// 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"), require("../htmlmixed/htmlmixed"));
  else if (typeof define == "function" && define.amd) // AMD
    define(["../../lib/codemirror", "../htmlmixed/htmlmixed"], mod);
  else // Plain browser env
    mod(CodeMirror);
})(function(CodeMirror) {
  "use strict";

  var paramData = { noEndTag: true, soyState: "param-def" };
  var tags = {
    "alias": { noEndTag: true },
    "delpackage": { noEndTag: true },
    "namespace": { noEndTag: true, soyState: "namespace-def" },
    "@param": paramData,
    "@param?": paramData,
    "@inject": paramData,
    "@inject?": paramData,
    "@state": paramData,
    "@state?": paramData,
    "template": { soyState: "templ-def", variableScope: true},
    "literal": { },
    "msg": {},
    "fallbackmsg": { noEndTag: true, reduceIndent: true},
    "select": {},
    "plural": {},
    "let": { soyState: "var-def" },
    "if": {},
    "elseif": { noEndTag: true, reduceIndent: true},
    "else": { noEndTag: true, reduceIndent: true},
    "switch": {},
    "case": { noEndTag: true, reduceIndent: true},
    "default": { noEndTag: true, reduceIndent: true},
    "foreach": { variableScope: true, soyState: "var-def" },
    "ifempty": { noEndTag: true, reduceIndent: true},
    "for": { variableScope: true, soyState: "var-def" },
    "call": { soyState: "templ-ref" },
    "param": { soyState: "param-ref"},
    "print": { noEndTag: true },
    "deltemplate": { soyState: "templ-def", variableScope: true},
    "delcall": { soyState: "templ-ref" },
    "log": {},
    "element": { variableScope: true },
  };

  var indentingTags = Object.keys(tags).filter(function(tag) {
    return !tags[tag].noEndTag || tags[tag].reduceIndent;
  });

  CodeMirror.defineMode("soy", function(config) {
    var textMode = CodeMirror.getMode(config, "text/plain");
    var modes = {
      html: CodeMirror.getMode(config, {name: "text/html", multilineTagIndentFactor: 2, multilineTagIndentPastTag: false}),
      attributes: textMode,
      text: textMode,
      uri: textMode,
      trusted_resource_uri: textMode,
      css: CodeMirror.getMode(config, "text/css"),
      js: CodeMirror.getMode(config, {name: "text/javascript", statementIndent: 2 * config.indentUnit})
    };

    function last(array) {
      return array[array.length - 1];
    }

    function tokenUntil(stream, state, untilRegExp) {
      if (stream.sol()) {
        for (var indent = 0; indent < state.indent; indent++) {
          if (!stream.eat(/\s/)) break;
        }
        if (indent) return null;
      }
      var oldString = stream.string;
      var match = untilRegExp.exec(oldString.substr(stream.pos));
      if (match) {
        // We don't use backUp because it backs up just the position, not the state.
        // This uses an undocumented API.
        stream.string = oldString.substr(0, stream.pos + match.index);
      }
      var result = stream.hideFirstChars(state.indent, function() {
        var localState = last(state.localStates);
        return localState.mode.token(stream, localState.state);
      });
      stream.string = oldString;
      return result;
    }

    function contains(list, element) {
      while (list) {
        if (list.element === element) return true;
        list = list.next;
      }
      return false;
    }

    function prepend(list, element) {
      return {
        element: element,
        next: list
      };
    }

    function popcontext(state) {
      if (!state.context) return;
      if (state.context.scope) {
        state.variables = state.context.scope;
      }
      state.context = state.context.previousContext;
    }

    // Reference a variable `name` in `list`.
    // Let `loose` be truthy to ignore missing identifiers.
    function ref(list, name, loose) {
      return contains(list, name) ? "variable-2" : (loose ? "variable" : "variable-2 error");
    }

    // Data for an open soy tag.
    function Context(previousContext, tag, scope) {
      this.previousContext = previousContext;
      this.tag = tag;
      this.kind = null;
      this.scope = scope;
    }

    return {
      startState: function() {
        return {
          soyState: [],
          templates: null,
          variables: prepend(null, 'ij'),
          scopes: null,
          indent: 0,
          quoteKind: null,
          context: null,
          localStates: [{
            mode: modes.html,
            state: CodeMirror.startState(modes.html)
          }]
        };
      },

      copyState: function(state) {
        return {
          tag: state.tag, // Last seen Soy tag.
          soyState: state.soyState.concat([]),
          templates: state.templates,
          variables: state.variables,
          context: state.context,
          indent: state.indent, // Indentation of the following line.
          quoteKind: state.quoteKind,
          localStates: state.localStates.map(function(localState) {
            return {
              mode: localState.mode,
              state: CodeMirror.copyState(localState.mode, localState.state)
            };
          })
        };
      },

