/* 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):
 *      Harutyun Amirjanyan <amirjanyan AT gmail DOT 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) {

var RangeList = require("./range_list").RangeList;
var Range = require("./range").Range;
var Selection = require("./selection").Selection;
var onMouseDown = require("./mouse/multi_select_handler").onMouseDown;
var event = require("./lib/event");
var commands = require("./commands/multi_select_commands");
exports.commands = commands.defaultCommands.concat(commands.multiSelectCommands);

// Todo: session.find or editor.findVolatile that returns range
var Search = require("./search").Search;
var search = new Search();

function find(session, needle, dir) {
    search.$options.wrap = true;
    search.$options.needle = needle;
    search.$options.backwards = dir == -1;
    return search.find(session);
}

// extend EditSession
var EditSession = require("./edit_session").EditSession;
(function() {
    this.getSelectionMarkers = function() {
        return this.$selectionMarkers;
    };
}).call(EditSession.prototype);

// extend Selection
(function() {
    // list of ranges in reverse addition order
    this.ranges = null;

    // automatically sorted list of ranges
    this.rangeList = null;

    /** extension
     * Selection.addRange(range, $blockChangeEvents) 
     * - range (Range): The new range to add
     * - $blockChangeEvents (Boolean): Whether or not to block changing events
     *
     * Adds a range to a selection by entering multiselect mode, if necessary.
     **/
    this.addRange = function(range, $blockChangeEvents) {
        if (!range)
            return;

        if (!this.inMultiSelectMode && this.rangeCount == 0) {
            var oldRange = this.toOrientedRange();
            if (range.intersects(oldRange))
                return $blockChangeEvents || this.fromOrientedRange(range);

            this.rangeList.add(oldRange);
            this.$onAddRange(oldRange);
        }

        if (!range.cursor)
            range.cursor = range.end;

        var removed = this.rangeList.add(range);

        this.$onAddRange(range);

        if (removed.length)
            this.$onRemoveRange(removed);

        if (this.rangeCount > 1 && !this.inMultiSelectMode) {
            this._emit("multiSelect");
            this.inMultiSelectMode = true;
            this.session.$undoSelect = false;
            this.rangeList.attach(this.session);
        }

        return $blockChangeEvents || this.fromOrientedRange(range);
    };

    this.toSingleRange = function(range) {
        range = range || this.ranges[0];
        var removed = this.rangeList.removeAll();
        if (removed.length)
            this.$onRemoveRange(removed);

        range && this.fromOrientedRange(range);
    };
    
    /** extension
     * Selection.substractPoint(pos) -> Range
     * - pos (Range): The position to remove, as a `{row, column}` object
     *
     * Removes a Range containing pos (if it exists).
     **/
    this.substractPoint = function(pos) {
        var removed = this.rangeList.substractPoint(pos);
        if (removed) {
            this.$onRemoveRange(removed);
            return removed[0];
        }
    };

    /** extension
     * Selection.mergeOverlappingRanges() 
     *
     * Merges overlapping ranges ensuring consistency after changes
     **/
    this.mergeOverlappingRanges = function() {
        var removed = this.rangeList.merge();
        if (removed.length)
            this.$onRemoveRange(removed);
        else if(this.ranges[0])
            this.fromOrientedRange(this.ranges[0]);
    };

    this.$onAddRange = function(range) {
        this.rangeCount = this.rangeList.ranges.length;
        this.ranges.unshift(range);
        this._emit("addRange", {range: range});
    };

    this.$onRemoveRange = function(removed) {
        this.rangeCount = this.rangeList.ranges.length;
        if (this.rangeCount == 1 && this.inMultiSelectMode) {
            var lastRange = this.rangeList.ranges.pop();
            removed.push(lastRange);
            this.rangeCount = 0;
        }

        for (var i = removed.length; i--; ) {
            var index = this.ranges.indexOf(removed[i]);
            this.ranges.splice(index, 1);
        }

        this._emit("removeRange", {ranges: removed});

        if (this.rangeCount == 0 && this.inMultiSelectMode) {
            this.inMultiSelectMode = false;
            this._emit("singleSelect");
            this.session.$undoSelect = true;
            this.rangeList.detach(this.session);
        }

        lastRange = lastRange || this.ranges[0];
        if (lastRange && !lastRange.isEqual(this.getRange()))
            this.fromOrientedRange(lastRange);
    };

