// oxlint-disable typescript/no-empty-object-type
import {
	Group2d,
	HandleSnapGeometry,
	SVGContainer,
	ShapeUtil,
	SvgExportContext,
	TLHandle,
	TLHandleDragInfo,
	TLLineShape,
	TLLineShapePoint,
	TLResizeInfo,
	Vec,
	WeakCache,
	ZERO_INDEX_KEY,
	assert,
	getColorValue,
	getIndexAbove,
	getIndexBetween,
	getIndices,
	lerp,
	lineShapeMigrations,
	lineShapeProps,
	mapObjectMapValues,
	maybeSnapToGrid,
	sortByIndex,
	useColorMode,
} from '@tldraw/editor'
import { STROKE_SIZES } from '../shared/default-shape-constants'
import { ShapeOptionsWithDisplayValues, getDisplayValues } from '../shared/getDisplayValues'
import { PathBuilder, PathBuilderGeometry2d } from '../shared/PathBuilder'

const handlesCache = new WeakCache<TLLineShape['props'], TLHandle[]>()

/** @public */
export interface LineShapeUtilDisplayValues {
	strokeColor: string
	strokeWidth: number
}

/** @public */
export interface LineShapeOptions extends ShapeOptionsWithDisplayValues<
	TLLineShape,
	LineShapeUtilDisplayValues
> {}

/** @public */
export class LineShapeUtil extends ShapeUtil<TLLineShape> {
	static override type = 'line' as const
	static override props = lineShapeProps
	static override migrations = lineShapeMigrations

	override options: LineShapeOptions = {
		getDefaultDisplayValues(_editor, shape, theme, colorMode): LineShapeUtilDisplayValues {
			const { color, size } = shape.props
			return {
				strokeColor: getColorValue(theme.colors[colorMode], color, 'solid'),
				strokeWidth: theme.strokeWidth * STROKE_SIZES[size],
			}
		},
		getCustomDisplayValues(): Partial<LineShapeUtilDisplayValues> {
			return {}
		},
	}

	override hideResizeHandles(shape: TLLineShape) {
		return true
	}
	override hideRotateHandle(shape: TLLineShape) {
		return true
	}
	override hideSelectionBoundsFg(shape: TLLineShape) {
		return true
	}
	override hideSelectionBoundsBg(shape: TLLineShape) {
		return true
	}
	override hideInMinimap() {
		return true
	}

	override getDefaultProps(): TLLineShape['props'] {
		const [start, end] = getIndices(2)
		return {
			dash: 'draw',
			size: 'm',
			color: 'black',
			spline: 'line',
			points: {
				[start]: { id: start, index: start, x: 0, y: 0 },
				[end]: { id: end, index: end, x: 0.1, y: 0.1 },
			},
			scale: 1,
		}
	}

	getGeometry(shape: TLLineShape) {
		// todo: should we have min size?
		const geometry = getPathForLineShape(shape).toGeometry()
		assert(geometry instanceof PathBuilderGeometry2d)
		return geometry
	}

	override getHandles(shape: TLLineShape) {
		return handlesCache.get(shape.props, () => {
			const spline = this.getGeometry(shape)

			const points = linePointsToArray(shape)
			const results: TLHandle[] = points.map((point) => ({
				...point,
				id: point.index,
				type: 'vertex',
				canSnap: true,
			}))

			for (let i = 0; i < points.length - 1; i++) {
				const index = getIndexBetween(points[i].index, points[i + 1].index)
				const segment = spline.getSegments()[i]
				const point = segment.interpolateAlongEdge(0.5)
				results.push({
					id: index,
					type: 'create',
					index,
					x: point.x,
					y: point.y,
					canSnap: true,
				})
			}

			return results.sort(sortByIndex)
		})
	}

	//   Events

	override onResize(shape: TLLineShape, info: TLResizeInfo<TLLineShape>) {
		const { scaleX, scaleY } = info

