import { Router } from 'express'
import db from '../db.js'
import { auth } from '../middleware/auth.js'

const router = Router({ mergeParams: true })
router.use(auth)

function getStory(storyId, userId) {
  return db.prepare('SELECT id FROM stories WHERE id = ? AND user_id = ?').get(storyId, userId)
}

// GET /api/stories/:storyId/characters
router.get('/', (req, res) => {
  if (!getStory(req.params.storyId, req.user.id)) return res.status(404).json({ error: 'Not found' })
  const rows = db.prepare(
    'SELECT * FROM characters WHERE story_id = ? AND user_id = ? ORDER BY name ASC'
  ).all(req.params.storyId, req.user.id)
  res.json(rows)
})

// POST /api/stories/:storyId/characters
router.post('/', (req, res) => {
  if (!getStory(req.params.storyId, req.user.id)) return res.status(404).json({ error: 'Not found' })
  const { name = 'New Character', role = 'supporting', age = '', description = '', notes = '', photo = null } = req.body || {}
  const { lastInsertRowid } = db.prepare(
    'INSERT INTO characters (story_id, user_id, name, role, age, description, notes, photo) VALUES (?, ?, ?, ?, ?, ?, ?, ?)'
  ).run(req.params.storyId, req.user.id, name, role, age, description, notes, photo)
  res.json(db.prepare('SELECT * FROM characters WHERE id = ?').get(lastInsertRowid))
})

// POST /api/stories/:storyId/characters/import-from
router.post('/import-from', (req, res) => {
  if (!getStory(req.params.storyId, req.user.id)) return res.status(404).json({ error: 'Not found' })
  const { from_story_id, character_ids } = req.body || {}
  if (!from_story_id || !Array.isArray(character_ids) || character_ids.length === 0)
    return res.status(400).json({ error: 'Missing from_story_id or character_ids' })
  if (!getStory(from_story_id, req.user.id)) return res.status(404).json({ error: 'Source story not found' })

  const placeholders = character_ids.map(() => '?').join(',')
  const sourceChars = db.prepare(
    `SELECT * FROM characters WHERE id IN (${placeholders}) AND story_id = ? AND user_id = ?`
  ).all(...character_ids, from_story_id, req.user.id)

  const insert = db.prepare(
    'INSERT INTO characters (story_id, user_id, name, role, age, description, notes, photo) VALUES (?, ?, ?, ?, ?, ?, ?, ?)'
  )
  const inserted = db.transaction(() =>
    sourceChars.map(c => {
      const { lastInsertRowid } = insert.run(
        req.params.storyId, req.user.id, c.name, c.role, c.age, c.description, c.notes, c.photo ?? null
      )
      return db.prepare('SELECT * FROM characters WHERE id = ?').get(lastInsertRowid)
    })
  )()

  res.json(inserted)
})

// PUT /api/stories/:storyId/characters/:charId
router.put('/:charId', (req, res) => {
  const char = db.prepare(
    'SELECT * FROM characters WHERE id = ? AND story_id = ? AND user_id = ?'
  ).get(req.params.charId, req.params.storyId, req.user.id)
  if (!char) return res.status(404).json({ error: 'Not found' })

  const { name, role, age, description, notes, photo } = req.body || {}
  db.prepare(
    'UPDATE characters SET name = ?, role = ?, age = ?, description = ?, notes = ?, photo = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?'
  ).run(
    name        !== undefined ? name        : char.name,
    role        !== undefined ? role        : char.role,
    age         !== undefined ? age         : char.age,
    description !== undefined ? description : char.description,
    notes       !== undefined ? notes       : char.notes,
    photo       !== undefined ? photo       : char.photo,
    char.id
  )
  res.json(db.prepare('SELECT * FROM characters WHERE id = ?').get(char.id))
})

// DELETE /api/stories/:storyId/characters/:charId
router.delete('/:charId', (req, res) => {
  const char = db.prepare(
    'SELECT * FROM characters WHERE id = ? AND story_id = ? AND user_id = ?'
  ).get(req.params.charId, req.params.storyId, req.user.id)
  if (!char) return res.status(404).json({ error: 'Not found' })
  db.prepare('DELETE FROM characters WHERE id = ?').run(char.id)
  res.json({ ok: true })
})

export default router