let isString = function(obj){
    return toString.call(obj) == '[object Stirng]'
}
let isFunction = function(obj){
    return toString.call(obj) == '[object Function]'
}

let isType = function(type){
    return function(obj){
        return toString.call(obj) == `[object ${type}]`;
    }
}

// 生成一个需要调用多次才能执行的函数
let _after = function(time,func){
    if(time<=0) return func()
    return function(){
        if(--time <= 0){
            return func.apply(this,arguments)
        }
    }
}
let after_hello = _after(3,function(){console.log('hello')})
after_hello() // -
after_hello() // -
after_hello() // hello

then(fulfilledHandler, errorHandler, progressHandler)

let Deferred = function () {
  this.state = 'unfilfilled'
  this.promise = new Promise()
}
Deferred.prototype.resolve = function (obj) {
  this.state = 'fulfilled'
  this.promise.emit('success', obj)
}
Deferred.prototype.reject = function (err) {
  this.state = 'failed'
  this.promise.emit('error', err)
}
Deferred.prototype.progress = function (data) {
  this.promise.emit('progress', data)
}

res.setEncoding('utf8')
res.on('data', function (chunk) {
  console.log('BODY: ' + chunk)
})
res.on('end', function () {
  // Done
})
res.on('error', function (err) {
  // Error
})

res.then(function () {
  // Done 
}, function (err) {
  // Error
}, function (chunk) {
  console.log('BODY: ' + chunk)
})

const promisify = function (res) {
  let deferred = new Deferred()
  let result = ''
  res.on('data', function (chunk) {
    result += chunk
    deferred.progress(chunk)
  })
  res.on('end', function () {
    deferred.resolve(result)
  })
  res.on('error', function (err) {
    deferred.reject(err)
  })
  return deferred.promise
}

promisify(res).then(function () {
  // Done
}, function (err) {
  // Error
}, function (chunk) {
  // progress
  console.log('BODY: ' + chunk)
})

const Q = require('q')
const fs = require('fs') 
const readFile = function (file, encoding) {
  let deferred = Q.defer()
  fs.readFile(file, encoding, deferred.makeNodeResolver())
  return deferred.promise
}
readFile('hello.txt', 'utf-8').then(function (data) { 
  // success case
  console.log(data)
}, function (err) {
  // failed case
  console.log(err)
})

promise()
  .then(obj.api1)
  .then(obj.api2)
  .then(obj.api3)
  .then(obj.api4)
  .then(function (value4) {
    // success
  }, function (err) {
    // error
  })
  .done()

obj.api1(value1)
    .then((value2)=>{
        return obj.api2(value2)
    })
    .then((value3)=>{
        return obj.api3(value3)
    })
    .then((value4)=>{
        callback(value4)
    })

const connect = require('connect')
const app = connect()
app.use('/', function (req, res, next) {
    // step1
    next()
})
app.use('/', function (req, res, next) {
  // step2
  next()
})
app.use('/', function (req, res, next) {
  // step3
  res.end()  
})
http.createServer(app).listen(3000)

let asyncCall = function (callback) {
  process.nextTick(function () { 
    callback(null,'result1','result2')
  })
}
step(
  function readFile1() { 
    fs.readFile('file1.txt', 'utf-8', this.parallel())
    fs.readFile('file2.txt', 'utf-8', this.parallel())
    asyncCall(this.parallel())
  },
  function done() {
    /**
     * 0:undefined
     * 1:file2.txt
     * 2:file content
     * 3:result1
     */
    console.log(arguments)
  }
)

step(
  function readDir() { 
    fs.readdir(__dirname, this)
  },
  function readFiles(err, results) {
    if (err) throw err
    let group = this.group()
    results.forEach(filename => {
      if (/\.txt$/.test(filename)) {
        fs.readFile(__dirname+'/'+filename,'utf-8',group())
      }
    })
  },
  function showAll(err, files) {
    if (err) throw err
    console.dir(files) //[ 'file2.txt', 'file content', 'file3 content' ]
  }
)

function swap(a, i, j) { 
  let t = a[i]
  a[i] = a[j]
  a[j] = t
}
function compare(a, b) { 
  return (a-b) > 0
}
function bubbleSort(array) {
  for (let i = 0; i < array.length; i++){
    for (let j = 0; j < array.length-i-1; j++){
      if (compare(array[j], array[j + 1])) {
        swap(array,j,j+1)
      }
    }
  }
  return array
}

const Wind = require('wind')

// swap进行异步包装
let swapAsync = eval(Wind.compile("async", function swap(a, i, j) {
  $await(Wind.Async.sleep(500)) // 暂停500s
  var t = a[i]
  a[i] = a[j]
  a[j] = t
  console.log('repaint') //重绘
}))

function compare(a, b) {
  return (a - b) > 0
}

let bubbleSort = eval(Wind.compile("async", function (array) {
  for(var i = 0;i<array.length;i++){
    for(var j = 0; j < array.length - i -1;j++){
      if(compare(array[j],array[j+1])){
        $await(swapAsync(array,j,j+1))
      }
    }
  }
}))

bubbleSort([7,-3,10,-1,0,99]).start()