		return {
			props: {
				points: mapObjectMapValues(shape.props.points, (_, { id, index, x, y }) => ({
					id,
					index,
					x: x * scaleX,
					y: y * scaleY,
				})),
			},
		}
	}

	override onBeforeCreate(next: TLLineShape): void | TLLineShape {
		const {
			props: { points },
		} = next
		const pointKeys = Object.keys(points)

		if (pointKeys.length < 2) {
			return
		}

		const firstPoint = points[pointKeys[0]]
		const allSame = pointKeys.every((key) => {
			const point = points[key]
			return point.x === firstPoint.x && point.y === firstPoint.y
		})
		if (allSame) {
			const lastKey = pointKeys[pointKeys.length - 1]
			points[lastKey] = {
				...points[lastKey],
				x: points[lastKey].x + 0.1,
				y: points[lastKey].y + 0.1,
			}
			return next
		}
		return
	}

	override onHandleDrag(shape: TLLineShape, { handle }: TLHandleDragInfo<TLLineShape>) {
		const newPoint = maybeSnapToGrid(new Vec(handle.x, handle.y), this.editor)
		return {
			...shape,
			props: {
				...shape.props,
				points: {
					...shape.props.points,
					[handle.id]: { id: handle.id, index: handle.index, x: newPoint.x, y: newPoint.y },
				},
			},
		}
	}

	override onHandleDragStart(shape: TLLineShape, { handle }: TLHandleDragInfo<TLLineShape>) {
		// For line shapes, if we're dragging a "create" handle, then
		// create a new vertex handle at that point; and make this handle
		// the handle that we're dragging.
		if (handle.type === 'create') {
			return {
				...shape,
				props: {
					...shape.props,
					points: {
						...shape.props.points,
						[handle.index]: { id: handle.index, index: handle.index, x: handle.x, y: handle.y },
					},
				},
			}
		}
		return
	}

	component(shape: TLLineShape) {
		// eslint-disable-next-line react-hooks/rules-of-hooks
		const colorMode = useColorMode()
		const dv = getDisplayValues(this, shape, colorMode)
		return (
			<SVGContainer style={{ minWidth: 50, minHeight: 50 }}>
				<LineShapeSvg shape={shape} strokeColor={dv.strokeColor} strokeWidth={dv.strokeWidth} />
			</SVGContainer>
		)
	}

	override getIndicatorPath(shape: TLLineShape): Path2D {
		const strokeWidth = getDisplayValues(this, shape).strokeWidth * shape.props.scale
		const path = getPathForLineShape(shape)
		const { dash } = shape.props

		return path.toPath2D({
			style: dash === 'draw' ? 'draw' : 'solid',
			strokeWidth: 1,
			passes: 1,
			randomSeed: shape.id,
			offset: 0,
			roundness: strokeWidth * 2,
		})
	}

	override toSvg(shape: TLLineShape, ctx: SvgExportContext) {
		const dv = getDisplayValues(this, shape, ctx.colorMode)
		return (
			<LineShapeSvg
				shouldScale
				shape={shape}
				strokeColor={dv.strokeColor}
				strokeWidth={dv.strokeWidth}
			/>
		)
	}

	override getHandleSnapGeometry(shape: TLLineShape): HandleSnapGeometry {
		const points = linePointsToArray(shape)
		return {
			points,
			getSelfSnapPoints: (handle) => {
				const index = this.getHandles(shape)
					.filter((h) => h.type === 'vertex')
					.findIndex((h) => h.id === handle.id)!

				// We want to skip the current and adjacent handles
				return points.filter((_, i) => Math.abs(i - index) > 1).map(Vec.From)
			},
			getSelfSnapOutline: (handle) => {
				// We want to skip the segments that include the handle, so
				// find the index of the handle that shares the same index property
				// as the initial dragging handle; this catches a quirk of create handles
				const index = this.getHandles(shape)
					.filter((h) => h.type === 'vertex')
					.findIndex((h) => h.id === handle.id)!

