/**
 * The picture list of a tile (#118): which blocks it is drawn from, and in which order – the
 * order is the animation, so moving a picture is an edit of its own rather than a cosmetic sort.
 * The kind, the rate and the playback are ordinary properties and go through `SetAssetPropertyCommand`.
 */
import type { Project } from '../model/Project';
import { resolvePicture } from '../model/texture';
import { moveItem } from '../util/list';
import { type Command, CommandError, MoveCommand } from './Command';
import { requireTile } from './require';

/** Appends a picture; `at` puts it before the picture with that index instead. */
export class AddTilePictureCommand implements Command {
  readonly label = 'Add tile picture';
  private index = -1;

  constructor(
    private readonly assetId: string,
    private readonly pictureId: string,
    private readonly at?: number,
  ) {}

  execute(project: Project): void {
    const asset = requireTile(project, this.assetId);
    // A texture or one of its frames – anything else names no block, and a list of dead ids is
    // the one thing the tab could not explain to whoever built it.
    if (!resolvePicture(project, this.pictureId))
      throw new CommandError(`${this.pictureId} is not a texture or a frame`);
    this.index = this.at === undefined ? asset.pictures.length : clampIndex(this.at, asset.pictures.length);
    asset.pictures.splice(this.index, 0, this.pictureId);
  }

  undo(project: Project): void {
    requireTile(project, this.assetId).pictures.splice(this.index, 1);
  }
}

export class RemoveTilePictureCommand implements Command {
  readonly label = 'Remove tile picture';
  private removed = '';

  constructor(
    private readonly assetId: string,
    private readonly index: number,
  ) {}

  execute(project: Project): void {
    const asset = requireTile(project, this.assetId);
    const picture = asset.pictures[this.index];
    if (picture === undefined) throw new CommandError(`${asset.name} has no picture ${this.index + 1}`);
    this.removed = picture;
    asset.pictures.splice(this.index, 1);
  }

  undo(project: Project): void {
    requireTile(project, this.assetId).pictures.splice(this.index, 0, this.removed);
  }
}

/** Moves one picture to another place in the list; the step in between is what changes the animation. */
export class MoveTilePictureCommand extends MoveCommand {
  constructor(
    private readonly assetId: string,
    from: number,
    to: number,
  ) {
    super('Reorder tile pictures', from, to);
  }

  protected move(project: Project, from: number, to: number): void {
    const asset = requireTile(project, this.assetId);
    if (asset.pictures[from] === undefined)
      throw new CommandError(`${asset.name} has no picture ${from + 1}`);
    if (!moveItem(asset.pictures, from, to))
      throw new CommandError(`${asset.name} has no place ${to + 1} to move it to`);
  }
}

function clampIndex(index: number, length: number): number {
  if (!Number.isFinite(index)) return length;
  return Math.max(0, Math.min(length, Math.floor(index)));
}