var zalozky = ["vlastnosti","technicke-parametry","kalkulace-ceny"];

var page = {
  calc_varianta : null,
  calc_sire     : null,
  calc_delka    : null,
  calc_vysledek : null,
  
  onload : function() {
    if (document.getElementById('sub-panel')) page.sp_onload();
    if (document.getElementById('calc')) page.calc_onload();
  },
  
  sp_onload : function() {
    for(var i=0; i<zalozky.length; i++) {
      var m = document.getElementById('menu-' + zalozky[i]);
      m.onclick = page.sp_onclick;
    }
  },
  
  sp_onclick : function() {
    var idMenu = '';
    for(var i=0; i<zalozky.length; i++) {
      idMenu  = 'menu-'  + zalozky[i];
      idPanel = 'panel-' + zalozky[i]; 
      if (this.id == idMenu) {
        document.getElementById(idMenu).className = 'active';
        document.getElementById(idPanel).className = 'sub-panel-in';
      } else {
        document.getElementById(idMenu).className = '';
        document.getElementById(idPanel).className = 'panel-hidden';
      }
    }
    return false;
  },

  calc_onload : function() {
    if (!calc) return;
    page.calc_varianta = document.getElementById('calc_varianta');
    page.calc_varianta.onchange = page.calc_change_var; 
    page.calc_sire = document.getElementById('calc_sire');
    page.calc_sire.onchange = page.calc_change; 
    page.calc_delka = document.getElementById('calc_delka');
    page.calc_delka.onkeyup = page.calc_change;
    page.calc_vysledek = document.getElementById('calc_vysledek');
    page.calc_change_var();
  },
  
  calc_change_var : function() {
    var data = calc[page.calc_varianta.value];
    while(page.calc_sire.hasChildNodes()) page.calc_sire.removeChild(page.calc_sire.childNodes[0]);
    for(var i=0; i<data['sire'].length; i++) {
      var sel = document.createElement('option');
      sel.setAttribute('value',data['sire'][i]);
      sel.appendChild(document.createTextNode(data['sire'][i]+' cm'));
      page.calc_sire.appendChild(sel);
    }
    page.calc_change();
  },

  calc_change : function() {
    var cena = calc[page.calc_varianta.value]['cena'];
    var plocha = page.calc_sire.value/100 * page.calc_delka.value/100;
    page.calc_vysledek.innerHTML = (plocha*cena) + ' Kč';
  }
  
}

window.onload = page.onload;