document.getElementById("info").innerHTML += "paper width (px)" + document.getElementById("paper").offsetWidth + "<br/>";

function css( element : HTMLElement, property : string ) {
    return window.getComputedStyle( element, null ).getPropertyValue( property );
}

let paper = document.getElementById('paper');
let paperPage1 = document.getElementById('paper-page1');


var font_family = css( paper, 'font-family')
var font_size = css(paper, 'font-size')

paper.addEventListener('input', getWordsWidth);

paper.addEventListener('keydown', (e)=>{
    if(e.key==" "){ //enter
        e.preventDefault(); //Prevent default browser behavior
        var sel : Selection;
        var range : Range;
        sel = window.getSelection();
        range = sel.getRangeAt(0);
        range.deleteContents();

        var textNode = document.createTextNode('\u00A0'); // no linebreaking-space
        range.insertNode(textNode);
        range.setStartAfter(textNode);
        sel.addRange(range);

        getWordsWidth();
        
        // paper.innerHTML+= paper.innerHTML;
        //var currentPage = document.getElementById(getCaretCurrentPageId());
        //var currentRange = getCursorLengthRange(currentPage);
        //var HTMLBeforeCaret = rangeToHTMLFragement(currentRange);
    }
});


// 如果游標在 contentdiveditable id "paper-page1" 裡面，
// 該函數返回 "paper-page1"
function getCaretCurrentPageId(){
    var anchorNode = window.getSelection().anchorNode;

    var currentNode = anchorNode;

    while((currentNode as Element).id === undefined || !((currentNode as Element).id.match(/^paper-page\d+/))){
      currentNode = currentNode.parentNode;
    }
    return (currentNode as Element).id;
  }

// 得到子節點（文字物件）
// ["dolore", [ "m ips", ["um si"], "t am"], "et"]
function getChildNodes(ele : HTMLElement){
  var res_array
  res_array = [];
  if (ele.nodeType == Node.TEXT_NODE){
    return ele;

  }else{
    for (var i =0; i <ele.childNodes.length;i++){
      res_array.push(getChildNodes(<HTMLElement>(ele.childNodes[i])))
    }

    return res_array
  }
}

  // 平坦化陣列
  // [a, [b, c, d], [[e]]] => [a, b, c, d, e]
  function flatten(arr){
    if (!Array.isArray(arr)){
      return arr;
    }
    else{
      var result = [];
      for (var i=0;i<arr.length;i++){
        if (Array.isArray(arr[i])){
          result = result.concat(flatten(arr[i]))
        }
        else{
          result.push(arr[i])
        }
      }
      return result;
    }
  }

/* 從第幾個字到第幾個字選 range. */
function selecRengeFromCharToChar(i : number, j : number, ele: ElementContentEditable){
  var range = document.createRange();
  var sel = document.getSelection();

  var flattened_ar = flatten(getChildNodes(<HTMLElement>ele));

  range.selectNodeContents((<Node><unknown>ele));
  var ran_start = i
  var ran_end = j
  var ran_start_is_set = false

  for (var i=0; i< flattened_ar.length;i++){
    var fragement_text_length = flattened_ar[i].textContent.length;
    // 如果 ran_start > 碎片長度
    if(ran_start > fragement_text_length){
      ran_start -= fragement_text_length;
      ran_end -= fragement_text_length;
    
    // 如果 ran_start <= 碎片長度
    }else if(ran_start <= fragement_text_length && ran_start_is_set == false){
      range.setStart(flattened_ar[i], ran_start);
      ran_start_is_set = true
      // 如果 ran_end > 碎片長度
      if (ran_end > fragement_text_length){
        ran_end -= fragement_text_length;
      // 如果 ran_end <= 碎片長度，setEnd 中止迴圈
      }else{
        range.setEnd(flattened_ar[i], ran_end);
        break;
      }
    // 如果 ran_end > 碎片長度
    }else if (ran_end > fragement_text_length && ran_start_is_set == true){
      ran_end -= fragement_text_length;
    }
    // 如果 ran_end <= 碎片長度，setEnd 中止迴圈
    else{
      range.setEnd(flattened_ar[i], ran_end);
      break;
    }
  }
  
  var sel = window.getSelection();
  sel.removeAllRanges();
  sel.addRange(range);

  return range

}


/*
設置游標位置於 ele 要素的第 col 個字（不含標籤），例子：

HTML <div>dolore<i>m ips<b>um si</b>t am</i>et&nbsp;1234<div>
setCaret(document.getElementById('paper-page1'),10)
                  V CARET
<div>dolore<i>m ip|s<b>um si</b>t am</i>et&nbsp;1234<div>
*/
function setCaret(ele: ElementContentEditable, col : number){
  var range = document.createRange();
  var sel = document.getSelection();



  var flattened_ar = flatten(getChildNodes(<HTMLElement>ele)); // flattened array

  range.selectNodeContents((<Node><unknown>ele));
  var ran_start = col

  for (var i=0; i< flattened_ar.length;i++){
    var fragement_text_length = flattened_ar[i].textContent.length;
    if(ran_start > fragement_text_length){
      ran_start -= fragement_text_length;
    }else{
      range.setEnd(flattened_ar[i], ran_start);
      range.collapse();
      break;
    }
  }
  
  var sel = window.getSelection();
  sel.removeAllRanges();
  sel.addRange(range);
}

