// CodeMirror, copyright © by Marijn Haverbeke and others // Distributed under an MIT license: codemirror.net/LICENSE

(function(mod) {

if (typeof exports == "object" && typeof module == "object") // CommonJS
  mod(require("../../lib/codemirror"), require("../htmlmixed/htmlmixed"),
      require("../../addon/mode/overlay"));
else if (typeof define == "function" && define.amd) // AMD
  define(["../../lib/codemirror", "../htmlmixed/htmlmixed",
          "../../addon/mode/overlay"], mod);
else // Plain browser env
  mod(CodeMirror);

})(function(CodeMirror) {

"use strict";

CodeMirror.defineMode("django:inner", function() {
  var keywords = ["block", "endblock", "for", "endfor", "true", "false", "filter", "endfilter",
                  "loop", "none", "self", "super", "if", "elif", "endif", "as", "else", "import",
                  "with", "endwith", "without", "context", "ifequal", "endifequal", "ifnotequal",
                  "endifnotequal", "extends", "include", "load", "comment", "endcomment",
                  "empty", "url", "static", "trans", "blocktrans", "endblocktrans", "now",
                  "regroup", "lorem", "ifchanged", "endifchanged", "firstof", "debug", "cycle",
                  "csrf_token", "autoescape", "endautoescape", "spaceless", "endspaceless",
                  "ssi", "templatetag", "verbatim", "endverbatim", "widthratio"],
      filters = ["add", "addslashes", "capfirst", "center", "cut", "date",
                 "default", "default_if_none", "dictsort",
                 "dictsortreversed", "divisibleby", "escape", "escapejs",
                 "filesizeformat", "first", "floatformat", "force_escape",
                 "get_digit", "iriencode", "join", "last", "length",
                 "length_is", "linebreaks", "linebreaksbr", "linenumbers",
                 "ljust", "lower", "make_list", "phone2numeric", "pluralize",
                 "pprint", "random", "removetags", "rjust", "safe",
                 "safeseq", "slice", "slugify", "stringformat", "striptags",
                 "time", "timesince", "timeuntil", "title", "truncatechars",
                 "truncatechars_html", "truncatewords", "truncatewords_html",
                 "unordered_list", "upper", "urlencode", "urlize",
                 "urlizetrunc", "wordcount", "wordwrap", "yesno"],
      operators = ["==", "!=", "<", ">", "<=", ">="],
      wordOperators = ["in", "not", "or", "and"];

  keywords = new RegExp("^\\b(" + keywords.join("|") + ")\\b");
  filters = new RegExp("^\\b(" + filters.join("|") + ")\\b");
  operators = new RegExp("^\\b(" + operators.join("|") + ")\\b");
  wordOperators = new RegExp("^\\b(" + wordOperators.join("|") + ")\\b");

  // We have to return "null" instead of null, in order to avoid string
  // styling as the default, when using Django templates inside HTML
  // element attributes
  function tokenBase (stream, state) {
    // Attempt to identify a variable, template or comment tag respectively
    if (stream.match("{{")) {
      state.tokenize = inVariable;
      return "tag";
    } else if (stream.match("{%")) {
      state.tokenize = inTag;
      return "tag";
    } else if (stream.match("{#")) {
      state.tokenize = inComment;
      return "comment";
    }

    // Ignore completely any stream series that do not match the
    // Django template opening tags.
    while (stream.next() != null && !stream.match(/\{[{%#]/, false)) {}
    return null;
  }

  // A string can be included in either single or double quotes (this is
  // the delimiter). Mark everything as a string until the start delimiter
  // occurs again.
  function inString (delimiter, previousTokenizer) {
    return function (stream, state) {
      if (!state.escapeNext && stream.eat(delimiter)) {
        state.tokenize = previousTokenizer;
      } else {
        if (state.escapeNext) {
          state.escapeNext = false;
        }

        var ch = stream.next();

        // Take into account the backslash for escaping characters, such as
        // the string delimiter.
        if (ch == "\\") {
          state.escapeNext = true;
        }
      }

      return "string";
    };
  }

  // Apply Django template variable syntax highlighting
  function inVariable (stream, state) {
    // Attempt to match a dot that precedes a property
    if (state.waitDot) {
      state.waitDot = false;

      if (stream.peek() != ".") {
        return "null";
      }

      // Dot followed by a non-word character should be considered an error.
      if (stream.match(/\.\W+/)) {
        return "error";
      } else if (stream.eat(".")) {
        state.waitProperty = true;
        return "null";
      } else {
        throw Error ("Unexpected error while waiting for property.");
      }
    }

    // Attempt to match a pipe that precedes a filter
    if (state.waitPipe) {
      state.waitPipe = false;

      if (stream.peek() != "|") {
        return "null";
      }

      // Pipe followed by a non-word character should be considered an error.
      if (stream.match(/\.\W+/)) {
        return "error";
      } else if (stream.eat("|")) {
        state.waitFilter = true;
        return "null";
      } else {
        throw Error ("Unexpected error while waiting for filter.");
      }
    }

    // Highlight properties
    if (state.waitProperty) {
      state.waitProperty = false;
      if (stream.match(/\b(\w+)\b/)) {
        state.waitDot = true;  // A property can be followed by another property
        state.waitPipe = true;  // A property can be followed by a filter
        return "property";
      }
    }

