import type { MimeClass } from "@tactical-media-broadcast-hub/core";

/**
 * One manifest entry = one `chat_media_archive` row for the room. Metadata
 * only; payloads stay in oCIS until the exporter pulls them over WebDAV.
 * Field names follow the index columns; nothing here can identify file bytes.
 */
export interface ManifestEntry {
  eventId: string;
  mxcUri: string;
  originalName: string;
  safeName: string;
  mime: string;
  mimeClass: MimeClass;
  byteSize: number;
  /** Lowercase hex SHA-256 of verified payload bytes; the restore script re-verifies it. */
  sha256: string;
  sender: string;
  /** UTC ISO-8601, from the Matrix event timestamp. */
  createdAt: string;
  ocisResourceId: string;
  /** False once redacted/retention marks the row unavailable. */
  available: boolean;
}

/** Static bundle metadata; `files` carries the per-row entries. */
export interface BundleManifest {
  format: "chat-media-archive-bundle";
  version: 1;
  roomId: string;
  workspaceId: string;
  groupId: string;
  /** Bundle build time (UTC ISO-8601). */
  exportedAt: string;
  /** Object key the ciphertext was uploaded to, filled in after the PUT. */
  objectKey: string | null;
  /** bech32 `age1...` recipients the file key was wrapped for. */
  recipients: string[];
  fileCount: number;
  /** Sum of ManifestEntry.byteSize. */
  totalBytes: number;
  files: ManifestEntry[];
}

/** Manifest + payload bytes in memory; the exporter packs and encrypts this. */
export interface BundlePayload {
  manifest: BundleManifest;
  /** Entry path inside the tar → payload bytes. Keyed by `files/<eventId>` style paths. */
  payloads: Map<string, Uint8Array>;
}

export type IndexedFile = ManifestEntry & { id: string };

/** Read side of `chat_media_archive` for exports; faked in tests. */
export interface ArchiveIndexPort {
  /**
   * Every archive row for the room, oldest first, including rows already
   * marked unavailable (the manifest records their state; unavailable rows
   * contribute no payload — see `buildBundle`).
   */
  listRoom(workspaceId: string, roomId: string): Promise<IndexedFile[]>;
}

export const MANIFEST_PATH = "manifest.json";
export const PAYLOAD_DIR = "files";

/** Deterministic, collision-free tar path for one archive row's payload. */
export function payloadPath(entry: ManifestEntry): string {
  return `${PAYLOAD_DIR}/${entry.eventId}/${entry.safeName}`;
}

export function newBundleId(): string {
  // Timetap + randomness: readable object keys, no crypto requirement.
  return `${Date.now().toString(36)}${Math.floor(Math.random() * 0x1_000_000).toString(36).padStart(4, "0")}`;
}