// Copyright Inrupt Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal in
// the Software without restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
// Software, and to permit persons to whom the Software is furnished to do so,
// subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
// PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

/**
 * @hidden
 * @packageDocumentation
 */

/**
 * Handles Common Oidc login functions (Like fetching the configuration)
 */

import type {
  IClientRegistrar,
  IIssuerConfig,
  IIssuerConfigFetcher,
  ILoginOptions,
  ILoginHandler,
  IOidcHandler,
  IOidcOptions,
  IStorageUtility,
  LoginResult,
} from "@inrupt/solid-client-authn-core";
import {
  ConfigurationError,
  handleRegistration,
  normalizeScopes,
} from "@inrupt/solid-client-authn-core";

function hasIssuer(
  options: ILoginOptions,
): options is ILoginOptions & { oidcIssuer: string } {
  return typeof options.oidcIssuer === "string";
}

function hasRedirectUrl(
  options: ILoginOptions,
): options is ILoginOptions & { redirectUrl: string } {
  return typeof options.redirectUrl === "string";
}

/**
 * @hidden
 */
export default class OidcLoginHandler implements ILoginHandler {
  constructor(
    private storageUtility: IStorageUtility,
    private oidcHandler: IOidcHandler,
    private issuerConfigFetcher: IIssuerConfigFetcher,
    private clientRegistrar: IClientRegistrar,
  ) {
    this.storageUtility = storageUtility;
    this.oidcHandler = oidcHandler;
    this.issuerConfigFetcher = issuerConfigFetcher;
    this.clientRegistrar = clientRegistrar;
  }

  async canHandle(options: ILoginOptions): Promise<boolean> {
    return hasIssuer(options) && hasRedirectUrl(options);
  }

  async handle(options: ILoginOptions): Promise<LoginResult> {
    if (!hasIssuer(options)) {
      throw new ConfigurationError(
        `OidcLoginHandler requires an OIDC issuer: missing property 'oidcIssuer' in ${JSON.stringify(
          options,
        )}`,
      );
    }
    if (!hasRedirectUrl(options)) {
      throw new ConfigurationError(
        `OidcLoginHandler requires a redirect URL: missing property 'redirectUrl' in ${JSON.stringify(
          options,
        )}`,
      );
    }

    // Fetch issuer config.
    const issuerConfig: IIssuerConfig =
      await this.issuerConfigFetcher.fetchConfig(options.oidcIssuer);

    const clientRegistration = await handleRegistration(
      options,
      issuerConfig,
      this.storageUtility,
      this.clientRegistrar,
    );

    // Construct OIDC Options
    const OidcOptions: IOidcOptions = {
      // Note that here, the issuer is not the one from the received options, but
      // from the issuer's config. This enforces the canonical URL is used and stored,
      // which is also the one present in the ID token, so storing a technically
      // valid, but different issuer URL (e.g. using a trailing slash or not) now
      // could prevent from validating the ID token later.
      issuer: issuerConfig.issuer,
      // TODO: differentiate if DPoP should be true
      dpop: options.tokenType.toLowerCase() === "dpop",
      ...options,
      issuerConfiguration: issuerConfig,
      client: clientRegistration,
      scopes: normalizeScopes(options.customScopes),
    };

    // Call proper OIDC Handler
    return this.oidcHandler.handle(OidcOptions);
  }
}