/**
 * This class provides an abstract grid editing plugin on selected {@link Ext.grid.column.Column columns}.
 * The editable columns are specified by providing an {@link Ext.grid.column.Column#editor editor}
 * in the {@link Ext.grid.column.Column column configuration}.
 *
 * **Note:** This class should not be used directly. See {@link Ext.grid.plugin.CellEditing} and
 * {@link Ext.grid.plugin.RowEditing}.
 */
Ext.define('Ext.grid.plugin.Editing', {
    alias: 'editing.editing',
    extend: 'Ext.AbstractPlugin',

    requires: [
        'Ext.grid.column.Column',
        'Ext.util.KeyNav'
    ],

    mixins: {
        observable: 'Ext.util.Observable'
    },

    /**
     * @cfg {Number} clicksToEdit
     * The number of clicks on a grid required to display the editor.
     * The only accepted values are **1** and **2**.
     */
    clicksToEdit: 2,

    /**
     * @cfg {String} triggerEvent
     * The event which triggers editing. Supercedes the {@link #clicksToEdit} configuration. Maybe one of:
     *
     *  * cellclick
     *  * celldblclick
     *  * cellfocus
     *  * rowfocus
     */
    triggerEvent: undefined,

    relayedEvents: [
        'beforeedit',
        'edit',
        'validateedit',
        'canceledit'
    ],

    // @private
    defaultFieldXType: 'textfield',

    // cell, row, form
    editStyle: '',

    constructor: function(config) {
        var me = this;

        me.addEvents(
            /**
             * @event beforeedit
             * Fires before editing is triggered. Return false from event handler to stop the editing.
             *
             * @param {Ext.grid.plugin.Editing} editor
             * @param {Object} context The editing context with the following properties:
             *  @param {Ext.grid.Panel}         context.grid The owning grid Panel.
             *  @param {Ext.data.Model}         context.record The record being edited.
             *  @param {String}                 context.field The name of the field being edited.
             *  @param {Mixed}                  context.value The field's current value.
             *  @param {HTMLElement}            context.row The grid row element.
             *  @param {Ext.grid.column.Column} context.column The Column being edited.
             *  @param {Number}                 context.rowIdx The index of the row being edited.
             *  @param {Number}                 context.colIdx The index of the column being edited.
             *  @param {Boolean}                context.cancel Set this to `true` to cancel the edit or return false from your handler.
             *  @param {Mixed}                  context.originalValue Alias for value (only when using {@link Ext.grid.plugin.CellEditing CellEditing}).
             */
            'beforeedit',

            /**
             * @event edit
             * Fires after a editing. Usage example:
             *
             *     grid.on('edit', function(editor, e) {
             *         // commit the changes right after editing finished
             *         e.record.commit();
             *     });
             *
             * @param {Ext.grid.plugin.Editing} editor
             * @param {Object} context The editing context with the following properties:
             *  @param {Ext.grid.Panel}         context.grid The owning grid Panel.
             *  @param {Ext.data.Model}         context.record The record being edited.
             *  @param {String}                 context.field The name of the field being edited.
             *  @param {Mixed}                  context.value The field's current value.
             *  @param {HTMLElement}            context.row The grid row element.
             *  @param {Ext.grid.column.Column} context.column The Column being edited.
             *  @param {Number}                 context.rowIdx The index of the row being edited.
             *  @param {Number}                 context.colIdx The index of the column being edited.
             */
            'edit',

            /**
             * @event validateedit
             * Fires after editing, but before the value is set in the record. Return false from event handler to
             * cancel the change.
             *
             * Usage example showing how to remove the red triangle (dirty record indicator) from some records (not all). By
             * observing the grid's validateedit event, it can be cancelled if the edit occurs on a targeted row (for example)
             * and then setting the field's new value in the Record directly:
             *
             *     grid.on('validateedit', function(editor, e) {
             *       var myTargetRow = 6;
             *
             *       if (e.rowIdx == myTargetRow) {
             *         e.cancel = true;
             *         e.record.data[e.field] = e.value;
             *       }
             *     });
             *
             * @param {Ext.grid.plugin.Editing} editor
             * @param {Object} context The editing context with the following properties:
             *  @param {Ext.grid.Panel}         context.grid The owning grid Panel.
             *  @param {Ext.data.Model}         context.record The record being edited.
             *  @param {String}                 context.field The name of the field being edited.
             *  @param {Mixed}                  context.value The field's current value.
             *  @param {HTMLElement}            context.row The grid row element.
             *  @param {Ext.grid.column.Column} context.column The Column being edited.
             *  @param {Number}                 context.rowIdx The index of the row being edited.
             *  @param {Number}                 context.colIdx The index of the column being edited.
             */
            'validateedit',
            /**
             * @event canceledit
             * Fires when the user started editing but then cancelled the edit.
             * @param {Ext.grid.plugin.Editing} editor
             * @param {Object} context The editing context with the following properties:
             *  @param {Ext.grid.Panel}         context.grid The owning grid Panel.
             *  @param {Ext.data.Model}         context.record The record being edited.
             *  @param {String}                 context.field The name of the field being edited.
             *  @param {Mixed}                  context.value The field's current value.
             *  @param {HTMLElement}            context.row The grid row element.
             *  @param {Ext.grid.column.Column} context.column The Column being edited.
             *  @param {Number}                 context.rowIdx The index of the row being edited.
             *  @param {Number}                 context.colIdx The index of the column being edited.
             */
            'canceledit'

