Aislo/B07_DesignDetail/openwebcad/src/helpers/undo-stack.ts

export interface UndoState {
	variable: StateVariable;

	// biome-ignore lint/suspicious/noExplicitAny: TODO list all undo state types
	value: any;
}

export enum StateVariable {
	canvasSize = 'canvasSize',
	canvas = 'canvas',
	context = 'context',
	screenMouseLocation = 'screenMouseLocation',
	activeTool = 'activeTool',
	entities = 'entities',
	activeEntity = 'activeEntity',
	shouldDrawCursor = 'shouldDrawCursor',
	helperEntities = 'helperEntities',
	debugEntities = 'debugEntities',
	angleStep = 'angleStep',
	screenOffset = 'screenOffset',
	screenZoom = 'screenZoom',
	panStartLocation = 'panStartLocation',
	snapPoint = 'snapPoint',
	snapPointOnAngleGuide = 'snapPointOnAngleGuide',
	hoveredSnapPoints = 'hoveredSnapPoints',
	lastDrawTimestamp = 'lastDrawTimestamp',
	activeLineColor = 'activeLineColor',
	activeLineWidth = 'activeLineWidth',
	activeLineDash = 'activeLineDash',
	activeTextStyle = 'activeTextStyle',
	designMeta = 'designMeta',
	layers = 'layers',
}

/**
 * Based on https://github.com/wobsoriano/undo-stacker
 */
export function createStack() {
	let stack: UndoState[] = [];

	let index = stack.length;

	function peek() {
		return stack[index - 1];
	}

	return {
		push: (value: UndoState) => {
			stack.length = index;
			stack[index++] = value;

			// console.log('stack push', JSON.stringify(stack, null, 2));
			return peek();
		},
		replace: (value: UndoState) => {
			stack[index - 1] = value;

			// console.log('stack replace', JSON.stringify(stack, null, 2));
			return peek();
		},
		peek: () => {
			return peek();
		},
		undo: () => {
			if (index > 1) index -= 1;

			// console.log('stack undo', JSON.stringify(stack, null, 2));
			return peek();
		},
		redo: () => {
			if (index < stack.length) index += 1;

			// console.log('stack redo', JSON.stringify(stack, null, 2));
			return peek();
		},
		// Clear certain states from the undo stack
		clear: (variable: StateVariable) => {
			// Update the index be reducing it by the number of states that are removed to the left of the index
			index = index - stack.slice(0, index).filter((state) => state.variable === variable).length;

			stack = stack.filter((state) => state.variable !== variable);
		},
	};
}