import { CircleEntity } from '../entities/CircleEntity';
import type { Point } from '@flatten-js/core';
import {
	addEntities,
	getActiveLayerId,
	getActiveLineColor,
	getActiveLineDash,
	getActiveLineWidth,
	setAngleGuideOriginPoint,
	setGhostHelperEntities,
	setSelectedEntityIds,
	setShouldDrawHelpers,
} from '../state';
import type { DrawEvent, PointInputEvent, StateEvent, ToolContext } from './tool.types';
import { Tool } from '../tools';
import { assign, createMachine } from 'xstate';
import { pointDistance } from '../helpers/distance-between-points';
import { LineState } from './line-tool.ts';
import { getPointFromEvent } from '../helpers/get-point-from-event.ts';

export interface CircleContext extends ToolContext {
	centerPoint: Point | null;
}

export enum CircleState {
	WAITING_FOR_CENTER_POINT = 'WAITING_FOR_CENTER_POINT',
	WAITING_FOR_POINT_ON_CIRCLE = 'WAITING_FOR_POINT_ON_CIRCLE',
	INIT = 'INIT',
}

export enum CircleAction {
	INIT_CIRCLE_TOOL = 'INIT_CIRCLE_TOOL',
	RECORD_START_POINT = 'RECORD_START_POINT',
	DRAW_TEMP_CIRCLE = 'DRAW_TEMP_CIRCLE',
	DRAW_FINAL_CIRCLE = 'DRAW_FINAL_CIRCLE',
}

export const circleToolStateMachine = createMachine(
	{
		types: {} as {
			context: CircleContext;
			events: StateEvent;
		},
		context: {
			centerPoint: null,
			type: Tool.CIRCLE,
		},
		initial: CircleState.INIT,
		states: {
			[CircleState.INIT]: {
				description: 'Initializing the circle tool',
				always: {
					actions: CircleAction.INIT_CIRCLE_TOOL,
					target: CircleState.WAITING_FOR_CENTER_POINT,
				},
			},
			[CircleState.WAITING_FOR_CENTER_POINT]: {
				description: 'Select the center point of the circle tool',
				meta: {
					instructions: 'Select the center point of the circle',
				},
				on: {
					MOUSE_CLICK: {
						actions: CircleAction.RECORD_START_POINT,
						target: CircleState.WAITING_FOR_POINT_ON_CIRCLE,
					},
					ABSOLUTE_POINT_INPUT: {
						actions: CircleAction.RECORD_START_POINT,
						target: CircleState.WAITING_FOR_POINT_ON_CIRCLE,
					},
				},
			},
			[CircleState.WAITING_FOR_POINT_ON_CIRCLE]: {
				description: 'Select a point on the circle',
				meta: {
					instructions: 'Select the point on the circle',
				},
				on: {
					DRAW: {
						actions: CircleAction.DRAW_TEMP_CIRCLE,
					},
					MOUSE_CLICK: {
						actions: CircleAction.DRAW_FINAL_CIRCLE,
						target: CircleState.INIT,
					},
					NUMBER_INPUT: {
						actions: CircleAction.DRAW_FINAL_CIRCLE,
						target: LineState.INIT,
					},
					ABSOLUTE_POINT_INPUT: {
						actions: CircleAction.DRAW_FINAL_CIRCLE,
						target: LineState.INIT,
					},
					RELATIVE_POINT_INPUT: {
						actions: CircleAction.DRAW_FINAL_CIRCLE,
						target: LineState.INIT,
					},
					ESC: {
						target: CircleState.INIT,
					},
				},
			},
		},
	},
	{
		actions: {
			[CircleAction.INIT_CIRCLE_TOOL]: assign(() => {
				setShouldDrawHelpers(true);
				setGhostHelperEntities([]);
				setSelectedEntityIds([]);
				setAngleGuideOriginPoint(null);
				return {
					centerPoint: null,
				};
			}),
			[CircleAction.RECORD_START_POINT]: assign(({ event }) => {
				const startPoint = getPointFromEvent(null, event as PointInputEvent);
				setAngleGuideOriginPoint(startPoint);
				return {
					centerPoint: startPoint,
				};
			}),
			[CircleAction.DRAW_TEMP_CIRCLE]: ({ context, event }) => {
				const activeCircle = new CircleEntity(
					getActiveLayerId(),
					context.centerPoint as Point,
					pointDistance(
						(event as DrawEvent).drawController.getWorldMouseLocation(),
						context.centerPoint as Point
					)
				);
				activeCircle.lineColor = getActiveLineColor();
				activeCircle.lineWidth = getActiveLineWidth();
				activeCircle.lineDash = getActiveLineDash();
				setGhostHelperEntities([activeCircle]);
			},
			[CircleAction.DRAW_FINAL_CIRCLE]: assign(({ context, event }) => {
				if (!context.centerPoint) {
					throw new Error(
						'Trying to DRAW_FINAL_CIRCLE when centerPoint is not yet defined in circle tool'
					);
				}
				const pointOnCircle: Point = getPointFromEvent(
					context.centerPoint,
					event as PointInputEvent
				);
				const activeCircle = new CircleEntity(
					getActiveLayerId(),
					context.centerPoint as Point,
					pointDistance(pointOnCircle, context.centerPoint as Point)
				);
				activeCircle.lineColor = getActiveLineColor();
				activeCircle.lineWidth = getActiveLineWidth();
				activeCircle.lineDash = getActiveLineDash();
				addEntities([activeCircle], true);

				setGhostHelperEntities([]);
				return {
					centerPoint: null,
				};
			}),
		},
	}
);