/* vim:ts=4:sts=4:sw=4:
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 * 
 * The Original Code is Ajax.org Code Editor (ACE).
 *
 * The Initial Developer of the Original Code is
 * Ajax.org B.V.
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *      Fabian Jakobs <fabian AT ajax DOT org>
 *      Irakli Gozalishvili <rfobic@gmail.com> (http://jeditoolkit.com)
 *      Julian Viereck <julian.viereck@gmail.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

define(function(require, exports, module) {

require("pilot/fixoldbrowsers");

var oop = require("pilot/oop");
var event = require("pilot/event");
var lang = require("pilot/lang");
var useragent = require("pilot/useragent");
var TextInput = require("ace/keyboard/textinput").TextInput;
var MouseHandler = require("ace/mouse/mouse_handler").MouseHandler;
//var TouchHandler = require("ace/touch_handler").TouchHandler;
var KeyBinding = require("ace/keyboard/keybinding").KeyBinding;
var EditSession = require("ace/edit_session").EditSession;
var Search = require("ace/search").Search;
var Range = require("ace/range").Range;
var EventEmitter = require("pilot/event_emitter").EventEmitter;

var Editor =function(renderer, session) {
    var container = renderer.getContainerElement();
    this.container = container;
    this.renderer = renderer;
    
    this.textInput = new TextInput(renderer.getTextAreaContainer(), this);
    this.keyBinding = new KeyBinding(this);

    // TODO detect touch event support
    if (useragent.isIPad) {
        //this.$mouseHandler = new TouchHandler(this);
    } else {
        this.$mouseHandler = new MouseHandler(this);
    }

    this.$blockScrolling = 0;
    this.$search = new Search().set({
        wrap: true
    });

    this.setSession(session || new EditSession(""));
};

(function(){

    oop.implement(this, EventEmitter);

    this.$forwardEvents = {
        gutterclick: 1,
        gutterdblclick: 1
    };

    this.$originalAddEventListener = this.addEventListener;
    this.$originalRemoveEventListener = this.removeEventListener;

    this.addEventListener = function(eventName, callback) {
        if (this.$forwardEvents[eventName]) {
            return this.renderer.addEventListener(eventName, callback);
        } else {
            return this.$originalAddEventListener(eventName, callback);
        }
    };

    this.removeEventListener = function(eventName, callback) {
        if (this.$forwardEvents[eventName]) {
            return this.renderer.removeEventListener(eventName, callback);
        } else {
            return this.$originalRemoveEventListener(eventName, callback);
        }
    };

    this.setKeyboardHandler = function(keyboardHandler) {
        this.keyBinding.setKeyboardHandler(keyboardHandler);
    };

    this.getKeyboardHandler = function() {
        return this.keyBinding.getKeyboardHandler();
    };

    this.setSession = function(session) {
        if (this.session == session)
            return;

        if (this.session) {
            var oldSession = this.session;
            this.session.removeEventListener("change", this.$onDocumentChange);
            this.session.removeEventListener("changeMode", this.$onChangeMode);
            this.session.removeEventListener("tokenizerUpdate", this.$onTokenizerUpdate);
            this.session.removeEventListener("changeTabSize", this.$onChangeTabSize);
            this.session.removeEventListener("changeWrapLimit", this.$onChangeWrapLimit);
            this.session.removeEventListener("changeWrapMode", this.$onChangeWrapMode);
            this.session.removeEventListener("onChangeFold", this.$onChangeFold);
            this.session.removeEventListener("changeFrontMarker", this.$onChangeFrontMarker);
            this.session.removeEventListener("changeBackMarker", this.$onChangeBackMarker);
            this.session.removeEventListener("changeBreakpoint", this.$onChangeBreakpoint);
            this.session.removeEventListener("changeAnnotation", this.$onChangeAnnotation);
            this.session.removeEventListener("changeOverwrite", this.$onCursorChange);

            var selection = this.session.getSelection();
            selection.removeEventListener("changeCursor", this.$onCursorChange);
            selection.removeEventListener("changeSelection", this.$onSelectionChange);

            this.session.setScrollTopRow(this.renderer.getScrollTopRow());
        }

        this.session = session;

