/* 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>
 *      Mihai Sucan <mihai DOT sucan 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 event = require("pilot/event");
var dom = require("pilot/dom");
var BrowserFocus = require("pilot/browser_focus").BrowserFocus;

var STATE_UNKNOWN = 0;
var STATE_SELECT = 1;
var STATE_DRAG = 2;

var DRAG_TIMER = 250; // milliseconds
var DRAG_OFFSET = 5; // pixels

var MouseHandler = function(editor) {
    this.editor = editor;
    
    this.browserFocus = new BrowserFocus();
    event.addListener(editor.container, "mousedown", function(e) {
        editor.focus();
        return event.preventDefault(e);
    });
    event.addListener(editor.container, "selectstart", function(e) {
        return event.preventDefault(e);
    });

    var mouseTarget = editor.renderer.getMouseEventTarget();
    event.addListener(mouseTarget, "mousedown", this.onMouseDown.bind(this));
    event.addMultiMouseDownListener(mouseTarget, 0, 2, 500, this.onMouseDoubleClick.bind(this));
    event.addMultiMouseDownListener(mouseTarget, 0, 3, 600, this.onMouseTripleClick.bind(this));
    event.addMultiMouseDownListener(mouseTarget, 0, 4, 600, this.onMouseQuadClick.bind(this));
    event.addMouseWheelListener(editor.container, this.onMouseWheel.bind(this));
};

(function() {

    this.$scrollSpeed = 1;
    this.setScrollSpeed = function(speed) {
        this.$scrollSpeed = speed;
    };

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

    this.$getEventPosition = function(e) {
        var pageX = event.getDocumentX(e);
        var pageY = event.getDocumentY(e);
        var pos = this.editor.renderer.screenToTextCoordinates(pageX, pageY);
        pos.row = Math.max(0, Math.min(pos.row, this.editor.session.getLength()-1));
        return pos;
    };

    this.$distance = function(ax, ay, bx, by) {
        return Math.sqrt(Math.pow(bx - ax, 2) + Math.pow(by - ay, 2));
    };

    this.onMouseDown = function(e) {
        var pageX = event.getDocumentX(e);
        var pageY = event.getDocumentY(e);
        
        var pos = this.$getEventPosition(e);
        
        var editor = this.editor;
        var self = this;
        var selectionRange = editor.getSelectionRange();
        var selectionEmpty = selectionRange.isEmpty();
        var inSelection = !editor.getReadOnly()
            && !selectionEmpty
            && selectionRange.contains(pos.row, pos.column);
        
        var state = STATE_UNKNOWN;
        
        // if this click caused the editor to be focused should not clear the
        // selection
        if (
            inSelection && (
                !this.browserFocus.isFocused()
                || new Date().getTime() - this.browserFocus.lastFocus < 20
                || !this.editor.isFocused()
            )
        ) {
            this.editor.focus();
            return;
        }

        var button = event.getButton(e);
        if (button !== 0) {
            if (selectionEmpty) {
                editor.moveCursorToPosition(pos);
            }
            if(button == 2) {
                editor.textInput.onContextMenu({x: pageX, y: pageY}, selectionEmpty);
                event.capture(editor.container, function(){}, editor.textInput.onContextMenuClose);
            }
            return;
        } else {
            // Select the fold as the user clicks it.
            var fold = editor.session.getFoldAt(pos.row, pos.column, 1);
            if (fold) {
                editor.selection.setSelectionRange(fold.range);
                return;
            }
        }

        if (!inSelection) {
            // Directly pick STATE_SELECT, since the user is not clicking inside
            // a selection.
            onStartSelect(pos);
        }

        var mousePageX, mousePageY;
        var overwrite = editor.getOverwrite();
        var mousedownTime = (new Date()).getTime();
        var dragCursor, dragRange;

        var onMouseSelection = function(e) {
            mousePageX = event.getDocumentX(e);
            mousePageY = event.getDocumentY(e);
        };

        var onMouseSelectionEnd = function() {
            clearInterval(timerId);
            if (state == STATE_UNKNOWN)
                onStartSelect(pos);
            else if (state == STATE_DRAG)
                onMouseDragSelectionEnd();

            self.$clickSelection = null;
            state = STATE_UNKNOWN;
        };

        var onMouseDragSelectionEnd = function() {
            dom.removeCssClass(editor.container, "ace_dragging");
            editor.session.removeMarker(dragSelectionMarker);

            if (!self.$clickSelection) {
                if (!dragCursor) {
                    editor.moveCursorToPosition(pos);
                    editor.selection.clearSelection(pos.row, pos.column);
                }
            }

