blockchainExplorer = function(){

  // Init array

  var _known_blocks   = null;

  var _liste_blocks   = null;

  var _classes        = ['bg-grey-even','bg-grey-odd'];

  var _cur_class      = 0;

  var _cur_methode    = 'hasard';

  var _mode           = 1;

  var _infos          = false;

  var _flag_nav        = true;

  function _precisionRound(number) {

      var precision = 4;

      var factor = Math.pow(10, precision);

      return Math.round((number/100000000) * factor) / factor;

  }

  function _getblockNameFromHash(hash)

  {

    var retour = '';

    if (_known_blocks != null)

      _known_blocks.forEach(function(item){

        if (hash == item.hash) retour = item.name;

      });

    return retour;

  }

  function _getblocHashFromName(name)

  {

    var retour = '';

    if (_known_blocks != null)

     _known_blocks.forEach(function(item){

       if (name == item.name) retour = item.hash;

     });

    return retour;

  }

  function _convertUTCDateToLocalDate(date) {

    var newDate = new Date(date.getTime()+date.getTimezoneOffset()*60*1000);

    var offset = date.getTimezoneOffset() / 60;

    var hours = date.getHours();

    newDate.setHours(hours - offset);

    return newDate;   

  }

  function _formatDate(unixtime)

  {

    var ladate = new Date(unixtime*1000);

    var ladateStr = "";

    // ladate = _convertUTCDateToLocalDate(ladate);

    ladateStr += ladate.getFullYear();

    ladateStr += "/" +("00"+(ladate.getMonth()+1)).slice(-2);

    ladateStr += "/" +("00" + ladate.getDate()).slice(-2);

    ladateStr += " " +("00" + ladate.getHours()).slice(-2);

    ladateStr += ":" +("00" + ladate.getMinutes()).slice(-2);

    // ladateStr += ":" +("00" + ladate.getSeconds()).slice(-2);

    return ladateStr;

  }

  function _addInfoForBlock(block)

  {

    var contenu = '';

    var downloadingImage = new Image();

    var div_label = block.height;

    _cur_class  = 1 - _cur_class;

    _flag_nav = false;

    blockName = _getblockNameFromHash(block.hash);

    if (block.hash == _liste_blocks['TOP']) {

      blockName = 'LAST BLOCK';

      if (_mode == 1) div_label = 'LAST';

    }

    if (blockName == '') blockName = 'block';

    else blockName = '<b>'+blockName+'</b>';

    visibility='hidden';

    if (_infos) visibility='visible';

    contenu += '<div id="img_'+block.height+'" style="color:black;height:220px">';

    contenu += '      <table class="block_infos" width="100%" align="center" height="220px" style="margin-top:3px;visibility:'+visibility+';background:rgba(255,255,255,0.7)">';

    contenu += '        <tr><td>'+blockName+'</td><td align="right"><b>'+block.height+'</b></td></tr>';

    contenu += '        <tr><td>timestamp&nbsp;&nbsp;&nbsp;</td><td align="right"><b>'+_formatDate(block.time)+'</b></td></tr>';

    contenu += '        <tr><td>nonce</td><td align="right"><b>'+block.nonce+'</b></td></tr>';

    contenu += '        <tr><td>nb tx</td><td align="right"><b>'+block.n_tx+'</b></td></tr>';

    contenu += '        <tr><td>outputs</td><td align="right"><b>'+_precisionRound(block.topisto_outputs).toFixed(4)+'</b></td></tr>';

    contenu += '        <tr><td>inputs</td><td align="right"><b>'+_precisionRound(block.topisto_inputs).toFixed(4)+'</b></td></tr>';

    contenu += '        <tr><td>fees</td><td align="right"><b>'+_precisionRound(block.topisto_fees).toFixed(4)+'</b></td></tr>';

    contenu += '        <tr><td>reward</td><td align="right"><b>'+_precisionRound(block.topisto_reward).toFixed(4)+'</b></td></tr>';

    contenu += '      </table>';

    contenu += '</div>';