        this.$onDocumentChange = this.onDocumentChange.bind(this);
        session.addEventListener("change", this.$onDocumentChange);
        this.renderer.setSession(session);

        this.$onChangeMode = this.onChangeMode.bind(this);
        session.addEventListener("changeMode", this.$onChangeMode);

        this.$onTokenizerUpdate = this.onTokenizerUpdate.bind(this);
        session.addEventListener("tokenizerUpdate", this.$onTokenizerUpdate);

        this.$onChangeTabSize = this.renderer.updateText.bind(this.renderer);
        session.addEventListener("changeTabSize", this.$onChangeTabSize);

        this.$onChangeWrapLimit = this.onChangeWrapLimit.bind(this);
        session.addEventListener("changeWrapLimit", this.$onChangeWrapLimit);

        this.$onChangeWrapMode = this.onChangeWrapMode.bind(this);
        session.addEventListener("changeWrapMode", this.$onChangeWrapMode);

        this.$onChangeFold = this.onChangeFold.bind(this);
        session.addEventListener("changeFold", this.$onChangeFold);

        this.$onChangeFrontMarker = this.onChangeFrontMarker.bind(this);
        this.session.addEventListener("changeFrontMarker", this.$onChangeFrontMarker);

        this.$onChangeBackMarker = this.onChangeBackMarker.bind(this);
        this.session.addEventListener("changeBackMarker", this.$onChangeBackMarker);

        this.$onChangeBreakpoint = this.onChangeBreakpoint.bind(this);
        this.session.addEventListener("changeBreakpoint", this.$onChangeBreakpoint);

        this.$onChangeAnnotation = this.onChangeAnnotation.bind(this);
        this.session.addEventListener("changeAnnotation", this.$onChangeAnnotation);

        this.$onCursorChange = this.onCursorChange.bind(this);
        this.session.addEventListener("changeOverwrite", this.$onCursorChange);

        this.selection = session.getSelection();
        this.selection.addEventListener("changeCursor", this.$onCursorChange);

        this.$onSelectionChange = this.onSelectionChange.bind(this);
        this.selection.addEventListener("changeSelection", this.$onSelectionChange);

        this.onChangeMode();

        this.onCursorChange();
        this.onSelectionChange();
        this.onChangeFrontMarker();
        this.onChangeBackMarker();
        this.onChangeBreakpoint();
        this.onChangeAnnotation();
        this.session.getUseWrapMode() && this.renderer.adjustWrapLimit();
        this.renderer.scrollToRow(session.getScrollTopRow());
        this.renderer.updateFull();

        this._dispatchEvent("changeSession", {
            session: session,
            oldSession: oldSession
        });
    };

    this.getSession = function() {
        return this.session;
    };

    this.getSelection = function() {
        return this.selection;
    };

    this.resize = function() {
        this.renderer.onResize();
    };

    this.setTheme = function(theme) {
        this.renderer.setTheme(theme);
    };

    this.getTheme = function() {
        return this.renderer.getTheme();
    };

    this.setStyle = function(style) {
        this.renderer.setStyle(style);
    };

    this.unsetStyle = function(style) {
        this.renderer.unsetStyle(style);
    };

    this.setFontSize = function(size) {
        this.container.style.fontSize = size;
    };

    this.$highlightBrackets = function() {
        if (this.session.$bracketHighlight) {
            this.session.removeMarker(this.session.$bracketHighlight);
            this.session.$bracketHighlight = null;
        }

        if (this.$highlightPending) {
            return;
        }

        // perform highlight async to not block the browser during navigation
        var self = this;
        this.$highlightPending = true;
        setTimeout(function() {
            self.$highlightPending = false;

            var pos = self.session.findMatchingBracket(self.getCursorPosition());
            if (pos) {
                var range = new Range(pos.row, pos.column, pos.row, pos.column+1);
                self.session.$bracketHighlight = self.session.addMarker(range, "ace_bracket", "text");
            }
        }, 10);
    };

    this.focus = function() {
        // Safari needs the timeout
        // iOS and Firefox need it called immediately
        // to be on the save side we do both
        var _self = this;
        setTimeout(function() {
            _self.textInput.focus();
        });
        this.textInput.focus();
    };

    this.isFocused = function() {
        return this.textInput.isFocused();
    };

