/*前端压缩上传：upimgfile(this)*/
if(typeof(maxfilesize)=='undefined') maxfilesize = 1024 * 1024;//最大文件体积
if(typeof(maxsize)=='undefined') maxsize = 2000 * 2000;//最大像素大小
if(typeof(postUrl)=='undefined') postUrl = './?ac=up';//上传路径

var canvas = document.createElement("canvas");//    用于压缩图片的canvas
var ctx = canvas.getContext('2d');
var tCanvas = document.createElement("canvas");//    瓦片canvas
var tctx = tCanvas.getContext("2d");

function upimgfile(o) {
    o.parentNode.getElementsByTagName('img')[0].src='/Editor/loading.gif';
    for(var i=0;i<o.files.length;i++){
        var file =  o.files[i];
        if (!/\/(?:jpeg|png|gif)/i.test(file.type)) return;
        var reader = new FileReader(), name = file.name;
        reader.type = file.type;
        reader.onload = function() {
            var result = this.result;
            var img = new Image();
            img.src = result;
            //如果图片体积不大，则直接上传
            if (result.length <= maxfilesize) {
                img = null;
                upload(result, this.type, o, name);
                return;
            }
            //图片加载完毕之后进行压缩，然后上传
            if (img.complete) {
                callback( this.type, o, name);
            } else {
                img.onload = callback;
            }
            
            function callback(type) {
                console.log(type,name);
                var data = compress(img);
                upload(data, type, o, name);
                img = null;
            }
        };
        reader.readAsDataURL(file);
    }
}

  //    使用canvas对大图片进行压缩
  function compress(img) {
    var initSize = img.src.length;
    var width = img.width;
    var height = img.height;

    //计算像素压缩比并压至maxsize以下
    var ratio;
    if ((ratio = width * height / maxsize) > 1) {
      ratio = Math.sqrt(ratio);
      width /= ratio;
      height /= ratio;
    } else {
      ratio = 1;
    }

    canvas.width = width;
    canvas.height = height;

//        铺底色
    ctx.fillStyle = "#fff";
    ctx.fillRect(0, 0, canvas.width, canvas.height);

    //如果图片像素大于100万则使用瓦片绘制
    var count;
    if ((count = width * height / 1000000) > 1) {
      count = ~~(Math.sqrt(count) + 1); //计算要分成多少块瓦片

//            计算每块瓦片的宽和高
      var nw = ~~(width / count);
      var nh = ~~(height / count);

      tCanvas.width = nw;
      tCanvas.height = nh;

      for (var i = 0; i < count; i++) {
        for (var j = 0; j < count; j++) {
          tctx.drawImage(img, i * nw * ratio, j * nh * ratio, nw * ratio, nh * ratio, 0, 0, nw, nh);

          ctx.drawImage(tCanvas, i * nw, j * nh, nw, nh);
        }
      }
    } else {
      ctx.drawImage(img, 0, 0, width, height);
    }

    //进行最小压缩
    var ndata = canvas.toDataURL('image/jpeg', 0.6);
/*
    console.log('压缩前：' + initSize);
    console.log('压缩后：' + ndata.length);
    console.log('压缩率：' + ~~(100 * (initSize - ndata.length) / initSize) + "%");
*/
    tCanvas.width = tCanvas.height = canvas.width = canvas.height = 0;
    return ndata;
  }
  //    图片上传，将base64的图片转成二进制对象，塞进formdata上传
  function upload(basestr, type, o, name) {
    var text = window.atob(basestr.split(",")[1]);
    var buffer = new Uint8Array(text.length);
    var pecent = 0, loop = null;

    for (var i = 0; i < text.length; i++) {
      buffer[i] = text.charCodeAt(i);
    }

    var blob = getBlob([buffer], type);

    var xhr = new XMLHttpRequest();

    var formdata = getFormData();

    formdata.append('Filedata', blob);
    formdata.append('filename', name);

    xhr.open('post', postUrl);
    xhr.onload = function () {upReturn(xhr.responseText,o);};
    xhr.send(formdata);
  }

  /**
   * 获取blob对象的兼容性写法
   * @param buffer
   * @param format
   * @returns {*}
   */
  function getBlob(buffer, format) {
    try {
      return new Blob(buffer, {type: format});
    } catch (e) {
      var bb = new (window.BlobBuilder || window.WebKitBlobBuilder || window.MSBlobBuilder);
      buffer.forEach(function(buf) {
        bb.append(buf);
      });
      return bb.getBlob(format);
    }
  }

