import { describe, expect, it } from 'vitest';
import { DeleteAssetCommand } from '../../src/core/commands/assetCommands';
import {
  MoveSceneObjectCommand,
  RemoveSceneObjectsCommand,
  ReorderObjectCommand,
  SetParentCommand,
} from '../../src/core/commands/sceneObjectCommands';
import { type Graph, GraphInterpreter, worldPositionOf } from '../../src/core/graph';
import {
  ancestorIdsOf,
  descendantsOf,
  findObject,
  type ObjectTree,
  treeOrder,
  hierarchyRows,
} from '../../src/core/model/hierarchy';
import { findScene } from '../../src/core/model/Project';
import { localPositionFor } from '../../src/core/properties/transform';
import { deserializeProject, serializeProject } from '../../src/core/store/serialize';
import {
  fakeContext,
  fakeEntity,
  makeBehavior,
  makeSpriteScene,
  place,
  roundTrip,
  startWorld,
  fire,
} from '../helpers';

/** Three boxes, all top level: a at (100,100,z1), b at (10,0), c at (0,5). */
function threeBoxes() {
  const f = makeSpriteScene();
  const a = place(f, f.spriteId, { x: 100, y: 100, z: 1 });
  const b = place(f, f.spriteId, { x: 10, y: 0 });
  const c = place(f, f.spriteId, { x: 0, y: 5 });
  return { ...f, a, b, c };
}

describe('scene hierarchy', () => {
  it('re-parenting keeps the world position and moves children along with the parent', () => {
    const { project, stack, sceneId, a, b, c, sceneOf, object, world } = threeBoxes();
    stack.execute(new SetParentCommand(sceneId, b, a));
    // b stays at world (10,0): local becomes (-90,-100,-1).
    expect(object(b).parentId).toBe(a);
    expect(object(b).position).toEqual({ x: -90, y: -100, z: -1 });
    expect(world(b)).toEqual({ x: 10, y: 0, z: 0 });

    stack.execute(new SetParentCommand(sceneId, c, b));
    expect(world(c)).toEqual({ x: 0, y: 5, z: 0 });

    // Moving the root drags the whole subtree.
    stack.execute(new MoveSceneObjectCommand(sceneId, a, { x: 200, y: 100, z: 1 }));
    expect(world(b)).toEqual({ x: 110, y: 0, z: 0 });
    expect(world(c)).toEqual({ x: 100, y: 5, z: 0 });

    // Undo restores the previous parent and local position exactly.
    stack.undo();
    stack.undo();
    expect(object(c).parentId).toBe('');
    expect(object(c).position).toEqual({ x: 0, y: 5, z: 0 });
    stack.undo();
    expect(object(b).parentId).toBe('');
    expect(object(b).position).toEqual({ x: 10, y: 0, z: 0 });

    expect(localPositionFor(project, sceneOf(), a, { x: 100, y: 100, z: 1 })).toEqual({ x: 0, y: 0, z: 0 });
  });

  it('refuses cycles and self-parenting', () => {
    const { stack, sceneId, a, b, c } = threeBoxes();
    stack.execute(new SetParentCommand(sceneId, b, a));
    stack.execute(new SetParentCommand(sceneId, c, b));
    expect(() => stack.execute(new SetParentCommand(sceneId, a, a))).toThrow(/own parent/);
    expect(() => stack.execute(new SetParentCommand(sceneId, a, c))).toThrow(/own children/);
    expect(() => stack.execute(new SetParentCommand(sceneId, a, b))).toThrow(/own children/);
  });

  it('lists objects in tree order and descendants depth-first', () => {
    const { stack, sceneId, a, b, c, sceneOf } = threeBoxes();
    // Storage order is a, b, c; parent c under a → c is shown right after a, before b.
    stack.execute(new SetParentCommand(sceneId, c, a));
    expect(treeOrder(sceneOf()).map((e) => [e.object.id, e.depth])).toEqual([
      [a, 0],
      [c, 1],
      [b, 0],
    ]);
    stack.execute(new SetParentCommand(sceneId, b, c));
    expect(descendantsOf(sceneOf(), a).map((o) => o.id)).toEqual([c, b]);
  });

  it('hides the subtrees of collapsed objects and marks the rows that can fold', () => {
    const { stack, sceneId, a, b, c, sceneOf } = threeBoxes();
    // a > c > b: two levels, so folding a hides both descendants.
    stack.execute(new SetParentCommand(sceneId, c, a));
    stack.execute(new SetParentCommand(sceneId, b, c));
    const rows = (expanded: string[]) =>
      hierarchyRows(sceneOf(), new Set(expanded)).flatMap((e) =>
        e.kind === 'object' ? [[e.object.id, e.depth, e.hasChildren]] : [],
      );

