flack / openpsa

(function(mod) {

  if (typeof exports == "object" && typeof module == "object") // CommonJS

    mod(require("../../lib/codemirror"));

  else if (typeof define == "function" && define.amd) // AMD

    define(["../../lib/codemirror"], mod);

  else // Plain browser env

    mod(CodeMirror);

})(function(CodeMirror) {

  var defaults = {

    pairs: "()[]{}''\"\"",

    triples: "",

    explode: "[]{}"

  };

  var Pos = CodeMirror.Pos;

  CodeMirror.defineOption("autoCloseBrackets", false, function(cm, val, old) {

    if (old && old != CodeMirror.Init) {

      cm.removeKeyMap(keyMap);

      cm.state.closeBrackets = null;

    }

    if (val) {

      cm.state.closeBrackets = val;

      cm.addKeyMap(keyMap);

    }

  });

  function getOption(conf, name) {

    if (name == "pairs" && typeof conf == "string") return conf;

    if (typeof conf == "object" && conf[name] != null) return conf[name];

    return defaults[name];

  }

  var bind = defaults.pairs + "`";

  var keyMap = {Backspace: handleBackspace, Enter: handleEnter};

  for (var i = 0; i < bind.length; i++)

    keyMap["'" + bind.charAt(i) + "'"] = handler(bind.charAt(i));

  function handler(ch) {

    return function(cm) { return handleChar(cm, ch); };

  }

  function getConfig(cm) {

    var deflt = cm.state.closeBrackets;

    if (!deflt) return null;

    var mode = cm.getModeAt(cm.getCursor());

    return mode.closeBrackets || deflt;

  }

  function handleBackspace(cm) {

    var conf = getConfig(cm);

    if (!conf || cm.getOption("disableInput")) return CodeMirror.Pass;

    var pairs = getOption(conf, "pairs");

    var ranges = cm.listSelections();

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

      if (!ranges[i].empty()) return CodeMirror.Pass;

      var around = charsAround(cm, ranges[i].head);

      if (!around || pairs.indexOf(around) % 2 != 0) return CodeMirror.Pass;

    }

    for (var i = ranges.length - 1; i >= 0; i--) {

      var cur = ranges[i].head;

      cm.replaceRange("", Pos(cur.line, cur.ch - 1), Pos(cur.line, cur.ch + 1));

    }

  }

  function handleEnter(cm) {

    var conf = getConfig(cm);

    var explode = conf && getOption(conf, "explode");

    if (!explode || cm.getOption("disableInput")) return CodeMirror.Pass;

    var ranges = cm.listSelections();

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

      if (!ranges[i].empty()) return CodeMirror.Pass;

      var around = charsAround(cm, ranges[i].head);

      if (!around || explode.indexOf(around) % 2 != 0) return CodeMirror.Pass;

    }

    cm.operation(function() {

      cm.replaceSelection("\n\n", null);

      cm.execCommand("goCharLeft");

      ranges = cm.listSelections();

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

        var line = ranges[i].head.line;

        cm.indentLine(line, null, true);

        cm.indentLine(line + 1, null, true);

      }

    });

  }

  function contractSelection(sel) {

    var inverted = CodeMirror.cmpPos(sel.anchor, sel.head) > 0;

    return {anchor: new Pos(sel.anchor.line, sel.anchor.ch + (inverted ? -1 : 1)),

            head: new Pos(sel.head.line, sel.head.ch + (inverted ? 1 : -1))};

  }

  function handleChar(cm, ch) {

    var conf = getConfig(cm);

    if (!conf || cm.getOption("disableInput")) return CodeMirror.Pass;

    var pairs = getOption(conf, "pairs");

    var pos = pairs.indexOf(ch);

    if (pos == -1) return CodeMirror.Pass;

    var triples = getOption(conf, "triples");

    var identical = pairs.charAt(pos + 1) == ch;

    var ranges = cm.listSelections();

    var opening = pos % 2 == 0;

    var type, next;

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

      var range = ranges[i], cur = range.head, curType;

      var next = cm.getRange(cur, Pos(cur.line, cur.ch + 1));

      if (opening && !range.empty()) {

        curType = "surround";

      } else if ((identical || !opening) && next == ch) {

        if (triples.indexOf(ch) >= 0 && cm.getRange(cur, Pos(cur.line, cur.ch + 3)) == ch + ch + ch)

          curType = "skipThree";

        else

          curType = "skip";

      } else if (identical && cur.ch > 1 && triples.indexOf(ch) >= 0 &&

                 cm.getRange(Pos(cur.line, cur.ch - 2), cur) == ch + ch &&

                 (cur.ch <= 2 || cm.getRange(Pos(cur.line, cur.ch - 3), Pos(cur.line, cur.ch - 2)) != ch)) {

        curType = "addFour";

      } else if (identical) {

        if (!CodeMirror.isWordChar(next) && enteringString(cm, cur, ch)) curType = "both";

        else return CodeMirror.Pass;

      } else if (opening && (cm.getLine(cur.line).length == cur.ch ||

                             isClosingBracket(next, pairs) ||

                             /\s/.test(next))) {

        curType = "both";

      } else {

        return CodeMirror.Pass;

      }

      if (!type) type = curType;

      else if (type != curType) return CodeMirror.Pass;

    }

    var left = pos % 2 ? pairs.charAt(pos - 1) : ch;

    var right = pos % 2 ? ch : pairs.charAt(pos + 1);

    cm.operation(function() {

      if (type == "skip") {

        cm.execCommand("goCharRight");

      } else if (type == "skipThree") {

        for (var i = 0; i < 3; i++)

          cm.execCommand("goCharRight");

      } else if (type == "surround") {

        var sels = cm.getSelections();

        for (var i = 0; i < sels.length; i++)

          sels[i] = left + sels[i] + right;

        cm.replaceSelections(sels, "around");

        sels = cm.listSelections().slice();

        for (var i = 0; i < sels.length; i++)

          sels[i] = contractSelection(sels[i]);

        cm.setSelections(sels);

      } else if (type == "both") {

        cm.replaceSelection(left + right, null);

        cm.triggerElectric(left + right);

        cm.execCommand("goCharLeft");

      } else if (type == "addFour") {

        cm.replaceSelection(left + left + left + left, "before");

        cm.execCommand("goCharRight");

      }

    });

  }

  function isClosingBracket(ch, pairs) {

    var pos = pairs.lastIndexOf(ch);

    return pos > -1 && pos % 2 == 1;

  }

  function charsAround(cm, pos) {

    var str = cm.getRange(Pos(pos.line, pos.ch - 1),

                          Pos(pos.line, pos.ch + 1));

    return str.length == 2 ? str : null;

  }

  // Project the token type that will exists after the given char is

  // typed, and use it to determine whether it would cause the start

  // of a string token.

  function enteringString(cm, pos, ch) {

    var line = cm.getLine(pos.line);

    var token = cm.getTokenAt(pos);

    if (/\bstring2?\b/.test(token.type)) return false;

    var stream = new CodeMirror.StringStream(line.slice(0, pos.ch) + ch + line.slice(pos.ch), 4);

    stream.pos = stream.start = token.start;

    for (;;) {

      var type1 = cm.getMode().token(stream, token.state);

      if (stream.pos >= pos.ch + 1) return /\bstring2?\b/.test(type1);

      stream.start = stream.pos;

    }

  }

});