import {
  buildConversationPackageManifest,
  buildConversationStoragePrefix,
  createConversationArtifact,
  createConversationPackageRecord,
} from './mindspace-conversation-package.mjs';
import {
  createMindSpacePublicPageUrl,
  createMindSpacePublicUrl,
  normalizeMindSpacePublicRelativePath,
} from './mindspace-canonical-url.mjs';
import { normalizeMindSpaceStorageKey } from './mindspace-storage-adapter.mjs';

function serviceError(message, code, details = {}) {
  return Object.assign(new Error(message), { code, ...details });
}

function requireStorageAdapter(storageAdapter) {
  if (!storageAdapter || typeof storageAdapter.putObject !== 'function') {
    throw serviceError('MindSpace storage adapter is required', 'missing_mindspace_storage_adapter');
  }
  return storageAdapter;
}

function packageStorageKey(packageRecord, relativePath) {
  const record = createConversationPackageRecord(packageRecord);
  const relative = normalizeMindSpaceStorageKey(relativePath);
  return `${record.storagePrefix}/${relative}`;
}

export function createMindSpaceServiceFacade({
  storageAdapter,
  publicBaseUrl,
  conversationPackageBackfill,
  conversationPackagePublicHtmlHydrator,
  logger = console,
} = {}) {
  const storage = requireStorageAdapter(storageAdapter);

  return {
    createConversationPackage(input) {
      return createConversationPackageRecord(input);
    },

    createConversationArtifact(input) {
      return createConversationArtifact(input);
    },

    buildConversationManifest(input) {
      return buildConversationPackageManifest(input);
    },

    async putConversationManifest({ packageRecord, artifacts = [] }) {
      const manifest = buildConversationPackageManifest({ packageRecord, artifacts });
      const body = `${JSON.stringify(manifest, null, 2)}\n`;
      const writeResult = await this.putPackageObject({
        packageRecord: manifest,
        relativePath: 'manifest.json',
        body,
      });
      return {
        manifest,
        storageKey: writeResult.key,
        writeResult,
      };
    },

    buildConversationStoragePrefix(input) {
      return buildConversationStoragePrefix(input);
    },

    createPublicPageUrl({ ownerKey, filename }) {
      return createMindSpacePublicPageUrl({ publicBaseUrl, ownerKey, filename });
    },

    createPublicObjectUrl({ ownerKey, relativePath }) {
      return createMindSpacePublicUrl({ publicBaseUrl, ownerKey, relativePath });
    },

    resolvePackageStorageKey({ packageRecord, relativePath }) {
      return packageStorageKey(packageRecord, relativePath);
    },

    async putPackageObject({ packageRecord, relativePath, body }) {
      return storage.putObject(packageStorageKey(packageRecord, relativePath), body);
    },

    async getPackageObject({ packageRecord, relativePath }) {
      return storage.getObject(packageStorageKey(packageRecord, relativePath));
    },

    async statPackageObject({ packageRecord, relativePath }) {
      return storage.statObject(packageStorageKey(packageRecord, relativePath));
    },

    async listPackageObjects({ packageRecord, prefix = '' }) {
      const record = createConversationPackageRecord(packageRecord);
      const cleanPrefix = prefix ? normalizeMindSpacePublicRelativePath(prefix) : '';
      const storagePrefix = cleanPrefix ? `${record.storagePrefix}/${cleanPrefix}` : record.storagePrefix;
      return storage.listObjects(storagePrefix);
    },

    async prepareConversationPackageRead({ user, sessionId } = {}) {
      if (typeof conversationPackageBackfill === 'function') {
        await conversationPackageBackfill({ user, sessionId }).catch((error) => {
          logger?.warn?.('[MindSpace] conversation package DB backfill failed:', error?.message ?? error);
        });
      }
      if (typeof conversationPackagePublicHtmlHydrator === 'function') {
        return conversationPackagePublicHtmlHydrator({ user, sessionId });
      }
      return [];
    },
  };
}

export const mindspaceServiceInternals = {
  serviceError,
  packageStorageKey,
};