import type { MapEntry, ProjectFile, ProjectManifest } from '../project/types';
import { decodeMapDefinition } from './mapSchema';
import { resolveProjectAssetPath } from './mapPaths';
import type { MapSelection, ResolvedProjectMap, VisualMapAsset } from './types';
import { decodeEditableMapDocument } from './editor/editorSchema';

function projectFile(manifest: ProjectManifest, path: string): ProjectFile {
  const file = manifest.files.find((candidate) => candidate.path === path);
  if (!file) throw new Error(`地图引用的资源不存在：${path}`);
  return file;
}

export function discoverMapEntries(files: ProjectFile[]): MapEntry[] {
  const paths = new Set(files.map((file) => file.path));
  const filesByPath = new Map(files.map((file) => [file.path, file]));
  const ids = new Set<string>();
  return files
    .filter((file) => /(^|\/)map\.json$/i.test(file.path))
    .map((file) => {
      const definition = decodeMapDefinition(file.data);
      if (ids.has(definition.id)) throw new Error(`地图 id 重复：${definition.id}`);
      ids.add(definition.id);
      const physicsPath = definition.physics
        ? resolveProjectAssetPath(file.path, definition.physics.source)
        : undefined;
      const visualPath = definition.visual
        ? resolveProjectAssetPath(file.path, definition.visual.source)
        : undefined;
      const authoringPath = definition.authoring
        ? resolveProjectAssetPath(file.path, definition.authoring.source)
        : undefined;
      for (const resolved of [physicsPath, visualPath, authoringPath]) {
        if (resolved && !paths.has(resolved))
          throw new Error(`地图 ${definition.name} 引用的资源不存在：${resolved}`);
      }
      if (authoringPath) {
        const authoring = filesByPath.get(authoringPath);
        if (!authoring) throw new Error(`地图 ${definition.name} 的创作层不存在`);
        const editable = decodeEditableMapDocument(authoring.data);
        if (editable.mapId !== definition.id)
          throw new Error(`地图 ${definition.name} 的创作层 mapId 必须为 ${definition.id}`);
      }
      return {
        descriptorPath: file.path,
        schemaVersion: definition.schemaVersion,
        id: definition.id,
        name: definition.name,
        physicsPath,
        visualPath,
        ...(authoringPath ? { authoringPath } : {}),
        spawnPoints: definition.spawnPoints.map(({ id, name }) => ({ id, name })),
      };
    });
}

export function resolveProjectMap(
  manifest: ProjectManifest,
  descriptorPath: string,
): ResolvedProjectMap {
  const descriptor = projectFile(manifest, descriptorPath);
  const definition = decodeMapDefinition(descriptor.data);
  const physicsPath = definition.physics
    ? resolveProjectAssetPath(descriptorPath, definition.physics.source)
    : undefined;
  const visualPath = definition.visual
    ? resolveProjectAssetPath(descriptorPath, definition.visual.source)
    : undefined;
  const authoringPath = definition.authoring
    ? resolveProjectAssetPath(descriptorPath, definition.authoring.source)
    : undefined;
  if (physicsPath) projectFile(manifest, physicsPath);
  if (visualPath) projectFile(manifest, visualPath);
  if (authoringPath) {
    const editable = decodeEditableMapDocument(projectFile(manifest, authoringPath).data);
    if (editable.mapId !== definition.id)
      throw new Error(`地图 ${definition.name} 的创作层 mapId 必须为 ${definition.id}`);
  }
  return {
    definition,
    descriptorPath,
    physicsPath,
    visualPath,
    authoringPath,
  };
}

export function visualMapAsset(
  manifest: ProjectManifest,
  selection: MapSelection,
): VisualMapAsset | null {
  if (selection.kind !== 'project') return null;
  const resolved = resolveProjectMap(manifest, selection.descriptorPath);
  if (!resolved.visualPath || !resolved.definition.visual) return null;
  const visual = projectFile(manifest, resolved.visualPath);
  return {
    id: resolved.definition.id,
    name: resolved.definition.name,
    path: resolved.visualPath,
    data: visual.data,
    castShadow: resolved.definition.visual.castShadow ?? true,
    receiveShadow: resolved.definition.visual.receiveShadow ?? true,
  };
}