/*
 *
 * Copyright 2016 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 <string.h>

#include <grpc/grpc.h>
#include <grpc/support/alloc.h>

#include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
#include "src/core/lib/iomgr/executor.h"
#include "src/core/lib/slice/slice_internal.h"
#include "src/core/lib/surface/channel.h"
#include "test/core/util/memory_counters.h"
#include "test/core/util/mock_endpoint.h"

bool squelch = true;
bool leak_check = true;

static void discard_write(grpc_slice slice) {}

static void *tag(int n) { return (void *)(uintptr_t)n; }

static void dont_log(gpr_log_func_args *args) {}

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
  grpc_test_only_set_slice_hash_seed(0);
  struct grpc_memory_counters counters;
  if (squelch) gpr_set_log_function(dont_log);
  if (leak_check) grpc_memory_counters_init();
  grpc_init();
  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
  grpc_executor_set_threading(&exec_ctx, false);

  grpc_resource_quota *resource_quota =
      grpc_resource_quota_create("client_fuzzer");
  grpc_endpoint *mock_endpoint =
      grpc_mock_endpoint_create(discard_write, resource_quota);
  grpc_resource_quota_unref_internal(&exec_ctx, resource_quota);

  grpc_completion_queue *cq = grpc_completion_queue_create_for_next(NULL);
  grpc_transport *transport =
      grpc_create_chttp2_transport(&exec_ctx, NULL, mock_endpoint, 1);
  grpc_chttp2_transport_start_reading(&exec_ctx, transport, NULL);

  grpc_channel *channel = grpc_channel_create(
      &exec_ctx, "test-target", NULL, GRPC_CLIENT_DIRECT_CHANNEL, transport);
  grpc_slice host = grpc_slice_from_static_string("localhost");
  grpc_call *call = grpc_channel_create_call(
      channel, NULL, 0, cq, grpc_slice_from_static_string("/foo"), &host,
      gpr_inf_future(GPR_CLOCK_REALTIME), NULL);

  grpc_metadata_array initial_metadata_recv;
  grpc_metadata_array_init(&initial_metadata_recv);
  grpc_byte_buffer *response_payload_recv = NULL;
  grpc_metadata_array trailing_metadata_recv;
  grpc_metadata_array_init(&trailing_metadata_recv);
  grpc_status_code status;
  grpc_slice details = grpc_empty_slice();

  grpc_op ops[6];
  memset(ops, 0, sizeof(ops));
  grpc_op *op = ops;
  op->op = GRPC_OP_SEND_INITIAL_METADATA;
  op->data.send_initial_metadata.count = 0;
  op->flags = 0;
  op->reserved = NULL;
  op++;
  op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
  op->flags = 0;
  op->reserved = NULL;
  op++;
  op->op = GRPC_OP_RECV_INITIAL_METADATA;
  op->data.recv_initial_metadata.recv_initial_metadata = &initial_metadata_recv;
  op->flags = 0;
  op->reserved = NULL;
  op++;
  op->op = GRPC_OP_RECV_MESSAGE;
  op->data.recv_message.recv_message = &response_payload_recv;
  op->flags = 0;
  op->reserved = NULL;
  op++;
  op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
  op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
  op->data.recv_status_on_client.status = &status;
  op->data.recv_status_on_client.status_details = &details;
  op->flags = 0;
  op->reserved = NULL;
  op++;
  grpc_call_error error =
      grpc_call_start_batch(call, ops, (size_t)(op - ops), tag(1), NULL);
  int requested_calls = 1;
  GPR_ASSERT(GRPC_CALL_OK == error);

  grpc_mock_endpoint_put_read(
      &exec_ctx, mock_endpoint,
      grpc_slice_from_copied_buffer((const char *)data, size));

  grpc_event ev;
  while (1) {
    grpc_exec_ctx_flush(&exec_ctx);
    ev = grpc_completion_queue_next(cq, gpr_inf_past(GPR_CLOCK_REALTIME), NULL);
    switch (ev.type) {
      case GRPC_QUEUE_TIMEOUT:
        goto done;
      case GRPC_QUEUE_SHUTDOWN:
        break;
      case GRPC_OP_COMPLETE:
        requested_calls--;
        break;
    }
  }

done:
  if (requested_calls) {
    grpc_call_cancel(call, NULL);
  }
  for (int i = 0; i < requested_calls; i++) {
    ev = grpc_completion_queue_next(cq, gpr_inf_past(GPR_CLOCK_REALTIME), NULL);
    GPR_ASSERT(ev.type == GRPC_OP_COMPLETE);
  }
  grpc_completion_queue_shutdown(cq);
  for (int i = 0; i < requested_calls; i++) {
    ev = grpc_completion_queue_next(cq, gpr_inf_past(GPR_CLOCK_REALTIME), NULL);
    GPR_ASSERT(ev.type == GRPC_QUEUE_SHUTDOWN);
  }
  grpc_call_unref(call);
  grpc_completion_queue_destroy(cq);
  grpc_metadata_array_destroy(&initial_metadata_recv);
  grpc_metadata_array_destroy(&trailing_metadata_recv);
  grpc_slice_unref(details);
  grpc_channel_destroy(channel);
  if (response_payload_recv != NULL) {
    grpc_byte_buffer_destroy(response_payload_recv);
  }
  grpc_shutdown();
  if (leak_check) {
    counters = grpc_memory_counters_snapshot();
    grpc_memory_counters_destroy();
    GPR_ASSERT(counters.total_size_relative == 0);
  }
  return 0;
}