    // Nothing expanded (the default when a scene is opened) – only the top level is listed.
    expect(rows([])).toEqual([[a, 0, true]]);
    expect(rows([a])).toEqual([
      [a, 0, true],
      [c, 1, true],
    ]);
    expect(rows([a, c])).toEqual([
      [a, 0, true],
      [c, 1, true],
      [b, 2, false],
    ]);
    // Expanding a nested object without its parent shows nothing extra: every ancestor must be open.
    expect(rows([c])).toEqual([[a, 0, true]]);
  });

  it('lists the ancestors of an object nearest first, so a selection can be unfolded', () => {
    const { stack, sceneId, a, b, c, sceneOf } = threeBoxes();
    stack.execute(new SetParentCommand(sceneId, c, a));
    stack.execute(new SetParentCommand(sceneId, b, c));
    expect(ancestorIdsOf(sceneOf(), b)).toEqual([c, a]);
    expect(ancestorIdsOf(sceneOf(), a)).toEqual([]);
  });

  it('removing an object or deleting an asset takes the subtree along, undo restores it', () => {
    const f = threeBoxes();
    const { project, stack, sceneId, spriteId, a, b, c, sceneOf, object } = f;
    const logic = place(f, makeBehavior(f, 'Logic').id, { x: 0, y: 0 }, a);
    expect(object(logic).position).toEqual({ x: -100, y: -100, z: -1 });
    stack.execute(new SetParentCommand(sceneId, b, a));

    stack.execute(new RemoveSceneObjectsCommand(sceneId, [a]));
    expect(sceneOf().objects.map((o) => o.id)).toEqual([c]);
    stack.undo();
    expect(sceneOf().objects.map((o) => o.id)).toEqual([a, b, c, logic]);
    expect(object(b).parentId).toBe(a);

    // Deleting the sprite asset removes a, b, c – and the behavior parented below a.
    stack.execute(new DeleteAssetCommand(spriteId));
    expect(sceneOf().objects).toHaveLength(0);
    stack.undo();
    expect(sceneOf().objects.map((o) => o.id)).toEqual([a, b, c, logic]);
    expect(project.assets.map((x) => x.id)).toContain(spriteId);
  });

  it('a behavior is parented like any object: validated, kept across a round trip, dropped when dangling', () => {
    const f = makeSpriteScene();
    const { project, stack, sceneId, object } = f;
    const box = place(f, f.spriteId, { x: 0, y: 0 });
    const logic = place(f, makeBehavior(f).id, { x: 0, y: 0 });
    expect(() => stack.execute(new SetParentCommand(sceneId, logic, logic))).toThrow(/own parent/);
    stack.execute(new SetParentCommand(sceneId, logic, box));
    expect(object(logic).parentId).toBe(box);
    expect(findObject(findScene(roundTrip(project), sceneId)!, logic)!.parentId).toBe(box);

    // A dangling parent is dropped by the loader.
    const raw = serializeProject(project) as { assets: { objects?: { id: string; parentId: string }[] }[] };
    raw.assets[0]!.objects!.find((o) => o.id === logic)!.parentId = 'ghost';
    expect(findObject(findScene(deserializeProject(raw), sceneId)!, logic)!.parentId).toBe('');
  });

  it('the loader drops dangling parents and breaks cycles', () => {
    const { project, stack, sceneId, a, b, c } = threeBoxes();
    stack.execute(new SetParentCommand(sceneId, b, a));
    const raw = serializeProject(project) as { assets: { objects?: Record<string, unknown>[] }[] };
    const objects = raw.assets[0]!.objects!;
    // A cycle a → c → a and a dangling reference are both cleared.
    objects[0]!.parentId = c;
    objects[2]!.parentId = a;
    const loaded = findScene(deserializeProject(raw), sceneId)!;
    const parentOf = (id: string) => findObject(loaded, id)!.parentId;
    expect(parentOf(b)).toBe(a);
    expect([parentOf(a), parentOf(c)].filter(Boolean)).toHaveLength(1); // one link of the cycle survives
    objects[1]!.parentId = 'ghost';
    expect(findScene(deserializeProject(raw), sceneId)!.objects[1]!.parentId).toBe('');
  });
});

describe('ReorderObjectCommand', () => {
  /** Ids in tree order – the order the panel lists and the tie-break for equal `z`. */
  const order = (scene: ObjectTree) => treeOrder(scene).map((e) => e.object.id);

  it('moves an object in front of a sibling and undo puts it back', () => {
    const { stack, sceneId, a, b, c, sceneOf } = threeBoxes();
    expect(order(sceneOf())).toEqual([a, b, c]);
    stack.execute(new ReorderObjectCommand(sceneId, c, a));
    expect(order(sceneOf())).toEqual([c, a, b]);
    stack.undo();
    expect(order(sceneOf())).toEqual([a, b, c]);
  });

