import type { EditableMapDocument } from './editor/types';
import { normalizePhysicalMapConfig } from './physicalMap';
import {
  mapSelectionTransform,
  updatePlacedMapAsset,
  type MapInstanceTransform,
  type PlacedMapAsset,
} from './types';

function sameAsset(left: PlacedMapAsset | undefined, right: PlacedMapAsset | undefined): boolean {
  return Boolean(
    left &&
    right &&
    left.id === right.id &&
    left.name === right.name &&
    JSON.stringify(left.selection) === JSON.stringify(right.selection),
  );
}

function cloneAsset(asset: PlacedMapAsset): PlacedMapAsset {
  return { ...asset, selection: structuredClone(asset.selection) };
}

export interface MapSceneDraftSummary {
  dirty: boolean;
  changeCount: number;
  /** 当前仍存在且相对应用基线新增或发生修改的实例 ID。 */
  changedIds: string[];
  /** 可直接在 Three.js 中预览的新增或已修改程序地图。 */
  previewAssets: PlacedMapAsset[];
}

export interface MapEditorDraftPreviewInstance {
  id: string;
  document: EditableMapDocument;
  transform: MapInstanceTransform;
}

/**
 * 当前激活的认证场景由交互编辑层绘制；其余待提交工程地图必须保留只读预览，
 * 否则切换到参数地形时会因为清空交互文档而从画布消失。
 */
export function mapEditorDraftPreviewInstances(
  assets: readonly PlacedMapAsset[],
  pendingIds: readonly string[],
  documents: ReadonlyMap<string, EditableMapDocument>,
  activeId?: string,
): MapEditorDraftPreviewInstance[] {
  const pending = new Set(pendingIds);
  return assets.flatMap((asset) => {
    if (asset.id === activeId || !pending.has(asset.id) || asset.selection.kind !== 'project')
      return [];
    const document = documents.get(asset.selection.descriptorPath);
    return document
      ? [{ id: asset.id, document, transform: mapSelectionTransform(asset.selection) }]
      : [];
  });
}

/**
 * 所有地图实例共享同一个场景草稿边界。新增、删除、替换和实例参数修改只更新
 * `current`，显式应用成功后才推进 `applied` 基线。
 */
export function summarizeMapSceneDraft(
  current: readonly PlacedMapAsset[],
  applied: readonly PlacedMapAsset[],
): MapSceneDraftSummary {
  const currentById = new Map(current.map((asset) => [asset.id, asset]));
  const appliedById = new Map(applied.map((asset) => [asset.id, asset]));
  const changed = current.filter((asset) => !sameAsset(asset, appliedById.get(asset.id)));
  const removed = applied.filter((asset) => !currentById.has(asset.id));
  return {
    dirty: changed.length + removed.length > 0,
    changeCount: changed.length + removed.length,
    changedIds: changed.map((asset) => asset.id),
    previewAssets: changed.filter((asset) => asset.selection.kind === 'builtin').map(cloneAsset),
  };
}

/** 放弃完整场景草稿，严格恢复上一次成功编译的实例顺序和状态。 */
export function restoreAppliedMapScene(applied: readonly PlacedMapAsset[]): PlacedMapAsset[] {
  return applied.map(cloneAsset);
}

export function clonePlacedMapAssets(assets: readonly PlacedMapAsset[]): PlacedMapAsset[] {
  return assets.map(cloneAsset);
}

/** 普通模型重载使用应用基线；只有显式场景提交才传入候选实例。 */
export function resolveMapSceneLoadAssets(
  applied: readonly PlacedMapAsset[],
  requested?: readonly PlacedMapAsset[],
): PlacedMapAsset[] {
  return clonePlacedMapAssets(requested ?? applied);
}

/** 视口操纵器只更新参数地形草稿，不触发 MuJoCo 编译。 */
export function transformParametricMapAsset(
  assets: readonly PlacedMapAsset[],
  id: string,
  position: readonly [number, number],
  yawDeg: number,
): PlacedMapAsset[] | readonly PlacedMapAsset[] {
  const target = assets.find((asset) => asset.id === id);
  if (!target || target.selection.kind !== 'builtin' || target.selection.config.preset === 'none')
    return assets;
  const clean = (value: number) => Math.round(value * 1_000_000) / 1_000_000;
  const config = normalizePhysicalMapConfig({
    ...target.selection.config,
    positionX: clean(position[0]),
    positionY: clean(position[1]),
    yawDeg: clean(yawDeg),
  });
  if (
    config.positionX === target.selection.config.positionX &&
    config.positionY === target.selection.config.positionY &&
    config.yawDeg === target.selection.config.yawDeg
  )
    return assets;
  return updatePlacedMapAsset(assets, id, { kind: 'builtin', config });
}