import type { TangledApiClient } from '../lib/api-client.js';

/**
 * Parse an AT-URI into its components
 * @param uri - AT-URI string (e.g., "at://did:plc:abc/collection/rkey")
 * @returns Parsed components or null if invalid
 */
export function parseAtUri(uri: string): {
  did: string;
  collection: string;
  rkey?: string;
} | null {
  // AT-URI format: at://did:method:identifier/collection[/rkey]
  const match = uri.match(
    /^at:\/\/(did:[a-z]+:[a-zA-Z0-9._:%-]+)\/([a-zA-Z0-9._-]+(?:\.[a-zA-Z0-9._-]+)*)(?:\/([a-zA-Z0-9._-]+))?$/
  );

  if (!match) {
    return null;
  }

  const [, did, collection, rkey] = match;
  return {
    did,
    collection,
    ...(rkey && { rkey }),
  };
}

/**
 * Resolve a handle to a DID using the AT Protocol identity resolution
 * @param handle - Handle string (e.g., "mark.bsky.social" or "@mark.bsky.social")
 * @param client - Authenticated API client
 * @returns DID string (e.g., "did:plc:abc123")
 * @throws Error if handle cannot be resolved
 */
export async function resolveHandleToDid(
  handle: string,
  client: TangledApiClient
): Promise<string> {
  // Strip leading @ if present
  const cleanHandle = handle.startsWith('@') ? handle.slice(1) : handle;

  try {
    const response = await client.getAgent().com.atproto.identity.resolveHandle({
      handle: cleanHandle,
    });

    if (!response.data.did) {
      throw new Error(`No DID found for handle: ${cleanHandle}`);
    }

    return response.data.did;
  } catch (error) {
    if (error instanceof Error) {
      throw new Error(`Failed to resolve handle '${cleanHandle}': ${error.message}`);
    }
    throw new Error(`Failed to resolve handle '${cleanHandle}': Unknown error`);
  }
}

/**
 * Build a repository AT-URI from owner and repository name
 * @param ownerDidOrHandle - DID (e.g., "did:plc:abc") or handle (e.g., "mark.bsky.social")
 * @param repoName - Repository name
 * @param client - Authenticated API client
 * @returns AT-URI string (e.g., "at://did:plc:abc/sh.tangled.repo/3mef23waqwq22")
 * @throws Error if repository not found
 */
export async function buildRepoAtUri(
  ownerDidOrHandle: string,
  repoName: string,
  client: TangledApiClient
): Promise<string> {
  // Resolve owner to DID
  const isDid = ownerDidOrHandle.startsWith('did:');
  const did = isDid ? ownerDidOrHandle : await resolveHandleToDid(ownerDidOrHandle, client);

  try {
    // Query for sh.tangled.repo records
    const response = await client.getAgent().com.atproto.repo.listRecords({
      repo: did,
      collection: 'sh.tangled.repo',
      limit: 100, // Reasonable limit for most users
    });

    // Find the record matching the repo name
    const repoRecord = response.data.records.find((record) => {
      const recordData = record.value as { name?: string };
      return recordData.name === repoName;
    });

    if (!repoRecord) {
      throw new Error(`Repository '${repoName}' not found for ${ownerDidOrHandle}`);
    }

    // Return the record's URI (which includes the correct rkey)
    return repoRecord.uri;
  } catch (error) {
    if (error instanceof Error) {
      throw new Error(`Failed to resolve repository AT-URI: ${error.message}`);
    }
    throw new Error('Failed to resolve repository AT-URI: Unknown error');
  }
}