: { id: Number(runId), eventId: event.id },
      select: {
        id: true,
        trigger: true,
        status: true,
        startedAt: true,
        endedAt: true,
        matchedCount: true,
        notFoundCount: true,
      },
    });
    if (!run) {
      return res.status(404).json({ success: false, error: 'Run not found for event' });
    }

    // Build where for suggestions in this run
    const where = {
      eventId: event.id,
      originRunId: Number(runId),
    };

    if (onlyAssigned && !includeNotFound) {
      // Only pairs with assigned recorder
      where.recorderId = { not: null };
    }

    const suggestions = await prisma.recordingSuggestion.findMany({
      where,
      take: limit,
      orderBy: { id: 'asc' },
      include: {
        heat: {
          include: {
            division: { select: { id: true, name: true, abbreviation: true } },
            competitionType: { select: { id: true, name: true, abbreviation: true } },
            user: { select: { id: true, username: true, avatar: true, city: true, country: true } },
          },
        },
        recorder: { select: { id: true, username: true, avatar: true, city: true, country: true } },
      },
    });

    const formatted = suggestions
      .filter((s) => includeNotFound || s.status !== 'not_found')
      .map((s) => {
        const div = s.heat.division;
        const ct = s.heat.competitionType;
        const label = `${div?.name || ''} ${ct?.abbreviation || ct?.name || ''} #${s.heat.heatNumber}`.trim();
        return {
          id: s.id,
          status: s.status,
          heat: {
            id: s.heat.id,
            heatNumber: s.heat.heatNumber,
            label,
            division: div,
            competitionType: ct,
          },
          dancer: s.heat.user,
          recorder: s.recorder || null,
        };
      });

    return res.json({ success: true, run, suggestions: formatted });
  } catch (error) {
    next(error);
  }
});

// ==================================================================
// ACTIVITY LOGS ENDPOINTS
// ==================================================================

// GET /api/admin/activity-logs - Query activity logs with filters
router.get('/activity-logs', authenticate, requireAdmin, async (req, res, next) => {
  try {
    const {
      startDate,
      endDate,
      action,
      category,
      username,
      userId,
      success,
      limit = 100,
      offset = 0,
    } = req.query;

    // Parse query parameters
    const filters = {
      startDate: startDate ? new Date(startDate) : null,
      endDate: endDate ? new Date(endDate) : null,
      action: action || null,
      category: category || null,
      username: username || null,
      userId: userId ? parseInt(userId) : null,
      success: success !== undefined ? success === 'true' : null,
      limit: parseInt(limit),
      offset: parseInt(offset),
    };

    // Query logs
    const result = await queryLogs(filters);

    // Log admin viewing activity logs
    activityLog({
      userId: req.user.id,
      username: req.user.username,
      ipAddress: getClientIP(req),
      action: ACTIONS.ADMIN_VIEW_LOGS,
      method: req.method,
      path: req.path,
      metadata: {
        filters: {
          startDate,
          endDate,
          action,
          category,
          username,
          userId,
          success,
        },
        resultCount: result.logs.length,
      },
    });

    res.json({
      success: true,
      data: result,
    });
  } catch (error) {
    next(error);
  }
});

// GET /api/admin/activity-logs/actions - Get unique action types
router.get('/activity-logs/actions', authenticate, requireAdmin, async (req, res, next) => {
  try {
    const actions = await getActionTypes();

    res.json({
      success: true,
      count: actions.length,
      data: actions,
    });
  } catch (error) {
    next(error);
  }
});

// GET /api/admin/activity-logs/stats - Get activity log statistics
router.get('/activity-logs/stats', authenticate, requireAdmin, async (req, res, next) => {
  try {
    const stats = await getStats();

    res.json({
      success: true,
      data: stats,
    });
  } catch (error) {
    next(error);
  }
});