/*
 *
 * Copyright 2015 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include <grpc/support/port_platform.h>

#include "src/core/lib/security/credentials/credentials.h"

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

#include "src/core/lib/channel/channel_args.h"
#include "src/core/lib/gpr/string.h"
#include "src/core/lib/http/httpcli.h"
#include "src/core/lib/http/parser.h"
#include "src/core/lib/iomgr/executor.h"
#include "src/core/lib/json/json.h"
#include "src/core/lib/surface/api_trace.h"

#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>
#include <grpc/support/sync.h>
#include <grpc/support/time.h>

/* -- Common. -- */

grpc_credentials_metadata_request* grpc_credentials_metadata_request_create(
    grpc_call_credentials* creds) {
  grpc_credentials_metadata_request* r =
      static_cast<grpc_credentials_metadata_request*>(
          gpr_zalloc(sizeof(grpc_credentials_metadata_request)));
  r->creds = grpc_call_credentials_ref(creds);
  return r;
}

void grpc_credentials_metadata_request_destroy(
    grpc_credentials_metadata_request* r) {
  grpc_call_credentials_unref(r->creds);
  grpc_http_response_destroy(&r->response);
  gpr_free(r);
}

grpc_channel_credentials* grpc_channel_credentials_ref(
    grpc_channel_credentials* creds) {
  if (creds == nullptr) return nullptr;
  gpr_ref(&creds->refcount);
  return creds;
}

void grpc_channel_credentials_unref(grpc_channel_credentials* creds) {
  if (creds == nullptr) return;
  if (gpr_unref(&creds->refcount)) {
    if (creds->vtable->destruct != nullptr) {
      creds->vtable->destruct(creds);
    }
    gpr_free(creds);
  }
}

void grpc_channel_credentials_release(grpc_channel_credentials* creds) {
  GRPC_API_TRACE("grpc_channel_credentials_release(creds=%p)", 1, (creds));
  grpc_core::ExecCtx exec_ctx;
  grpc_channel_credentials_unref(creds);
}

grpc_call_credentials* grpc_call_credentials_ref(grpc_call_credentials* creds) {
  if (creds == nullptr) return nullptr;
  gpr_ref(&creds->refcount);
  return creds;
}

void grpc_call_credentials_unref(grpc_call_credentials* creds) {
  if (creds == nullptr) return;
  if (gpr_unref(&creds->refcount)) {
    if (creds->vtable->destruct != nullptr) {
      creds->vtable->destruct(creds);
    }
    gpr_free(creds);
  }
}

void grpc_call_credentials_release(grpc_call_credentials* creds) {
  GRPC_API_TRACE("grpc_call_credentials_release(creds=%p)", 1, (creds));
  grpc_core::ExecCtx exec_ctx;
  grpc_call_credentials_unref(creds);
}

bool grpc_call_credentials_get_request_metadata(
    grpc_call_credentials* creds, grpc_polling_entity* pollent,
    grpc_auth_metadata_context context, grpc_credentials_mdelem_array* md_array,
    grpc_closure* on_request_metadata, grpc_error** error) {
  if (creds == nullptr || creds->vtable->get_request_metadata == nullptr) {
    return true;
  }
  return creds->vtable->get_request_metadata(creds, pollent, context, md_array,
                                             on_request_metadata, error);
}

void grpc_call_credentials_cancel_get_request_metadata(
    grpc_call_credentials* creds, grpc_credentials_mdelem_array* md_array,
    grpc_error* error) {
  if (creds == nullptr ||
      creds->vtable->cancel_get_request_metadata == nullptr) {
    return;
  }
  creds->vtable->cancel_get_request_metadata(creds, md_array, error);
}

grpc_security_status grpc_channel_credentials_create_security_connector(
    grpc_channel_credentials* channel_creds, const char* target,
    const grpc_channel_args* args, grpc_channel_security_connector** sc,
    grpc_channel_args** new_args) {
  *new_args = nullptr;
  if (channel_creds == nullptr) {
    return GRPC_SECURITY_ERROR;
  }
  GPR_ASSERT(channel_creds->vtable->create_security_connector != nullptr);
  return channel_creds->vtable->create_security_connector(
      channel_creds, nullptr, target, args, sc, new_args);
}

grpc_channel_credentials*
grpc_channel_credentials_duplicate_without_call_credentials(
    grpc_channel_credentials* channel_creds) {
  if (channel_creds != nullptr && channel_creds->vtable != nullptr &&
      channel_creds->vtable->duplicate_without_call_credentials != nullptr) {
    return channel_creds->vtable->duplicate_without_call_credentials(
        channel_creds);
  } else {
    return grpc_channel_credentials_ref(channel_creds);
  }
}

static void credentials_pointer_arg_destroy(void* p) {
  grpc_channel_credentials_unref(static_cast<grpc_channel_credentials*>(p));
}

static void* credentials_pointer_arg_copy(void* p) {
  return grpc_channel_credentials_ref(
      static_cast<grpc_channel_credentials*>(p));
}

static int credentials_pointer_cmp(void* a, void* b) { return GPR_ICMP(a, b); }

static const grpc_arg_pointer_vtable credentials_pointer_vtable = {
    credentials_pointer_arg_copy, credentials_pointer_arg_destroy,
    credentials_pointer_cmp};

