/**
 * Task Queue API Routes
 *
 * Endpoints for managing worker tasks, viewing capacity metrics,
 * and generating batch tasks.
 */

import { Router, Request, Response } from 'express';
import {
  taskService,
  TaskRole,
  TaskStatus,
  TaskFilter,
} from '../tasks/task-service';
import { pool } from '../db/pool';
import {
  isTaskPoolPaused,
  pauseTaskPool,
  resumeTaskPool,
  getTaskPoolStatus,
} from '../tasks/task-pool-state';

const router = Router();

/**
 * GET /api/tasks
 * List tasks with optional filters
 *
 * Query params:
 * - role: Filter by role
 * - status: Filter by status (comma-separated for multiple)
 * - dispensary_id: Filter by dispensary
 * - worker_id: Filter by worker
 * - limit: Max results (default 100)
 * - offset: Pagination offset
 */
router.get('/', async (req: Request, res: Response) => {
  try {
    const filter: TaskFilter = {};

    if (req.query.role) {
      filter.role = req.query.role as TaskRole;
    }

    if (req.query.status) {
      const statuses = (req.query.status as string).split(',') as TaskStatus[];
      filter.status = statuses.length === 1 ? statuses[0] : statuses;
    }

    if (req.query.dispensary_id) {
      filter.dispensary_id = parseInt(req.query.dispensary_id as string, 10);
    }

    if (req.query.worker_id) {
      filter.worker_id = req.query.worker_id as string;
    }

    if (req.query.limit) {
      filter.limit = parseInt(req.query.limit as string, 10);
    }

    if (req.query.offset) {
      filter.offset = parseInt(req.query.offset as string, 10);
    }

    const tasks = await taskService.listTasks(filter);
    res.json({ tasks, count: tasks.length });
  } catch (error: unknown) {
    console.error('Error listing tasks:', error);
    res.status(500).json({ error: 'Failed to list tasks' });
  }
});

/**
 * GET /api/tasks/counts
 * Get task counts by status
 */
router.get('/counts', async (_req: Request, res: Response) => {
  try {
    const counts = await taskService.getTaskCounts();
    res.json(counts);
  } catch (error: unknown) {
    console.error('Error getting task counts:', error);
    res.status(500).json({ error: 'Failed to get task counts' });
  }
});

/**
 * GET /api/tasks/capacity
 * Get capacity metrics for all roles
 */
router.get('/capacity', async (_req: Request, res: Response) => {
  try {
    const metrics = await taskService.getCapacityMetrics();
    res.json({ metrics });
  } catch (error: unknown) {
    console.error('Error getting capacity metrics:', error);
    res.status(500).json({ error: 'Failed to get capacity metrics' });
  }
});

/**
 * GET /api/tasks/capacity/:role
 * Get capacity metrics for a specific role
 */
router.get('/capacity/:role', async (req: Request, res: Response) => {
  try {
    const role = req.params.role as TaskRole;
    const capacity = await taskService.getRoleCapacity(role);

    if (!capacity) {
      return res.status(404).json({ error: 'Role not found or no data' });
    }

    // Calculate workers needed for different SLAs
    const workersFor1Hour = await taskService.calculateWorkersNeeded(role, 1);
    const workersFor4Hours = await taskService.calculateWorkersNeeded(role, 4);
    const workersFor8Hours = await taskService.calculateWorkersNeeded(role, 8);

    res.json({
      ...capacity,
      workers_needed: {
        for_1_hour: workersFor1Hour,
        for_4_hours: workersFor4Hours,
        for_8_hours: workersFor8Hours,
      },
    });
  } catch (error: unknown) {
    console.error('Error getting role capacity:', error);
    res.status(500).json({ error: 'Failed to get role capacity' });
  }
});

/**
 * GET /api/tasks/:id
 * Get a specific task by ID
 */
router.get('/:id', async (req: Request, res: Response) => {
  try {
    const taskId = parseInt(req.params.id, 10);
    const task = await taskService.getTask(taskId);

    if (!task) {
      return res.status(404).json({ error: 'Task not found' });
    }

    res.json(task);
  } catch (error: unknown) {
    console.error('Error getting task:', error);
    res.status(500).json({ error: 'Failed to get task' });
  }
});

/**
 * DELETE /api/tasks/:id
 * Delete a specific task by ID
 * Only allows deletion of failed, completed, or pending tasks (not running)
 */
router.delete('/:id', async (req: Request, res: Response) => {
  try {
    const taskId = parseInt(req.params.id, 10);