        );
        me.callParent(arguments);
        me.mixins.observable.constructor.call(me);
        // TODO: Deprecated, remove in 5.0
        me.on("edit", function(editor, e) {
            me.fireEvent("afteredit", editor, e);
        });
    },

    // @private
    init: function(grid) {
        var me = this;

        me.grid = grid;
        me.view = grid.view;
        me.initEvents();

        // Set up fields at render and reconfigure time
        me.mon(grid, {
            reconfigure: me.onReconfigure,
            scope: me,
            beforerender: {
                fn: me.onReconfigure,
                single: true,
                scope: me
            }
        });

        grid.relayEvents(me, me.relayedEvents);

        // If the editable grid is owned by a lockable, relay up another level.
        if (me.grid.ownerLockable) {
            me.grid.ownerLockable.relayEvents(me, me.relayedEvents);
        }
        // Marks the grid as editable, so that the SelectionModel
        // can make appropriate decisions during navigation
        grid.isEditable = true;
        grid.editingPlugin = grid.view.editingPlugin = me;
    },

    /**
     * Fires after the grid is reconfigured
     * @private
     */
    onReconfigure: function() {
        var grid = this.grid;

        // In a Lockable assembly, the owner's view aggregates all grid columns across both sides.
        // We grab all columns here.
        grid = grid.ownerLockable ? grid.ownerLockable : grid;
        this.initFieldAccessors(grid.getView().getGridColumns());
    },

    /**
     * @private
     * AbstractComponent calls destroy on all its plugins at destroy time.
     */
    destroy: function() {
        var me = this,
            grid = me.grid;

        Ext.destroy(me.keyNav);
        // Clear all listeners from all our events, clear all managed listeners we added to other Observables
        me.clearListeners();

        if (grid) {
            me.removeFieldAccessors(grid.columnManager.getColumns());
            grid.editingPlugin = grid.view.editingPlugin = me.grid = me.view = me.editor = me.keyNav = null;
        }
    },

    // @private
    getEditStyle: function() {
        return this.editStyle;
    },

    // @private
    initFieldAccessors: function(columns) {
        // If we have been passed a group header, process its leaf headers
        if (columns.isGroupHeader) {
            columns = columns.getGridColumns();
        }

        // Ensure we are processing an array
        else if (!Ext.isArray(columns)) {
            columns = [columns];
        }

        var me   = this,
            c,
            cLen = columns.length,
            column;

        for (c = 0; c < cLen; c++) {
            column = columns[c];

            if (!column.getEditor) {
                column.getEditor = function(record, defaultField) {
                    return me.getColumnField(this, defaultField);
                };
            }
            if (!column.hasEditor) {
                column.hasEditor = function() {
                    return me.hasColumnField(this);
                };
            }
            if (!column.setEditor) {
                column.setEditor = function(field) {
                    me.setColumnField(this, field);
                };
            }
        }
    },

    // @private
    removeFieldAccessors: function(columns) {
        // If we have been passed a group header, process its leaf headers
        if (columns.isGroupHeader) {
            columns = columns.getGridColumns();
        }

        // Ensure we are processing an array
        else if (!Ext.isArray(columns)) {
            columns = [columns];
        }

        var c,
            cLen = columns.length,
            column;

        for (c = 0; c < cLen; c++) {
            column = columns[c];

            column.getEditor = column.hasEditor = column.setEditor = null;
        }
    },

    // @private
    // remaps to the public API of Ext.grid.column.Column.getEditor
    getColumnField: function(columnHeader, defaultField) {
        var field = columnHeader.field;
        if (!(field && field.isFormField)) {
            field = columnHeader.field = this.createColumnField(columnHeader, defaultField);
        }
        return field;
    },

    // @private
    // remaps to the public API of Ext.grid.column.Column.hasEditor
    hasColumnField: function(columnHeader) {
        return !!columnHeader.field;
    },