    this.blur = function() {
        this.textInput.blur();
    };

    this.onFocus = function() {
        this.renderer.showCursor();
        this.renderer.visualizeFocus();
        this._dispatchEvent("focus");
    };

    this.onBlur = function() {
        this.renderer.hideCursor();
        this.renderer.visualizeBlur();
        this._dispatchEvent("blur");
    };

    this.onDocumentChange = function(e) {
        var delta = e.data;
        var range = delta.range;

        if (range.start.row == range.end.row && delta.action != "insertLines" && delta.action != "removeLines")
            var lastRow = range.end.row;
        else
            lastRow = Infinity;
        this.renderer.updateLines(range.start.row, lastRow);

        this._dispatchEvent("change", e);

        // update cursor because tab characters can influence the cursor position
        this.renderer.updateCursor();
    };

    this.onTokenizerUpdate = function(e) {
        var rows = e.data;
        this.renderer.updateLines(rows.first, rows.last);
    };

    this.onCursorChange = function(e) {
        this.renderer.updateCursor();

        if (!this.$blockScrolling) {
            this.renderer.scrollCursorIntoView();
        }

        // move text input over the cursor
        // this is required for iOS and IME
        this.renderer.moveTextAreaToCursor(this.textInput.getElement());

        this.$highlightBrackets();
        this.$updateHighlightActiveLine();
    };

    this.$updateHighlightActiveLine = function() {
        var session = this.getSession();

        if (session.$highlightLineMarker) {
            session.removeMarker(session.$highlightLineMarker);
        }
        session.$highlightLineMarker = null;

        if (this.getHighlightActiveLine() && (this.getSelectionStyle() != "line" || !this.selection.isMultiLine())) {
            var cursor = this.getCursorPosition(),
                foldLine = this.session.getFoldLine(cursor.row);
            var range;
            if (foldLine) {
                range = new Range(foldLine.start.row, 0, foldLine.end.row + 1, 0);
            } else {
                range = new Range(cursor.row, 0, cursor.row+1, 0);
            }
            session.$highlightLineMarker = session.addMarker(range, "ace_active_line", "background");
        }
    };

    this.onSelectionChange = function(e) {
        var session = this.getSession();

        if (session.$selectionMarker) {
            session.removeMarker(session.$selectionMarker);
        }
        session.$selectionMarker = null;

        if (!this.selection.isEmpty()) {
            var range = this.selection.getRange();
            var style = this.getSelectionStyle();
            session.$selectionMarker = session.addMarker(range, "ace_selection", style);
        } else {
            this.$updateHighlightActiveLine();
        }

        if (this.$highlightSelectedWord)
            this.session.getMode().highlightSelection(this);
    };

    this.onChangeFrontMarker = function() {
        this.renderer.updateFrontMarkers();
    };

    this.onChangeBackMarker = function() {
        this.renderer.updateBackMarkers();
    };

    this.onChangeBreakpoint = function() {
        this.renderer.setBreakpoints(this.session.getBreakpoints());
    };

    this.onChangeAnnotation = function() {
        this.renderer.setAnnotations(this.session.getAnnotations());
    };

    this.onChangeMode = function() {
        this.renderer.updateText();
    };

    this.onChangeWrapLimit = function() {
        this.renderer.updateFull();
    };

    this.onChangeWrapMode = function() {
        this.renderer.onResize(true);
    };

    this.onChangeFold = function() {
        // Update the active line marker as due to folding changes the current
        // line range on the screen might have changed.
        this.$updateHighlightActiveLine();
        // TODO: This might be too much updating. Okay for now.
        this.renderer.updateFull();
    };

    this.getCopyText = function() {
        var text = "";
        if (!this.selection.isEmpty())
            text = this.session.getTextRange(this.getSelectionRange());

        this._emit("copy", text);
        return text;
    };

    this.onCut = function() {
        if (this.$readOnly)
            return;

        var range = this.getSelectionRange();
        this._emit("cut", range);

        if (!this.selection.isEmpty()) {
            this.session.remove(range);
            this.clearSelection();
        }
    };

    this.insert = function(text) {
        if (this.$readOnly)
            return;

        var session = this.session;
        var mode = session.getMode();

        var cursor = this.getCursorPosition();

        if (this.getBehavioursEnabled()) {
            // Get a transform if the current mode wants one.
            var transform = mode.transformAction(session.getState(cursor.row), 'insertion', this, session, text);
            if (transform)
                text = transform.text;
        }

        text = text.replace("\t", this.session.getTabString());