    // First check if task exists and its status
    const task = await taskService.getTask(taskId);
    if (!task) {
      return res.status(404).json({ error: 'Task not found' });
    }

    // Don't allow deleting running tasks
    if (task.status === 'running' || task.status === 'claimed') {
      return res.status(400).json({ error: 'Cannot delete a running or claimed task' });
    }

    // Delete the task
    await pool.query('DELETE FROM worker_tasks WHERE id = $1', [taskId]);

    res.json({ success: true, message: `Task ${taskId} deleted` });
  } catch (error: unknown) {
    console.error('Error deleting task:', error);
    res.status(500).json({ error: 'Failed to delete task' });
  }
});

/**
 * POST /api/tasks
 * Create a new task
 *
 * Body:
 * - role: TaskRole (required)
 * - dispensary_id: number (optional)
 * - platform: string (optional)
 * - priority: number (optional, default 0)
 * - scheduled_for: ISO date string (optional)
 */
router.post('/', async (req: Request, res: Response) => {
  try {
    const { role, dispensary_id, platform, priority, scheduled_for } = req.body;

    if (!role) {
      return res.status(400).json({ error: 'Role is required' });
    }

    // Check if store already has an active task
    if (dispensary_id) {
      const hasActive = await taskService.hasActiveTask(dispensary_id);
      if (hasActive) {
        return res.status(409).json({
          error: 'Store already has an active task',
          dispensary_id,
        });
      }
    }

    const task = await taskService.createTask({
      role,
      dispensary_id,
      platform,
      priority,
      scheduled_for: scheduled_for ? new Date(scheduled_for) : undefined,
    });

    res.status(201).json(task);
  } catch (error: unknown) {
    console.error('Error creating task:', error);
    res.status(500).json({ error: 'Failed to create task' });
  }
});

/**
 * POST /api/tasks/generate/resync
 * Generate daily resync tasks for all active stores
 *
 * Body:
 * - batches_per_day: number (optional, default 6 = every 4 hours)
 * - date: ISO date string (optional, default today)
 */
router.post('/generate/resync', async (req: Request, res: Response) => {
  try {
    const { batches_per_day, date } = req.body;
    const batchesPerDay = batches_per_day ?? 6;
    const targetDate = date ? new Date(date) : new Date();

    const createdCount = await taskService.generateDailyResyncTasks(
      batchesPerDay,
      targetDate
    );

    res.json({
      success: true,
      tasks_created: createdCount,
      batches_per_day: batchesPerDay,
      date: targetDate.toISOString().split('T')[0],
    });
  } catch (error: unknown) {
    console.error('Error generating resync tasks:', error);
    res.status(500).json({ error: 'Failed to generate resync tasks' });
  }
});

/**
 * POST /api/tasks/generate/discovery
 * Generate store discovery tasks for a platform
 *
 * Body:
 * - platform: string (required, e.g., 'dutchie')
 * - state_code: string (optional, e.g., 'AZ')
 * - priority: number (optional)
 */
router.post('/generate/discovery', async (req: Request, res: Response) => {
  try {
    const { platform, state_code, priority } = req.body;

    if (!platform) {
      return res.status(400).json({ error: 'Platform is required' });
    }

    const task = await taskService.createStoreDiscoveryTask(
      platform,
      state_code,
      priority ?? 0
    );

    res.status(201).json(task);
  } catch (error: unknown) {
    console.error('Error creating discovery task:', error);
    res.status(500).json({ error: 'Failed to create discovery task' });
  }
});

/**
 * POST /api/tasks/recover-stale
 * Recover stale tasks from dead workers
 *
 * Body:
 * - threshold_minutes: number (optional, default 10)
 */
router.post('/recover-stale', async (req: Request, res: Response) => {
  try {
    const { threshold_minutes } = req.body;
    const recovered = await taskService.recoverStaleTasks(threshold_minutes ?? 10);

    res.json({
      success: true,
      tasks_recovered: recovered,
    });
  } catch (error: unknown) {
    console.error('Error recovering stale tasks:', error);
    res.status(500).json({ error: 'Failed to recover stale tasks' });
  }
});

/**
 * GET /api/tasks/role/:role/last-completion
 * Get the last completion time for a role
 */
router.get('/role/:role/last-completion', async (req: Request, res: Response) => {
  try {
    const role = req.params.role as TaskRole;
    const lastCompletion = await taskService.getLastCompletion(role);

    res.json({
      role,
      last_completion: lastCompletion?.toISOString() ?? null,
      time_since: lastCompletion
        ? Math.floor((Date.now() - lastCompletion.getTime()) / 1000)
        : null,
    });
  } catch (error: unknown) {
    console.error('Error getting last completion:', error);
    res.status(500).json({ error: 'Failed to get last completion' });
  }
});