				// Get all the outline segments from the shape that don't include the handle
				const segments = this.getGeometry(shape)
					.getSegments()
					.filter((_, i) => i !== index - 1 && i !== index)

				if (!segments.length) return null
				return new Group2d({ children: segments })
			},
		}
	}
	override getInterpolatedProps(
		startShape: TLLineShape,
		endShape: TLLineShape,
		t: number
	): TLLineShape['props'] {
		const startPoints = linePointsToArray(startShape)
		const endPoints = linePointsToArray(endShape)

		const pointsToUseStart: TLLineShapePoint[] = []
		const pointsToUseEnd: TLLineShapePoint[] = []

		let index = ZERO_INDEX_KEY

		if (startPoints.length > endPoints.length) {
			// we'll need to expand points
			for (let i = 0; i < startPoints.length; i++) {
				pointsToUseStart[i] = { ...startPoints[i] }
				if (endPoints[i] === undefined) {
					pointsToUseEnd[i] = { ...endPoints[endPoints.length - 1], id: index }
				} else {
					pointsToUseEnd[i] = { ...endPoints[i], id: index }
				}
				index = getIndexAbove(index)
			}
		} else if (endPoints.length > startPoints.length) {
			// we'll need to converge points
			for (let i = 0; i < endPoints.length; i++) {
				pointsToUseEnd[i] = { ...endPoints[i] }
				if (startPoints[i] === undefined) {
					pointsToUseStart[i] = {
						...startPoints[startPoints.length - 1],
						id: index,
					}
				} else {
					pointsToUseStart[i] = { ...startPoints[i], id: index }
				}
				index = getIndexAbove(index)
			}
		} else {
			// noop, easy
			for (let i = 0; i < endPoints.length; i++) {
				pointsToUseStart[i] = startPoints[i]
				pointsToUseEnd[i] = endPoints[i]
			}
		}

		return {
			...(t > 0.5 ? endShape.props : startShape.props),
			points: Object.fromEntries(
				pointsToUseStart.map((point, i) => {
					const endPoint = pointsToUseEnd[i]
					return [
						point.id,
						{
							...point,
							x: lerp(point.x, endPoint.x, t),
							y: lerp(point.y, endPoint.y, t),
						},
					]
				})
			),
			scale: lerp(startShape.props.scale, endShape.props.scale, t),
		}
	}
}

function linePointsToArray(shape: TLLineShape) {
	return Object.values(shape.props.points).sort(sortByIndex)
}

const pathCache = new WeakCache<TLLineShape, PathBuilder>()
function getPathForLineShape(shape: TLLineShape): PathBuilder {
	return pathCache.get(shape, () => {
		const points = linePointsToArray(shape).map(Vec.From)

		switch (shape.props.spline) {
			case 'cubic': {
				return PathBuilder.cubicSplineThroughPoints(points, { endOffsets: 0 })
			}
			case 'line': {
				return PathBuilder.lineThroughPoints(points, { endOffsets: 0 })
			}
		}
	})
}

function LineShapeSvg({
	shape,
	shouldScale = false,
	forceSolid = false,
	strokeColor,
	strokeWidth: baseStrokeWidth,
}: {
	shape: TLLineShape
	shouldScale?: boolean
	forceSolid?: boolean
	strokeColor: string
	strokeWidth: number
}) {
	const path = getPathForLineShape(shape)
	const { dash } = shape.props

	const scaleFactor = 1 / shape.props.scale

	const scale = shouldScale ? scaleFactor : 1

	const strokeWidth = baseStrokeWidth * shape.props.scale

	return path.toSvg({
		style: dash,
		strokeWidth,
		forceSolid,
		randomSeed: shape.id,
		props: {
			transform: `scale(${scale})`,
			stroke: strokeColor,
			fill: 'none',
		},
	})
}