  /**
   * 获取formdata
   */
  function getFormData() {
    var isNeedShim = ~navigator.userAgent.indexOf('Android')
        && ~navigator.vendor.indexOf('Google')
        && !~navigator.userAgent.indexOf('Chrome')
        && navigator.userAgent.match(/AppleWebKit\/(\d+)/).pop() <= 534;

    return isNeedShim ? new FormDataShim() : new FormData()
  }

  /**
   * formdata 补丁, 给不支持formdata上传blob的android机打补丁
   * @constructor
   */
function FormDataShim() {
console.warn('using formdata shim');

var o = this,
    parts = [],
    boundary = Array(21).join('-') + (+new Date() * (1e16 * Math.random())).toString(36),
    oldSend = XMLHttpRequest.prototype.send;

this.append = function(name, value, filename) {
  parts.push('--' + boundary + '\r\nContent-Disposition: form-data; name="' + name + '"');

  if (value instanceof Blob) {
    parts.push('; filename="' + (filename || 'blob') + '"\r\nContent-Type: ' + value.type + '\r\n\r\n');
    parts.push(value);
  }
  else {
    parts.push('\r\n\r\n' + value);
  }
  parts.push('\r\n');
};

// Override XHR send()
XMLHttpRequest.prototype.send = function(val) {
  var fr,
      data,
      oXHR = this;

  if (val === o) {
    // Append the final boundary string
    parts.push('--' + boundary + '--\r\n');

    // Create the blob
    data = getBlob(parts);

    // Set up and read the blob into an array to be sent
    fr = new FileReader();
    fr.onload = function() {
      oldSend.call(oXHR, fr.result);
    };
    fr.onerror = function(err) {
      throw err;
    };
    fr.readAsArrayBuffer(data);

    // Set the multipart content type and boudary
    this.setRequestHeader('Content-Type', 'multipart/form-data; boundary=' + boundary);
    XMLHttpRequest.prototype.send = oldSend;
  }
  else {
    oldSend.call(this, val);
  }
};
}
function getTag(tag,obj){
    if(obj==null){
        return document.getElementsByTagName(tag)
    }else{
        return obj.getElementsByTagName(tag)
    }
}
function upReturn(str,obj){
    if (str.indexOf('非法') != -1){
        alert(str);
        return;
    }
    var input=getTag('input',obj.parentNode)[0];
    if (input.type=='hidden'){
        input.value = str;
    }else{
        if(obj.multiple){
            input.value += '/pic/' + str + ';';
        }else{
            input.value = '/pic/' + str;
        }
    }
    getTag('img',obj.parentNode)[0].src ='/pic/s/'+ str;
}

/*多图增减*/
function addimgs(){
    var tr=document.createElement('p');
    tr.innerHTML='<label><input name="imgs[]" type="hidden" />\
<img src="../imgs/add.gif"/><input accept="image/*" onchange="upimgfile(this)" type="file" /></label>\
<a onclick="showxc(this,0)">选择</a><a onclick="delimgs(this)">&times;</a><a onclick="leftimgs(this,0)">←</a><a onclick="leftimgs(this,1)">→</a>';
    getid('pics').appendChild(tr);
    return tr.getElementsByTagName('input')[0];
}
function climgs(d){
    var o=d.parentNode;
    o.getElementsByTagName('img')[0].src='../imgs/add.gif';
    o.getElementsByTagName('input')[0].value='';
}
function delimgs(d){
    if (confirm('确定删除吗')){
        d.parentNode.remove();
    }
}
/*多图排序*/
function leftimgs(d,a){
    d=d.parentNode;
    var p=getTag('p',d.parentNode),c=0,v='';
    for(var i=0; i<p.length; i++){ //查找被执行的位置
        if (p[i] == d){
            c=i;
            v=p[i].innerHTML;
            break;
        }
    }
    if (a){ //右移
        if(c==p.length-1){
            return;//已经是最右一个了
        }
        d.innerHTML=p[c+1].innerHTML;
        p[c+1].innerHTML=v;
    }else{ //左移
        if(c==0){
            return;//已经是最左一个了
        }
        d.innerHTML=p[c-1].innerHTML;
        p[c-1].innerHTML=v;
    }
    //console.log(p);
}