/**
 * GET /api/tasks/role/:role/recent
 * Get recent completions for a role
 */
router.get('/role/:role/recent', async (req: Request, res: Response) => {
  try {
    const role = req.params.role as TaskRole;
    const limit = parseInt(req.query.limit as string, 10) || 10;

    const tasks = await taskService.getRecentCompletions(role, limit);
    res.json({ tasks });
  } catch (error: unknown) {
    console.error('Error getting recent completions:', error);
    res.status(500).json({ error: 'Failed to get recent completions' });
  }
});

/**
 * GET /api/tasks/store/:dispensaryId/active
 * Check if a store has an active task
 */
router.get('/store/:dispensaryId/active', async (req: Request, res: Response) => {
  try {
    const dispensaryId = parseInt(req.params.dispensaryId, 10);
    const hasActive = await taskService.hasActiveTask(dispensaryId);

    res.json({
      dispensary_id: dispensaryId,
      has_active_task: hasActive,
    });
  } catch (error: unknown) {
    console.error('Error checking active task:', error);
    res.status(500).json({ error: 'Failed to check active task' });
  }
});

// ============================================================
// MIGRATION ROUTES - Disable old job systems
// ============================================================

/**
 * GET /api/tasks/migration/status
 * Get status of old job systems vs new task queue
 */
router.get('/migration/status', async (_req: Request, res: Response) => {
  try {
    // Get old job system counts
    const [schedules, crawlJobs, rawPayloads, taskCounts] = await Promise.all([
      pool.query(`
        SELECT
          COUNT(*) as total,
          COUNT(*) FILTER (WHERE enabled = true) as enabled
        FROM job_schedules
      `),
      pool.query(`
        SELECT
          COUNT(*) as total,
          COUNT(*) FILTER (WHERE status = 'pending') as pending,
          COUNT(*) FILTER (WHERE status = 'running') as running
        FROM dispensary_crawl_jobs
      `),
      pool.query(`
        SELECT
          COUNT(*) as total,
          COUNT(*) FILTER (WHERE processed = false) as unprocessed
        FROM raw_payloads
      `),
      taskService.getTaskCounts(),
    ]);

    res.json({
      old_systems: {
        job_schedules: {
          total: parseInt(schedules.rows[0].total) || 0,
          enabled: parseInt(schedules.rows[0].enabled) || 0,
        },
        dispensary_crawl_jobs: {
          total: parseInt(crawlJobs.rows[0].total) || 0,
          pending: parseInt(crawlJobs.rows[0].pending) || 0,
          running: parseInt(crawlJobs.rows[0].running) || 0,
        },
        raw_payloads: {
          total: parseInt(rawPayloads.rows[0].total) || 0,
          unprocessed: parseInt(rawPayloads.rows[0].unprocessed) || 0,
        },
      },
      new_task_queue: taskCounts,
      recommendation: schedules.rows[0].enabled > 0
        ? 'Disable old job schedules before switching to new task queue'
        : 'Ready to use new task queue',
    });
  } catch (error: unknown) {
    console.error('Error getting migration status:', error);
    res.status(500).json({ error: 'Failed to get migration status' });
  }
});

/**
 * POST /api/tasks/migration/disable-old-schedules
 * Disable all old job schedules to prepare for new task queue
 */
router.post('/migration/disable-old-schedules', async (_req: Request, res: Response) => {
  try {
    const result = await pool.query(`
      UPDATE job_schedules
      SET enabled = false,
          updated_at = NOW()
      WHERE enabled = true
      RETURNING id, job_name
    `);

    res.json({
      success: true,
      disabled_count: result.rowCount,
      disabled_schedules: result.rows.map(r => ({ id: r.id, job_name: r.job_name })),
    });
  } catch (error: unknown) {
    console.error('Error disabling old schedules:', error);
    res.status(500).json({ error: 'Failed to disable old schedules' });
  }
});

/**
 * POST /api/tasks/migration/cancel-pending-crawl-jobs
 * Cancel all pending crawl jobs from the old system
 */
router.post('/migration/cancel-pending-crawl-jobs', async (_req: Request, res: Response) => {
  try {
    const result = await pool.query(`
      UPDATE dispensary_crawl_jobs
      SET status = 'cancelled',
          completed_at = NOW(),
          updated_at = NOW()
      WHERE status = 'pending'
      RETURNING id
    `);

    res.json({
      success: true,
      cancelled_count: result.rowCount,
    });
  } catch (error: unknown) {
    console.error('Error cancelling pending crawl jobs:', error);
    res.status(500).json({ error: 'Failed to cancel pending crawl jobs' });
  }
});

