/**
 * @module modules/history
 */

import type { CanUndef, IStack } from 'jodit/types';
import type { Command } from './command';

export class Stack implements IStack {
	private readonly commands: Command[] = [];
	private stackPosition: number = -1;

	constructor(private readonly size: number) {}

	get length(): number {
		return this.commands.length;
	}

	private clearRedo(): void {
		this.commands.length = this.stackPosition + 1;
	}

	clear(): void {
		this.commands.length = 0;
		this.stackPosition = -1;
	}

	push(command: Command): void {
		this.clearRedo();
		this.commands.push(command);
		this.stackPosition += 1;

		if (this.commands.length > this.size) {
			this.commands.shift();
			this.stackPosition -= 1;
		}
	}

	replace(command: Command): void {
		this.commands[this.stackPosition] = command;
	}

	current(): CanUndef<Command> {
		return this.commands[this.stackPosition];
	}

	undo(): boolean {
		if (this.canUndo()) {
			if (this.commands[this.stackPosition]) {
				this.commands[this.stackPosition].undo();
			}

			this.stackPosition -= 1;

			return true;
		}

		return false;
	}

	redo(): boolean {
		if (this.canRedo()) {
			this.stackPosition += 1;

			if (this.commands[this.stackPosition]) {
				this.commands[this.stackPosition].redo();
			}

			return true;
		}

		return false;
	}

	canUndo(): boolean {
		return this.stackPosition >= 0;
	}

	canRedo(): boolean {
		return this.stackPosition < this.commands.length - 1;
	}
}