    $('#info_'+div_label).html(contenu);

    downloadingImage.onload = function(){

      var div0 = document.getElementById('img_'+block.height);

      div0.style.backgroundImage = "url(" + this.src + ")";

      div0.style.backgroundRepeat = "no-repeat";

      div0.style.backgroundPosition = "center";

      div0.style.backgroundSize = "auto 100%";

      _flag_nav = true;

    };

    downloadingImage.src = 'images/block_image.php?methode='+_cur_methode+'&hash='+block.hash;

    return true;

  }

  function _addDiv(block_height)

  {

    var contenu = '';

    contenu += '<div id="block_'+block_height+'" class="container-fluid '+_classes[_cur_class]+'">';

    contenu += '  <div class="row">';

    contenu += '###BLOCK_DESC###';

    contenu += '  </div>';

    contenu += '</div>';

    return contenu;

  }

  function _addDivForBlock(block_height, onTop = false)

  {

    var lediv = document.getElementById('info_'+block_height);

    if (lediv === null)

    {

      var tmp;

      var contenu = _addDiv(block_height);

      var block_desc = '';

      block_desc += '    <div class="col-sm-12" id="info_'+block_height+'">';

      block_desc += '      <div class="loading">LOADING ...</div>';

      block_desc += '    </div>';

      tmp = contenu.replace('###BLOCK_DESC###',block_desc)

      if (onTop) {

        tmp += $('#blockchain').html();

        $('#blockchain').html(tmp);

      } else {

        $('#blockchain').append(tmp);

      }

    }

    return true;

  }

  function _addDivForVoid()

  {

    return _addDivForBlock('void');

  }

  function _gotoBlock(block_name)

  {

    $(document).scrollTop( $("#explorer").offset().top );

    // Bloquer la navigation pendant le calcul

    if (!flag_nav)

    {

      window.alert('A block image is currently computed, please wait ...');

      return false;

    }

    flag_nav   = false;

    if (block_name == 'NEXT')

    {

      flag_nav   = true;

      // Supprimer un block

      if (cur_height.length < 3)

      {

        window.alert('No Next Block, you are at '+$('#blockSelector').val()+' block !');

        return false;

      }

      _liste_blocks['PREVIOUS'] = _liste_blocks['BLOCK_'+cur_height[cur_height.length-1]];

      cur_height.pop();

      _toggleForwardBtn();

      $('#block_'+cur_height[cur_height.length-2]).slideDown(400, function() {

        // Animation complete.

        $('#blockchain').children('div:last').remove();

        _cur_class = 1 - _cur_class;

      });

    } else {

      // Ajouter un block

      _addDivForBlock(cur_height[cur_height.length-1] - 1);

      // Décaler d'un block vers le haut

      if (cur_height.length > 1) $('#block_'+cur_height[cur_height.length-2]).slideUp();

      block_hash = '';

      if (block_name != 'LAST') block_hash = '?block_hash='+_liste_blocks[block_name];

      $.getJSON('data/getBlockInfo.php'+block_hash, function( data ) {

        _liste_blocks['PREVIOUS'] = data.prev;

        _liste_blocks['BLOCK_'+data.height] = data.hash;

        _addInfoForBlock(data);

        _toggleForwardBtn();

      });

    }

    return true;

  }

  function _addTopBlock(data, flag = false)

  {

    if (flag) return "_addTopBlock";

    var old_hash = _liste_blocks['TOP'];

    if (old_hash == data.hash) return false;

    // Maintenir la liste des blocks

    _liste_blocks['TOP'] = data.hash;

    _liste_blocks['BLOCK_'+data.height] = data.hash;

    // Rafraîchir l'ancien block TOP

    if (_mode == 0) {

      $.getJSON('data/getBlockInfo.php?block_hash='+old_hash, function( old ) {

        _addInfoForBlock(old);

      });

      _addDivForBlock(data.height,true);

    }

    // Mettre les infos dans le div

    _addInfoForBlock(data);

    topistoConsole.log('Last Block on top : '+data.hash);