        // remove selected text
        if (!this.selection.isEmpty()) {
            var cursor = this.session.remove(this.getSelectionRange());
            this.clearSelection();
        }
        else if (this.session.getOverwrite()) {
            var range = new Range.fromPoints(cursor, cursor);
            range.end.column += text.length;
            this.session.remove(range);
        }

        this.clearSelection();

        var start = cursor.column;
        var lineState = session.getState(cursor.row);
        var shouldOutdent = mode.checkOutdent(lineState, session.getLine(cursor.row), text);
        var line = session.getLine(cursor.row);
        var lineIndent = mode.getNextLineIndent(lineState, line.slice(0, cursor.column), session.getTabString());
        var end = session.insert(cursor, text);

        if (transform && transform.selection) {
            if (transform.selection.length == 2) { // Transform relative to the current column
                this.selection.setSelectionRange(
                    new Range(cursor.row, start + transform.selection[0],
                              cursor.row, start + transform.selection[1]));
            } else { // Transform relative to the current row.
                this.selection.setSelectionRange(
                    new Range(cursor.row + transform.selection[0],
                              transform.selection[1],
                              cursor.row + transform.selection[2],
                              transform.selection[3]));
            }
        }

        var lineState = session.getState(cursor.row);

        // TODO disabled multiline auto indent
        // possibly doing the indent before inserting the text
        // if (cursor.row !== end.row) {
        if (session.getDocument().isNewLine(text)) {
            this.moveCursorTo(cursor.row+1, 0);

            var size = session.getTabSize();
            var minIndent = Number.MAX_VALUE;

            for (var row = cursor.row + 1; row <= end.row; ++row) {
                var indent = 0;

                line = session.getLine(row);
                for (var i = 0; i < line.length; ++i)
                    if (line.charAt(i) == '\t')
                        indent += size;
                    else if (line.charAt(i) == ' ')
                        indent += 1;
                    else
                        break;
                if (/[^\s]/.test(line))
                    minIndent = Math.min(indent, minIndent);
            }

            for (var row = cursor.row + 1; row <= end.row; ++row) {
                var outdent = minIndent;

                line = session.getLine(row);
                for (var i = 0; i < line.length && outdent > 0; ++i)
                    if (line.charAt(i) == '\t')
                        outdent -= size;
                    else if (line.charAt(i) == ' ')
                        outdent -= 1;
                session.remove(new Range(row, 0, row, i));
            }
            session.indentRows(cursor.row + 1, end.row, lineIndent);
        }
        if (shouldOutdent)
            mode.autoOutdent(lineState, session, cursor.row);
    };

    this.onTextInput = function(text, notPasted) {
        if (!notPasted)
            this._emit("paste", text);

        // In case the text was not pasted and we got only one character, then
        // handel it as a command key stroke.
        if (notPasted && text.length == 1) {
            // Note: The `null` as `keyCode` is important here, as there are
            // some checks in the code for `keyCode == 0` meaning the text comes
            // from the keyBinding.onTextInput code path.
            var handled = this.keyBinding.onCommandKey({}, 0, null, text);

            // Check if the text was handled. If not, then handled it as "normal"
            // text and insert it to the editor directly. This shouldn't be done
            // using the this.keyBinding.onTextInput(text) function, as it would
            // make the `text` get sent to the keyboardHandler twice, which might
            // turn out to be a bad thing in case there is a custome keyboard
            // handler like the StateHandler.
            if (!handled) {
                this.insert(text);
            }
        } else {
            this.keyBinding.onTextInput(text);
        }
    };

    this.onCommandKey = function(e, hashId, keyCode) {
        this.keyBinding.onCommandKey(e, hashId, keyCode);
    };

    this.setOverwrite = function(overwrite) {
        this.session.setOverwrite(overwrite);
    };

    this.getOverwrite = function() {
        return this.session.getOverwrite();
    };

