//==UserScript==
//@name migemo-search-with-google-suggest.js
//@author mallowlabs (http://d.hatena.ne.jp/mallowlabs)
//@version 0.0.1
//@description : Inclemental migemo search with Google Suggest
//@include *
//==/UserScript==
// Usage
// Ctrl/Cmd + "/" : 検索ボックス表示
// 検索ボックス表示状態
//   Shift + G        : 次を選択
//   Shift + Ctrl + G : 前を選択
//   Enter            : 選択項目のリンクを開く
//   Ctrl/Cmd + "/"   : リンクのみから検索モードとトグル(文字が赤い時はリンクのみ)
//   Escape           : 検索ボックス非表示
(function(document) {
  // http://d.hatena.ne.jp/javascripter/20080517/1211055234
  var uniq = function(r) {
    return r.filter(function(a,i) {
        return !r.slice(i+1).some(
          function(b) { return a === b; }
        );
      }
    )
  }

  var MigemoServer = {
    MIGEMO_URL : "http://suggestqueries.google.com/complete/search?hl=ja&json=t&jsonp=migemoCallback&qu=",
    SCRIPT_ID : "opera-migemo-script",
    isBusy : false,
    send : function(query) {
      if (this.isBusy || query == "") return;
      this.isBusy = true;

      // JSONP のコールバックを登録
      window["migemoCallback"] = this.callback;

      // 前回appendしたスクリプトがあれば削除
      var head = document.getElementsByTagName("head")[0];
      var old = document.getElementById(MigemoServer.SCRIPT_ID);
      if (old != null) head.removeChild(old);

      // migemo-serverから正規表現を受け取る．
      // migemo-serverと通信．関数migemoCallbackが呼ばれる．
      var s = head.appendChild(document.createElement("script"));
      s.id = MigemoServer.SCRIPT_ID;
      s.type = "text/javascript";
      s.charset = "euc-jp";
      s.src = this.MIGEMO_URL + query;
    },

    callback : function(json) {
      var re = ""; // 例: goo|google|good
      if (json[1].length > 0) {
        /* google map
           google search
           ...
           となっているので先頭だけ取って unique する
        */
        re = uniq(json[1].map(function(item) {
          return item.split(" ")[0];
        })).join("|");
      } else {
        re = json[0];
      }

      SearchBox.setResult(re);
      MigemoServer.isBusy = false;
    }
  };

  var SearchBox = {
    SEARCH_BOX_ID : "opera-migemo-search-box",
    INPUT_BOX_ID : "opera-migemo-input-box",
    currentWord : "",
    intervalId : null,
    linkonly : false,

    create: function(linkonly) {
      this.linkonly = !!linkonly;
      var d = document.createElement("div");
      d.setAttribute("id", SearchBox.SEARCH_BOX_ID);
      d.setAttribute("style", "position:fixed!important;bottom:0.5%;left:0.5%;border:silver 2px solid;opacity:0.7;z-index:50");
      var i = document.createElement("input");
      i.setAttribute("id", SearchBox.INPUT_BOX_ID);
      i.setAttribute("size", "50");
      var self = this;
      i.addEventListener('keyup',
        function(event) { self.currentWord = i.value; },
      false);
      i.addEventListener('keypress',
        function(e) {
          switch(e.keyCode) {
          case 13: // enter
            self.onEnterKey(e);
            break;
          case 27: // escape
            self.onEscapeKey(e);
            break;
          case 71: // G
            self.onNext(e);
            e.preventDefault();
            break;
          case 47: // '/'
            self.onToggle(e);
            break;
          }
        },
      false);
      d.appendChild(i);
      document.body.appendChild(d);
      intervalId = window.setInterval(function() { self.search(); }, 100);
      i.focus();
    },

    onEscapeKey : function(e) {
      //終了する
      window.clearInterval(this.intervalId);
      TextHilighter.unhilightAll();
      // 検索ボックスを削除
      var m = document.getElementById(SearchBox.SEARCH_BOX_ID);
      m.parentNode.removeChild(m);
    },

    onEnterKey : function(e) {
      TextHilighter.followLink();
    },

    onNext : function(e) {
      if (e.ctrlKey || e.metaKey) {
        TextHilighter.hilightNext(-1);
      } else {
        TextHilighter.hilightNext(1);
      }
    },

