/* ***** BEGIN LICENSE BLOCK *****
 * Distributed under the BSD license:
 *
 * Copyright (c) 2010, Ajax.org B.V.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of Ajax.org B.V. nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL AJAX.ORG B.V. BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * ***** END LICENSE BLOCK ***** */

define(function (require, exports, module) {
    "use strict";
    var oop = require("./lib/oop");
    var EventEmitter = require("./lib/event_emitter").EventEmitter;
    var lang = require("./lib/lang");
    var Range = require("./range").Range;
    var Anchor = require("./anchor").Anchor;
    var HashHandler = require("./keyboard/hash_handler").HashHandler;
    var Tokenizer = require("./tokenizer").Tokenizer;
    var comparePoints = Range.comparePoints;

    var SnippetManager = function () {
        this.snippetMap = {};
        this.snippetNameMap = {};
    };

    (function () {
        oop.implement(this, EventEmitter);

        this.getTokenizer = function () {
            function TabstopToken(str, _, stack) {
                str = str.substr(1);
                if (/^\d+$/.test(str) && !stack.inFormatString)
                    return [{tabstopId: parseInt(str, 10)}];
                return [{text: str}];
            }

            function escape(ch) {
                return "(?:[^\\\\" + ch + "]|\\\\.)";
            }

            SnippetManager.$tokenizer = new Tokenizer({
                start: [
                    {
                        regex: /:/, onMatch: function (val, state, stack) {
                        if (stack.length && stack[0].expectIf) {
                            stack[0].expectIf = false;
                            stack[0].elseBranch = stack[0];
                            return [stack[0]];
                        }
                        return ":";
                    }
                    },
                    {
                        regex: /\\./, onMatch: function (val, state, stack) {
                        var ch = val[1];
                        if (ch == "}" && stack.length) {
                            val = ch;
                        } else if ("`$\\".indexOf(ch) != -1) {
                            val = ch;
                        } else if (stack.inFormatString) {
                            if (ch == "n")
                                val = "\n";
                            else if (ch == "t")
                                val = "\n";
                            else if ("ulULE".indexOf(ch) != -1) {
                                val = {changeCase: ch, local: ch > "a"};
                            }
                        }

                        return [val];
                    }
                    },
                    {
                        regex: /}/, onMatch: function (val, state, stack) {
                        return [stack.length ? stack.shift() : val];
                    }
                    },
                    {regex: /\$(?:\d+|\w+)/, onMatch: TabstopToken},
                    {
                        regex: /\$\{[\dA-Z_a-z]+/, onMatch: function (str, state, stack) {
                        var t = TabstopToken(str.substr(1), state, stack);
                        stack.unshift(t[0]);
                        return t;
                    }, next: "snippetVar"
                    },
                    {regex: /\n/, token: "newline", merge: false}
                ],
                snippetVar: [
                    {
                        regex: "\\|" + escape("\\|") + "*\\|", onMatch: function (val, state, stack) {
                        stack[0].choices = val.slice(1, -1).split(",");
                    }, next: "start"
                    },
                    {
                        regex: "/(" + escape("/") + "+)/(?:(" + escape("/") + "*)/)(\\w*):?",
                        onMatch: function (val, state, stack) {
                            var ts = stack[0];
                            ts.fmtString = val;

                            val = this.splitRegex.exec(val);
                            ts.guard = val[1];
                            ts.fmt = val[2];
                            ts.flag = val[3];
                            return "";
                        }, next: "start"
                    },
                    {
                        regex: "`" + escape("`") + "*`", onMatch: function (val, state, stack) {
                        stack[0].code = val.splice(1, -1);
                        return "";
                    }, next: "start"
                    },
                    {
                        regex: "\\?", onMatch: function (val, state, stack) {
                        if (stack[0])
                            stack[0].expectIf = true;
                    }, next: "start"
                    },
                    {regex: "([^:}\\\\]|\\\\.)*:?", token: "", next: "start"}
                ],
                formatString: [
                    {regex: "/(" + escape("/") + "+)/", token: "regex"},
                    {
                        regex: "", onMatch: function (val, state, stack) {
                        stack.inFormatString = true;
                    }, next: "start"
                    }
                ]
            });
            SnippetManager.prototype.getTokenizer = function () {
                return SnippetManager.$tokenizer;
            };
            return SnippetManager.$tokenizer;
        };