    // adds multicursor support to selection
    this.$initRangeList = function() {
        if (this.rangeList)
            return;

        this.rangeList = new RangeList();
        this.ranges = [];
        this.rangeCount = 0;
    };

    this.getAllRanges = function() {
        return this.rangeList.ranges.concat();
    };

    this.splitIntoLines = function () {
        if (this.rangeCount > 1) {
            var ranges = this.rangeList.ranges;
            var lastRange = ranges[ranges.length - 1];
            var range = Range.fromPoints(ranges[0].start, lastRange.end);

            this.toSingleRange();
            this.setSelectionRange(range, lastRange.cursor == lastRange.start);
        } else {
            var range = this.getRange();
            var startRow = range.start.row;
            var endRow = range.end.row;
            if (startRow == endRow)
                return;

            var rectSel = [];
            var r = this.getLineRange(startRow, true);
            r.start.column = range.start.column;
            rectSel.push(r);

            for (var i = startRow + 1; i < endRow; i++)
                rectSel.push(this.getLineRange(i, true));

            r = this.getLineRange(endRow, true);
            r.end.column = range.end.column;
            rectSel.push(r);

            rectSel.forEach(this.addRange, this);
        }
    };

    this.toggleBlockSelection = function () {
        if (this.rangeCount > 1) {
            var ranges = this.rangeList.ranges;
            var lastRange = ranges[ranges.length - 1];
            var range = Range.fromPoints(ranges[0].start, lastRange.end);

            this.toSingleRange();
            this.setSelectionRange(range, lastRange.cursor == lastRange.start);
        } else {
            var cursor = this.session.documentToScreenPosition(this.selectionLead);
            var anchor = this.session.documentToScreenPosition(this.selectionAnchor);

            var rectSel = this.rectangularRangeBlock(cursor, anchor);
            rectSel.forEach(this.addRange, this);
        }
    };

    /** extension
     * Selection.rectangularRangeBlock(screenCursor, screenAnchor, includeEmptyLines) -> Range
     * - screenCursor (Cursor): The cursor to use
     * - screenAnchor (Anchor): The anchor to use
     * - includeEmptyLins (Boolean): If true, this includes ranges inside the block which are empty due to clipping
     *  
     * Gets list of ranges composing rectangular block on the screen
     *
     */
    this.rectangularRangeBlock = function(screenCursor, screenAnchor, includeEmptyLines) {
        var rectSel = [];

        var xBackwards = screenCursor.column < screenAnchor.column;
        if (xBackwards) {
            var startColumn = screenCursor.column;
            var endColumn = screenAnchor.column;
        } else {
            var startColumn = screenAnchor.column;
            var endColumn = screenCursor.column;
        }

        var yBackwards = screenCursor.row < screenAnchor.row;
        if (yBackwards) {
            var startRow = screenCursor.row;
            var endRow = screenAnchor.row;
        } else {
            var startRow = screenAnchor.row;
            var endRow = screenCursor.row;
        }

        if (startColumn < 0)
            startColumn = 0;
        if (startRow < 0)
            startRow = 0;

        if (startRow == endRow)
            includeEmptyLines = true;

        for (var row = startRow; row <= endRow; row++) {
            var range = Range.fromPoints(
                this.session.screenToDocumentPosition(row, startColumn),
                this.session.screenToDocumentPosition(row, endColumn)
            );
            if (range.isEmpty()) {
                if (docEnd && isSamePoint(range.end, docEnd))
                    break;
                var docEnd = range.end;
            }
            range.cursor = xBackwards ? range.start : range.end;
            rectSel.push(range);
        }

        if (yBackwards)
            rectSel.reverse();

        if (!includeEmptyLines) {
            var end = rectSel.length - 1;
            while (rectSel[end].isEmpty() && end > 0)
                end--;
            if (end > 0) {
                var start = 0;
                while (rectSel[start].isEmpty())
                    start++;
            }
            for (var i = end; i >= start; i--) {
                if (rectSel[i].isEmpty())
                    rectSel.splice(i, 1);
            }
        }

        return rectSel;
    };
}).call(Selection.prototype);

// extend Editor
var Editor = require("./editor").Editor;
(function() {
    
    /** extension
     * Editor.updateSelectionMarkers() 
     *
     * Updates the cursor and marker layers.
     **/
    this.updateSelectionMarkers = function() {
        this.renderer.updateCursor();
        this.renderer.updateBackMarkers();
    };