    // Highlight filters
    if (state.waitFilter) {
        state.waitFilter = false;
      if (stream.match(filters)) {
        return "variable-2";
      }
    }

    // Ignore all white spaces
    if (stream.eatSpace()) {
      state.waitProperty = false;
      return "null";
    }

    // Identify numbers
    if (stream.match(/\b\d+(\.\d+)?\b/)) {
      return "number";
    }

    // Identify strings
    if (stream.match("'")) {
      state.tokenize = inString("'", state.tokenize);
      return "string";
    } else if (stream.match('"')) {
      state.tokenize = inString('"', state.tokenize);
      return "string";
    }

    // Attempt to find the variable
    if (stream.match(/\b(\w+)\b/) && !state.foundVariable) {
      state.waitDot = true;
      state.waitPipe = true;  // A property can be followed by a filter
      return "variable";
    }

    // If found closing tag reset
    if (stream.match("}}")) {
      state.waitProperty = null;
      state.waitFilter = null;
      state.waitDot = null;
      state.waitPipe = null;
      state.tokenize = tokenBase;
      return "tag";
    }

    // If nothing was found, advance to the next character
    stream.next();
    return "null";
  }

  function inTag (stream, state) {
    // Attempt to match a dot that precedes a property
    if (state.waitDot) {
      state.waitDot = false;

      if (stream.peek() != ".") {
        return "null";
      }

      // Dot followed by a non-word character should be considered an error.
      if (stream.match(/\.\W+/)) {
        return "error";
      } else if (stream.eat(".")) {
        state.waitProperty = true;
        return "null";
      } else {
        throw Error ("Unexpected error while waiting for property.");
      }
    }

    // Attempt to match a pipe that precedes a filter
    if (state.waitPipe) {
      state.waitPipe = false;

      if (stream.peek() != "|") {
        return "null";
      }

      // Pipe followed by a non-word character should be considered an error.
      if (stream.match(/\.\W+/)) {
        return "error";
      } else if (stream.eat("|")) {
        state.waitFilter = true;
        return "null";
      } else {
        throw Error ("Unexpected error while waiting for filter.");
      }
    }

    // Highlight properties
    if (state.waitProperty) {
      state.waitProperty = false;
      if (stream.match(/\b(\w+)\b/)) {
        state.waitDot = true;  // A property can be followed by another property
        state.waitPipe = true;  // A property can be followed by a filter
        return "property";
      }
    }

    // Highlight filters
    if (state.waitFilter) {
        state.waitFilter = false;
      if (stream.match(filters)) {
        return "variable-2";
      }
    }

    // Ignore all white spaces
    if (stream.eatSpace()) {
      state.waitProperty = false;
      return "null";
    }

    // Identify numbers
    if (stream.match(/\b\d+(\.\d+)?\b/)) {
      return "number";
    }

    // Identify strings
    if (stream.match("'")) {
      state.tokenize = inString("'", state.tokenize);
      return "string";
    } else if (stream.match('"')) {
      state.tokenize = inString('"', state.tokenize);
      return "string";
    }

    // Attempt to match an operator
    if (stream.match(operators)) {
      return "operator";
    }

    // Attempt to match a word operator
    if (stream.match(wordOperators)) {
      return "keyword";
    }

    // Attempt to match a keyword
    var keywordMatch = stream.match(keywords);
    if (keywordMatch) {
      if (keywordMatch[0] == "comment") {
        state.blockCommentTag = true;
      }
      return "keyword";
    }

    // Attempt to match a variable
    if (stream.match(/\b(\w+)\b/)) {
      state.waitDot = true;
      state.waitPipe = true;  // A property can be followed by a filter
      return "variable";
    }

    // If found closing tag reset
    if (stream.match("%}")) {
      state.waitProperty = null;
      state.waitFilter = null;
      state.waitDot = null;
      state.waitPipe = null;
      // If the tag that closes is a block comment tag, we want to mark the
      // following code as comment, until the tag closes.
      if (state.blockCommentTag) {
        state.blockCommentTag = false;  // Release the "lock"
        state.tokenize = inBlockComment;
      } else {
        state.tokenize = tokenBase;
      }
      return "tag";
    }

    // If nothing was found, advance to the next character
    stream.next();
    return "null";
  }

  // Mark everything as comment inside the tag and the tag itself.
  function inComment (stream, state) {
    if (stream.match(/^.*?#\}/)) state.tokenize = tokenBase
    else stream.skipToEnd()
    return "comment";
  }

  // Mark everything as a comment until the `blockcomment` tag closes.
  function inBlockComment (stream, state) {
    if (stream.match(/\{%\s*endcomment\s*%\}/, false)) {
      state.tokenize = inTag;
      stream.match("{%");
      return "tag";
    } else {
      stream.next();
      return "comment";
    }
  }

  return {
    startState: function () {
      return {tokenize: tokenBase};
    },
    token: function (stream, state) {
      return state.tokenize(stream, state);
    },
    blockCommentStart: "{% comment %}",
    blockCommentEnd: "{% endcomment %}"
  };
});

CodeMirror.defineMode("django", function(config) {
  var htmlBase = CodeMirror.getMode(config, "text/html");
  var djangoInner = CodeMirror.getMode(config, "django:inner");
  return CodeMirror.overlayMode(htmlBase, djangoInner);
});

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

});