const express = require('express');
const router = express.Router();
const { getDatabase } = require('../db/init');

// GET all litters
router.get('/', (req, res) => {
  try {
    const db = getDatabase();
    const litters = db.prepare(`
      SELECT l.*, 
        s.name as sire_name, s.registration_number as sire_reg,
        d.name as dam_name, d.registration_number as dam_reg
      FROM litters l
      JOIN dogs s ON l.sire_id = s.id
      JOIN dogs d ON l.dam_id = d.id
      ORDER BY l.breeding_date DESC
    `).all();
    
    // Get puppies for each litter using litter_id
    litters.forEach(litter => {
      litter.puppies = db.prepare(`
        SELECT * FROM dogs WHERE litter_id = ? AND is_active = 1
      `).all(litter.id);
      
      litter.puppies.forEach(puppy => {
        puppy.photo_urls = puppy.photo_urls ? JSON.parse(puppy.photo_urls) : [];
      });
      
      // Update puppy_count based on actual puppies
      litter.actual_puppy_count = litter.puppies.length;
    });
    
    res.json(litters);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// GET single litter
router.get('/:id', (req, res) => {
  try {
    const db = getDatabase();
    const litter = db.prepare(`
      SELECT l.*, 
        s.*, s.name as sire_name,
        d.*, d.name as dam_name
      FROM litters l
      JOIN dogs s ON l.sire_id = s.id
      JOIN dogs d ON l.dam_id = d.id
      WHERE l.id = ?
    `).get(req.params.id);
    
    if (!litter) {
      return res.status(404).json({ error: 'Litter not found' });
    }
    
    // Get puppies using litter_id
    litter.puppies = db.prepare(`
      SELECT * FROM dogs WHERE litter_id = ? AND is_active = 1
    `).all(litter.id);
    
    litter.puppies.forEach(puppy => {
      puppy.photo_urls = puppy.photo_urls ? JSON.parse(puppy.photo_urls) : [];
    });
    
    litter.actual_puppy_count = litter.puppies.length;
    
    res.json(litter);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// POST create new litter
router.post('/', (req, res) => {
  try {
    const { sire_id, dam_id, breeding_date, whelping_date, notes } = req.body;
    
    if (!sire_id || !dam_id || !breeding_date) {
      return res.status(400).json({ error: 'Sire, dam, and breeding date are required' });
    }
    
    const db = getDatabase();
    
    // Verify sire is male and dam is female
    const sire = db.prepare('SELECT sex FROM dogs WHERE id = ?').get(sire_id);
    const dam = db.prepare('SELECT sex FROM dogs WHERE id = ?').get(dam_id);
    
    if (!sire || sire.sex !== 'male') {
      return res.status(400).json({ error: 'Invalid sire' });
    }
    if (!dam || dam.sex !== 'female') {
      return res.status(400).json({ error: 'Invalid dam' });
    }
    
    const result = db.prepare(`
      INSERT INTO litters (sire_id, dam_id, breeding_date, whelping_date, notes)
      VALUES (?, ?, ?, ?, ?)
    `).run(sire_id, dam_id, breeding_date, whelping_date, notes);
    
    const litter = db.prepare('SELECT * FROM litters WHERE id = ?').get(result.lastInsertRowid);
    
    res.status(201).json(litter);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// PUT update litter
router.put('/:id', (req, res) => {
  try {
    const { breeding_date, whelping_date, puppy_count, notes } = req.body;
    
    const db = getDatabase();
    db.prepare(`
      UPDATE litters 
      SET breeding_date = ?, whelping_date = ?, puppy_count = ?, notes = ?
      WHERE id = ?
    `).run(breeding_date, whelping_date, puppy_count, notes, req.params.id);
    
    const litter = db.prepare('SELECT * FROM litters WHERE id = ?').get(req.params.id);
    res.json(litter);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// POST link puppy to litter
router.post('/:id/puppies/:puppyId', (req, res) => {
  try {
    const { id: litterId, puppyId } = req.params;
    const db = getDatabase();
    
    // Verify litter exists
    const litter = db.prepare('SELECT sire_id, dam_id FROM litters WHERE id = ?').get(litterId);
    if (!litter) {
      return res.status(404).json({ error: 'Litter not found' });
    }
    
    // Verify puppy exists
    const puppy = db.prepare('SELECT id FROM dogs WHERE id = ?').get(puppyId);
    if (!puppy) {
      return res.status(404).json({ error: 'Puppy not found' });
    }
    
    // Link puppy to litter
    db.prepare('UPDATE dogs SET litter_id = ? WHERE id = ?').run(litterId, puppyId);
    
    // Also update parent relationships if not set
    const existingParents = db.prepare('SELECT parent_type FROM parents WHERE dog_id = ?').all(puppyId);
    const hasSire = existingParents.some(p => p.parent_type === 'sire');
    const hasDam = existingParents.some(p => p.parent_type === 'dam');
    
    if (!hasSire) {
      db.prepare('INSERT OR IGNORE INTO parents (dog_id, parent_id, parent_type) VALUES (?, ?, \'sire\')').run(puppyId, litter.sire_id);
    }
    if (!hasDam) {
      db.prepare('INSERT OR IGNORE INTO parents (dog_id, parent_id, parent_type) VALUES (?, ?, \'dam\')').run(puppyId, litter.dam_id);
    }
    
    res.json({ message: 'Puppy linked to litter successfully' });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// DELETE remove puppy from litter
router.delete('/:id/puppies/:puppyId', (req, res) => {
  try {
    const { puppyId } = req.params;
    const db = getDatabase();
    
    db.prepare('UPDATE dogs SET litter_id = NULL WHERE id = ?').run(puppyId);
    
    res.json({ message: 'Puppy removed from litter' });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

// DELETE litter
router.delete('/:id', (req, res) => {
  try {
    const db = getDatabase();
    
    // Remove litter_id from associated puppies
    db.prepare('UPDATE dogs SET litter_id = NULL WHERE litter_id = ?').run(req.params.id);
    
    // Delete the litter
    db.prepare('DELETE FROM litters WHERE id = ?').run(req.params.id);
    
    res.json({ message: 'Litter deleted successfully' });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

module.exports = router;