    // @private
    // remaps to the public API of Ext.grid.column.Column.setEditor
    setColumnField: function(columnHeader, field) {
        columnHeader.field = field;
        columnHeader.field = this.createColumnField(columnHeader);
    },

    createColumnField:  function(columnHeader, defaultField) {
        var field = columnHeader.field;

        if (!field && columnHeader.editor) {
            field = columnHeader.editor;
            columnHeader.editor = null;
        }

        if (!field && defaultField) {
            field = defaultField;
        }

        if (field) {
            if (field.isFormField) {
                field.column = columnHeader;
            } else {
                if (Ext.isString(field)) {
                    field = {
                        name: columnHeader.dataIndex,
                        xtype: field,
                        column: columnHeader
                    };
                } else {
                    field = Ext.apply({
                        name: columnHeader.dataIndex,
                        column: columnHeader
                    }, field);
                }
                field = Ext.ComponentManager.create(field, this.defaultFieldXType);
            }
            columnHeader.field = field;
        }
        return field;
    },

    // @private
    initEvents: function() {
        var me = this;
        me.initEditTriggers();
        me.initCancelTriggers();
    },

    // @abstract
    initCancelTriggers: Ext.emptyFn,

    // @private
    initEditTriggers: function() {
        var me = this,
            view = me.view;

        // Listen for the edit trigger event.
        if (me.triggerEvent == 'cellfocus') {
            me.mon(view, 'cellfocus', me.onCellFocus, me);
        } else if (me.triggerEvent == 'rowfocus') {
            me.mon(view, 'rowfocus', me.onRowFocus, me);
        } else {

            // Prevent the View from processing when the SelectionModel focuses.
            // This is because the SelectionModel processes the mousedown event, and
            // focusing causes a scroll which means that the subsequent mouseup might
            // take place at a different document XY position, and will therefore
            // not trigger a click.
            // This Editor must call the View's focusCell method directly when we recieve a request to edit
            if (view.getSelectionModel().isCellModel) {
                view.onCellFocus = Ext.Function.bind(me.beforeViewCellFocus, me);
            }

            // Listen for whichever click event we are configured to use
            me.mon(view, me.triggerEvent || ('cell' + (me.clicksToEdit === 1 ? 'click' : 'dblclick')), me.onCellClick, me);
        }

        // add/remove header event listeners need to be added immediately because
        // columns can be added/removed before render
        me.initAddRemoveHeaderEvents()
        // wait until render to initialize keynav events since they are attached to an element
        view.on('render', me.initKeyNavHeaderEvents, me, {single: true});
    },

    // Override of View's method so that we can pre-empt the View's processing if the view is being triggered by a mousedown
    beforeViewCellFocus: function(position) {
        // Pass call on to view if the navigation is from the keyboard, or we are not going to edit this cell.
        if (this.view.selModel.keyNavigation || !this.editing || !this.isCellEditable || !this.isCellEditable(position.row, position.columnHeader)) {
            this.view.focusCell.apply(this.view, arguments);
        }
    },

    // @private Used if we are triggered by the rowfocus event
    onRowFocus: function(record, row, rowIdx) {
        this.startEdit(row, 0);
    },

    // @private Used if we are triggered by the cellfocus event
    onCellFocus: function(record, cell, position) {
        this.startEdit(position.row, position.column);
    },

    // @private Used if we are triggered by a cellclick event
    onCellClick: function(view, cell, colIdx, record, row, rowIdx, e) {
        // cancel editing if the element that was clicked was a tree expander
        if(!view.expanderSelector || !e.getTarget(view.expanderSelector)) {
            this.startEdit(record, view.ownerCt.columnManager.getHeaderAtIndex(colIdx));
        }
    },

    initAddRemoveHeaderEvents: function(){
        var me = this;
        me.mon(me.grid.headerCt, {
            scope: me,
            add: me.onColumnAdd,
            remove: me.onColumnRemove,
            columnmove: me.onColumnMove
        });
    },

    initKeyNavHeaderEvents: function() {
        var me = this;

        me.keyNav = Ext.create('Ext.util.KeyNav', me.view.el, {
            enter: me.onEnterKey,
            esc: me.onEscKey,
            scope: me
        });
    },

    // @private
    onColumnAdd: function(ct, column) {
        this.initFieldAccessors(column);
    },

    // @private
    onColumnRemove: function(ct, column) {
        this.removeFieldAccessors(column);
    },

    // @private
    // Inject field accessors on move because if the move FROM the main headerCt and INTO a grouped header,
    // the accessors will have been deleted but not added. They are added conditionally.
    onColumnMove: function(headerCt, column, fromIdx, toIdx) {
        this.initFieldAccessors(column);
    },

