/*
 *
 * 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. -- */

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;
  if (creds) creds->Unref();
}

static grpc_core::Map<grpc_core::UniquePtr<char>,
                      grpc_core::RefCountedPtr<grpc_channel_credentials>,
                      grpc_core::StringLess>* g_grpc_control_plane_creds;
static gpr_mu g_control_plane_creds_mu;

static void do_control_plane_creds_init() {
  gpr_mu_init(&g_control_plane_creds_mu);
  GPR_ASSERT(g_grpc_control_plane_creds == nullptr);
  g_grpc_control_plane_creds = grpc_core::New<
      grpc_core::Map<grpc_core::UniquePtr<char>,
                     grpc_core::RefCountedPtr<grpc_channel_credentials>,
                     grpc_core::StringLess>>();
}

void grpc_control_plane_credentials_init() {
  static gpr_once once_init_control_plane_creds = GPR_ONCE_INIT;
  gpr_once_init(&once_init_control_plane_creds, do_control_plane_creds_init);
}

void grpc_test_only_control_plane_credentials_destroy() {
  grpc_core::Delete(g_grpc_control_plane_creds);
  g_grpc_control_plane_creds = nullptr;
  gpr_mu_destroy(&g_control_plane_creds_mu);
}

void grpc_test_only_control_plane_credentials_force_init() {
  if (g_grpc_control_plane_creds == nullptr) {
    do_control_plane_creds_init();
  }
}

bool grpc_channel_credentials_attach_credentials(
    grpc_channel_credentials* credentials, const char* authority,
    grpc_channel_credentials* control_plane_creds) {
  grpc_core::ExecCtx exec_ctx;
  return credentials->attach_credentials(authority, control_plane_creds->Ref());
}

bool grpc_control_plane_credentials_register(
    const char* authority, grpc_channel_credentials* control_plane_creds) {
  grpc_core::ExecCtx exec_ctx;
  {
    grpc_core::MutexLock lock(&g_control_plane_creds_mu);
    auto key = grpc_core::UniquePtr<char>(gpr_strdup(authority));
    if (g_grpc_control_plane_creds->find(key) !=
        g_grpc_control_plane_creds->end()) {
      return false;
    }
    (*g_grpc_control_plane_creds)[std::move(key)] = control_plane_creds->Ref();
  }
  return true;
}

bool grpc_channel_credentials::attach_credentials(
    const char* authority,
    grpc_core::RefCountedPtr<grpc_channel_credentials> control_plane_creds) {
  auto key = grpc_core::UniquePtr<char>(gpr_strdup(authority));
  if (local_control_plane_creds_.find(key) !=
      local_control_plane_creds_.end()) {
    return false;
  }
  local_control_plane_creds_[std::move(key)] = std::move(control_plane_creds);
  return true;
}

grpc_core::RefCountedPtr<grpc_channel_credentials>
grpc_channel_credentials::get_control_plane_credentials(const char* authority) {
  {
    auto key = grpc_core::UniquePtr<char>(gpr_strdup(authority));
    auto local_lookup = local_control_plane_creds_.find(key);
    if (local_lookup != local_control_plane_creds_.end()) {
      return local_lookup->second;
    }
    {
      grpc_core::MutexLock lock(&g_control_plane_creds_mu);
      auto global_lookup = g_grpc_control_plane_creds->find(key);
      if (global_lookup != g_grpc_control_plane_creds->end()) {
        return global_lookup->second;
      }
    }
  }
  return duplicate_without_call_credentials();
}

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;
  if (creds) creds->Unref();
}

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

static void* credentials_pointer_arg_copy(void* p) {
  return static_cast<grpc_channel_credentials*>(p)->Ref().release();
}

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;
}

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;
  if (creds) creds->Unref();
}

void grpc_server_credentials::set_auth_metadata_processor(
    const 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, (this, (void*)(intptr_t)processor.process, processor.state));
  DestroyProcessor();
  processor_ = processor;
}

void grpc_server_credentials_set_auth_metadata_processor(
    grpc_server_credentials* creds, grpc_auth_metadata_processor processor) {
  GPR_DEBUG_ASSERT(creds != nullptr);
  creds->set_auth_metadata_processor(processor);
}

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

static void* server_credentials_pointer_arg_copy(void* p) {
  return static_cast<grpc_server_credentials*>(p)->Ref().release();
}

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;
}