        this.tokenizeTmSnippet = function (str, startState) {
            return this.getTokenizer().getLineTokens(str, startState).tokens.map(function (x) {
                return x.value || x;
            });
        };

        this.$getDefaultValue = function (editor, name) {
            if (/^[A-Z]\d+$/.test(name)) {
                var i = name.substr(1);
                return (this.variables[name[0] + "__"] || {})[i];
            }
            if (/^\d+$/.test(name)) {
                return (this.variables.__ || {})[name];
            }
            name = name.replace(/^TM_/, "");

            if (!editor)
                return;
            var s = editor.session;
            switch (name) {
                case "CURRENT_WORD":
                    var r = s.getWordRange();
                /* falls through */
                case "SELECTION":
                case "SELECTED_TEXT":
                    return s.getTextRange(r);
                case "CURRENT_LINE":
                    return s.getLine(editor.getCursorPosition().row);
                case "PREV_LINE": // not possible in textmate
                    return s.getLine(editor.getCursorPosition().row - 1);
                case "LINE_INDEX":
                    return editor.getCursorPosition().column;
                case "LINE_NUMBER":
                    return editor.getCursorPosition().row + 1;
                case "SOFT_TABS":
                    return s.getUseSoftTabs() ? "YES" : "NO";
                case "TAB_SIZE":
                    return s.getTabSize();
                // default but can't fill :(
                case "FILENAME":
                case "FILEPATH":
                    return "";
                case "FULLNAME":
                    return "Ace";
            }
        };
        this.variables = {};
        this.getVariableValue = function (editor, varName) {
            if (this.variables.hasOwnProperty(varName))
                return this.variables[varName](editor, varName) || "";
            return this.$getDefaultValue(editor, varName) || "";
        };

        // returns string formatted according to http://manual.macromates.com/en/regular_expressions#replacement_string_syntax_format_strings
        this.tmStrFormat = function (str, ch, editor) {
            var flag = ch.flag || "";
            var re = ch.guard;
            re = new RegExp(re, flag.replace(/[^gi]/, ""));
            var fmtTokens = this.tokenizeTmSnippet(ch.fmt, "formatString");
            var _self = this;
            var formatted = str.replace(re, function () {
                _self.variables.__ = arguments;
                var fmtParts = _self.resolveVariables(fmtTokens, editor);
                var gChangeCase = "E";
                for (var i = 0; i < fmtParts.length; i++) {
                    var ch = fmtParts[i];
                    if (typeof ch == "object") {
                        fmtParts[i] = "";
                        if (ch.changeCase && ch.local) {
                            var next = fmtParts[i + 1];
                            if (next && typeof next == "string") {
                                if (ch.changeCase == "u")
                                    fmtParts[i] = next[0].toUpperCase();
                                else
                                    fmtParts[i] = next[0].toLowerCase();
                                fmtParts[i + 1] = next.substr(1);
                            }
                        } else if (ch.changeCase) {
                            gChangeCase = ch.changeCase;
                        }
                    } else if (gChangeCase == "U") {
                        fmtParts[i] = ch.toUpperCase();
                    } else if (gChangeCase == "L") {
                        fmtParts[i] = ch.toLowerCase();
                    }
                }
                return fmtParts.join("");
            });
            this.variables.__ = null;
            return formatted;
        };

        this.resolveVariables = function (snippet, editor) {
            var result = [];
            for (var i = 0; i < snippet.length; i++) {
                var ch = snippet[i];
                if (typeof ch == "string") {
                    result.push(ch);
                } else if (typeof ch != "object") {
                    continue;
                } else if (ch.skip) {
                    gotoNext(ch);
                } else if (ch.processed < i) {
                    continue;
                } else if (ch.text) {
                    var value = this.getVariableValue(editor, ch.text);
                    if (value && ch.fmtString)
                        value = this.tmStrFormat(value, ch);
                    ch.processed = i;
                    if (ch.expectIf == null) {
                        if (value) {
                            result.push(value);
                            gotoNext(ch);
                        }
                    } else {
                        if (value) {
                            ch.skip = ch.elseBranch;
                        } else
                            gotoNext(ch);
                    }
                } else if (ch.tabstopId != null) {
                    result.push(ch);
                } else if (ch.changeCase != null) {
                    result.push(ch);
                }
            }
            function gotoNext(ch) {
                var i1 = snippet.indexOf(ch, i + 1);
                if (i1 != -1)
                    i = i1;
            }