  }

  function _maintenirListe(data){

    _liste_blocks['BLOCK_'+data.height] = data.hash;

    _liste_blocks['LENGTH'] += 1;

    // Récursivité pour précharger par paquets

    // Tant qu'on n'est pas sur le GENESIS

    if (data.height > 0)

      switch(_mode)

      {

          case 0:

              // En mode "Full Blockchain", on suit le chainage

              _liste_blocks['BOTTOM'] = data.prev;

              break;

          case 1:

              // En mode "Blocks Connus", on prend le prochain de la liste

              _liste_blocks['BOTTOM'] = _known_blocks[0].hash;

              for(i = 0; i < _known_blocks.length; i++){ 

                if (data.height == _known_blocks[i].height)

                  _liste_blocks['BOTTOM'] = _known_blocks[i+1].hash;

              }

              //_liste_blocks['BOTTOM'] = _known_blocks[_liste_blocks['LENGTH']-1].hash;

              break;

      }

      if (data.height > 0)

        if (_liste_blocks['LENGTH'] % 15)

          _addBottomBlock();

  }

  function _addBottomBlock()

  {  

    // Mettre les infos du block

    block_hash = '?block_hash='+_liste_blocks['BOTTOM'];

    $.getJSON('data/getBlockInfo.php'+block_hash, function( data ) {

        console.log('add '+ data.height + ' : ' + _liste_blocks['BOTTOM']);

        // Ajouter un div

        _addDivForBlock(data.height, false);

        // Mettre les infos dans le div

        _addInfoForBlock(data);

        // Maintenir la Liste

        _maintenirListe(data);

    });

  }

  function _initBlockchain(block_name)

  {

    var block_hash_url = 'data/getBlockInfo.php';

    _liste_blocks = [];

    _liste_blocks['LENGTH'] = 0;

    $(document).scrollTop( $("#explorer").offset().top );

    $('#blockchain').html('');

    if (block_name != 'LAST') block_hash_url += '?block_hash='+_getblocHashFromName(block_name);

    $.getJSON(block_hash_url, function( data ) {

      div_label = data.height;

      if (_mode == 1) 

        if (block_name == 'LAST') 

          div_label = 'LAST';

      _liste_blocks['TOP'] = data.hash;

      _addDivForBlock(div_label);        

      _addInfoForBlock(data);

      _maintenirListe(data);

      // Cela fout le boxon pour l'instant

      blockchainListener.addBlockHook(_addTopBlock);

    });

    return true;

  }

  function _blockSelectorChange()

  {

    _initBlockchain($('#blockSelector').val());

  }

  function _initBlockSelector()

  {

    // Init the selector

    var select = $('#blockSelector');

    $.each(_liste_blocks, function (key, bloc) {

      select.append(new Option(bloc.name, bloc.name));

    });

  }

  function _init(mode, infos)

  {

    _mode = mode;

    _infos = infos;

    if (_known_blocks == null)

    {

      $.getJSON('data/getKnownBlocksList.php', function( data ) {

        _known_blocks = data;

        _known_blocks.sort(function(a,b){

          // sort desc ...

          if (parseInt(a.height) < parseInt(b.height)) return 1;

          if (parseInt(a.height) > parseInt(b.height)) return -1;

          return 0;

        });

        return true;

      });

    }

    return _initBlockchain('LAST');

  }

  function _toggleInfos()

  {

    var infos = Array.from(document.getElementsByClassName('block_infos'));

    _infos = ! _infos;

    infos.forEach((item, index) => {

      if (_infos) item.style.visibility = 'visible'; 

      else item.style.visibility = 'hidden';

    });

  }

  function _getLength() {

    if ( _liste_blocks === null) return 0;

    return _liste_blocks['LENGTH'];

  }

  return {

    addTopBlock: _addTopBlock,

    addBottomBlock: _addBottomBlock,

    getblocHashFromName: _getblocHashFromName,

    toggleInfos: _toggleInfos,

    getLength: _getLength,

    init: _init

  };

}();