    this.toggleOverwrite = function() {
        this.session.toggleOverwrite();
    };

    this.setScrollSpeed = function(speed) {
        this.$mouseHandler.setScrollSpeed(speed);
    };

    this.getScrollSpeed = function() {
        return this.$mouseHandler.getScrollSpeed()
    };

    this.$selectionStyle = "line";
    this.setSelectionStyle = function(style) {
        if (this.$selectionStyle == style) return;

        this.$selectionStyle = style;
        this.onSelectionChange();
        this._dispatchEvent("changeSelectionStyle", {data: style});
    };

    this.getSelectionStyle = function() {
        return this.$selectionStyle;
    };

    this.$highlightActiveLine = true;
    this.setHighlightActiveLine = function(shouldHighlight) {
        if (this.$highlightActiveLine == shouldHighlight) return;

        this.$highlightActiveLine = shouldHighlight;
        this.$updateHighlightActiveLine();
    };

    this.getHighlightActiveLine = function() {
        return this.$highlightActiveLine;
    };

    this.$highlightSelectedWord = true;
    this.setHighlightSelectedWord = function(shouldHighlight) {
        if (this.$highlightSelectedWord == shouldHighlight)
            return;

        this.$highlightSelectedWord = shouldHighlight;
        if (shouldHighlight)
            this.session.getMode().highlightSelection(this);
        else
            this.session.getMode().clearSelectionHighlight(this);
    };

    this.getHighlightSelectedWord = function() {
        return this.$highlightSelectedWord;
    };

    this.setShowInvisibles = function(showInvisibles) {
        if (this.getShowInvisibles() == showInvisibles)
            return;

        this.renderer.setShowInvisibles(showInvisibles);
    };

    this.getShowInvisibles = function() {
        return this.renderer.getShowInvisibles();
    };

    this.setShowPrintMargin = function(showPrintMargin) {
        this.renderer.setShowPrintMargin(showPrintMargin);
    };

    this.getShowPrintMargin = function() {
        return this.renderer.getShowPrintMargin();
    };

    this.setPrintMarginColumn = function(showPrintMargin) {
        this.renderer.setPrintMarginColumn(showPrintMargin);
    };

    this.getPrintMarginColumn = function() {
        return this.renderer.getPrintMarginColumn();
    };

    this.$readOnly = false;
    this.setReadOnly = function(readOnly) {
        this.$readOnly = readOnly;
    };

    this.getReadOnly = function() {
        return this.$readOnly;
    };

    this.$modeBehaviours = true;
    this.setBehavioursEnabled = function (enabled) {
        this.$modeBehaviours = enabled;
    };

    this.getBehavioursEnabled = function () {
        return this.$modeBehaviours;
    };

    this.remove = function(dir) {
        if (this.$readOnly)
            return;

        if (this.selection.isEmpty()){
            if (dir == "left")
                this.selection.selectLeft();
            else
                this.selection.selectRight();
        }

        var range = this.getSelectionRange();
        if (this.getBehavioursEnabled()) {
            var session = this.session;
            var state = session.getState(range.start.row);
            var new_range = session.getMode().transformAction(state, 'deletion', this, session, range);
            if (new_range)
                range = new_range;
        }

        this.session.remove(range);
        this.clearSelection();
    };

    this.removeWordRight = function() {
        if (this.$readOnly)
            return;

        if (this.selection.isEmpty())
            this.selection.selectWordRight();

        this.session.remove(this.getSelectionRange());
        this.clearSelection();
    };

    this.removeWordLeft = function() {
        if (this.$readOnly)
            return;

        if (this.selection.isEmpty())
            this.selection.selectWordLeft();

        this.session.remove(this.getSelectionRange());
        this.clearSelection();
    };

    this.removeToLineStart = function() {
        if (this.$readOnly)
            return;

        if (this.selection.isEmpty())
            this.selection.selectLineStart();

        this.session.remove(this.getSelectionRange());
        this.clearSelection();
    };

    this.removeToLineEnd = function() {
        if (this.$readOnly)
            return;

        if (this.selection.isEmpty())
            this.selection.selectLineEnd();

        var range = this.getSelectionRange();
        if (range.start.column == range.end.column && range.start.row == range.end.row) {
            range.end.column = 0;
            range.end.row++;
        }

