const app = new (require('koa'))()
const cors = require('@koa/cors')
const koaBody = require('koa-body')
const router = require('./routes')
const timer = require('./timer')

timer()

app
  .use(async (ctx, next) => {
    try {
      await next()
      if (ctx.request.method === 'OPTIONS') { ctx.status = 204 }
      else if (!ctx.body && ctx.body !== false) { ctx.body = { code: -4, message: 'No Response Content' } }
    }
    catch (err) {
      const code = err.code
      const message = err.message
      if (code === -2) { ctx.body = { code, message: message || 'Invalid Argument' } }
      else if (code === -6) { ctx.body = { code, message: 'Method Not Allowed: ' + ctx.method } }
      else if (code === -7) { ctx.body = { code, message: 'No Permission' } }
      else if (code === -8) { ctx.body = { code, message: message || 'Request Third-party API Error' } }
      else if (code === -3 || code === -5 || code > 0) { ctx.body = { code, message: message || 'Unknown Error' } }
      else {
        console.log(err)
        ctx.body = { code: -1, message: 'Internal Server Error' }
      }
    }
  })
  .on('error', (err, ctx) => ctx.body = { code: -1, message: 'Internal Server Error' })
  .use(cors({ allowMethods: 'GET,POST,PUT,DELETE', maxAge: 600 }))
  .use(koaBody({ multipart: true, formLimit: '2mb', formidable: { keepExtensions: true, multiples: false } }))
  .use(router.routes())
  .use(router.allowedMethods())
  .listen(process.env.PORT || 81)
  .setTimeout(1000 * 60 * 5)

/**
 * 全局返回错误码
 * -1 未知错误（数据库错误）
 * -2 请求参数不符合接口要求
 * -3 Token验证未通过
 * -4 无返回内容
 * -5 路由未找到
 * -6 接口不支持该方法
 * -7 操作权限不足
 * -8 第三方接口调用出错
 */