import {
	OnKeyDownEventArgs,
	SlickDataView,
	SlickEventData,
	SlickGrid,
} from "slickgrid";

import {
	IExternalVariables,
	IHotKeysBehavior,
	ISlickRow,
	ISlickTable,
	TGridRow,
} from "shared/model/types";

import {
	copySelectedRows,
	hotKeysCopy,
	hotKeysDelete,
	hotKeysRedo,
	hotKeysUndo,
	nothingToCopy,
} from "../../../lib";

export class DefaultHotKeys implements IHotKeysBehavior {
	private externalVariables: IExternalVariables = {};
	private commandQueue: ISlickRow[][] = [];
	private queueIndex = -1;

	private getQueueIndex(): number {
		return this.queueIndex;
	}
	private setQueueIndex(queueIndex: number): void {
		this.queueIndex = queueIndex;
	}

	public handleKeyboardEvent(
		event: SlickEventData<OnKeyDownEventArgs>,
		table: ISlickTable,
	): void {
		if (!table.isActive) return;
		const grid = table.grid;
		if (!grid || !grid.getOptions().editable) return;
		const dataView: SlickDataView = grid.getData();
		if (hotKeysCopy(event)) {
			event.preventDefault();
			event.stopImmediatePropagation();
			if (nothingToCopy(grid)) return;
			copySelectedRows(grid);
			grid.invalidate();
			this.pushToCommandQueue(grid);
			table.isEdited = true;
		} else if (hotKeysDelete(event)) {
			event.preventDefault();
			event.stopImmediatePropagation();
			const selectedRows = grid.getSelectedRows();
			if (!selectedRows.length) return;
			selectedRows.forEach((rowNumber): void => {
				const row = dataView.getItem<TGridRow>(rowNumber);
				row.isDeleted = true;
			});
			grid.setSelectedRows([]);
			dataView.refresh();
			grid.invalidate();
			this.pushToCommandQueue(grid);
			table.isEdited = true;
		} else if (hotKeysUndo(event)) {
			event.preventDefault();
			event.stopImmediatePropagation();
			const queueIndex = this.getQueueIndex();
			if (queueIndex < 1) {
				return;
			}
			const newQueueIndex = queueIndex - 1;
			this.setQueueIndex(newQueueIndex);
			dataView.setItems(copy(this.commandQueue[newQueueIndex]));
			grid.invalidate();
			table.isEdited = newQueueIndex !== 0;
		} else if (hotKeysRedo(event)) {
			event.preventDefault();
			event.stopImmediatePropagation();
			const queueIndex = this.getQueueIndex();
			if (queueIndex === this.commandQueue.length - 1) return;
			const newQueueIndex = queueIndex + 1;
			this.setQueueIndex(newQueueIndex);
			dataView.setItems(copy(this.commandQueue[newQueueIndex]));
			grid.invalidate();
			table.isEdited = true;
		}
	}
	public pushToCommandQueue(grid: SlickGrid | null): void {
		if (!grid) return;
		const dataView: SlickDataView = grid.getData();
		const rows = dataView.getItems();
		const queueIndex = this.getQueueIndex();
		const newQueueIndex = queueIndex + 1;
		this.commandQueue.length = newQueueIndex;
		this.commandQueue.push(copy(rows));
		this.setQueueIndex(newQueueIndex);
	}
	public resetQueue(): void {
		this.commandQueue.length = 0;
		this.queueIndex = -1;
	}
	public setExternalVariables(variables: IExternalVariables): void {
		this.externalVariables = { ...this.externalVariables, ...variables };
	}
	public getExternalVariables(): IExternalVariables {
		return this.externalVariables;
	}
}

function copy(rows: ISlickRow[]): ISlickRow[] {
	return rows.map((row) => ({ ...row }));
}