/**
 * Container assets hold placed objects just like scenes do, so anything that walks "all placed
 * objects" has to cover both. Plus: a rejected undo leaves the stacks usable.
 */
import { describe, expect, it } from 'vitest';
import { type Command, CommandError } from '../../src/core/commands/Command';
import { CommandStack } from '../../src/core/commands/CommandStack';
import { CreateContainerCommand } from '../../src/core/commands/containerCommands';
import { SetOverrideCommand } from '../../src/core/commands/sceneObjectCommands';
import { RemoveVariableCommand, RenameVariableCommand } from '../../src/core/commands/variableCommands';
import type { ContainerAsset } from '../../src/core/model/Asset';
import { findAsset, findObjectHolder, objectHolders } from '../../src/core/model/Project';
import { defaultSceneVisibility } from '../../src/core/model/sceneVisibility';
import { instanceChildId } from '../../src/core/model/instance';
import { findUsages } from '../../src/core/model/usages';
import { makeBehavior, makeSpriteScene, place } from '../helpers';

/** A behavior with a `speed` variable, placed and overridden to 42, then wrapped in a container. */
function containerWithOverride() {
  const f = makeSpriteScene();
  const behavior = makeBehavior(f, 'B', ['speed']);
  const objectId = place(f, behavior.id, { x: 0, y: 0 });
  f.stack.execute(new SetOverrideCommand(f.sceneId, objectId, 'speed', 42));
  const container = new CreateContainerCommand(f.sceneId, [objectId]);
  f.stack.execute(container);
  const template = () => (findAsset(f.project, container.assetId) as ContainerAsset).objects[0]!;
  // The object moved into the template; what the scene shows is resolved from it.
  const placed = () => f.object(instanceChildId(container.objectId, template().id));
  return { ...f, behaviorId: behavior.id, containerId: container.assetId, objectId, template, placed };
}

describe('object holders', () => {
  it('counts scenes and container assets alike', () => {
    const { project } = containerWithOverride();
    expect(
      objectHolders(project)
        .map((h) => h.type)
        .sort(),
    ).toEqual(['container', 'scene']);
  });

  it('resolves a scene or a container by id, but no other asset', () => {
    const { project, sceneId, containerId, spriteId, behaviorId } = containerWithOverride();
    expect(findObjectHolder(project, sceneId)?.type).toBe('scene');
    expect(findObjectHolder(project, containerId)?.type).toBe('container');
    expect(findObjectHolder(project, spriteId)).toBeUndefined();
    expect(findObjectHolder(project, behaviorId)).toBeUndefined();
    expect(findObjectHolder(project, 'nope')).toBeUndefined();
  });

  it('finds usages inside container templates, not just in scenes', () => {
    const { project, behaviorId, containerId, template } = containerWithOverride();
    // Only the template: what the scene shows is resolved from it, never stored.
    const usages = findUsages(project, behaviorId);
    expect(usages).toHaveLength(1);
    expect(usages[0]!.holder.id).toBe(containerId);
    expect(template().overrides.speed).toBe(42);
  });
});

describe('RemoveVariableCommand', () => {
  it('clears the override on container templates too, and puts it back on undo', () => {
    const { stack, behaviorId, template, placed } = containerWithOverride();

    stack.execute(new RemoveVariableCommand(behaviorId, 'speed'));
    expect(placed().overrides.speed).toBeUndefined();
    expect(template().overrides.speed).toBeUndefined();

    stack.undo();
    expect(placed().overrides.speed).toBe(42);
    expect(template().overrides.speed).toBe(42);
  });
});

/**
 * A behavior inside a placed container is not stored in the scene, and a value changed on it lives
 * in the instance's `instanceEdits`. Anything rewriting overrides project-wide has to reach in
 * there, or renaming a variable silently drops the value.
 */
describe('variables overridden on container content', () => {
  function withInstanceEdit() {
    const f = containerWithOverride();
    f.stack.execute(new SetOverrideCommand(f.sceneId, f.placed().id, 'speed', 7));
    const edits = () =>
      f.sceneOf().objects.find((o) => o.id !== f.objectId)!.instanceEdits[f.template().id]!.overrides;
    return { ...f, edits };
  }

  it('renames the key kept on the instance', () => {
    const { stack, behaviorId, edits, placed } = withInstanceEdit();
    expect(edits().speed).toBe(7);
    stack.execute(new RenameVariableCommand(behaviorId, 'speed', 'velocity'));
    expect(edits().speed).toBeUndefined();
    expect(edits().velocity).toBe(7);
    expect(placed().overrides.velocity).toBe(7);
    stack.undo();
    expect(edits().speed).toBe(7);
  });

  it('removes the value kept on the instance, and puts it back on undo', () => {
    const { stack, behaviorId, edits } = withInstanceEdit();
    stack.execute(new RemoveVariableCommand(behaviorId, 'speed'));
    expect(edits().speed).toBeUndefined();
    stack.undo();
    expect(edits().speed).toBe(7);
  });
});

describe('RenameVariableCommand', () => {
  it('renames the override on container templates too', () => {
    const { stack, behaviorId, template } = containerWithOverride();
    stack.execute(new RenameVariableCommand(behaviorId, 'speed', 'velocity'));
    expect(template().overrides.speed).toBeUndefined();
    expect(template().overrides.velocity).toBe(42);

    stack.undo();
    expect(template().overrides.speed).toBe(42);
    expect(template().overrides.velocity).toBeUndefined();
  });
});

class RefusingUndo implements Command {
  readonly label = 'Refusing';
  execute(project: { name: string }): void {
    project.name = 'executed';
  }
  undo(): void {
    throw new CommandError('target is gone');
  }
}

describe('CommandStack', () => {
  it('keeps a command on the undo stack when its undo is rejected', () => {
    const { project, stack } = makeSpriteScene();
    stack.execute(new RefusingUndo());
    expect(stack.canUndo).toBe(true);

    expect(() => stack.undo()).toThrow(CommandError);
    // Not swallowed by the history: still undoable, and not queued for redo.
    expect(stack.canUndo).toBe(true);
    expect(stack.canRedo).toBe(false);
    expect(project.name).toBe('executed');
  });

  it('keeps a command on the redo stack when its redo is rejected', () => {
    const project = {
      formatVersion: 1,
      id: 'p',
      name: 'P',
      assets: [],
      activeSceneId: '',
      startSceneId: '',
      plugins: [],
      collisionLayers: ['Default'],
      symbolScale: 1,
      playFrom: 'start' as const,
      whilePlaying: 'live' as const,
      gameScale: 1,
      gameLinkZoom: 'auto' as const,
      sceneVisibility: defaultSceneVisibility(),
    };
    const stack = new CommandStack(project);
    let failing = false;
    stack.execute({
      label: 'Toggle',
      execute: () => {
        if (failing) throw new CommandError('nope');
      },
      undo: () => {},
    });
    stack.undo();
    failing = true;

    expect(() => stack.redo()).toThrow(CommandError);
    expect(stack.canRedo).toBe(true);
    expect(stack.canUndo).toBe(false);
  });
});