/*
 *
 * 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 <string.h>

#include <grpc/grpc.h>
#include <grpc/support/alloc.h>
#include <grpc/support/host_port.h>
#include <grpc/support/log.h>
#include <grpc/support/slice.h>
#include <grpc/support/thd.h>

#include "src/core/ext/client_config/initial_connect_string.h"
#include "src/core/lib/iomgr/sockaddr.h"
#include "src/core/lib/security/credentials/fake/fake_credentials.h"
#include "src/core/lib/support/string.h"
#include "test/core/util/port.h"
#include "test/core/util/test_config.h"
#include "test/core/util/test_tcp_server.h"

struct rpc_state {
  char *target;
  grpc_channel_credentials *creds;
  grpc_completion_queue *cq;
  grpc_channel *channel;
  grpc_call *call;
  grpc_op op;
  gpr_slice_buffer incoming_buffer;
  gpr_slice_buffer temp_incoming_buffer;
  grpc_endpoint *tcp;
  gpr_atm done_atm;
};

static const char *magic_connect_string = "magic initial string";
static int server_port;
static struct rpc_state state;
static grpc_closure on_read;

static void handle_read(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
  GPR_ASSERT(error == GRPC_ERROR_NONE);
  gpr_slice_buffer_move_into(&state.temp_incoming_buffer,
                             &state.incoming_buffer);
  gpr_log(GPR_DEBUG, "got %" PRIuPTR " bytes, magic is %" PRIuPTR " bytes",
          state.incoming_buffer.length, strlen(magic_connect_string));
  if (state.incoming_buffer.length > strlen(magic_connect_string)) {
    gpr_atm_rel_store(&state.done_atm, 1);
    grpc_endpoint_shutdown(exec_ctx, state.tcp);
    grpc_endpoint_destroy(exec_ctx, state.tcp);
  } else {
    grpc_endpoint_read(exec_ctx, state.tcp, &state.temp_incoming_buffer,
                       &on_read);
  }
}

static void on_connect(grpc_exec_ctx *exec_ctx, void *arg, grpc_endpoint *tcp,
                       grpc_pollset *accepting_pollset,
                       grpc_tcp_server_acceptor *acceptor) {
  test_tcp_server *server = arg;
  grpc_closure_init(&on_read, handle_read, NULL);
  gpr_slice_buffer_init(&state.incoming_buffer);
  gpr_slice_buffer_init(&state.temp_incoming_buffer);
  state.tcp = tcp;
  grpc_endpoint_add_to_pollset(exec_ctx, tcp, server->pollset);
  grpc_endpoint_read(exec_ctx, tcp, &state.temp_incoming_buffer, &on_read);
}

static void set_magic_initial_string(struct sockaddr **addr, size_t *addr_len,
                                     gpr_slice *connect_string) {
  GPR_ASSERT(addr);
  GPR_ASSERT(addr_len);
  *connect_string = gpr_slice_from_copied_string(magic_connect_string);
}

static void reset_addr_and_set_magic_string(struct sockaddr **addr,
                                            size_t *addr_len,
                                            gpr_slice *connect_string) {
  struct sockaddr_in target;
  *connect_string = gpr_slice_from_copied_string(magic_connect_string);
  gpr_free(*addr);
  target.sin_family = AF_INET;
  target.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  target.sin_port = htons((uint16_t)server_port);
  *addr_len = sizeof(target);
  *addr = (struct sockaddr *)gpr_malloc(sizeof(target));
  memcpy(*addr, &target, sizeof(target));
}

static gpr_timespec n_sec_deadline(int seconds) {
  return gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
                      gpr_time_from_seconds(seconds, GPR_TIMESPAN));
}

static void start_rpc(int use_creds, int target_port) {
  state.cq = grpc_completion_queue_create(NULL);
  if (use_creds) {
    state.creds = grpc_fake_transport_security_credentials_create();
  } else {
    state.creds = NULL;
  }
  gpr_join_host_port(&state.target, "127.0.0.1", target_port);
  if (use_creds) {
    state.channel =
        grpc_secure_channel_create(state.creds, state.target, NULL, NULL);
  } else {
    state.channel = grpc_insecure_channel_create(state.target, NULL, NULL);
  }
  state.call = grpc_channel_create_call(
      state.channel, NULL, GRPC_PROPAGATE_DEFAULTS, state.cq, "/Service/Method",
      "localhost", gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
  memset(&state.op, 0, sizeof(state.op));
  state.op.op = GRPC_OP_SEND_INITIAL_METADATA;
  state.op.data.send_initial_metadata.count = 0;
  state.op.flags = 0;
  state.op.reserved = NULL;
  GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(state.call, &state.op,
                                                   (size_t)(1), NULL, NULL));
  grpc_completion_queue_next(state.cq, n_sec_deadline(5), NULL);
}

