const fs = require('fs')
const path = require('path')

function config() {
  const commander = require('commander')
  const deepmerge = require('deepmerge')

  var Config = {}

  // 读取配置文件
try {
  if (fs.existsSync('./envar-base-basic.js')) {
    Config=require('./envar-base-basic.js')
    console.info('envar-base-basic.js loaded')
  }
  if (fs.existsSync('./envar-base-custom.js')) { // 如果存在，覆盖掉 envar-base-basic.js 里的默认参数
    Config=deepmerge(Config, require('./envar-base-custom.js')) // 注意，objectMerge后，产生了一个新的对象，而不是在原来的Config里添加
    console.info('envar-base-custom.js loaded')
  }
  if (fs.existsSync('./envar-base-secret.js')) { // 如果存在，覆盖掉 envar-base-basic.js 和 envar-base-custom.js 里的参数
    Config=deepmerge(Config, require('./envar-base-secret.js'))
    console.info('envar-base-secret.js loaded')
  }
}catch(err){
  console.error('Loading config files failed: '+err.message)
}

  // 载入命令行参数
  commander
  .version(Config.Base_Version, '-v, --version') // 默认是 -V。如果要 -v，就要加 '-v --version'
  .option('-H, --host <host>', 'Host ip or domain name. Default to ' + Config.host)
  .option('-P, --protocol <protocol>', 'Web server protocol http|https|httpall|http2https. Default to ' + Config.protocol)
  .option('-p, --port <port>', `Server port. Default to ${Config.port?Config.port:'80|443'}`)
  .option('--sslCert <cert>', 'SSL cert file. Default to ' + Config.sslCert)
  .option('--sslKey <key>', 'SSL privkey file. Default to ' + Config.sslKey)
  .option('--sslCA <ca>', 'SSL ca bundle file')
  .option('--sslType <type>', `SSL provider type. Default to ${Config.sslType}`)
  .parse(process.argv)

  // 把命令行参数 合并入配置。
  Config.host = commander.host || Config.host
  Config.protocol = commander.protocol || Config.protocol // 默认同时启用 http 和 https
  Config.port = parseInt(commander.port) || parseInt(Config.port) || (Config.protocol==='http'?80:Config.protocol==='https'?443:undefined) // 端口默认为 http:80, https:443, httpall: 80|443
  Config.sslCert = commander.sslCert || Config.sslCert
  Config.sslKey = commander.sslKey || Config.sslKey
  Config.sslCA = commander.sslCA || Config.sslCA
  Config.sslType = commander.sslType || Config.sslType

  console.info('Configuration is ready.')

  return Config
}

async function init() {  /*** 设置全局对象 ***/
  global.wo = {} // wo 代表 world或‘我’，是当前的命名空间，把各种类都放在这里，防止和其他库的冲突。
  wo.Config = config() // 依次载入系统默认配置、用户配置文件、命令行参数
}

(async function start() {
  await init()

  const express = require('express')
  const logger = require('morgan')
  const cookieParser = require('cookie-parser')
  const bodyParser = require('body-parser')
  const compression = require('compression')

  const server = express()

  const greenlock = (wo.Config.sslType === 'greenlock') ? require('greenlock-express').create({
    version: 'draft-11',
    server: 'https://acme-v02.api.letsencrypt.org/directory', // for test: acme-staging-v02
    agreeTos: true,
    communityMember: false,
    store: require('greenlock-store-fs'),
    email: 'ssl@faronear.org',
    approvedDomains: wo.Config.sslDomainList,
    configDir: path.resolve(__dirname, 'ssl'),
    app: server,
  }) : null

  /*** 通用中间件 ***/
  server.use(logger('development'===server.get('env')?'dev':'combined'))
  server.use(bodyParser.json())
  server.use(bodyParser.urlencoded({ extended: false }))
  server.use(cookieParser())
  server.use(compression())

  /*** 路由 ***/
  server.use(express.static(path.join(__dirname, 'dist'), {index: 'index.html'}))
  //server.use(require('serve-favicon')(path.join(__dirname, 'public', 'favicon.ico')))  // uncomment after placing your favicon in /public

  /*** 启动 Web 服务 ***/
  let webServer
  if ('http' === wo.Config.protocol) {
    webServer = require('http').createServer(server).listen(wo.Config.port, function(err) {
      if (err) console.log(err)
      else console.log(`Server listening on ${wo.Config.protocol}://${wo.Config.host}:${wo.Config.port} for ${server.settings.env} environment`)
    })
  } else if ('https' === wo.Config.protocol) {
    webServer = require('https').createServer(wo.Config.sslType === 'greenlock' ? greenlock.httpsOptions : {
      key: fs.readFileSync(wo.Config.sslKey),
      cert: fs.readFileSync(wo.Config.sslCert),
      // ca: [ fs.readFileSync(wo.Config.sslCA) ] // only for self-signed certificate: https://nodejs.org/api/tls.html#tls_tls_createserver_options_secureconnectionlistener
    }, server).listen(wo.Config.port, function (err) {
      if (err) console.log(err)
      else console.log(`Server listening on ${wo.Config.protocol}://${wo.Config.host}:${wo.Config.port} for ${server.settings.env} environment`)
    })
  } else if ('httpall' === wo.Config.protocol) {
    let portHttp = wo.Config.port ? wo.Config.port : 80 // 如果port参数已设置，使用它；否则默认为80
    let portHttps = (wo.Config.port && wo.Config.port !== 80) ? wo.Config.port + 443 : 443 // 如果port参数已设置，使用它+443；否则默认为443
    if (wo.Config.sslType === 'greenlock') {
      webServer = greenlock.listen(portHttp, portHttps, function (err) {
        if (err) console.log(err)
        else console.log(`Server listening on [${wo.Config.protocol}] http=>https://${wo.Config.host}:${portHttp}=>${portHttps} for ${server.settings.env} environment`)
      })
    } else {
      require('http').createServer(server.all('*', function (ask, reply) {
        reply.redirect(`https://${wo.Config.host}:${portHttps}`)
      })).listen(portHttp, function(err) {
        if (err) console.log(err)
        else console.log(`Server listening on [${wo.Config.protocol}] http://${wo.Config.host}:${portHttp} for ${server.settings.env} environment`)  
      })
      webServer = require('https').createServer({
        key: fs.readFileSync(wo.Config.sslKey),
        cert: fs.readFileSync(wo.Config.sslCert),
        // ca: [ fs.readFileSync(wo.Config.sslCA) ] // only for self-signed certificate: https://nodejs.org/api/tls.html#tls_tls_createserver_options_secureconnectionlistener
      }, server).listen(portHttps, function (err) {
        if (err) console.log(err)
        else console.log(`Server listening on [${wo.Config.protocol}] https://${wo.Config.host}:${portHttps} for ${server.settings.env} environment`)
      })
    }
  } else if ('http2https' === wo.Config.protocol) {
    wo.Config.port = wo.Config.port || 80
    webServer = require('http').createServer(server.all('*', function(ask, reply) {    /* 错误的API调用进入这里。*/
      reply.redirect(`https://${wo.Config.host}`)
    })).listen(wo.Config.port, function(err) {
      if (err) console.log(err)
      else console.log(`Server listening on ${wo.Config.protocol}://${wo.Config.host}:${wo.Config.port} for ${server.settings.env} environment`)
    })
  }

})()