// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: https://codemirror.net/LICENSE

(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) {
  "use strict";

  CodeMirror.defineMode("oz", function (conf) {

    function wordRegexp(words) {
      return new RegExp("^((" + words.join(")|(") + "))\\b");
    }

    var singleOperators = /[\^@!\|<>#~\.\*\-\+\\/,=]/;
    var doubleOperators = /(<-)|(:=)|(=<)|(>=)|(<=)|(<:)|(>:)|(=:)|(\\=)|(\\=:)|(!!)|(==)|(::)/;
    var tripleOperators = /(:::)|(\.\.\.)|(=<:)|(>=:)/;

    var middle = ["in", "then", "else", "of", "elseof", "elsecase", "elseif", "catch",
      "finally", "with", "require", "prepare", "import", "export", "define", "do"];
    var end = ["end"];

    var atoms = wordRegexp(["true", "false", "nil", "unit"]);
    var commonKeywords = wordRegexp(["andthen", "at", "attr", "declare", "feat", "from", "lex",
      "mod", "div", "mode", "orelse", "parser", "prod", "prop", "scanner", "self", "syn", "token"]);
    var openingKeywords = wordRegexp(["local", "proc", "fun", "case", "class", "if", "cond", "or", "dis",
      "choice", "not", "thread", "try", "raise", "lock", "for", "suchthat", "meth", "functor"]);
    var middleKeywords = wordRegexp(middle);
    var endKeywords = wordRegexp(end);

    // Tokenizers
    function tokenBase(stream, state) {
      if (stream.eatSpace()) {
        return null;
      }

      // Brackets
      if (stream.match(/[{}]/)) {
        return "bracket";
      }

      // Special [] keyword
      if (stream.match(/(\[])/)) {
        return "keyword"
      }

      // Operators
      if (stream.match(tripleOperators) || stream.match(doubleOperators)) {
        return "operator";
      }

      // Atoms
      if (stream.match(atoms)) {
        return 'atom';
      }

      // Opening keywords
      var matched = stream.match(openingKeywords);
      if (matched) {
        if (!state.doInCurrentLine)
          state.currentIndent++;
        else
          state.doInCurrentLine = false;

        // Special matching for signatures
        if (matched[0] == "proc" || matched[0] == "fun")
          state.tokenize = tokenFunProc;
        else if (matched[0] == "class")
          state.tokenize = tokenClass;
        else if (matched[0] == "meth")
          state.tokenize = tokenMeth;

        return 'keyword';
      }

      // Middle and other keywords
      if (stream.match(middleKeywords) || stream.match(commonKeywords)) {
        return "keyword"
      }

      // End keywords
      if (stream.match(endKeywords)) {
        state.currentIndent--;
        return 'keyword';
      }

      // Eat the next char for next comparisons
      var ch = stream.next();

      // Strings
      if (ch == '"' || ch == "'") {
        state.tokenize = tokenString(ch);
        return state.tokenize(stream, state);
      }

      // Numbers
      if (/[~\d]/.test(ch)) {
        if (ch == "~") {
          if (!/^[0-9]/.test(stream.peek()))
            return null;
          else if ((stream.next() == "0" && stream.match(/^[xX][0-9a-fA-F]+/)) || stream.match(/^[0-9]*(\.[0-9]+)?([eE][~+]?[0-9]+)?/))
            return "number";
        }

        if ((ch == "0" && stream.match(/^[xX][0-9a-fA-F]+/)) || stream.match(/^[0-9]*(\.[0-9]+)?([eE][~+]?[0-9]+)?/))
          return "number";

        return null;
      }

      // Comments
      if (ch == "%") {
        stream.skipToEnd();
        return 'comment';
      } else if (ch == "/") {
        if (stream.eat("*")) {
          state.tokenize = tokenComment;
          return tokenComment(stream, state);
        }
      }

      // Single operators
      if (singleOperators.test(ch)) {
        return "operator";
      }

      // If nothing match, we skip the entire alphanumerical block
      stream.eatWhile(/\w/);

      return "variable";
    }

    function tokenClass(stream, state) {
      if (stream.eatSpace()) {
        return null;
      }
      stream.match(/([A-Z][A-Za-z0-9_]*)|(`.+`)/);
      state.tokenize = tokenBase;
      return "variable-3"
    }

    function tokenMeth(stream, state) {
      if (stream.eatSpace()) {
        return null;
      }
      stream.match(/([a-zA-Z][A-Za-z0-9_]*)|(`.+`)/);
      state.tokenize = tokenBase;
      return "def"
    }

    function tokenFunProc(stream, state) {
      if (stream.eatSpace()) {
        return null;
      }

      if (!state.hasPassedFirstStage && stream.eat("{")) {
        state.hasPassedFirstStage = true;
        return "bracket";
      } else if (state.hasPassedFirstStage) {
        stream.match(/([A-Z][A-Za-z0-9_]*)|(`.+`)|\$/);
        state.hasPassedFirstStage = false;
        state.tokenize = tokenBase;
        return "def"
      } else {
        state.tokenize = tokenBase;
        return null;
      }
    }

    function tokenComment(stream, state) {
      var maybeEnd = false, ch;
      while (ch = stream.next()) {
        if (ch == "/" && maybeEnd) {
          state.tokenize = tokenBase;
          break;
        }
        maybeEnd = (ch == "*");
      }
      return "comment";
    }

    function tokenString(quote) {
      return function (stream, state) {
        var escaped = false, next, end = false;
        while ((next = stream.next()) != null) {
          if (next == quote && !escaped) {
            end = true;
            break;
          }
          escaped = !escaped && next == "\\";
        }
        if (end || !escaped)
          state.tokenize = tokenBase;
        return "string";
      };
    }

    function buildElectricInputRegEx() {
      // Reindentation should occur on [] or on a match of any of
      // the block closing keywords, at the end of a line.
      var allClosings = middle.concat(end);
      return new RegExp("[\\[\\]]|(" + allClosings.join("|") + ")$");
    }

    return {

      startState: function () {
        return {
          tokenize: tokenBase,
          currentIndent: 0,
          doInCurrentLine: false,
          hasPassedFirstStage: false
        };
      },

      token: function (stream, state) {
        if (stream.sol())
          state.doInCurrentLine = 0;

        return state.tokenize(stream, state);
      },

      indent: function (state, textAfter) {
        var trueText = textAfter.replace(/^\s+|\s+$/g, '');

        if (trueText.match(endKeywords) || trueText.match(middleKeywords) || trueText.match(/(\[])/))
          return conf.indentUnit * (state.currentIndent - 1);

        if (state.currentIndent < 0)
          return 0;

        return state.currentIndent * conf.indentUnit;
      },
      fold: "indent",
      electricInput: buildElectricInputRegEx(),
      lineComment: "%",
      blockCommentStart: "/*",
      blockCommentEnd: "*/"
    };
  });

  CodeMirror.defineMIME("text/x-oz", "oz");

});