grpc_arg grpc_channel_credentials_to_arg(
    grpc_channel_credentials* credentials) {
  return grpc_channel_arg_pointer_create((char*)GRPC_ARG_CHANNEL_CREDENTIALS,
                                         credentials,
                                         &credentials_pointer_vtable);
}

grpc_channel_credentials* grpc_channel_credentials_from_arg(
    const grpc_arg* arg) {
  if (strcmp(arg->key, GRPC_ARG_CHANNEL_CREDENTIALS)) return nullptr;
  if (arg->type != GRPC_ARG_POINTER) {
    gpr_log(GPR_ERROR, "Invalid type %d for arg %s", arg->type,
            GRPC_ARG_CHANNEL_CREDENTIALS);
    return nullptr;
  }
  return static_cast<grpc_channel_credentials*>(arg->value.pointer.p);
}

grpc_channel_credentials* grpc_channel_credentials_find_in_args(
    const grpc_channel_args* args) {
  size_t i;
  if (args == nullptr) return nullptr;
  for (i = 0; i < args->num_args; i++) {
    grpc_channel_credentials* credentials =
        grpc_channel_credentials_from_arg(&args->args[i]);
    if (credentials != nullptr) return credentials;
  }
  return nullptr;
}

grpc_server_credentials* grpc_server_credentials_ref(
    grpc_server_credentials* creds) {
  if (creds == nullptr) return nullptr;
  gpr_ref(&creds->refcount);
  return creds;
}

void grpc_server_credentials_unref(grpc_server_credentials* creds) {
  if (creds == nullptr) return;
  if (gpr_unref(&creds->refcount)) {
    if (creds->vtable->destruct != nullptr) {
      creds->vtable->destruct(creds);
    }
    if (creds->processor.destroy != nullptr &&
        creds->processor.state != nullptr) {
      creds->processor.destroy(creds->processor.state);
    }
    gpr_free(creds);
  }
}

void grpc_server_credentials_release(grpc_server_credentials* creds) {
  GRPC_API_TRACE("grpc_server_credentials_release(creds=%p)", 1, (creds));
  grpc_core::ExecCtx exec_ctx;
  grpc_server_credentials_unref(creds);
}

grpc_security_status grpc_server_credentials_create_security_connector(
    grpc_server_credentials* creds, grpc_server_security_connector** sc) {
  if (creds == nullptr || creds->vtable->create_security_connector == nullptr) {
    gpr_log(GPR_ERROR, "Server credentials cannot create security context.");
    return GRPC_SECURITY_ERROR;
  }
  return creds->vtable->create_security_connector(creds, sc);
}

void grpc_server_credentials_set_auth_metadata_processor(
    grpc_server_credentials* creds, grpc_auth_metadata_processor processor) {
  GRPC_API_TRACE(
      "grpc_server_credentials_set_auth_metadata_processor("
      "creds=%p, "
      "processor=grpc_auth_metadata_processor { process: %p, state: %p })",
      3, (creds, (void*)(intptr_t)processor.process, processor.state));
  if (creds == nullptr) return;
  if (creds->processor.destroy != nullptr &&
      creds->processor.state != nullptr) {
    creds->processor.destroy(creds->processor.state);
  }
  creds->processor = processor;
}

static void server_credentials_pointer_arg_destroy(void* p) {
  grpc_server_credentials_unref(static_cast<grpc_server_credentials*>(p));
}

static void* server_credentials_pointer_arg_copy(void* p) {
  return grpc_server_credentials_ref(static_cast<grpc_server_credentials*>(p));
}

static int server_credentials_pointer_cmp(void* a, void* b) {
  return GPR_ICMP(a, b);
}

static const grpc_arg_pointer_vtable cred_ptr_vtable = {
    server_credentials_pointer_arg_copy, server_credentials_pointer_arg_destroy,
    server_credentials_pointer_cmp};

grpc_arg grpc_server_credentials_to_arg(grpc_server_credentials* p) {
  return grpc_channel_arg_pointer_create((char*)GRPC_SERVER_CREDENTIALS_ARG, p,
                                         &cred_ptr_vtable);
}

grpc_server_credentials* grpc_server_credentials_from_arg(const grpc_arg* arg) {
  if (strcmp(arg->key, GRPC_SERVER_CREDENTIALS_ARG) != 0) return nullptr;
  if (arg->type != GRPC_ARG_POINTER) {
    gpr_log(GPR_ERROR, "Invalid type %d for arg %s", arg->type,
            GRPC_SERVER_CREDENTIALS_ARG);
    return nullptr;
  }
  return static_cast<grpc_server_credentials*>(arg->value.pointer.p);
}

grpc_server_credentials* grpc_find_server_credentials_in_args(
    const grpc_channel_args* args) {
  size_t i;
  if (args == nullptr) return nullptr;
  for (i = 0; i < args->num_args; i++) {
    grpc_server_credentials* p =
        grpc_server_credentials_from_arg(&args->args[i]);
    if (p != nullptr) return p;
  }
  return nullptr;
}