/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to

 * deal in the Software without restriction, including without limitation the

 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or

 * sell copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS

 * IN THE SOFTWARE.

 */

/*

 * TODO: Add explanation of why we want on_close to be called from fresh

 * stack.

 */

#include "uv.h"

#include "task.h"

static const char MESSAGE[] = "Failure is for the weak. Everyone dies alone.";

static uv_tcp_t client;

static uv_timer_t timer;

static uv_connect_t connect_req;

static uv_write_t write_req;

static uv_shutdown_t shutdown_req;

static int nested = 0;

static int close_cb_called = 0;

static int connect_cb_called = 0;

static int write_cb_called = 0;

static int timer_cb_called = 0;

static int bytes_received = 0;

static int shutdown_cb_called = 0;

static void alloc_cb(uv_handle_t* handle, size_t size, uv_buf_t* buf) {

  buf->len = size;

  buf->base = malloc(size);

  ASSERT(buf->base != NULL);

}

static void close_cb(uv_handle_t* handle) {

  ASSERT(nested == 0 && "close_cb must be called from a fresh stack");

  close_cb_called++;

}

static void shutdown_cb(uv_shutdown_t* req, int status) {

  ASSERT(status == 0);

  ASSERT(nested == 0 && "shutdown_cb must be called from a fresh stack");

  shutdown_cb_called++;

}

static void read_cb(uv_stream_t* tcp, ssize_t nread, const uv_buf_t* buf) {

  ASSERT(nested == 0 && "read_cb must be called from a fresh stack");

  printf("Read. nread == %d\n", (int)nread);

  free(buf->base);

  if (nread == 0) {

    return;

  } else if (nread < 0) {

    ASSERT(nread == UV_EOF);

    nested++;

    uv_close((uv_handle_t*)tcp, close_cb);

    nested--;

    return;

  }

  bytes_received += nread;

  /* We call shutdown here because when bytes_received == sizeof MESSAGE there

   * will be no more data sent nor received, so here it would be possible for a

   * backend to call shutdown_cb immediately and *not* from a fresh stack. */

  if (bytes_received == sizeof MESSAGE) {

    nested++;

    puts("Shutdown");

    if (uv_shutdown(&shutdown_req, (uv_stream_t*)tcp, shutdown_cb)) {

      FATAL("uv_shutdown failed");

    }

    nested--;

  }

}

static void timer_cb(uv_timer_t* handle) {

  ASSERT(handle == &timer;;

  ASSERT(nested == 0 && "timer_cb must be called from a fresh stack");

  puts("Timeout complete. Now read data...");

  nested++;

  if (uv_read_start((uv_stream_t*)&client, alloc_cb, read_cb)) {

    FATAL("uv_read_start failed");

  }

  nested--;

  timer_cb_called++;

  uv_close((uv_handle_t*)handle, close_cb);

}

static void write_cb(uv_write_t* req, int status) {

  int r;

  ASSERT(status == 0);

  ASSERT(nested == 0 && "write_cb must be called from a fresh stack");

  puts("Data written. 500ms timeout...");

  /* After the data has been sent, we're going to wait for a while, then start

   * reading. This makes us certain that the message has been echoed back to

   * our receive buffer when we start reading. This maximizes the temptation

   * for the backend to use dirty stack for calling read_cb. */

  nested++;

  r = uv_timer_init(uv_default_loop(), &timer;;

  ASSERT(r == 0);

  r = uv_timer_start(&timer, timer_cb, 500, 0);

  ASSERT(r == 0);

  nested--;

  write_cb_called++;

}

static void connect_cb(uv_connect_t* req, int status) {

  uv_buf_t buf;

  puts("Connected. Write some data to echo server...");

  ASSERT(status == 0);

  ASSERT(nested == 0 && "connect_cb must be called from a fresh stack");

  nested++;

  buf.base = (char*) &MESSAGE;

  buf.len = sizeof MESSAGE;

  if (uv_write(&write_req, (uv_stream_t*)req->handle, &buf, 1, write_cb)) {

    FATAL("uv_write failed");

  }

  nested--;

  connect_cb_called++;

}

TEST_IMPL(callback_stack) {

  struct sockaddr_in addr;

  ASSERT(0 == uv_ip4_addr("127.0.0.1", TEST_PORT, &addr));

  if (uv_tcp_init(uv_default_loop(), &client)) {

    FATAL("uv_tcp_init failed");

  }

  puts("Connecting...");

  nested++;

  if (uv_tcp_connect(&connect_req,

                     &client,

                     (const struct sockaddr*) &addr,

                     connect_cb)) {

    FATAL("uv_tcp_connect failed");

  }

  nested--;

  uv_run(uv_default_loop(), UV_RUN_DEFAULT);

  ASSERT(nested == 0);

  ASSERT(connect_cb_called == 1 && "connect_cb must be called exactly once");

  ASSERT(write_cb_called == 1 && "write_cb must be called exactly once");

  ASSERT(timer_cb_called == 1 && "timer_cb must be called exactly once");

  ASSERT(bytes_received == sizeof MESSAGE);

  ASSERT(shutdown_cb_called == 1 && "shutdown_cb must be called exactly once");

  ASSERT(close_cb_called == 2 && "close_cb must be called exactly twice");

  MAKE_VALGRIND_HAPPY();

  return 0;

}