        this.session.remove(range);
        this.clearSelection();
    };

    this.splitLine = function() {
        if (this.$readOnly)
            return;

        if (!this.selection.isEmpty()) {
            this.session.remove(this.getSelectionRange());
            this.clearSelection();
        }

        var cursor = this.getCursorPosition();
        this.insert("\n");
        this.moveCursorToPosition(cursor);
    };

    this.transposeLetters = function() {
        if (this.$readOnly)
            return;

        if (!this.selection.isEmpty()) {
            return;
        }

        var cursor = this.getCursorPosition();
        var column = cursor.column;
        if (column === 0)
            return;

        var line = this.session.getLine(cursor.row);
        var swap, range;
        if (column < line.length) {
            swap = line.charAt(column) + line.charAt(column-1);
            range = new Range(cursor.row, column-1, cursor.row, column+1);
        }
        else {
            swap = line.charAt(column-1) + line.charAt(column-2);
            range = new Range(cursor.row, column-2, cursor.row, column);
        }
        this.session.replace(range, swap);
    };

    this.indent = function() {
        if (this.$readOnly)
            return;

        var session = this.session;
        var range = this.getSelectionRange();

        if (range.start.row < range.end.row || range.start.column < range.end.column) {
            var rows = this.$getSelectedRows();
            session.indentRows(rows.first, rows.last, "\t");
        } else {
            var indentString;

            if (this.session.getUseSoftTabs()) {
                var size = session.getTabSize(),
                    position = this.getCursorPosition(),
                    column = session.documentToScreenColumn(position.row, position.column),
                    count = (size - column % size);

                indentString = lang.stringRepeat(" ", count);
            } else
                indentString = "\t";
            return this.onTextInput(indentString);
        }
    };

    this.blockOutdent = function() {
        if (this.$readOnly)
            return;

        var selection = this.session.getSelection();
        this.session.outdentRows(selection.getRange());
    };

    this.toggleCommentLines = function() {
        if (this.$readOnly)
            return;

        var state = this.session.getState(this.getCursorPosition().row);
        var rows = this.$getSelectedRows();
        this.session.getMode().toggleCommentLines(state, this.session, rows.first, rows.last);
    };

    this.removeLines = function() {
        if (this.$readOnly)
            return;

        var rows = this.$getSelectedRows();
        var range;
        if (rows.last == 0 || rows.last+1 < this.session.getLength())
            range = new Range(rows.first, 0, rows.last+1, 0);
        else
            range = new Range(
                rows.first-1, this.session.getLine(rows.first-1).length,
                rows.last, this.session.getLine(rows.last).length
            );
        this.session.remove(range);
        this.clearSelection();
    };

    this.moveLinesDown = function() {
        if (this.$readOnly)
            return;

        this.$moveLines(function(firstRow, lastRow) {
            return this.session.moveLinesDown(firstRow, lastRow);
        });
    };

    this.moveLinesUp = function() {
        if (this.$readOnly)
            return;

        this.$moveLines(function(firstRow, lastRow) {
            return this.session.moveLinesUp(firstRow, lastRow);
        });
    };

    this.moveText = function(range, toPosition) {
        if (this.$readOnly)
            return null;

        return this.session.moveText(range, toPosition);
    };

    this.copyLinesUp = function() {
        if (this.$readOnly)
            return;

        this.$moveLines(function(firstRow, lastRow) {
            this.session.duplicateLines(firstRow, lastRow);
            return 0;
        });
    };

    this.copyLinesDown = function() {
        if (this.$readOnly)
            return;

        this.$moveLines(function(firstRow, lastRow) {
            return this.session.duplicateLines(firstRow, lastRow);
        });
    };


    this.$moveLines = function(mover) {
        var rows = this.$getSelectedRows();

        var linesMoved = mover.call(this, rows.first, rows.last);

        var selection = this.selection;
        selection.setSelectionAnchor(rows.last+linesMoved+1, 0);
        selection.$moveSelection(function() {
            selection.moveCursorTo(rows.first+linesMoved, 0);
        });
    };

    this.$getSelectedRows = function() {
        var range = this.getSelectionRange().collapseRows();