            return result;
        };

        this.insertSnippetForSelection = function (editor, snippetText) {
            var cursor = editor.getCursorPosition();
            var line = editor.session.getLine(cursor.row);
            var tabString = editor.session.getTabString();
            var indentString = line.match(/^\s*/)[0];

            if (cursor.column < indentString.length)
                indentString = indentString.slice(0, cursor.column);

            snippetText = snippetText.replace(/\r/g, "");
            var tokens = this.tokenizeTmSnippet(snippetText);
            tokens = this.resolveVariables(tokens, editor);
            // indent
            tokens = tokens.map(function (x) {
                if (x == "\n")
                    return x + indentString;
                if (typeof x == "string")
                    return x.replace(/\t/g, tabString);
                return x;
            });
            // tabstop values
            var tabstops = [];
            tokens.forEach(function (p, i) {
                if (typeof p != "object")
                    return;
                var id = p.tabstopId;
                var ts = tabstops[id];
                if (!ts) {
                    ts = tabstops[id] = [];
                    ts.index = id;
                    ts.value = "";
                }
                if (ts.indexOf(p) !== -1)
                    return;
                ts.push(p);
                var i1 = tokens.indexOf(p, i + 1);
                if (i1 === -1)
                    return;

                var value = tokens.slice(i + 1, i1);
                var isNested = value.some(function (t) {
                    return typeof t === "object"
                });
                if (isNested && !ts.value) {
                    ts.value = value;
                } else if (value.length && (!ts.value || typeof ts.value !== "string")) {
                    ts.value = value.join("");
                }
            });

            // expand tabstop values
            tabstops.forEach(function (ts) {
                ts.length = 0
            });
            var expanding = {};

            function copyValue(val) {
                var copy = [];
                for (var i = 0; i < val.length; i++) {
                    var p = val[i];
                    if (typeof p == "object") {
                        if (expanding[p.tabstopId])
                            continue;
                        var j = val.lastIndexOf(p, i - 1);
                        p = copy[j] || {tabstopId: p.tabstopId};
                    }
                    copy[i] = p;
                }
                return copy;
            }

            for (var i = 0; i < tokens.length; i++) {
                var p = tokens[i];
                if (typeof p != "object")
                    continue;
                var id = p.tabstopId;
                var i1 = tokens.indexOf(p, i + 1);
                if (expanding[id]) {
                    // if reached closing bracket clear expanding state
                    if (expanding[id] === p)
                        expanding[id] = null;
                    // otherwise just ignore recursive tabstop
                    continue;
                }

                var ts = tabstops[id];
                var arg = typeof ts.value == "string" ? [ts.value] : copyValue(ts.value);
                arg.unshift(i + 1, Math.max(0, i1 - i));
                arg.push(p);
                expanding[id] = p;
                tokens.splice.apply(tokens, arg);

                if (ts.indexOf(p) === -1)
                    ts.push(p);
            }

            // convert to plain text
            var row = 0, column = 0;
            var text = "";
            tokens.forEach(function (t) {
                if (typeof t === "string") {
                    var lines = t.split("\n");
                    if (lines.length > 1) {
                        column = lines[lines.length - 1].length;
                        row += lines.length - 1;
                    } else
                        column += t.length;
                    text += t;
                } else {
                    if (!t.start)
                        t.start = {row: row, column: column};
                    else
                        t.end = {row: row, column: column};
                }
            });
            var range = editor.getSelectionRange();
            var end = editor.session.replace(range, text);

            var tabstopManager = new TabstopManager(editor);
            var selectionId = editor.inVirtualSelectionMode && editor.selection.index;
            tabstopManager.addTabstops(tabstops, range.start, end, selectionId);
        };

        this.insertSnippet = function (editor, snippetText) {
            var self = this;
            if (editor.inVirtualSelectionMode)
                return self.insertSnippetForSelection(editor, snippetText);

            editor.forEachSelection(function () {
                self.insertSnippetForSelection(editor, snippetText);
            }, null, {keepOrder: true});

            if (editor.tabstopManager)
                editor.tabstopManager.tabNext();
        };

