import { isUndefined, isDate, toggleClass, addClass} from '@grapecity/wijmo';
/**
 * Class that highlights cells that have been edited in a FlexGrid.
 */
export class EditHighlighter {
    /**
     * Initializes a new instance of the {@link EditHighlighter} class.
     *
     * @param grid FlexGrid to highlight.
     * @param cssClass Class name to apply to changed cells.
     */
    constructor(grid, cssClass) {
        this._originalValue = null;
        this._originalValues = new Map();
        this._grid = grid;
        let cellChanging = this._cellChanging.bind(this),
            cellChanged = this._cellChanged.bind(this);
        grid.beginningEdit.addHandler(cellChanging);
        grid.cellEditEnded.addHandler(cellChanged);
        grid.pastingCell.addHandler(cellChanging);
        grid.pastedCell.addHandler(cellChanged);
        // grid.formatItem.addHandler((s, e) => {
        //     if (e.panel == s.cells) {
        //         let changed = this._hasChange(e.getRow().dataItem, e.getColumn().binding);
        //         toggleClass(e.cell, 'cell-changed', changed);
        //     }
        // });
    }
    /**
     * Clears all the changes and removes all highlights.
     */
    clearChanges() {
        this._originalValues.clear();
        this._grid.invalidate();
    }
    // checks whether a cell has changed
    _hasChange(item, binding) {
        item = this._originalValues.get(item);
        return item != null && !isUndefined(item[binding]);
    }
    // handles cell changing (edit or paste)
    _cellChanging(s, e) {
        this._originalValue = s.getCellData(e.row, e.col, false);
    }
    // handles cell changed (edit or paste)
    _cellChanged(s, e) {
        let newValue = s.getCellData(e.row, e.col, false);
        this._storeChange(e.getRow().dataItem, e.getColumn().binding, this._originalValue, newValue);
        const cellElement = e.panel.getCellElement(e.row, e.col);
        addClass(cellElement, 'cell-changed');
    
    }
    // store a change into the _originalValues map
    _storeChange(item, binding, originalValue, newValue) {
        // get the item with the original values
        let editItem = this._originalValues.get(item);
        if (editItem == null) {
            editItem = {};
            this._originalValues.set(item, editItem);
        }
        // get the original value from the item if possible
        let editValue = editItem[binding];
        if (!isUndefined(editValue)) {
            originalValue = editValue;
        }
        // store or clear the change
        if (this._sameValue(originalValue, newValue)) {
            delete editItem[binding];
            if (Object.keys(editItem).length == 0) {
                this._originalValues.delete(item);
            }
        }
        else {
            editItem[binding] = originalValue;
        }
    }
    // compare two values taking dates into account
    _sameValue(item1, item2) {
        if (item1 === item2) {
            return true;
        }
        if (isDate(item1) && isDate(item2)) {
            return item1.getTime() == item2.getTime();
        }
        return false;
    }
}