/* eslint-disable @typescript-eslint/no-non-null-assertion */
import { Vec } from '@tldraw/vec';
import { Utils } from '@tldraw/core';
import {
    AlignType,
    TldrawCommand,
    TDShapeType,
} from '@toeverything/components/board-types';
import { TLDR } from '@toeverything/components/board-state';
import type { TldrawApp } from '@toeverything/components/board-state';

export function alignShapes(
    app: TldrawApp,
    ids: string[],
    type: AlignType
): TldrawCommand {
    const { currentPageId } = app;

    const initialShapes = ids.map(id => app.getShape(id));

    const boundsForShapes = initialShapes.map(shape => {
        return {
            id: shape.id,
            point: [...shape.point],
            bounds: TLDR.get_bounds(shape),
        };
    });

    const commonBounds = Utils.getCommonBounds(
        boundsForShapes.map(({ bounds }) => bounds)
    );

    const midX = commonBounds.minX + commonBounds.width / 2;
    const midY = commonBounds.minY + commonBounds.height / 2;

    const deltaMap = Object.fromEntries(
        boundsForShapes.map(({ id, point, bounds }) => {
            return [
                id,
                {
                    prev: point,
                    next: {
                        [AlignType.CenterVertical]: [
                            point[0],
                            midY - bounds.height / 2,
                        ],
                        [AlignType.CenterHorizontal]: [
                            midX - bounds.width / 2,
                            point[1],
                        ],
                        [AlignType.Top]: [point[0], commonBounds.minY],
                        [AlignType.Bottom]: [
                            point[0],
                            commonBounds.maxY - bounds.height,
                        ],
                        [AlignType.Left]: [commonBounds.minX, point[1]],
                        [AlignType.Right]: [
                            commonBounds.maxX - bounds.width,
                            point[1],
                        ],
                    }[type],
                },
            ];
        })
    );

    const { before, after } = TLDR.mutate_shapes(
        app.state,
        ids,
        shape => {
            if (!deltaMap[shape.id]) return shape;
            return { point: deltaMap[shape.id].next };
        },
        currentPageId
    );

    initialShapes.forEach(shape => {
        if (shape.type === TDShapeType.Group) {
            const delta = Vec.sub(
                after[shape.id].point!,
                before[shape.id].point!
            );

            shape.children.forEach(id => {
                const child = app.getShape(id);
                before[child.id] = { point: child.point };
                after[child.id] = { point: Vec.add(child.point, delta) };
            });

            delete before[shape.id];
            delete after[shape.id];
        }
    });

    return {
        id: 'align',
        before: {
            document: {
                pages: {
                    [currentPageId]: {
                        shapes: before,
                    },
                },
                pageStates: {
                    [currentPageId]: {
                        selectedIds: ids,
                    },
                },
            },
        },
        after: {
            document: {
                pages: {
                    [currentPageId]: {
                        shapes: after,
                    },
                },
                pageStates: {
                    [currentPageId]: {
                        selectedIds: ids,
                    },
                },
            },
        },
    };
}