// 將座標轉成座標所在位置的 range
function getCursorLengthRange(ele: HTMLElement){
  let win = ele.ownerDocument.defaultView;
  let range = win.getSelection().getRangeAt(0);
  
  let cloneRange = range.cloneRange();
  cloneRange.selectNodeContents(ele);
  cloneRange.setEnd(range.endContainer, range.endOffset);

  return cloneRange;

}

// 將座標 range 轉成字串的長度
function rangeToStringLen(range : Range){
  return range.toString().length;
}

// 將座標位置 range 轉成 html 斷片
function rangeToHTMLFragement(range : Range){
  var nodes =range.cloneContents().childNodes;
  var result = ""
   for(var i=0;i<nodes.length;i++){
    let parentNode = (<DocumentFragment> nodes[i].parentNode);
    let div=document.createElement("div");
    div.appendChild(parentNode);
    if (typeof ((<HTMLElement> nodes[i]).outerHTML) === "undefined"){
      result += nodes[i].textContent;}
    else{
      result += (<HTMLElement> nodes[i]).outerHTML;}
      console.log("Parent Node"+div.outerHTML);
  } 
  return result;
  }

// 得到一個 word 或是 character 的寬度
function getTextWidth(text, fontfamily, fontsize) {
    console.log(text)
    var decodedText = decodeEntities(text)
    let canvas = document.createElement("canvas");
    var context = canvas.getContext("2d");
    context.font = fontsize + " " + fontfamily;
    let width = context.measureText(decodedText).width;
    return width;
  }

// 得到字寬
function getWordsWidth(){
   document.getElementById('line-info').innerHTML = "";

   var array = paper.childNodes;
   var res = [];

   for (var i=0;i<array.length;i++){
    if( array[i].nodeType != Node.TEXT_NODE){
      res.push(array[i]);
    }
   }

   var innerArray = res.map((x)=>x.innerHTML);

   var innerHTMLTotal = innerArray.reduce((x,y)=>(x+y));

   var innerHTMLRemoveTags = innerHTMLTotal.replace(/[<][\/]?[^<]+[\/]?[>]/gi,"") // 移除標籤

   var innerHTMLSplitted = innerHTMLRemoveTags.split(/(　|\s|&nbsp;|[⺀-\u2efe\u3000-〾㇀-\u31ee㌀-㏾㐀-\u4dbe一-\u9ffe豈-\ufafe︰-﹎]|[\ud840-\ud868\ud86a-\ud86c][\udc00-\udfff]|\ud869[\udc00-\udede\udf00-\udfff]|\ud86d[\udc00-\udf3e\udf40-\udfff]|\ud86e[\udc00-\udc1e]|\ud87e[\udc00-\ude1e])/).filter(item => item != "")

   console.log(innerHTMLSplitted);
   //var innerHTMLSplittedLength = innerHTMLSplitted.map((x)=>x.length)
   
   //var innerHTMLSelectedRange = [];

   /*var sum = 0
   for (var i=0; i<innerHTMLSplittedLength.length;i++){
    var head = sum;
    var tail = sum + innerHTMLSplittedLength[i];
    innerHTMLSelectedRange.push([head, tail]);
    sum+= innerHTMLSplittedLength[i];
   }*/


  /*var innerHTMLSplittedRange = innerHTMLSelectedRange.map((x) => rangeToHTMLFragement(selecRengeFromCharToChar(x[0],x[1],paper)))

  console.log("Range 結果"+innerHTMLSplittedRange);*/


  let textWidthList = innerHTMLSplitted.map(x => getTextWidth(x,font_family, font_size));


  var lineInfoLength = [];

  for (var i=0; i<innerHTMLSplitted.length;i++){
    var object = {"content":innerHTMLSplitted[i],
                    "length":textWidthList[i]}
    
    document.getElementById("line-info").innerHTML += "(" + innerHTMLSplitted[i] + ",";
    document.getElementById("line-info").innerHTML += textWidthList[i] + ")";
    
    lineInfoLength.push(object);
  }


  // document.getElementById("info").innerHTML += lineInfoLength;
}


// 將要在地幾個字插入符號，改為修正為在有標籤的 HTML 的片段中，第幾個不算標籤的字插入符號
/*
> getrealcol(5, "example")
> 5
> getrealcol(5, "e<em>xam</em>ple")
> 14
*/
function getrealcol(n, str) {
    var arr = str.split(RegExp("(<[^<>]+>)")).map((x) => ({ cont: x, len: x.length }));

    var j = 0;
    var k = 0;
    for (var i = 0; i < arr.length; i++) {
      if (arr[i].cont.match(/^[<]/)) { continue; }
      else {
        if (n > arr[i].len) { n = n - arr[i].len; }
        else { j = i; k = n; break; }
      };
    }

    var res_col = 0;

    for (var i = 0; i < j; i++) {
      res_col += arr[i].len;
    }

    res_col += k;

    return res_col;
  }

// 解碼 &1234; 這種東西用
function decodeEntities(encodedString) {
  var textArea = document.createElement('textarea');
  textArea.innerHTML = encodedString;
  return textArea.value;
}