static void cleanup_rpc(void) {
  grpc_event ev;
  gpr_slice_buffer_destroy(&state.incoming_buffer);
  gpr_slice_buffer_destroy(&state.temp_incoming_buffer);
  grpc_channel_credentials_unref(state.creds);
  grpc_call_destroy(state.call);
  grpc_completion_queue_shutdown(state.cq);
  do {
    ev = grpc_completion_queue_next(state.cq, n_sec_deadline(1), NULL);
  } while (ev.type != GRPC_QUEUE_SHUTDOWN);
  grpc_completion_queue_destroy(state.cq);
  grpc_channel_destroy(state.channel);
  gpr_free(state.target);
}

typedef struct {
  test_tcp_server *server;
  gpr_event *signal_when_done;
} poll_args;

static void actually_poll_server(void *arg) {
  poll_args *pa = arg;
  gpr_timespec deadline = n_sec_deadline(10);
  while (true) {
    bool done = gpr_atm_acq_load(&state.done_atm) != 0;
    gpr_timespec time_left =
        gpr_time_sub(deadline, gpr_now(GPR_CLOCK_REALTIME));
    gpr_log(GPR_DEBUG, "done=%d, time_left=%" PRId64 ".%09" PRId32, done,
            time_left.tv_sec, time_left.tv_nsec);
    if (done || gpr_time_cmp(time_left, gpr_time_0(GPR_TIMESPAN)) < 0) {
      break;
    }
    test_tcp_server_poll(pa->server, 1);
  }
  gpr_event_set(pa->signal_when_done, (void *)1);
  gpr_free(pa);
}

static void poll_server_until_read_done(test_tcp_server *server,
                                        gpr_event *signal_when_done) {
  gpr_atm_rel_store(&state.done_atm, 0);
  gpr_thd_id id;
  poll_args *pa = gpr_malloc(sizeof(*pa));
  pa->server = server;
  pa->signal_when_done = signal_when_done;
  gpr_thd_new(&id, actually_poll_server, pa, NULL);
}

static void match_initial_magic_string(gpr_slice_buffer *buffer) {
  size_t i, j, cmp_length;
  size_t magic_length = strlen(magic_connect_string);
  GPR_ASSERT(buffer->length >= magic_length);
  for (i = 0, j = 0; i < state.incoming_buffer.count && j < magic_length; i++) {
    char *dump =
        gpr_dump_slice(state.incoming_buffer.slices[i], GPR_DUMP_ASCII);
    cmp_length = GPR_MIN(strlen(dump), magic_length - j);
    GPR_ASSERT(strncmp(dump, magic_connect_string + j, cmp_length) == 0);
    j += cmp_length;
    gpr_free(dump);
  }
}

static void test_initial_string(test_tcp_server *server, int secure) {
  gpr_event ev;
  gpr_event_init(&ev);
  grpc_test_set_initial_connect_string_function(set_magic_initial_string);
  poll_server_until_read_done(server, &ev);
  start_rpc(secure, server_port);
  gpr_event_wait(&ev, gpr_inf_future(GPR_CLOCK_REALTIME));
  match_initial_magic_string(&state.incoming_buffer);
  cleanup_rpc();
}

static void test_initial_string_with_redirect(test_tcp_server *server,
                                              int secure) {
  gpr_event ev;
  gpr_event_init(&ev);
  int another_port = grpc_pick_unused_port_or_die();
  grpc_test_set_initial_connect_string_function(
      reset_addr_and_set_magic_string);
  poll_server_until_read_done(server, &ev);
  start_rpc(secure, another_port);
  gpr_event_wait(&ev, gpr_inf_future(GPR_CLOCK_REALTIME));
  match_initial_magic_string(&state.incoming_buffer);
  cleanup_rpc();
}

static void run_test(void (*test)(test_tcp_server *server, int secure),
                     int secure) {
  test_tcp_server test_server;
  server_port = grpc_pick_unused_port_or_die();
  test_tcp_server_init(&test_server, on_connect, &test_server);
  test_tcp_server_start(&test_server, server_port);
  test(&test_server, secure);
  test_tcp_server_destroy(&test_server);
}

int main(int argc, char **argv) {
  grpc_test_init(argc, argv);
  grpc_init();

  run_test(test_initial_string, 0);
  run_test(test_initial_string, 1);
  run_test(test_initial_string_with_redirect, 0);
  run_test(test_initial_string_with_redirect, 1);

  grpc_shutdown();
  return 0;
}