    /** extension
     * Editor.addSelectionMarker(orientedRange) -> Range
     * - orientedRange (Range): A range containing a cursor
     *
     * Adds the selection and cursor.
     **/
    this.addSelectionMarker = function(orientedRange) {
        if (!orientedRange.cursor)
            orientedRange.cursor = orientedRange.end;

        var style = this.getSelectionStyle();
        orientedRange.marker = this.session.addMarker(orientedRange, "ace_selection", style);

        this.session.$selectionMarkers.push(orientedRange);
        this.session.selectionMarkerCount = this.session.$selectionMarkers.length;
        return orientedRange;
    };

    /** extension
     * Editor.removeSelectionMarker(range) 
     * - range (Range): The selection range added with [[Editor.addSelectionMarker `addSelectionMarker()`]].
     *
     * Removes the selection marker.
     **/
    this.removeSelectionMarker = function(range) {
        if (!range.marker)
            return;
        this.session.removeMarker(range.marker);
        var index = this.session.$selectionMarkers.indexOf(range);
        if (index != -1)
            this.session.$selectionMarkers.splice(index, 1);
        this.session.selectionMarkerCount = this.session.$selectionMarkers.length;
    };

    this.removeSelectionMarkers = function(ranges) {
        var markerList = this.session.$selectionMarkers;
        for (var i = ranges.length; i--; ) {
            var range = ranges[i];
            if (!range.marker)
                continue;
            this.session.removeMarker(range.marker);
            var index = markerList.indexOf(range);
            if (index != -1)
                markerList.splice(index, 1);
        }
        this.session.selectionMarkerCount = markerList.length;
    };

    this.$onAddRange = function(e) {
        this.addSelectionMarker(e.range);
        this.renderer.updateCursor();
        this.renderer.updateBackMarkers();
    };

    this.$onRemoveRange = function(e) {
        this.removeSelectionMarkers(e.ranges);
        this.renderer.updateCursor();
        this.renderer.updateBackMarkers();
    };

    this.$onMultiSelect = function(e) {
        if (this.inMultiSelectMode)
            return;
        this.inMultiSelectMode = true;

        this.setStyle("multiselect");
        this.keyBinding.addKeyboardHandler(commands.keyboardHandler);
        this.commands.on("exec", this.$onMultiSelectExec);

        this.renderer.updateCursor();
        this.renderer.updateBackMarkers();
    };

    this.$onSingleSelect = function(e) {
        if (this.session.multiSelect.inVirtualMode)
            return;
        this.inMultiSelectMode = false;

        this.unsetStyle("multiselect");
        this.keyBinding.removeKeyboardHandler(commands.keyboardHandler);

        this.commands.removeEventListener("exec", this.$onMultiSelectExec);
        this.renderer.updateCursor();
        this.renderer.updateBackMarkers();
    };

    this.$onMultiSelectExec = function(e) {
        var command = e.command;
        var editor = e.editor;
        if (!editor.multiSelect)
            return;
        if (!command.multiSelectAction) {
            command.exec(editor, e.args || {});
            editor.multiSelect.addRange(editor.multiSelect.toOrientedRange());
            editor.multiSelect.mergeOverlappingRanges();
        } else if (command.multiSelectAction == "forEach") {
            editor.forEachSelection(command, e.args);
        } else if (command.multiSelectAction == "single") {
            editor.exitMultiSelectMode();
            command.exec(editor, e.args || {});
        } else {
            command.multiSelectAction(editor, e.args || {});
        }
        e.preventDefault();
    };

    /** extension
     * Editor.forEachSelection(cmd, args) 
     * - cmd (String): The command to execute
     * - args (String): Any arguments for the command
     *
     * Executes a command for each selection range.
     **/
    this.forEachSelection = function(cmd, args) {
        if (this.inVirtualSelectionMode)
            return;

        var session = this.session;
        var selection = this.selection;
        var rangeList = selection.rangeList;

        var reg = selection._eventRegistry;
        selection._eventRegistry = {};

        var tmpSel = new Selection(session);
        this.inVirtualSelectionMode = true;
        for (var i = rangeList.ranges.length; i--;) {
            tmpSel.fromOrientedRange(rangeList.ranges[i]);
            this.selection = session.selection = tmpSel;
            cmd.exec(this, args || {});
            tmpSel.toOrientedRange(rangeList.ranges[i]);
        }
        tmpSel.detach();

        this.selection = session.selection = selection;
        this.inVirtualSelectionMode = false;
        selection._eventRegistry = reg;
        selection.mergeOverlappingRanges();

        this.onCursorChange();
        this.onSelectionChange();
    };