    onToggle : function(e) {
      if (e.ctrlKey || e.metaKey) {
        this.linkonly = !this.linkonly;
        var i = document.getElementById(SearchBox.INPUT_BOX_ID);
        if (this.linkonly) {
          i.setAttribute("style", "color:red");
        } else {
          i.setAttribute("style", "");
        }
      }
    },

    searchWord : "",

    search : function() {
      if (this.currentWord == "") {
        TextHilighter.unhilightAll();
      } else if (!MigemoServer.isBusy && this.currentWord != this.searchWord) {
        this.searchWord = this.currentWord;
        MigemoServer.send(this.searchWord);
      }
    },

    setResult : function(re) {
      TextHilighter.hilightAll(re, this.linkonly);
      TextHilighter.hilightNext(1);
    }
  }

  var TextHilighter = {
    hilightNodes : [],
    currentIndex : -1,

    hilightAll : function(re, linkonly) {
      var xpath = "descendant::text()";
      if (!!linkonly) {
        xpath = "descendant::a/descendant::text()";
      }
      this.unhilightAll();

      var result = document.evaluate(xpath, document.body, null, 7, null);
      for (var i = 0; i < result.snapshotLength; i ++) {
        var t = result.snapshotItem(i);
        var f = t.textContent.search(RegExp(re, "i"));
        if (f != -1) {
          this.hilightNode(t, f, re);
        }
      }
    },

    hilightNode : function(node, f, re) {
      var str = node.textContent;
      var pre = str.substring(0, f);
      var post = str.substring(f);
      var mid = post.match(RegExp(re, "i"))[0];
      post = post.substring(mid.length);

      var parentNode = node.parentNode;
      var e1 = document.createTextNode(pre);
      var e2 = document.createElement("span")
      e2.setAttribute("style", "color:black;background:yellow");
      e2.appendChild(document.createTextNode(mid));
      var e3 = document.createTextNode(post)
      parentNode.insertBefore(e1, node);
      parentNode.insertBefore(e2, node);
      parentNode.insertBefore(e3, node);
      parentNode.removeChild(node);
      this.hilightNodes.push(e2);

      // recursive call
      var f2 = e3.textContent.search(RegExp(re, "i"));
      if (f2 != -1) {
        this.hilightNode(e3, f2, re);
      }
     },

    unhilightAll : function() {
      for (var i = 0, length = this.hilightNodes.length; i < length; i++ ) {
        var node = this.hilightNodes[i];
        var text = node.textContent;
        var tn = document.createTextNode(text);
        var parentNode = node.parentNode;
        parentNode.insertBefore(tn, node);
        parentNode.removeChild(node);
        parentNode.normalize();
      }
      this.hilightNodes = [];
      this.currentIndex = -1;
    },

    hilightNext : function(dir) {
      if (this.hilightNodes.length == 0) return;
      if (this.currentIndex >= 0) {
        this.hilightNodes[this.currentIndex]
         .setAttribute("style", "color:black;background:yellow");
      }
      this.currentIndex += dir;
      if (this.currentIndex >= this.hilightNodes.length) {
        this.currentIndex = 0;
      } else if (this.currentIndex < 0) {
        this.currentIndex = this.hilightNodes.length -1;
      }
      var n = this.hilightNodes[this.currentIndex];
      if (n != null) {
        n.setAttribute("style", "color:white;background:green");
        this.scrollToElem(n);
      }
    },

    scrollToElem : function(ele) {
      window.scrollTo(0, getElementYpos(ele) - window.innerHeight / 2);

      // 指定したエレメントのY座標を取得
      function getElementYpos(ele){
        var y = 0;
        var tmp = ele;
        while (tmp.nodeName != "BODY") {
          y += tmp.offsetTop;
          tmp = tmp.offsetParent;
        }
        return y;
      }
    },

    followLink : function() {
      if (this.hilightNodes.length == 0) return;
      var node = this.hilightNodes[this.currentIndex];

      var name = node.nodeName;
      while (name != "BODY") {
        if (name == "A") {
          var url = node.getAttribute("href");
          if (url != "" && url != null) {
            SearchBox.onEscapeKey(null);
            node.click();
            break;
          }
        }
        node = node.parentNode;
        name = node.nodeName;
      }
    }
  }

  document.addEventListener("keypress",
    function(e) {
      if (e.keyCode == 47 && (e.ctrlKey || e.metaKey)) { // ctrl/cmd + "/"
        if (document.getElementById(SearchBox.INPUT_BOX_ID) == null) {
          SearchBox.create();
        }
      }
    },
  false);

})(document);