      token: function(stream, state) {
        var match;

        switch (last(state.soyState)) {
          case "comment":
            if (stream.match(/^.*?\*\//)) {
              state.soyState.pop();
            } else {
              stream.skipToEnd();
            }
            if (!state.context || !state.context.scope) {
              var paramRe = /@param\??\s+(\S+)/g;
              var current = stream.current();
              for (var match; (match = paramRe.exec(current)); ) {
                state.variables = prepend(state.variables, match[1]);
              }
            }
            return "comment";

          case "string":
            var match = stream.match(/^.*?(["']|\\[\s\S])/);
            if (!match) {
              stream.skipToEnd();
            } else if (match[1] == state.quoteKind) {
              state.quoteKind = null;
              state.soyState.pop();
            }
            return "string";
        }

        if (!state.soyState.length || last(state.soyState) != "literal") {
          if (stream.match(/^\/\*/)) {
            state.soyState.push("comment");
            return "comment";
          } else if (stream.match(stream.sol() ? /^\s*\/\/.*/ : /^\s+\/\/.*/)) {
            return "comment";
          }
        }

        switch (last(state.soyState)) {
          case "templ-def":
            if (match = stream.match(/^\.?([\w]+(?!\.[\w]+)*)/)) {
              state.templates = prepend(state.templates, match[1]);
              state.soyState.pop();
              return "def";
            }
            stream.next();
            return null;

          case "templ-ref":
            if (match = stream.match(/(\.?[a-zA-Z_][a-zA-Z_0-9]+)+/)) {
              state.soyState.pop();
              // If the first character is '.', it can only be a local template.
              if (match[0][0] == '.') {
                return "variable-2"
              }
              // Otherwise
              return "variable";
            }
            stream.next();
            return null;

          case "namespace-def":
            if (match = stream.match(/^\.?([\w\.]+)/)) {
              state.soyState.pop();
              return "variable";
            }
            stream.next();
            return null;

          case "param-def":
            if (match = stream.match(/^\w+/)) {
              state.variables = prepend(state.variables, match[0]);
              state.soyState.pop();
              state.soyState.push("param-type");
              return "def";
            }
            stream.next();
            return null;

          case "param-ref":
            if (match = stream.match(/^\w+/)) {
              state.soyState.pop();
              return "property";
            }
            stream.next();
            return null;

          case "param-type":
            if (stream.peek() == "}") {
              state.soyState.pop();
              return null;
            }
            if (stream.eatWhile(/^([\w]+|[?])/)) {
              return "type";
            }
            stream.next();
            return null;

          case "var-def":
            if (match = stream.match(/^\$([\w]+)/)) {
              state.variables = prepend(state.variables, match[1]);
              state.soyState.pop();
              return "def";
            }
            stream.next();
            return null;

          case "tag":
            var endTag = state.tag[0] == "/";
            var tagName = endTag ? state.tag.substring(1) : state.tag;
            var tag = tags[tagName];
            if (stream.match(/^\/?}/)) {
              var selfClosed = stream.current() == "/}";
              if (selfClosed && !endTag) {
                popcontext(state);
              }
              if (state.tag == "/template" || state.tag == "/deltemplate") {
                state.variables = prepend(null, 'ij');
                state.indent = 0;
              } else {
                state.indent -= config.indentUnit *
                    (selfClosed || indentingTags.indexOf(state.tag) == -1 ? 2 : 1);
              }
              state.soyState.pop();
              return "keyword";
            } else if (stream.match(/^([\w?]+)(?==)/)) {
              if (stream.current() == "kind" && (match = stream.match(/^="([^"]+)/, false))) {
                var kind = match[1];
                state.context.kind = kind;
                var mode = modes[kind] || modes.html;
                var localState = last(state.localStates);
                if (localState.mode.indent) {
                  state.indent += localState.mode.indent(localState.state, "", "");
                }
                state.localStates.push({
                  mode: mode,
                  state: CodeMirror.startState(mode)
                });
              }
              return "attribute";
            } else if (match = stream.match(/([\w]+)(?=\()/)) {
              return "variable callee";
            } else if (match = stream.match(/^["']/)) {
              state.soyState.push("string");
              state.quoteKind = match;
              return "string";
            }
            if (stream.match(/(null|true|false)(?!\w)/) ||
              stream.match(/0x([0-9a-fA-F]{2,})/) ||
              stream.match(/-?([0-9]*[.])?[0-9]+(e[0-9]*)?/)) {
              return "atom";
            }
            if (stream.match(/(\||[+\-*\/%]|[=!]=|\?:|[<>]=?)/)) {
              // Tokenize filter, binary, null propagator, and equality operators.
              return "operator";
            }
            if (match = stream.match(/^\$([\w]+)/)) {
              return ref(state.variables, match[1]);
            }
            if (match = stream.match(/^\w+/)) {
              return /^(?:as|and|or|not|in)$/.test(match[0]) ? "keyword" : null;
            }
            stream.next();
            return null;

