/**
 * RUZEE.ShadedBorder 0.5
 * (c) 2006 Steffen Rusitschka
 *
 * RUZEE.ShadedBorder is freely distributable under the terms of an MIT-style license.
 * For details, see http://www.ruzee.com/
 */

var RUZEE = window.RUZEE || {};

RUZEE.ShadedBorder = {

create: function(opts) {
  var isie = /msie/i.test(navigator.userAgent) && !window.opera;
  function sty(el, h) {
    for(k in h) {
      if (/ie_/.test(k)) {
        if (isie) el.style[k.substr(3)]=h[k];
      } else el.style[k]=h[k];
    }
  }
  function crdiv(h) {
    var el=document.createElement("div");
    el.className = "sb-gen";
    sty(el, h);
    return el;
  }
  function op(v) {
    v = v<0 ? 0 : v;
    v = v>0.99999 ? 0.99999 : v;
    return isie ? " filter:alpha(opacity=" + (v*100) + ");" : " opacity:" + v + ';';
  }

  var sr = opts.shadow || 0;
  var r = opts.corner || 0;
  var bor = 0;
  var bow = opts.border || 0;
  var shadow = sr != 0;
  var lw = r > sr ? r : sr;
  var rw = lw;
  var th = lw;
  var bh = lw;
  if (bow > 0) {
    bor = r;
    r = r - bow;
  }
  var cx = r != 0 && shadow ? Math.round(lw/3) : 0;
  var cy = cx;
  var cs = Math.round(cx/2);
  var iclass = r > 0 ? "sb-inner" : "sb-shadow";
  var sclass = "sb-shadow";
  var bclass = "sb-border";
  var edges = opts.edges || "trlb";
  if (!/t/i.test(edges)) th=0;
  if (!/b/i.test(edges)) bh=0;
  if (!/l/i.test(edges)) lw=0;
  if (!/r/i.test(edges)) rw=0;

  var p = { position:"absolute", left:"0", top:"0", width:lw + "px", height:th + "px", 
            ie_fontSize:"1px", overflow:"hidden", margin:"0", padding:"0" }; var tl = crdiv(p);
  delete p.left; p.right="0"; p.width=rw + "px"; var tr = crdiv(p);
  delete p.top; p.bottom="0"; p.height=bh + "px"; var br = crdiv(p);
  delete p.right; p.left="0"; p.width=lw + "px"; var bl = crdiv(p);

  var tw = crdiv({ position:"absolute", width:"100%", height:th + "px", ie_fontSize:"1px",
                   top:"0", left:"0", overflow:"hidden", margin:"0", padding:"0" });
  var t = crdiv({ position:"relative", height:th + "px", ie_fontSize:"1px",
                  margin:"0 "+ rw + "px 0 " + lw + "px", overflow:"hidden", padding:"0" });
  tw.appendChild(t);

  var bw = crdiv({ position:"absolute", left:"0", bottom:"0", width:"100%", height:bh + "px", 
                   ie_fontSize:"1px", overflow:"hidden", margin:"0", padding:"0" });
                   
  var b = crdiv({ position:"relative", height:bh + "px", ie_fontSize:"1px",
                  margin:"0 "+ rw + "px 0 " + lw + "px", overflow:"hidden", padding:"0" });
                  
  bw.appendChild(b);

  var mw = crdiv({ position:"absolute", top:(-bh)+"px", left:"0", width:"100%", height:"100%",
                   overflow:"hidden", ie_fontSize:"1px", padding:"0", margin:"0" });

  function corner(el,t,l) {
    var w = l ? lw : rw;
    var h = t ? th : bh;
    var s = t ? cs : -cs;
    var dsb = []; var dsi = []; var dss = [];
    
    var xp=0; var xd=1; if (l) { xp=w-1; xd=-1; }
    for (var x=0; x<w; ++x) {
      var yp=h-1; var yd=-1; if (t) { yp=0; yd=1; }
      var finished=false;
      for (var y=h-1; y>=0 && !finished; --y) {
        var div = '<div style="position:absolute; top:' + yp + 'px; left:' + xp + 'px; ' +
                  'width:1px; height:1px; overflow:hidden; margin:0; padding:0;';

        var xc = x - cx; var yc = y - cy - s;
        var d = Math.sqrt(xc*xc+yc*yc);
        var doShadow = false;

        if (r > 0) {
          // draw border
          if (xc < 0 && yc < bor && yc >= r || yc < 0 && xc < bor && xc >= r) {
            dsb.push(div + '" class="' + bclass + '"></div>');
          } else
          if (d<bor && d>=r-1 && xc>=0 && yc>=0) {
            var dd = div;
            if (d>=bor-1) {
              dd += op(bor-d);
              doShadow = true;
            }
            dsb.push(dd + '" class="' + bclass + '"></div>');
          }
          