        this.$getScope = function (editor) {
            var scope = editor.session.$mode.$id || "";
            scope = scope.split("/").pop();
            if (scope === "html" || scope === "php") {
                // PHP is actually HTML
                if (scope === "php" && !editor.session.$mode.inlinePhp)
                    scope = "html";
                var c = editor.getCursorPosition();
                var state = editor.session.getState(c.row);
                if (typeof state === "object") {
                    state = state[0];
                }
                if (state.substring) {
                    if (state.substring(0, 3) == "js-")
                        scope = "javascript";
                    else if (state.substring(0, 4) == "css-")
                        scope = "css";
                    else if (state.substring(0, 4) == "php-")
                        scope = "php";
                }
            }

            return scope;
        };

        this.getActiveScopes = function (editor) {
            var scope = this.$getScope(editor);
            var scopes = [scope];
            var snippetMap = this.snippetMap;
            if (snippetMap[scope] && snippetMap[scope].includeScopes) {
                scopes.push.apply(scopes, snippetMap[scope].includeScopes);
            }
            scopes.push("_");
            return scopes;
        };

        this.expandWithTab = function (editor, options) {
            var self = this;
            var result = editor.forEachSelection(function () {
                return self.expandSnippetForSelection(editor, options);
            }, null, {keepOrder: true});
            if (result && editor.tabstopManager)
                editor.tabstopManager.tabNext();
            return result;
        };

        this.expandSnippetForSelection = function (editor, options) {
            var cursor = editor.getCursorPosition();
            var line = editor.session.getLine(cursor.row);
            var before = line.substring(0, cursor.column);
            var after = line.substr(cursor.column);

            var snippetMap = this.snippetMap;
            var snippet;
            this.getActiveScopes(editor).some(function (scope) {
                var snippets = snippetMap[scope];
                if (snippets)
                    snippet = this.findMatchingSnippet(snippets, before, after);
                return !!snippet;
            }, this);
            if (!snippet)
                return false;
            if (options && options.dryRun)
                return true;
            editor.session.doc.removeInLine(cursor.row,
                cursor.column - snippet.replaceBefore.length,
                cursor.column + snippet.replaceAfter.length
            );

            this.variables.M__ = snippet.matchBefore;
            this.variables.T__ = snippet.matchAfter;
            this.insertSnippetForSelection(editor, snippet.content);

            this.variables.M__ = this.variables.T__ = null;
            return true;
        };

        this.findMatchingSnippet = function (snippetList, before, after) {
            for (var i = snippetList.length; i--;) {
                var s = snippetList[i];
                if (s.startRe && !s.startRe.test(before))
                    continue;
                if (s.endRe && !s.endRe.test(after))
                    continue;
                if (!s.startRe && !s.endRe)
                    continue;

                s.matchBefore = s.startRe ? s.startRe.exec(before) : [""];
                s.matchAfter = s.endRe ? s.endRe.exec(after) : [""];
                s.replaceBefore = s.triggerRe ? s.triggerRe.exec(before)[0] : "";
                s.replaceAfter = s.endTriggerRe ? s.endTriggerRe.exec(after)[0] : "";
                return s;
            }
        };

        this.snippetMap = {};
        this.snippetNameMap = {};
        this.register = function (snippets, scope) {
            var snippetMap = this.snippetMap;
            var snippetNameMap = this.snippetNameMap;
            var self = this;

            if (!snippets)
                snippets = [];

            function wrapRegexp(src) {
                if (src && !/^\^?\(.*\)\$?$|^\\b$/.test(src))
                    src = "(?:" + src + ")";

                return src || "";
            }

            function guardedRegexp(re, guard, opening) {
                re = wrapRegexp(re);
                guard = wrapRegexp(guard);
                if (opening) {
                    re = guard + re;
                    if (re && re[re.length - 1] != "$")
                        re = re + "$";
                } else {
                    re = re + guard;
                    if (re && re[0] != "^")
                        re = "^" + re;
                }
                return new RegExp(re);
            }

            function addSnippet(s) {
                if (!s.scope)
                    s.scope = scope || "_";
                scope = s.scope;
                if (!snippetMap[scope]) {
                    snippetMap[scope] = [];
                    snippetNameMap[scope] = {};
                }

                var map = snippetNameMap[scope];
                if (s.name) {
                    var old = map[s.name];
                    if (old)
                        self.unregister(old);
                    map[s.name] = s;
                }
                snippetMap[scope].push(s);

                if (s.tabTrigger && !s.trigger) {
                    if (!s.guard && /^\w/.test(s.tabTrigger))
                        s.guard = "\\b";
                    s.trigger = lang.escapeRegExp(s.tabTrigger);
                }