        return {
            first: range.start.row,
            last: range.end.row
        };
    };

    this.onCompositionStart = function(text) {
        this.renderer.showComposition(this.getCursorPosition());
    };

    this.onCompositionUpdate = function(text) {
        this.renderer.setCompositionText(text);
    };

    this.onCompositionEnd = function() {
        this.renderer.hideComposition();
    };

    this.getFirstVisibleRow = function() {
        return this.renderer.getFirstVisibleRow();
    };

    this.getLastVisibleRow = function() {
        return this.renderer.getLastVisibleRow();
    };

    this.isRowVisible = function(row) {
        return (row >= this.getFirstVisibleRow() && row <= this.getLastVisibleRow());
    };

    this.$getVisibleRowCount = function() {
        return this.renderer.getScrollBottomRow() - this.renderer.getScrollTopRow() + 1;
    };

    this.$getTabDownRow = function() {
        return this.renderer.getScrollBottomRow();
    };

    this.$getTabUpRow = function() {
        var firstRow = this.renderer.getScrollTopRow();
        var lastRow = this.renderer.getScrollBottomRow();

        return firstRow - (lastRow - firstRow);
    };

    this.selectTabDown = function() {
        var row = this.$getTabDownRow() + Math.floor(this.$getVisibleRowCount() / 2);

        this.scrollTabDown();

        var selection = this.getSelection();
        var leadScreenPos = this.session.documentToScreenPosition(selection.getSelectionLead());
        var dest = this.session.screenToDocumentPosition(row, leadScreenPos.column);
        selection.selectTo(dest.row, dest.column);
    };

    this.selectTabUp = function() {
        var visibleRows = this.renderer.getScrollTopRow() - this.renderer.getScrollBottomRow();
        var row = this.$getTabUpRow() + Math.round(visibleRows / 2);

        this.scrollTabUp();

        var selection = this.getSelection();
        var leadScreenPos = this.session.documentToScreenPosition(selection.getSelectionLead());
        var dest = this.session.screenToDocumentPosition(row, leadScreenPos.column);
        selection.selectTo(dest.row, dest.column);
    };

    this.gotoTabDown = function() {
        var row = this.$getTabDownRow();
        var column = this.getCursorPositionScreen().column;

        this.scrollToRow(row);
        this.getSelection().moveCursorToScreen(row, column);
    };

    this.gotoTabUp = function() {
        var row = this.$getTabUpRow();
        var column = this.getCursorPositionScreen().column;

       this.scrollToRow(row);
       this.getSelection().moveCursorToScreen(row, column);
    };

    this.scrollTabDown = function() {
        this.scrollToRow(this.$getTabDownRow());
    };

    this.scrollTabUp = function() {
        this.renderer.scrollToRow(this.$getTabUpRow());
    };

    this.scrollToRow = function(row) {
        this.renderer.scrollToRow(row);
    };

    this.scrollToLine = function(line, center) {
        this.renderer.scrollToLine(line, center);
    };

    this.centerSelection = function() {
        var range = this.getSelectionRange();
        var line = Math.floor(range.start.row + (range.end.row - range.start.row) / 2);
        this.renderer.scrollToLine(line, true);
    };

    this.getCursorPosition = function() {
        return this.selection.getCursor();
    };

    this.getCursorPositionScreen = function() {
        return this.session.documentToScreenPosition(this.getCursorPosition());
    };

    this.getSelectionRange = function() {
        return this.selection.getRange();
    };


    this.selectAll = function() {
        this.$blockScrolling += 1;
        this.selection.selectAll();
        this.$blockScrolling -= 1;
    };

    this.clearSelection = function() {
        this.selection.clearSelection();
    };

    this.moveCursorTo = function(row, column) {
        this.selection.moveCursorTo(row, column);
    };

    this.moveCursorToPosition = function(pos) {
        this.selection.moveCursorToPosition(pos);
    };


    this.gotoLine = function(lineNumber, column) {
        this.selection.clearSelection();

        this.$blockScrolling += 1;
        this.moveCursorTo(lineNumber-1, column || 0);
        this.$blockScrolling -= 1;

        if (!this.isRowVisible(this.getCursorPosition().row)) {
            this.scrollToLine(lineNumber, true);
        }
    };