    // @private
    onEnterKey: function(e) {
        var me = this,
            grid = me.grid,
            selModel = grid.getSelectionModel(),
            record,
            pos,
            columnHeader;

        // Calculate editing start position from SelectionModel if there is a selection
        // Note that the condition below tests the result of an assignment to the "pos" variable.
        if (selModel.getCurrentPosition && (pos = selModel.getCurrentPosition())) {
            record = pos.record;
            columnHeader = pos.columnHeader;
        }
        // RowSelectionModel
        else {
            record = selModel.getLastSelected();
            columnHeader = grid.columnManager.getHeaderAtIndex(0);
        }

        // If there was a selection to provide a starting context...
        if (record && columnHeader) {
            me.startEdit(record, columnHeader);
        }
    },

    // @private
    onEscKey: function(e) {
        return this.cancelEdit();
    },

    /**
     * @private
     * @template
     * Template method called before editing begins.
     * @param {Object} context The current editing context
     * @return {Boolean} Return false to cancel the editing process
     */
    beforeEdit: Ext.emptyFn,

    /**
     * Starts editing the specified record, using the specified Column definition to define which field is being edited.
     * @param {Ext.data.Model/Number} record The Store data record which backs the row to be edited, or index of the record in Store.
     * @param {Ext.grid.column.Column/Number} columnHeader The Column object defining the column to be edited, or index of the column.
     */
    startEdit: function(record, columnHeader) {
        var me = this,
            context,
            layoutView = me.grid.lockable ? me.grid : me.view;

        // The view must have had a layout to show the editor correctly, defer until that time.
        // In case a grid's startup code invokes editing immediately.
        if (!layoutView.componentLayoutCounter) {
            layoutView.on({
                boxready: Ext.Function.bind(me.startEdit, me, [record, columnHeader]),
                single: true
            });
            return false;
        }

        // If grid collapsed, or view not truly visible, don't even calculate a context - we cannot edit
        if (me.grid.collapsed || !me.grid.view.isVisible(true)) {
            return false;
        }

        context = me.getEditingContext(record, columnHeader);
        if (context == null) {
            return false;
        }
        if (!me.preventBeforeCheck) {
            if (me.beforeEdit(context) === false || me.fireEvent('beforeedit', me, context) === false || context.cancel) {
                return false;
            }
        }

        /**
         * @property {Boolean} editing
         * Set to `true` while the editing plugin is active and an Editor is visible.
         */
        me.editing = true;
        return context;
    },

    // TODO: Have this use a new class Ext.grid.CellContext for use here, and in CellSelectionModel
    /**
     * @private
     * Collects all information necessary for any subclasses to perform their editing functions.
     * @param record
     * @param columnHeader
     * @returns {Object/undefined} The editing context based upon the passed record and column
     */
    getEditingContext: function(record, columnHeader) {
        var me = this,
            grid = me.grid,
            view = me.view,
            gridRow = view.getNode(record, true),
            rowIdx, colIdx;

        // An intervening listener may have deleted the Record
        if (!gridRow) {
            return;
        }

        // Coerce the column index to the closest visible column
        columnHeader = grid.columnManager.getVisibleHeaderClosestToIndex(Ext.isNumber(columnHeader) ? columnHeader : columnHeader.getVisibleIndex());

        // No corresponding column. Possible if all columns have been moved to the other side of a lockable grid pair
        if (!columnHeader) {
            return;
        }

        colIdx = columnHeader.getVisibleIndex();

        if (Ext.isNumber(record)) {
            // look up record if numeric row index was passed
            rowIdx = record;
            record = view.getRecord(gridRow);
        } else {
            rowIdx = view.indexOf(gridRow);
        }

        // The record may be removed from the store but the view
        // not yet updated, so check it exists
        if (!record) {
            return;
        }

        return {
            grid   : grid,
            view   : view,
            store  : view.dataSource,
            record : record,
            field  : columnHeader.dataIndex,
            value  : record.get(columnHeader.dataIndex),
            row    : gridRow,
            column : columnHeader,
            rowIdx : rowIdx,
            colIdx : colIdx
        };
    },

    /**
     * Cancels any active edit that is in progress.
     */
    cancelEdit: function() {
        var me = this;

        me.editing = false;
        me.fireEvent('canceledit', me, me.context);
    },

    /**
     * Completes the edit if there is an active edit in progress.
     */
    completeEdit: function() {
        var me = this;

        if (me.editing && me.validateEdit()) {
            me.fireEvent('edit', me, me.context);
        }

        me.context = null;
        me.editing = false;
    },

    // @abstract
    validateEdit: function() {
        var me = this,
            context = me.context;

        return me.fireEvent('validateedit', me, context) !== false && !context.cancel;
    }
});