import {
  AsyncAPIDocumentInterface,
  validateAsyncApi,
  isAllowedLocalSchemaUrl,
} from '@mintlify/common';
import * as fs from 'fs/promises';
import * as path from 'path';

import { fetchAsyncApi } from '../utils/network.js';

export const getAsyncApiDefinition = async (
  pathOrDocumentOrUrl: string | URL,
  localSchema?: boolean
): Promise<{ document: AsyncAPIDocumentInterface | undefined; isUrl: boolean }> => {
  let document: AsyncAPIDocumentInterface | undefined = undefined;
  if (typeof pathOrDocumentOrUrl === 'string') {
    if (pathOrDocumentOrUrl.startsWith('http:') && !localSchema) {
      // This is an invalid location either for a file or a URL
      throw new Error(
        'Only HTTPS URLs are supported. HTTP URLs are only supported with the cli option --local-schema.'
      );
    } else {
      try {
        const url = new URL(pathOrDocumentOrUrl);
        pathOrDocumentOrUrl = url;
      } catch {
        const pathname = path.join(process.cwd(), pathOrDocumentOrUrl.toString());
        try {
          const file = await fs.readFile(pathname, 'utf-8');
          const { document: asyncApiDocument, errorMessage } = await validateAsyncApi(file);
          if (!asyncApiDocument) {
            throw new Error(
              `${pathname} - this document is not a valid AsyncAPI document - ${errorMessage}`
            );
          }
          document = asyncApiDocument;
        } catch (error) {
          throw new Error(`Failed to read file ${pathname} - ${error}`);
        }
      }
    }
  }
  const isUrl = pathOrDocumentOrUrl instanceof URL;
  if (pathOrDocumentOrUrl instanceof URL) {
    if (!isAllowedLocalSchemaUrl(pathOrDocumentOrUrl.toString(), localSchema)) {
      throw new Error(
        'Only HTTPS URLs are supported. HTTP URLs are only supported with the cli option --local-schema.'
      );
    }
    document = await fetchAsyncApi(pathOrDocumentOrUrl);
  }

  return { document, isUrl };
};