import type { Point } from '@flatten-js/core';
import { LineEntity } from '../entities/LineEntity';
import {
	addEntities,
	getActiveLayerId,
	getActiveLineColor,
	getActiveLineDash,
	getActiveLineWidth,
	setActiveToolActor,
	setAngleGuideOriginPoint,
	setGhostHelperEntities,
	setSelectedEntityIds,
	setShouldDrawHelpers,
} from '../state';
import { Tool } from '../tools';
import { Actor, assign, createMachine } from 'xstate';
import type { DrawEvent, PointInputEvent, StateEvent, ToolContext } from './tool.types';
import { selectToolStateMachine } from './select-tool.ts';
import { getPointFromEvent } from '../helpers/get-point-from-event.ts';

export interface LineContext extends ToolContext {
	startPoint: Point | null;
}

export enum LineState {
	INIT = 'INIT',
	WAITING_FOR_START_POINT = 'WAITING_FOR_START_POINT',
	WAITING_FOR_END_POINT = 'WAITING_FOR_END_POINT',
}

export enum LineAction {
	INIT_LINE_TOOL = 'INIT_LINE_TOOL',
	RECORD_START_POINT = 'RECORD_START_POINT',
	DRAW_TEMP_LINE = 'DRAW_TEMP_LINE',
	DRAW_FINAL_LINE = 'DRAW_FINAL_LINE',
	SWITCH_TO_SELECT_TOOL = 'SWITCH_TO_SELECT_TOOL',
}

export const lineToolStateMachine = createMachine(
	{
		types: {} as {
			context: LineContext;
			events: StateEvent;
		},
		context: {
			startPoint: null,
			type: Tool.LINE,
		},
		initial: LineState.INIT,
		states: {
			[LineState.INIT]: {
				description: 'Initializing the line tool',
				always: {
					actions: LineAction.INIT_LINE_TOOL,
					target: LineState.WAITING_FOR_START_POINT,
				},
			},
			[LineState.WAITING_FOR_START_POINT]: {
				description: 'Select the start point of the line',
				meta: {
					instructions: 'Select the start point of the line',
				},
				on: {
					MOUSE_CLICK: {
						actions: LineAction.RECORD_START_POINT,
						target: LineState.WAITING_FOR_END_POINT,
					},
					ABSOLUTE_POINT_INPUT: {
						actions: LineAction.RECORD_START_POINT,
						target: LineState.WAITING_FOR_END_POINT,
					},
					ESC: {
						actions: LineAction.SWITCH_TO_SELECT_TOOL,
					},
				},
			},
			[LineState.WAITING_FOR_END_POINT]: {
				description: 'Select the end point of the line',
				meta: {
					instructions: 'Select the end point of the line',
				},
				on: {
					DRAW: {
						actions: LineAction.DRAW_TEMP_LINE,
					},
					MOUSE_CLICK: {
						actions: LineAction.DRAW_FINAL_LINE,
						target: LineState.WAITING_FOR_END_POINT,
					},
					NUMBER_INPUT: {
						actions: LineAction.DRAW_FINAL_LINE,
						target: LineState.WAITING_FOR_END_POINT,
					},
					ABSOLUTE_POINT_INPUT: {
						actions: LineAction.DRAW_FINAL_LINE,
						target: LineState.WAITING_FOR_END_POINT,
					},
					RELATIVE_POINT_INPUT: {
						actions: LineAction.DRAW_FINAL_LINE,
						target: LineState.WAITING_FOR_END_POINT,
					},
					ESC: {
						target: LineState.INIT,
					},
					ENTER: {
						target: LineState.INIT,
					},
				},
			},
		},
	},
	{
		actions: {
			[LineAction.INIT_LINE_TOOL]: assign(() => {
				setShouldDrawHelpers(true);
				setSelectedEntityIds([]);
				setGhostHelperEntities([]);
				setAngleGuideOriginPoint(null);
				return {
					startPoint: null,
				};
			}),
			[LineAction.RECORD_START_POINT]: assign(({ event }) => {
				const startPoint = getPointFromEvent(null, event as PointInputEvent);
				setAngleGuideOriginPoint(startPoint);
				return {
					startPoint,
				};
			}),
			[LineAction.DRAW_TEMP_LINE]: ({ context, event }) => {
				const activeLine = new LineEntity(
					getActiveLayerId(),
					context.startPoint as Point,
					(event as DrawEvent).drawController.getWorldMouseLocation()
				);
				activeLine.lineColor = getActiveLineColor();
				activeLine.lineWidth = getActiveLineWidth();
				activeLine.lineDash = getActiveLineDash();
				setGhostHelperEntities([activeLine]);
			},
			[LineAction.DRAW_FINAL_LINE]: assign(({ context, event }) => {
				if (!context.startPoint) {
					throw new Error('Start point is not set during DRAW_FINAL_LINE in LineEntity');
				}

				const endPoint = getPointFromEvent(context.startPoint, event as PointInputEvent);
				const activeLine = new LineEntity(
					getActiveLayerId(),
					context.startPoint as Point,
					endPoint
				);
				activeLine.lineColor = getActiveLineColor();
				activeLine.lineWidth = getActiveLineWidth();
				activeLine.lineDash = getActiveLineDash();
				addEntities([activeLine], true);

				// Keep drawing from the last point
				setGhostHelperEntities([new LineEntity(getActiveLayerId(), endPoint, endPoint)]);
				setAngleGuideOriginPoint(endPoint);
				return {
					startPoint: endPoint,
				};
			}),
			[LineAction.SWITCH_TO_SELECT_TOOL]: () => {
				setActiveToolActor(new Actor(selectToolStateMachine));
			},
		},
	}
);