          // draw inner
          var dd = div + ' z-index:2;' + (t ? 'background-position:0 -' + (r-yc-1) + 'px;' : 'background-image:none;');
          var finish = function() {
            if (!t) dd = dd.replace(/top\:\d+px/, "top:0px");
            dd = dd.replace(/height\:1px/, "height:" + (y+1) + "px");
            dsi.push(dd + '" class="' + iclass + '"></div>');
            finished = true;
          };
          if (xc < 0 && yc < r || yc < 0 && xc < r) {
            finish();
          } else
          if (d<r && xc>=0 && yc>=0) {
            if (d>=r-1) {
              dd += op(r-d);
              doShadow = true;
              dsi.push(dd + '" class="' + iclass + '"></div>');
            } else {
              finish();
            }
          } else doShadow = true;
        } else doShadow = true;
        
        // draw shadow
        if (sr > 0 && doShadow) {
          d = Math.sqrt(x*x+y*y);
          if (d<sr) {
            dss.push(div + ' z-index:0; ' + op(1-(d/sr)) + '" class="' + sclass + '"></div>');
          }
        }
        yp += yd;
      }
      xp += xd;
    }
    el.innerHTML = dss.concat(dsb.concat(dsi)).join('');
  }
  
  function mid(mw) {
    var ds = [];

    ds.push('<div style="position:relative; top:' + (th+bh) + 'px; height:2048px; ' +
            ' margin:0 ' + (rw-r-cx) + 'px 0 ' + (lw-r-cx) + 'px; ' +
            ' padding:0; overflow:hidden;' +
            ' background-position:0 ' + (th > 0 ? -(r+cy+cs) : '0') + 'px;"' +
            ' class="' + iclass + '"></div>');

    var dd = '<div style="position:absolute; width:1px;' +
        ' top:' + (th+bh) + 'px; height:2048px; padding:0; margin:0;';
    for (var x=0; x<lw-r-cx; ++x) {
      ds.push(dd + ' left:' + x + 'px;' + op((x+1.0)/lw) + 
          '" class="' + sclass + '"></div>');
    }

    for (var x=0; x<rw-r-cx; ++x) {
      ds.push(dd + ' right:' + x + 'px;' + op((x+1.0)/rw) + 
          '" class="' + sclass + '"></div>');
    }

    if (bow > 0) {
      var su = ' width:' + bow + 'px;' + '" class="' + bclass + '"></div>';
      ds.push(dd + ' left:' + (lw-bor-cx) + 'px;' + su);
      ds.push(dd + ' right:' + (rw-bor-cx) + 'px;' + su);
    }

    mw.innerHTML = ds.join('');
  }

  function tb(el, t) {
    var ds = [];
    var h = t ? th : bh;
    var dd = '<div style="height:1px; overflow:hidden; position:absolute; margin:0; padding:0;' +
        ' width:100%; left:0px; ';
    var s = t ? cs : -cs;
    for (var y=0; y<h-s-cy-r; ++y) {
      ds.push(dd + (t ? 'top:' : 'bottom:') + y + 'px;' + op((y+1)*1.0/h) + 
          '" class="' + sclass + '"></div>');
    }
    if (y >= bow) {
      ds.push(dd + (t ? 'top:' : 'bottom:') + (y - bow) + 'px;' +
          ' height:' + bow + 'px;" class="' + bclass + '"></div>');
    }

    ds.push(dd + (t ? 'background-position-y:0; top:' : 
                      'background-image:none; bottom:') + y + 'px;' +
        ' height:' + (r+cy+s) + 'px;" class="' + iclass + '"></div>');

    el.innerHTML = ds.join('');
  }

  corner(tl, true, true); corner(tr, true, false);
  corner(bl, false, true); corner(br, false, false);
  mid(mw); tb(t, true); tb(b, false);

  return {
    render: function(el) {
      if (typeof el == 'string') el = document.getElementById(el);
      if (el.length != undefined) {
        for (var i=0; i<el.length; ++i) this.render(el[i]);
        return;
      }
      el.className += " sb";
      sty(el, { position:"relative", background:"transparent" });

      // remove generated children
      var node = el.firstChild;
      while (node) {
        var nextNode = node.nextSibling;
        if (node.nodeType == 1 && node.className == 'sb-gen')
          el.removeChild(node);
        node = nextNode;
      }

      var iel = el.firstChild;

      var twc = tw.cloneNode(true);
      var mwc = mw.cloneNode(true);
      var bwc = bw.cloneNode(true);
      
      el.insertBefore(tl.cloneNode(true), iel); el.insertBefore(tr.cloneNode(true), iel);
      el.insertBefore(bl.cloneNode(true), iel); el.insertBefore(br.cloneNode(true), iel);
      el.insertBefore(twc, iel); el.insertBefore(mwc, iel);
      el.insertBefore(bwc, iel);

      if (isie) {
        function resize() {
          twc.style.width = bwc.style.width = mwc.style.width = el.offsetWidth + "px";
          mwc.firstChild.style.height = el.offsetHeight + "px";
        }
        el.onresize=resize;
        resize();
      }
    }
  };
}
}

// add our styles to the document
document.write('\
  <style type="text/css">\
  .sb, .sbi, .sb *, .sbi * { position:relative; z-index:1; }\
  * html .sb, * html .sbi { height:1%; }\
  .sbi { display:inline-block; }\
  .sb-inner { background:#ddd; }\
  .sb-shadow { background:#9eb8cf; }\
  .sb-border { background:#bbb; }\
  </style>\
');
