import { generateWalletJwt, generateJwt } from "./jwt.js";
import { version } from "../../version.js";

/**
 * Options for generating authentication headers for API requests.
 */
export interface GetAuthHeadersOptions {
  /**
   * The API key ID
   *
   * Examples:
   *  'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'
   *  'organizations/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/apiKeys/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'
   */
  apiKeyId: string;

  /**
   * The API key secret
   *
   * Examples:
   *  'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx==' (Edwards key (Ed25519))
   *  '-----BEGIN EC PRIVATE KEY-----\n...\n...\n...==\n-----END EC PRIVATE KEY-----\n' (EC key (ES256))
   */
  apiKeySecret: string;

  /**
   * The HTTP method for the request (e.g. 'GET', 'POST')
   */
  requestMethod: string;

  /**
   * The host for the request (e.g. 'api.cdp.coinbase.com')
   */
  requestHost: string;

  /**
   * The path for the request (e.g. '/platform/v1/wallets')
   */
  requestPath: string;

  /**
   * Optional request body data
   */
  requestBody?: unknown;

  /**
   * The Wallet Secret for wallet authentication
   */
  walletSecret?: string;

  /**
   * The source identifier for the request
   */
  source?: string;

  /**
   * The version of the source making the request
   */
  sourceVersion?: string;

  /**
   * Optional expiration time in seconds (defaults to 120)
   */
  expiresIn?: number;

  /**
   * Optional audience claim for the JWT
   */
  audience?: string[];
}

/**
 * Gets authentication headers for a request.
 *
 * @param options - The configuration options for generating auth headers
 * @returns Object containing the authentication headers
 */
export async function getAuthHeaders(
  options: GetAuthHeadersOptions,
): Promise<Record<string, string>> {
  const headers: Record<string, string> = {};

  // Generate and add JWT token
  const jwt = await generateJwt({
    apiKeyId: options.apiKeyId,
    apiKeySecret: options.apiKeySecret,
    requestMethod: options.requestMethod,
    requestHost: options.requestHost,
    requestPath: options.requestPath,
    expiresIn: options.expiresIn,
    audience: options.audience,
  });
  headers["Authorization"] = `Bearer ${jwt}`;
  headers["Content-Type"] = "application/json";

  // Add wallet auth if needed
  if (requiresWalletAuth(options.requestMethod, options.requestPath)) {
    if (!options.walletSecret) {
      throw new Error(
        "Wallet Secret not configured. Please set the CDP_WALLET_SECRET environment variable, or pass it as an option to the CdpClient constructor.",
      );
    }

    const walletAuthToken = await generateWalletJwt({
      walletSecret: options.walletSecret,
      requestMethod: options.requestMethod,
      requestHost: options.requestHost,
      requestPath: options.requestPath,
      requestData: options.requestBody || {},
    });
    headers["X-Wallet-Auth"] = walletAuthToken;
  }

  // Add correlation data
  headers["Correlation-Context"] = getCorrelationData(options.source, options.sourceVersion);

  return headers;
}

/**
 * Returns true if the request indicated by the method and URL requires wallet authentication.
 *
 * @param requestMethod - The HTTP method of the request
 * @param requestPath - The URL path of the request
 * @returns True if the request requires wallet authentication, false otherwise
 */
function requiresWalletAuth(requestMethod: string, requestPath: string): boolean {
  return (
    (requestPath?.includes("/accounts") || requestPath?.includes("/spend-permissions")) &&
    (requestMethod === "POST" || requestMethod === "DELETE" || requestMethod === "PUT")
  );
}

/**
 * Returns encoded correlation data including the SDK version and language.
 *
 * @param source - The source identifier for the request
 * @param sourceVersion - The version of the source making the request
 * @returns Encoded correlation data as a query string
 */
export function getCorrelationData(source?: string, sourceVersion?: string): string {
  const data = {
    sdk_version: version,
    sdk_language: "typescript",
    source: source || "sdk-auth",
  };
  if (sourceVersion) {
    data["source_version"] = sourceVersion;
  }
  return Object.keys(data)
    .map(key => `${key}=${encodeURIComponent(data[key])}`)
    .join(",");
}