const express = require('express');
const router = express.Router();
const { adminMiddleware } = require('../middleware/auth');
const db = require('../db/database');

// Get all milestones (optionally filtered by age group)
router.get('/milestones', adminMiddleware, async (req, res) => {
  try {
    const { age_group } = req.query;
    let query = 'SELECT * FROM developmental_milestones';
    let params = [];

    if (age_group) {
      query += ' WHERE age_group = $1';
      params.push(age_group);
    }

    query += ' ORDER BY age_group, domain, sort_order, id';

    const result = await db.query(query, params);
    res.json({ success: true, milestones: result.rows });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Get unique age groups and domains
router.get('/milestones/meta', adminMiddleware, async (req, res) => {
  try {
    const ageGroups = await db.query(
      'SELECT DISTINCT age_group FROM developmental_milestones ORDER BY age_group'
    );
    const domains = await db.query(
      'SELECT DISTINCT domain FROM developmental_milestones ORDER BY domain'
    );

    res.json({
      success: true,
      age_groups: ageGroups.rows.map(r => r.age_group),
      domains: domains.rows.map(r => r.domain)
    });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Create new milestone
router.post('/milestones', adminMiddleware, async (req, res) => {
  try {
    const { age_group, domain, milestone_text, sort_order } = req.body;

    if (!age_group || !domain || !milestone_text) {
      return res.status(400).json({ error: 'Missing required fields' });
    }

    const result = await db.query(
      `INSERT INTO developmental_milestones (age_group, domain, milestone_text, sort_order)
       VALUES ($1, $2, $3, $4)
       RETURNING *`,
      [age_group, domain, milestone_text, sort_order || 0]
    );

    res.json({ success: true, milestone: result.rows[0] });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Update milestone
router.put('/milestones/:id', adminMiddleware, async (req, res) => {
  try {
    const { id } = req.params;
    const { age_group, domain, milestone_text, sort_order } = req.body;

    if (!age_group || !domain || !milestone_text) {
      return res.status(400).json({ error: 'Missing required fields' });
    }

    const result = await db.query(
      `UPDATE developmental_milestones
       SET age_group = $1, domain = $2, milestone_text = $3, sort_order = $4, updated_at = NOW()
       WHERE id = $5
       RETURNING *`,
      [age_group, domain, milestone_text, sort_order || 0, id]
    );

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

    res.json({ success: true, milestone: result.rows[0] });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Delete milestone
router.delete('/milestones/:id', adminMiddleware, async (req, res) => {
  try {
    const { id } = req.params;

    const result = await db.query(
      'DELETE FROM developmental_milestones WHERE id = $1 RETURNING *',
      [id]
    );

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

    res.json({ success: true, message: 'Milestone deleted' });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Bulk import milestones (from static data)
router.post('/milestones/bulk-import', adminMiddleware, async (req, res) => {
  try {
    const { milestones, clearExisting } = req.body;

    if (!Array.isArray(milestones)) {
      return res.status(400).json({ error: 'Expected array of milestones' });
    }

    // Clear existing if requested
    if (clearExisting) {
      await db.query('DELETE FROM developmental_milestones');
    }

    let imported = 0;
    for (const m of milestones) {
      if (!m.age_group || !m.domain || !m.milestone_text) continue;

      await db.query(
        `INSERT INTO developmental_milestones (age_group, domain, milestone_text, sort_order)
         VALUES ($1, $2, $3, $4)`,
        [m.age_group, m.domain, m.milestone_text, m.sort_order || 0]
      );
      imported++;
    }

    res.json({ success: true, imported });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

module.exports = router;