/*
 *
 * Copyright 2015, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <stdio.h>
#include <string.h>

#include "src/core/security/jwt_verifier.h"
#include <grpc/grpc.h>
#include <grpc/grpc_security.h>
#include <grpc/support/alloc.h>
#include <grpc/support/cmdline.h>
#include <grpc/support/log.h>
#include <grpc/support/slice.h>
#include <grpc/support/sync.h>

typedef struct
{
  grpc_pollset pollset;
  int is_done;
  int success;
} synchronizer;

static void
print_usage_and_exit (gpr_cmdline * cl, const char *argv0)
{
  char *usage = gpr_cmdline_usage_string (cl, argv0);
  fprintf (stderr, "%s", usage);
  gpr_free (usage);
  gpr_cmdline_destroy (cl);
  exit (1);
}

static void
on_jwt_verification_done (void *user_data, grpc_jwt_verifier_status status, grpc_jwt_claims * claims)
{
  synchronizer *sync = user_data;

  sync->success = (status == GRPC_JWT_VERIFIER_OK);
  if (sync->success)
    {
      char *claims_str;
      GPR_ASSERT (claims != NULL);
      claims_str = grpc_json_dump_to_string ((grpc_json *) grpc_jwt_claims_json (claims), 2);
      printf ("Claims: \n\n%s\n", claims_str);
      gpr_free (claims_str);
      grpc_jwt_claims_destroy (claims);
    }
  else
    {
      GPR_ASSERT (claims == NULL);
      fprintf (stderr, "Verification failed with error %s\n", grpc_jwt_verifier_status_to_string (status));
    }

  gpr_mu_lock (GRPC_POLLSET_MU (&sync->pollset));
  sync->is_done = 1;
  grpc_pollset_kick (&sync->pollset, NULL);
  gpr_mu_unlock (GRPC_POLLSET_MU (&sync->pollset));
}

int
main (int argc, char **argv)
{
  synchronizer sync;
  grpc_jwt_verifier *verifier;
  gpr_cmdline *cl;
  char *jwt = NULL;
  char *aud = NULL;
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;

  cl = gpr_cmdline_create ("JWT verifier tool");
  gpr_cmdline_add_string (cl, "jwt", "JSON web token to verify", &jwt);
  gpr_cmdline_add_string (cl, "aud", "Audience for the JWT", &aud);
  gpr_cmdline_parse (cl, argc, argv);
  if (jwt == NULL || aud == NULL)
    {
      print_usage_and_exit (cl, argv[0]);
    }

  verifier = grpc_jwt_verifier_create (NULL, 0);

  grpc_init ();

  grpc_pollset_init (&sync.pollset);
  sync.is_done = 0;

  grpc_jwt_verifier_verify (verifier, &sync.pollset, jwt, aud, on_jwt_verification_done, &sync, &closure_list);

  gpr_mu_lock (GRPC_POLLSET_MU (&sync.pollset));
  while (!sync.is_done)
    {
      grpc_pollset_worker worker;
      grpc_pollset_work (&sync.pollset, &worker, gpr_now (GPR_CLOCK_MONOTONIC), gpr_inf_future (GPR_CLOCK_MONOTONIC), &closure_list);
      gpr_mu_unlock (GRPC_POLLSET_MU (&sync.pollset));
      grpc_closure_list_run (&closure_list);
      gpr_mu_lock (GRPC_POLLSET_MU (&sync.pollset));
    }
  gpr_mu_unlock (GRPC_POLLSET_MU (&sync.pollset));

  grpc_jwt_verifier_destroy (verifier);
  gpr_cmdline_destroy (cl);
  return !sync.success;
}