    /** extension
    * Editor.exitMultiSelectMode() -> Void
    *
    * Removes all the selections except the last added one.
    **/
    this.exitMultiSelectMode = function() {
        if (this.inVirtualSelectionMode)
            return;
        this.multiSelect.toSingleRange();
    };

    this.getCopyText = function() {
        var text = "";
        if (this.inMultiSelectMode) {
            var ranges = this.multiSelect.rangeList.ranges;
            text = [];
            for (var i = 0; i < ranges.length; i++) {
                text.push(this.session.getTextRange(ranges[i]));
            }
            text = text.join(this.session.getDocument().getNewLineCharacter());
        } else if (!this.selection.isEmpty()) {
            text = this.session.getTextRange(this.getSelectionRange());
        }

        return text;
    };

    this.onPaste = function(text) {
        this._emit("paste", text);
        if (!this.inMultiSelectMode)
            return this.insert(text);

        var lines = text.split(/\r\n|\r|\n/);
        var ranges = this.selection.rangeList.ranges;

        if (lines.length > ranges.length || (lines.length <= 2 || !lines[1]))
            return this.commands.exec("insertstring", this, text);

        for (var i = ranges.length; i--; ) {
            var range = ranges[i];
            if (!range.isEmpty())
                this.session.remove(range);

            this.session.insert(range.start, lines[i]);
        }
    };

    /** extension
     * Editor.findAll(needle, options, additive) -> Number
     * - needle (String): The text to find
     * - options (Object): The search options
     * - additive (Boolean): keeps
     *
     * Finds and selects all the occurences of `needle`.
     **/
    this.findAll = function(needle, options, additive) {
        options = options || {};
        options.needle = needle || options.needle;
        this.$search.set(options);

        var ranges = this.$search.findAll(this.session);
        if (!ranges.length)
            return 0;

        this.$blockScrolling += 1;
        var selection = this.multiSelect;

        if (!additive)
            selection.toSingleRange(ranges[0]);

        for (var i = ranges.length; i--; )
            selection.addRange(ranges[i], true);

        this.$blockScrolling -= 1;

        return ranges.length;
    };

    // commands
    /** extension
     * Editor.selectMoreLines(dir, skip) 
     * - dir (Number): The direction of lines to select: -1 for up, 1 for down
     * - skip (Boolean): If `true`, removes the active selection range
     *
     * Adds a cursor above or below the active cursor.
     **/
    this.selectMoreLines = function(dir, skip) {
        var range = this.selection.toOrientedRange();
        var isBackwards = range.cursor == range.end;

        var screenLead = this.session.documentToScreenPosition(range.cursor);
        if (this.selection.$desiredColumn)
            screenLead.column = this.selection.$desiredColumn;

        var lead = this.session.screenToDocumentPosition(screenLead.row + dir, screenLead.column);

        if (!range.isEmpty()) {
            var screenAnchor = this.session.documentToScreenPosition(isBackwards ? range.end : range.start);
            var anchor = this.session.screenToDocumentPosition(screenAnchor.row + dir, screenAnchor.column);
        } else {
            var anchor = lead;
        }

        if (isBackwards) {
            var newRange = Range.fromPoints(lead, anchor);
            newRange.cursor = newRange.start;
        } else {
            var newRange = Range.fromPoints(anchor, lead);
            newRange.cursor = newRange.end;
        }

        newRange.desiredColumn = screenLead.column;
        if (!this.selection.inMultiSelectMode) {
            this.selection.addRange(range);
        } else {
            if (skip)
                var toRemove = range.cursor;
        }

        this.selection.addRange(newRange);
        if (toRemove)
            this.selection.substractPoint(toRemove);
    };

    /** extension
     * Editor.transposeSelections(dir) 
     * - dir (Number): The direction to rotate selections
     *
     * Transposes the selected ranges. 
     **/
    this.transposeSelections = function(dir) {
        var session = this.session;
        var sel = session.multiSelect;
        var all = sel.ranges;

        for (var i = all.length; i--; ) {
            var range = all[i];
            if (range.isEmpty()) {
                var tmp = session.getWordRange(range.start.row, range.start.column);
                range.start.row = tmp.start.row;
                range.start.column = tmp.start.column;
                range.end.row = tmp.end.row;
                range.end.column = tmp.end.column;
            }
        }
        sel.mergeOverlappingRanges();

        var words = [];
        for (var i = all.length; i--; ) {
            var range = all[i];
            words.unshift(session.getTextRange(range));
        }

        if (dir < 0)
            words.unshift(words.pop());
        else
            words.push(words.shift());

        for (var i = all.length; i--; ) {
            var range = all[i];
            var tmp = range.clone();
            session.replace(range, words[i]);
            range.start.row = tmp.start.row;
            range.start.column = tmp.start.column;
        }
    }