                if (!s.trigger && !s.guard && !s.endTrigger && !s.endGuard)
                    return;

                s.startRe = guardedRegexp(s.trigger, s.guard, true);
                s.triggerRe = new RegExp(s.trigger, "", true);

                s.endRe = guardedRegexp(s.endTrigger, s.endGuard, true);
                s.endTriggerRe = new RegExp(s.endTrigger, "", true);
            }

            if (snippets && snippets.content)
                addSnippet(snippets);
            else if (Array.isArray(snippets))
                snippets.forEach(addSnippet);

            this._signal("registerSnippets", {scope: scope});
        };
        this.unregister = function (snippets, scope) {
            var snippetMap = this.snippetMap;
            var snippetNameMap = this.snippetNameMap;

            function removeSnippet(s) {
                var nameMap = snippetNameMap[s.scope || scope];
                if (nameMap && nameMap[s.name]) {
                    delete nameMap[s.name];
                    var map = snippetMap[s.scope || scope];
                    var i = map && map.indexOf(s);
                    if (i >= 0)
                        map.splice(i, 1);
                }
            }

            if (snippets.content)
                removeSnippet(snippets);
            else if (Array.isArray(snippets))
                snippets.forEach(removeSnippet);
        };
        this.parseSnippetFile = function (str) {
            str = str.replace(/\r/g, "");
            var list = [], snippet = {};
            var re = /^#.*|^({[\s\S]*})\s*$|^(\S+) (.*)$|^((?:\n*\t.*)+)/gm;
            var m;
            while (m = re.exec(str)) {
                if (m[1]) {
                    try {
                        snippet = JSON.parse(m[1]);
                        list.push(snippet);
                    } catch (e) {
                    }
                }
                if (m[4]) {
                    snippet.content = m[4].replace(/^\t/gm, "");
                    list.push(snippet);
                    snippet = {};
                } else {
                    var key = m[2], val = m[3];
                    if (key == "regex") {
                        var guardRe = /\/((?:[^\/\\]|\\.)*)|$/g;
                        snippet.guard = guardRe.exec(val)[1];
                        snippet.trigger = guardRe.exec(val)[1];
                        snippet.endTrigger = guardRe.exec(val)[1];
                        snippet.endGuard = guardRe.exec(val)[1];
                    } else if (key == "snippet") {
                        snippet.tabTrigger = val.match(/^\S*/)[0];
                        if (!snippet.name)
                            snippet.name = val;
                    } else {
                        snippet[key] = val;
                    }
                }
            }
            return list;
        };
        this.getSnippetByName = function (name, editor) {
            var snippetMap = this.snippetNameMap;
            var snippet;
            this.getActiveScopes(editor).some(function (scope) {
                var snippets = snippetMap[scope];
                if (snippets)
                    snippet = snippets[name];
                return !!snippet;
            }, this);
            return snippet;
        };

    }).call(SnippetManager.prototype);


    var TabstopManager = function (editor) {
        if (editor.tabstopManager)
            return editor.tabstopManager;
        editor.tabstopManager = this;
        this.$onChange = this.onChange.bind(this);
        this.$onChangeSelection = lang.delayedCall(this.onChangeSelection.bind(this)).schedule;
        this.$onChangeSession = this.onChangeSession.bind(this);
        this.$onAfterExec = this.onAfterExec.bind(this);
        this.attach(editor);
    };
    (function () {
        this.attach = function (editor) {
            this.index = 0;
            this.ranges = [];
            this.tabstops = [];
            this.$openTabstops = null;
            this.selectedTabstop = null;

            this.editor = editor;
            this.editor.on("change", this.$onChange);
            this.editor.on("changeSelection", this.$onChangeSelection);
            this.editor.on("changeSession", this.$onChangeSession);
            this.editor.commands.on("afterExec", this.$onAfterExec);
            this.editor.keyBinding.addKeyboardHandler(this.keyboardHandler);
        };
        this.detach = function () {
            this.tabstops.forEach(this.removeTabstopMarkers, this);
            this.ranges = null;
            this.tabstops = null;
            this.selectedTabstop = null;
            this.editor.removeListener("change", this.$onChange);
            this.editor.removeListener("changeSelection", this.$onChangeSelection);
            this.editor.removeListener("changeSession", this.$onChangeSession);
            this.editor.commands.removeListener("afterExec", this.$onAfterExec);
            this.editor.keyBinding.removeKeyboardHandler(this.keyboardHandler);
            this.editor.tabstopManager = null;
            this.editor = null;
        };