/**
 * POST /api/tasks/migration/create-resync-tasks
 * Create product_refresh tasks for all crawl-enabled dispensaries
 */
router.post('/migration/create-resync-tasks', async (req: Request, res: Response) => {
  try {
    const { priority = 0, state_code } = req.body;

    let query = `
      SELECT id, name FROM dispensaries
      WHERE crawl_enabled = true
        AND platform_dispensary_id IS NOT NULL
    `;
    const params: any[] = [];

    if (state_code) {
      query += `
        AND state_id = (SELECT id FROM states WHERE code = $1)
      `;
      params.push(state_code.toUpperCase());
    }

    query += ` ORDER BY id`;

    const dispensaries = await pool.query(query, params);
    let created = 0;

    for (const disp of dispensaries.rows) {
      // Check if already has pending/running task
      const hasActive = await taskService.hasActiveTask(disp.id);
      if (!hasActive) {
        await taskService.createTask({
          role: 'product_refresh',
          dispensary_id: disp.id,
          platform: 'dutchie',
          priority,
        });
        created++;
      }
    }

    res.json({
      success: true,
      tasks_created: created,
      dispensaries_checked: dispensaries.rows.length,
      state_filter: state_code || 'all',
    });
  } catch (error: unknown) {
    console.error('Error creating resync tasks:', error);
    res.status(500).json({ error: 'Failed to create resync tasks' });
  }
});

/**
 * POST /api/tasks/migration/full-migrate
 * One-click migration: disable old systems, create new tasks
 */
router.post('/migration/full-migrate', async (req: Request, res: Response) => {
  try {
    const results: any = {
      success: true,
      steps: [],
    };

    // Step 1: Disable old job schedules
    const disableResult = await pool.query(`
      UPDATE job_schedules
      SET enabled = false, updated_at = NOW()
      WHERE enabled = true
      RETURNING id
    `);
    results.steps.push({
      step: 'disable_job_schedules',
      count: disableResult.rowCount,
    });

    // Step 2: Cancel pending crawl jobs
    const cancelResult = await pool.query(`
      UPDATE dispensary_crawl_jobs
      SET status = 'cancelled', completed_at = NOW(), updated_at = NOW()
      WHERE status = 'pending'
      RETURNING id
    `);
    results.steps.push({
      step: 'cancel_pending_crawl_jobs',
      count: cancelResult.rowCount,
    });

    // Step 3: Generate initial resync tasks
    const resyncCount = await taskService.generateDailyResyncTasks(6);
    results.steps.push({
      step: 'generate_resync_tasks',
      count: resyncCount,
    });

    // Step 4: Create store discovery task
    const discoveryTask = await taskService.createStoreDiscoveryTask('dutchie', undefined, 0);
    results.steps.push({
      step: 'create_discovery_task',
      task_id: discoveryTask.id,
    });

    // Step 5: Create analytics refresh task
    const analyticsTask = await taskService.createTask({
      role: 'analytics_refresh',
      priority: 0,
    });
    results.steps.push({
      step: 'create_analytics_task',
      task_id: analyticsTask.id,
    });

    results.message = 'Migration complete. New task workers will pick up tasks.';
    res.json(results);
  } catch (error: unknown) {
    console.error('Error during full migration:', error);
    res.status(500).json({ error: 'Failed to complete migration' });
  }
});

/**
 * GET /api/tasks/pool/status
 * Check if task pool is paused
 */
router.get('/pool/status', async (_req: Request, res: Response) => {
  const status = getTaskPoolStatus();
  res.json({
    success: true,
    ...status,
  });
});

/**
 * POST /api/tasks/pool/pause
 * Pause the task pool - workers won't pick up new tasks
 */
router.post('/pool/pause', async (_req: Request, res: Response) => {
  pauseTaskPool();
  res.json({
    success: true,
    paused: true,
    message: 'Task pool paused - workers will not pick up new tasks',
  });
});

/**
 * POST /api/tasks/pool/resume
 * Resume the task pool - workers will pick up tasks again
 */
router.post('/pool/resume', async (_req: Request, res: Response) => {
  resumeTaskPool();
  res.json({
    success: true,
    paused: false,
    message: 'Task pool resumed - workers will pick up new tasks',
  });
});

export default router;