    /** extension
     * Editor.selectMore(dir, skip) 
     * - dir (Number): The direction of lines to select: -1 for up, 1 for down
     * - skip (Boolean): If `true`, removes the active selection range
     *
     * Finds the next occurence of text in an active selection and adds it to the selections.
     **/
    this.selectMore = function (dir, skip) {
        var session = this.session;
        var sel = session.multiSelect;

        var range = sel.toOrientedRange();
        if (range.isEmpty()) {
            var range = session.getWordRange(range.start.row, range.start.column);
            range.cursor = range.end;
            this.multiSelect.addRange(range);
        }
        var needle = session.getTextRange(range);

        var newRange = find(session, needle, dir);
        if (newRange) {
            newRange.cursor = dir == -1 ? newRange.start : newRange.end;
            this.multiSelect.addRange(newRange);
        }
        if (skip)
            this.multiSelect.substractPoint(range.cursor);
    };
}).call(Editor.prototype);


function isSamePoint(p1, p2) {
    return p1.row == p2.row && p1.column == p2.column;
}

// patch
// adds multicursor support to a session
exports.onSessionChange = function(e) {
    var session = e.session;
    if (!session.multiSelect) {
        session.$selectionMarkers = [];
        session.selection.$initRangeList();
        session.multiSelect = session.selection;
    }
    this.multiSelect = session.multiSelect;

    var oldSession = e.oldSession;
    if (oldSession) {
        // todo use events
        if (oldSession.multiSelect && oldSession.multiSelect.editor == this)
            oldSession.multiSelect.editor = null;

        session.multiSelect.removeEventListener("addRange", this.$onAddRange);
        session.multiSelect.removeEventListener("removeRange", this.$onRemoveRange);
        session.multiSelect.removeEventListener("multiSelect", this.$onMultiSelect);
        session.multiSelect.removeEventListener("singleSelect", this.$onSingleSelect);
    }

    session.multiSelect.on("addRange", this.$onAddRange);
    session.multiSelect.on("removeRange", this.$onRemoveRange);
    session.multiSelect.on("multiSelect", this.$onMultiSelect);
    session.multiSelect.on("singleSelect", this.$onSingleSelect);

    // this.$onSelectionChange = this.onSelectionChange.bind(this);

    if (this.inMultiSelectMode != session.selection.inMultiSelectMode) {
        if (session.selection.inMultiSelectMode)
            this.$onMultiSelect();
        else
            this.$onSingleSelect();
    }
};

// MultiSelect(editor) 
// adds multiple selection support to the editor
// (note: should be called only once for each editor instance)
function MultiSelect(editor) {
    editor.$onAddRange = editor.$onAddRange.bind(editor);
    editor.$onRemoveRange = editor.$onRemoveRange.bind(editor);
    editor.$onMultiSelect = editor.$onMultiSelect.bind(editor);
    editor.$onSingleSelect = editor.$onSingleSelect.bind(editor);

    exports.onSessionChange.call(editor, editor);
    editor.on("changeSession", exports.onSessionChange.bind(editor));

    editor.on("mousedown", onMouseDown);
    editor.commands.addCommands(commands.defaultCommands);

    addAltCursorListeners(editor);
}

function addAltCursorListeners(editor){
    var el = editor.textInput.getElement();
    var altCursor = false;
    var contentEl = editor.renderer.content;
    event.addListener(el, "keydown", function(e) {
        if (e.keyCode == 18 && !(e.ctrlKey || e.shiftKey || e.metaKey)) {
            if (!altCursor) {
                contentEl.style.cursor = "crosshair";
                altCursor = true;
            }
        } else if (altCursor) {
            contentEl.style.cursor = "";
        }
    });

    event.addListener(el, "keyup", reset);
    event.addListener(el, "blur", reset);
    function reset() {
        if (altCursor) {
            contentEl.style.cursor = "";
            altCursor = false;
        }
    }
}

exports.MultiSelect = MultiSelect;

});