    this.navigateTo = function(row, column) {
        this.clearSelection();
        this.moveCursorTo(row, column);
    };

    this.navigateUp = function(times) {
        this.selection.clearSelection();
        times = times || 1;
        this.selection.moveCursorBy(-times, 0);
    };

    this.navigateDown = function(times) {
        this.selection.clearSelection();
        times = times || 1;
        this.selection.moveCursorBy(times, 0);
    };

    this.navigateLeft = function(times) {
        if (!this.selection.isEmpty()) {
            var selectionStart = this.getSelectionRange().start;
            this.moveCursorToPosition(selectionStart);
        }
        else {
            times = times || 1;
            while (times--) {
                this.selection.moveCursorLeft();
            }
        }
        this.clearSelection();
    };

    this.navigateRight = function(times) {
        if (!this.selection.isEmpty()) {
            var selectionEnd = this.getSelectionRange().end;
            this.moveCursorToPosition(selectionEnd);
        }
        else {
            times = times || 1;
            while (times--) {
                this.selection.moveCursorRight();
            }
        }
        this.clearSelection();
    };

    this.navigateLineStart = function() {
        this.selection.moveCursorLineStart();
        this.clearSelection();
    };

    this.navigateLineEnd = function() {
        this.selection.moveCursorLineEnd();
        this.clearSelection();
    };

    this.navigateFileEnd = function() {
        this.selection.moveCursorFileEnd();
        this.clearSelection();
    };

    this.navigateFileStart = function() {
        this.selection.moveCursorFileStart();
        this.clearSelection();
    };

    this.navigateWordRight = function() {
        this.selection.moveCursorWordRight();
        this.clearSelection();
    };

    this.navigateWordLeft = function() {
        this.selection.moveCursorWordLeft();
        this.clearSelection();
    };

    this.replace = function(replacement, options) {
        if (options)
            this.$search.set(options);

        var range = this.$search.find(this.session);
        if (!range)
            return;

        this.$tryReplace(range, replacement);
        if (range !== null)
            this.selection.setSelectionRange(range);
    };

    this.replaceAll = function(replacement, options) {
        if (options) {
            this.$search.set(options);
        }

        var ranges = this.$search.findAll(this.session);
        if (!ranges.length)
            return;

        var selection = this.getSelectionRange();
        this.clearSelection();
        this.selection.moveCursorTo(0, 0);

        this.$blockScrolling += 1;
        for (var i = ranges.length - 1; i >= 0; --i)
            this.$tryReplace(ranges[i], replacement);

        this.selection.setSelectionRange(selection);
        this.$blockScrolling -= 1;
    };

    this.$tryReplace = function(range, replacement) {
        var input = this.session.getTextRange(range);
        replacement = this.$search.replace(input, replacement);
        if (replacement !== null) {
            range.end = this.session.replace(range, replacement);
            return range;
        } else {
            return null;
        }
    };

    this.getLastSearchOptions = function() {
        return this.$search.getOptions();
    };

    this.find = function(needle, options) {
        this.clearSelection();
        options = options || {};
        options.needle = needle;
        this.$search.set(options);
        this.$find();
    };

    this.findNext = function(options) {
        options = options || {};
        if (typeof options.backwards == "undefined")
            options.backwards = false;
        this.$search.set(options);
        this.$find();
    };

    this.findPrevious = function(options) {
        options = options || {};
        if (typeof options.backwards == "undefined")
            options.backwards = true;
        this.$search.set(options);
        this.$find();
    };

    this.$find = function(backwards) {
        if (!this.selection.isEmpty()) {
            this.$search.set({needle: this.session.getTextRange(this.getSelectionRange())});
        }

        if (typeof backwards != "undefined")
            this.$search.set({backwards: backwards});

        var range = this.$search.find(this.session);
        if (range) {
            this.gotoLine(range.end.row+1, range.end.column);
            this.selection.setSelectionRange(range);
        }
    };

    this.undo = function() {
        this.session.getUndoManager().undo();
    };

    this.redo = function() {
        this.session.getUndoManager().redo();
    };

    this.destroy = function() {
        this.renderer.destroy();
    };

}).call(Editor.prototype);


exports.Editor = Editor;
});