import type { McpRemoteServerConfig, McpServerConfig } from './config-schema';
import { ErrorCodes, Error2 } from '#/errors';

export function buildMcpRemoteHeaders(
  config: McpRemoteServerConfig,
  envLookup: (name: string) => string | undefined,
): Record<string, string> | undefined {
  const headers: Record<string, string> = { ...config.headers };
  if (config.bearerTokenEnvVar !== undefined) {
    const token = envLookup(config.bearerTokenEnvVar);
    if (token === undefined || token.length === 0) {
      throw new Error2(
        ErrorCodes.CONFIG_INVALID,
        `MCP ${config.transport.toUpperCase()} bearer token env var "${config.bearerTokenEnvVar}" is not set or is empty`,
      );
    }
    for (const key of Object.keys(headers)) {
      if (key.toLowerCase() === 'authorization') {
        delete headers[key];
      }
    }
    headers['Authorization'] = `Bearer ${token}`;
  }
  return Object.keys(headers).length > 0 ? headers : undefined;
}

export function isRemoteMcpConfig(config: McpServerConfig): config is McpRemoteServerConfig {
  return config.transport === 'http' || config.transport === 'sse';
}