        this.onChange = function (delta) {
            var changeRange = delta;
            var isRemove = delta.action[0] == "r";
            var start = delta.start;
            var end = delta.end;
            var startRow = start.row;
            var endRow = end.row;
            var lineDif = endRow - startRow;
            var colDiff = end.column - start.column;

            if (isRemove) {
                lineDif = -lineDif;
                colDiff = -colDiff;
            }
            if (!this.$inChange && isRemove) {
                var ts = this.selectedTabstop;
                var changedOutside = ts && !ts.some(function (r) {
                        return comparePoints(r.start, start) <= 0 && comparePoints(r.end, end) >= 0;
                    });
                if (changedOutside)
                    return this.detach();
            }
            var ranges = this.ranges;
            for (var i = 0; i < ranges.length; i++) {
                var r = ranges[i];
                if (r.end.row < start.row)
                    continue;

                if (isRemove && comparePoints(start, r.start) < 0 && comparePoints(end, r.end) > 0) {
                    this.removeRange(r);
                    i--;
                    continue;
                }

                if (r.start.row == startRow && r.start.column > start.column)
                    r.start.column += colDiff;
                if (r.end.row == startRow && r.end.column >= start.column)
                    r.end.column += colDiff;
                if (r.start.row >= startRow)
                    r.start.row += lineDif;
                if (r.end.row >= startRow)
                    r.end.row += lineDif;

                if (comparePoints(r.start, r.end) > 0)
                    this.removeRange(r);
            }
            if (!ranges.length)
                this.detach();
        };
        this.updateLinkedFields = function () {
            var ts = this.selectedTabstop;
            if (!ts || !ts.hasLinkedRanges)
                return;
            this.$inChange = true;
            var session = this.editor.session;
            var text = session.getTextRange(ts.firstNonLinked);
            for (var i = ts.length; i--;) {
                var range = ts[i];
                if (!range.linked)
                    continue;
                var fmt = exports.snippetManager.tmStrFormat(text, range.original);
                session.replace(range, fmt);
            }
            this.$inChange = false;
        };
        this.onAfterExec = function (e) {
            if (e.command && !e.command.readOnly)
                this.updateLinkedFields();
        };
        this.onChangeSelection = function () {
            if (!this.editor)
                return;
            var lead = this.editor.selection.lead;
            var anchor = this.editor.selection.anchor;
            var isEmpty = this.editor.selection.isEmpty();
            for (var i = this.ranges.length; i--;) {
                if (this.ranges[i].linked)
                    continue;
                var containsLead = this.ranges[i].contains(lead.row, lead.column);
                var containsAnchor = isEmpty || this.ranges[i].contains(anchor.row, anchor.column);
                if (containsLead && containsAnchor)
                    return;
            }
            this.detach();
        };
        this.onChangeSession = function () {
            this.detach();
        };
        this.tabNext = function (dir) {
            var max = this.tabstops.length;
            var index = this.index + (dir || 1);
            index = Math.min(Math.max(index, 1), max);
            if (index == max)
                index = 0;
            this.selectTabstop(index);
            if (index === 0)
                this.detach();
        };
        this.selectTabstop = function (index) {
            this.$openTabstops = null;
            var ts = this.tabstops[this.index];
            if (ts)
                this.addTabstopMarkers(ts);
            this.index = index;
            ts = this.tabstops[this.index];
            if (!ts || !ts.length)
                return;

            this.selectedTabstop = ts;
            if (!this.editor.inVirtualSelectionMode) {
                var sel = this.editor.multiSelect;
                sel.toSingleRange(ts.firstNonLinked.clone());
                for (var i = ts.length; i--;) {
                    if (ts.hasLinkedRanges && ts[i].linked)
                        continue;
                    sel.addRange(ts[i].clone(), true);
                }
                // todo investigate why is this needed
                if (sel.ranges[0])
                    sel.addRange(sel.ranges[0].clone());
            } else {
                this.editor.selection.setRange(ts.firstNonLinked);
            }

            this.editor.keyBinding.addKeyboardHandler(this.keyboardHandler);
        };
        this.addTabstops = function (tabstops, start, end) {
            if (!this.$openTabstops)
                this.$openTabstops = [];
            // add final tabstop if missing
            if (!tabstops[0]) {
                var p = Range.fromPoints(end, end);
                moveRelative(p.start, start);
                moveRelative(p.end, start);
                tabstops[0] = [p];
                tabstops[0].index = 0;
            }

