const { query, transaction } = require('../config/database')
const { paginate } = require('../utils/pagination')

async function getPointsGoods(ctx) {
  let sql = 'SELECT * FROM points_goods WHERE 1=1'
  const params = []

  if (ctx.query.visible === '1') {
    sql += ' AND is_show = 1'
  }

  sql += ' ORDER BY points ASC'

  if (ctx.query.page) {
    const result = await paginate(query, sql, params, ctx.query.page, ctx.query.pageSize)
    ctx.body = { code: 200, ...result }
    return
  }

  const goods = await query(sql, params)

  ctx.body = {
    code: 200,
    data: goods
  }
}

async function getPointsGoodsById(ctx) {
  const id = parseInt(ctx.params.id)
  const goods = await query('SELECT * FROM points_goods WHERE id = ?', [id])

  if (goods.length > 0) {
    ctx.body = { code: 200, data: goods[0] }
  } else {
    ctx.body = { code: 404, message: '积分商品不存在' }
  }
}

async function createPointsGoods(ctx) {
  const { name, points, stock, image, description } = ctx.request.body

  if (!name || points === undefined) {
    ctx.body = { code: 400, message: '请填写商品名称和所需积分' }
    return
  }

  const result = await query(
    'INSERT INTO points_goods (name, points, stock, image, description) VALUES (?, ?, ?, ?, ?)',
    [name, parseInt(points) || 0, parseInt(stock) || 0, image || '', description || '']
  )

  ctx.body = {
    code: 200,
    message: '添加成功',
    data: { id: result.insertId }
  }
}

async function updatePointsGoods(ctx) {
  const id = parseInt(ctx.params.id)
  const { name, points, stock, image, description } = ctx.request.body

  if (!name || points === undefined) {
    ctx.body = { code: 400, message: '请填写商品名称和所需积分' }
    return
  }

  const result = await query(
    'UPDATE points_goods SET name = ?, points = ?, stock = ?, image = ?, description = ? WHERE id = ?',
    [name, parseInt(points) || 0, parseInt(stock) || 0, image || '', description || '', id]
  )

  if (result.affectedRows > 0) {
    ctx.body = { code: 200, message: '更新成功' }
  } else {
    ctx.body = { code: 404, message: '积分商品不存在' }
  }
}

async function deletePointsGoods(ctx) {
  const id = parseInt(ctx.params.id)

  const result = await query('DELETE FROM points_goods WHERE id = ?', [id])
  if (result.affectedRows > 0) {
    ctx.body = { code: 200, message: '删除成功' }
  } else {
    ctx.body = { code: 404, message: '积分商品不存在' }
  }
}

async function exchangePointsGoods(ctx) {
  const user = ctx.state.user
  if (!user) {
    ctx.status = 401
    ctx.body = { code: 401, message: '未登录' }
    return
  }
  const { goodsId, quantity } = ctx.request.body || {}

  if (!goodsId) {
    ctx.body = { code: 400, message: '参数不完整' }
    return
  }

  const userId = user.id
  const qty = Math.max(1, Math.min(parseInt(quantity) || 1, 99))

  const users = await query('SELECT * FROM users WHERE id = ? AND status = 1', [userId])
  if (users.length === 0) {
    ctx.body = { code: 404, message: '用户不存在' }
    return
  }
  const currentUserRow = users[0]

  const goods = await query('SELECT * FROM points_goods WHERE id = ? AND is_show = 1', [goodsId])
  if (goods.length === 0) {
    ctx.body = { code: 404, message: '积分商品不存在' }
    return
  }
  const goodsItem = goods[0]

  if (goodsItem.stock < qty) {
    ctx.body = { code: 400, message: '库存不足' }
    return
  }

  const totalPoints = goodsItem.points * qty
  if (currentUserRow.points < totalPoints) {
    ctx.body = { code: 400, message: '积分不足' }
    return
  }

  let newPoints
  await transaction(async (conn) => {
    newPoints = currentUserRow.points - totalPoints
    await conn.execute('UPDATE users SET points = ? WHERE id = ?', [newPoints, userId])
    await conn.execute('UPDATE points_goods SET stock = stock - ? WHERE id = ?', [qty, goodsId])
    await conn.execute(
      'INSERT INTO points_logs (user_id, type, amount, description) VALUES (?, ?, ?, ?)',
      [userId, 'spend', totalPoints, `兑换「${goodsItem.name}」x${qty}`]
    )
  })

  ctx.body = {
    code: 200,
    message: '兑换成功',
    data: { remainingPoints: newPoints }
  }
}

module.exports = {
  getPointsGoods,
  getPointsGoodsById,
  createPointsGoods,
  updatePointsGoods,
  deletePointsGoods,
  exchangePointsGoods
}