          case "literal":
            if (stream.match(/^(?=\{\/literal})/)) {
              state.indent -= config.indentUnit;
              state.soyState.pop();
              return this.token(stream, state);
            }
            return tokenUntil(stream, state, /\{\/literal}/);
        }

        if (stream.match(/^\{literal}/)) {
          state.indent += config.indentUnit;
          state.soyState.push("literal");
          state.context = new Context(state.context, "literal", state.variables);
          return "keyword";

        // A tag-keyword must be followed by whitespace, comment or a closing tag.
        } else if (match = stream.match(/^\{([/@\\]?\w+\??)(?=$|[\s}]|\/[/*])/)) {
          var prevTag = state.tag;
          state.tag = match[1];
          var endTag = state.tag[0] == "/";
          var indentingTag = !!tags[state.tag];
          var tagName = endTag ? state.tag.substring(1) : state.tag;
          var tag = tags[tagName];
          if (state.tag != "/switch")
            state.indent += ((endTag || tag && tag.reduceIndent) && prevTag != "switch" ? 1 : 2) * config.indentUnit;

          state.soyState.push("tag");
          var tagError = false;
          if (tag) {
            if (!endTag) {
              if (tag.soyState) state.soyState.push(tag.soyState);
            }
            // If a new tag, open a new context.
            if (!tag.noEndTag && (indentingTag || !endTag)) {
              state.context = new Context(state.context, state.tag, tag.variableScope ? state.variables : null);
            // Otherwise close the current context.
            } else if (endTag) {
              if (!state.context || state.context.tag != tagName) {
                tagError = true;
              } else if (state.context) {
                if (state.context.kind) {
                  state.localStates.pop();
                  var localState = last(state.localStates);
                  if (localState.mode.indent) {
                    state.indent -= localState.mode.indent(localState.state, "", "");
                  }
                }
                popcontext(state);
              }
            }
          } else if (endTag) {
            // Assume all tags with a closing tag are defined in the config.
            tagError = true;
          }
          return (tagError ? "error " : "") + "keyword";

        // Not a tag-keyword; it's an implicit print tag.
        } else if (stream.eat('{')) {
          state.tag = "print";
          state.indent += 2 * config.indentUnit;
          state.soyState.push("tag");
          return "keyword";
        }

        return tokenUntil(stream, state, /\{|\s+\/\/|\/\*/);
      },

      indent: function(state, textAfter, line) {
        var indent = state.indent, top = last(state.soyState);
        if (top == "comment") return CodeMirror.Pass;

        if (top == "literal") {
          if (/^\{\/literal}/.test(textAfter)) indent -= config.indentUnit;
        } else {
          if (/^\s*\{\/(template|deltemplate)\b/.test(textAfter)) return 0;
          if (/^\{(\/|(fallbackmsg|elseif|else|ifempty)\b)/.test(textAfter)) indent -= config.indentUnit;
          if (state.tag != "switch" && /^\{(case|default)\b/.test(textAfter)) indent -= config.indentUnit;
          if (/^\{\/switch\b/.test(textAfter)) indent -= config.indentUnit;
        }
        var localState = last(state.localStates);
        if (indent && localState.mode.indent) {
          indent += localState.mode.indent(localState.state, textAfter, line);
        }
        return indent;
      },

      innerMode: function(state) {
        if (state.soyState.length && last(state.soyState) != "literal") return null;
        else return last(state.localStates);
      },

      electricInput: /^\s*\{(\/|\/template|\/deltemplate|\/switch|fallbackmsg|elseif|else|case|default|ifempty|\/literal\})$/,
      lineComment: "//",
      blockCommentStart: "/*",
      blockCommentEnd: "*/",
      blockCommentContinue: " * ",
      useInnerComments: false,
      fold: "indent"
    };
  }, "htmlmixed");

  CodeMirror.registerHelper("wordChars", "soy", /[\w$]/);

  CodeMirror.registerHelper("hintWords", "soy", Object.keys(tags).concat(
      ["css", "debugger"]));

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