            var i = this.index;
            var arg = [i + 1, 0];
            var ranges = this.ranges;
            tabstops.forEach(function (ts, index) {
                var dest = this.$openTabstops[index] || ts;

                for (var i = ts.length; i--;) {
                    var p = ts[i];
                    var range = Range.fromPoints(p.start, p.end || p.start);
                    movePoint(range.start, start);
                    movePoint(range.end, start);
                    range.original = p;
                    range.tabstop = dest;
                    ranges.push(range);
                    if (dest != ts)
                        dest.unshift(range);
                    else
                        dest[i] = range;
                    if (p.fmtString) {
                        range.linked = true;
                        dest.hasLinkedRanges = true;
                    } else if (!dest.firstNonLinked)
                        dest.firstNonLinked = range;
                }
                if (!dest.firstNonLinked)
                    dest.hasLinkedRanges = false;
                if (dest === ts) {
                    arg.push(dest);
                    this.$openTabstops[index] = dest;
                }
                this.addTabstopMarkers(dest);
            }, this);

            if (arg.length > 2) {
                // when adding new snippet inside existing one, make sure 0 tabstop is at the end
                if (this.tabstops.length)
                    arg.push(arg.splice(2, 1)[0]);
                this.tabstops.splice.apply(this.tabstops, arg);
            }
        };

        this.addTabstopMarkers = function (ts) {
            var session = this.editor.session;
            ts.forEach(function (range) {
                if (!range.markerId)
                    range.markerId = session.addMarker(range, "ace_snippet-marker", "text");
            });
        };
        this.removeTabstopMarkers = function (ts) {
            var session = this.editor.session;
            ts.forEach(function (range) {
                session.removeMarker(range.markerId);
                range.markerId = null;
            });
        };
        this.removeRange = function (range) {
            var i = range.tabstop.indexOf(range);
            range.tabstop.splice(i, 1);
            i = this.ranges.indexOf(range);
            this.ranges.splice(i, 1);
            this.editor.session.removeMarker(range.markerId);
            if (!range.tabstop.length) {
                i = this.tabstops.indexOf(range.tabstop);
                if (i != -1)
                    this.tabstops.splice(i, 1);
                if (!this.tabstops.length)
                    this.detach();
            }
        };

        this.keyboardHandler = new HashHandler();
        this.keyboardHandler.bindKeys({
            "Tab": function (ed) {
                if (exports.snippetManager && exports.snippetManager.expandWithTab(ed)) {
                    return;
                }

                ed.tabstopManager.tabNext(1);
            },
            "Shift-Tab": function (ed) {
                ed.tabstopManager.tabNext(-1);
            },
            "Esc": function (ed) {
                ed.tabstopManager.detach();
            },
            "Return": function (ed) {
                //ed.tabstopManager.tabNext(1);
                return false;
            }
        });
    }).call(TabstopManager.prototype);


    var changeTracker = {};
    changeTracker.onChange = Anchor.prototype.onChange;
    changeTracker.setPosition = function (row, column) {
        this.pos.row = row;
        this.pos.column = column;
    };
    changeTracker.update = function (pos, delta, $insertRight) {
        this.$insertRight = $insertRight;
        this.pos = pos;
        this.onChange(delta);
    };

    var movePoint = function (point, diff) {
        if (point.row == 0)
            point.column += diff.column;
        point.row += diff.row;
    };

    var moveRelative = function (point, start) {
        if (point.row == start.row)
            point.column -= start.column;
        point.row -= start.row;
    };


    require("./lib/dom").importCssString("\
.ace_snippet-marker {\
    -moz-box-sizing: border-box;\
    box-sizing: border-box;\
    background: rgba(194, 193, 208, 0.09);\
    border: 1px dotted rgba(211, 208, 235, 0.62);\
    position: absolute;\
}");

    exports.snippetManager = new SnippetManager();


    var Editor = require("./editor").Editor;
    (function () {
        this.insertSnippet = function (content, options) {
            return exports.snippetManager.insertSnippet(this, content, options);
        };
        this.expandSnippet = function (options) {
            return exports.snippetManager.expandWithTab(this, options);
        };
    }).call(Editor.prototype);

});