  it('moves it behind the last sibling when no successor is named', () => {
    const { stack, sceneId, a, b, c, sceneOf } = threeBoxes();
    stack.execute(new ReorderObjectCommand(sceneId, a, ''));
    expect(order(sceneOf())).toEqual([b, c, a]);
  });

  it('orders children among themselves, leaving the subtree where it is', () => {
    const f = threeBoxes();
    const { stack, sceneId, a, b, c } = f;
    const x = place(f, f.spriteId, { x: 0, y: 0 }, a);
    const y = place(f, f.spriteId, { x: 0, y: 0 }, a);
    expect(order(f.sceneOf())).toEqual([a, x, y, b, c]);
    stack.execute(new ReorderObjectCommand(sceneId, y, x));
    expect(order(f.sceneOf())).toEqual([a, y, x, b, c]);
    // The move is among siblings only: the parent keeps its own place in the list.
    expect(f.object(y).parentId).toBe(a);
  });

  it('refuses a target that is not a sibling, so a reorder never re-parents by accident', () => {
    const f = threeBoxes();
    const child = place(f, f.spriteId, { x: 0, y: 0 }, f.a);
    expect(() => f.stack.execute(new ReorderObjectCommand(f.sceneId, f.b, child))).toThrow(
      /among its own siblings/,
    );
    expect(() => f.stack.execute(new ReorderObjectCommand(f.sceneId, f.b, f.b))).toThrow(
      /in front of itself/,
    );
    expect(order(f.sceneOf())).toEqual([f.a, child, f.b, f.c]);
  });
});

describe('runtime hierarchy', () => {
  it('entities mirror parents: world positions follow the parent, Destroy takes children along', () => {
    const f = threeBoxes();
    const { stack, sceneId, a, b, c } = f;
    stack.execute(new SetParentCommand(sceneId, b, a));
    stack.execute(new SetParentCommand(sceneId, c, b));
    const { world } = startWorld(f);
    const entity = (id: string) => world.findByObjectId(id)!;
    expect(entity(b).parent).toBe(entity(a));
    expect(worldPositionOf(entity(c))).toEqual({ x: 0, y: 5, z: 0 });
    entity(a).x += 50;
    expect(worldPositionOf(entity(c))).toEqual({ x: 50, y: 5, z: 0 });
    expect(worldPositionOf(entity(b))).toEqual({ x: 60, y: 0, z: 0 });
    world.remove(entity(a));
    expect(world.entities).toHaveLength(0);
  });

  it('Get position exposes local and world coordinates, Parent walks up', () => {
    const parent = { ...fakeEntity('p', 100), y: 20 };
    const child = { ...fakeEntity('c', 5), y: 5, parent };
    // On start → Log(world x of self) → Log(local x of self) → Log(world x of self's parent)
    const graph: Graph = {
      nodes: [
        { id: 'start', type: 'OnStart', x: 0, y: 0, params: {} },
        { id: 'self', type: 'Self', x: 0, y: 0, params: {} },
        { id: 'pos', type: 'GetPosition', x: 0, y: 0, params: {} },
        { id: 'par', type: 'Parent', x: 0, y: 0, params: {} },
        { id: 'ppos', type: 'GetPosition', x: 0, y: 0, params: {} },
        { id: 'log1', type: 'Log', x: 0, y: 0, params: {} },
        { id: 'log2', type: 'Log', x: 0, y: 0, params: {} },
        { id: 'log3', type: 'Log', x: 0, y: 0, params: {} },
      ],
      edges: [
        { id: 'e1', from: { node: 'start', port: 'exec' }, to: { node: 'log1', port: 'exec' } },
        { id: 'e2', from: { node: 'log1', port: 'exec' }, to: { node: 'log2', port: 'exec' } },
        { id: 'e3', from: { node: 'log2', port: 'exec' }, to: { node: 'log3', port: 'exec' } },
        { id: 'e4', from: { node: 'self', port: 'object' }, to: { node: 'pos', port: 'object' } },
        { id: 'e5', from: { node: 'self', port: 'object' }, to: { node: 'par', port: 'object' } },
        { id: 'e6', from: { node: 'par', port: 'parent' }, to: { node: 'ppos', port: 'object' } },
        { id: 'e7', from: { node: 'pos', port: 'worldX' }, to: { node: 'log1', port: 'message' } },
        { id: 'e8', from: { node: 'pos', port: 'x' }, to: { node: 'log2', port: 'message' } },
        { id: 'e9', from: { node: 'ppos', port: 'worldX' }, to: { node: 'log3', port: 'message' } },
      ],
    };
    const ctx = fakeContext({ self: child, owner: parent, variables: {} });
    fire(new GraphInterpreter(graph), 'OnStart', ctx);
    expect(ctx.logs).toEqual(['105', '5', '100']);
  });
});