const fs = require('fs')
const path = require('path')
const express = require('express')
const bodyParser = require('body-parser')
const request = require('./util/request')
const package = require('./package.json')
const exec = require('child_process').exec
const cache = require('apicache').middleware

// version check
exec('npm info NeteaseCloudMusicApi version', (err, stdout, stderr) => {
    if(!err){
        let version = stdout.trim()
        if(package.version < version){
            console.log(`最新版本: ${version}, 当前版本: ${package.version}, 请及时更新`)
        }
    }
})

const app = express()

// CORS
app.use((req, res, next) => {
    if(req.path !== '/' && !req.path.includes('.')){
        res.header({
            'Access-Control-Allow-Credentials': true,
            'Access-Control-Allow-Origin': req.headers.origin || '*',
            'Access-Control-Allow-Headers': 'X-Requested-With',
            'Access-Control-Allow-Methods': 'PUT,POST,GET,DELETE,OPTIONS',
            'Content-Type': 'application/json; charset=utf-8'
        })
    }
    next()
})

// cookie parser
app.use((req, res, next) => {
    req.cookies = {}, (req.headers.cookie || '').split(/\s*;\s*/).forEach(pair => {
        let crack = pair.indexOf('=')
        if(crack < 1 || crack == pair.length - 1) return
        req.cookies[decodeURIComponent(pair.slice(0, crack)).trim()] = decodeURIComponent(pair.slice(crack + 1)).trim()
    })
    next()
})

// body parser
app.use(bodyParser.json())
app.use(bodyParser.urlencoded({extended: false}))

// cache
app.use(cache('2 minutes', ((req, res) => res.statusCode === 200)))

// static
app.use(express.static(path.join(__dirname, 'public')))

// router
const special = {
    'daily_signin.js': '/daily_signin',
    'fm_trash.js': '/fm_trash',
    'personal_fm.js': '/personal_fm'
}

fs.readdirSync(path.join(__dirname, 'module')).reverse().forEach(file => {
    if(!(/\.js$/i.test(file))) return
    let route = (file in special) ? special[file] : '/' + file.replace(/\.js$/i, '').replace(/_/g, '/')
    let question = require(path.join(__dirname, 'module', file))
    
    app.use(route, (req, res) => {
        let query = Object.assign({}, req.query, req.body, {cookie: req.cookies})
        question(query, request)
        .then(answer => {
            console.log('[OK]', decodeURIComponent(req.originalUrl))
            res.append('Set-Cookie', answer.cookie)
            res.status(answer.status).send(answer.body)
        })
        .catch(answer => {
            console.log('[ERR]', decodeURIComponent(req.originalUrl))
            if(answer.body.code =='301') answer.body.msg = '需要登录'
            res.append('Set-Cookie', answer.cookie)
            res.status(answer.status).send(answer.body)
        })
    })
})

const port = process.env.PORT || 3000

app.server = app.listen(port, () => {
    console.log(`server running @ http://localhost:${port}`)
})

module.exports = app