            if (!dragCursor)
                return;

            if (dragRange.contains(dragCursor.row, dragCursor.column)) {
                dragCursor = null;
                return;
            }

            editor.clearSelection();
            var newRange = editor.moveText(dragRange, dragCursor);
            if (!newRange) {
                dragCursor = null;
                return;
            }

            editor.selection.setSelectionRange(newRange);
        };

        var onSelectionInterval = function() {
            if (mousePageX === undefined || mousePageY === undefined)
                return;

            if (state == STATE_UNKNOWN) {
                var distance = self.$distance(pageX, pageY, mousePageX, mousePageY);
                var time = (new Date()).getTime();


                if (distance > DRAG_OFFSET) {
                    state = STATE_SELECT;
                    var cursor = editor.renderer.screenToTextCoordinates(mousePageX, mousePageY);
                    cursor.row = Math.max(0, Math.min(cursor.row, editor.session.getLength()-1));
                    onStartSelect(cursor);
                } else if ((time - mousedownTime) > DRAG_TIMER) {
                    state = STATE_DRAG;
                    dragRange = editor.getSelectionRange();
                    var style = editor.getSelectionStyle();
                    dragSelectionMarker = editor.session.addMarker(dragRange, "ace_selection", style);
                    editor.clearSelection();
                    dom.addCssClass(editor.container, "ace_dragging");
                }

            }

            if (state == STATE_DRAG)
                onDragSelectionInterval();
            else if (state == STATE_SELECT)
                onUpdateSelectionInterval();
        };

        function onStartSelect(pos) {
            if (e.shiftKey)
                editor.selection.selectToPosition(pos)
            else {
                if (!self.$clickSelection) {
                    editor.moveCursorToPosition(pos);
                    editor.selection.clearSelection(pos.row, pos.column);
                }
            }
            state = STATE_SELECT;
        }

        var onUpdateSelectionInterval = function() {
            var cursor = editor.renderer.screenToTextCoordinates(mousePageX, mousePageY);
            cursor.row = Math.max(0, Math.min(cursor.row, editor.session.getLength()-1));

            if (self.$clickSelection) {
                if (self.$clickSelection.contains(cursor.row, cursor.column)) {
                    editor.selection.setSelectionRange(self.$clickSelection);
                } else {
                    if (self.$clickSelection.compare(cursor.row, cursor.column) == -1) {
                        var anchor = self.$clickSelection.end;
                    } else {
                        var anchor = self.$clickSelection.start;
                    }
                    editor.selection.setSelectionAnchor(anchor.row, anchor.column);
                    editor.selection.selectToPosition(cursor);
                }
            }
            else {
                editor.selection.selectToPosition(cursor);
            }

            editor.renderer.scrollCursorIntoView();
        };

        var onDragSelectionInterval = function() {
            dragCursor = editor.renderer.screenToTextCoordinates(mousePageX, mousePageY);
            dragCursor.row = Math.max(0, Math.min(dragCursor.row, editor.session.getLength() - 1));

            editor.moveCursorToPosition(dragCursor);
        };

        event.capture(editor.container, onMouseSelection, onMouseSelectionEnd);
        var timerId = setInterval(onSelectionInterval, 20);

        return event.preventDefault(e);
    };

    this.onMouseDoubleClick = function(e) {
        var editor = this.editor;
        var pos = this.$getEventPosition(e);

        // If the user dclicked on a fold, then expand it.
        var fold = editor.session.getFoldAt(pos.row, pos.column, 1);
        if (fold) {
            editor.session.expandFold(fold);
        } else {
            editor.moveCursorToPosition(pos);
            editor.selection.selectWord();
            this.$clickSelection = editor.getSelectionRange();
        }
    };

    this.onMouseTripleClick = function(e) {
        var pos = this.$getEventPosition(e);
        this.editor.moveCursorToPosition(pos);
        this.editor.selection.selectLine();
        this.$clickSelection = this.editor.getSelectionRange();
    };

    this.onMouseQuadClick = function(e) {
        this.editor.selectAll();
        this.$clickSelection = this.editor.getSelectionRange();
    };

    this.onMouseWheel = function(e) {
        var speed = this.$scrollSpeed * 2;

        this.editor.renderer.scrollBy(e.wheelX * speed, e.wheelY * speed);
        if (this.editor.renderer.isScrollableBy(e.wheelX, e.wheelY))
            return event.preventDefault(e);
    };


}).call(MouseHandler.prototype);

exports.MouseHandler = MouseHandler;
});