/* 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.

 */

#include "uv.h"

#include "uv-common.h"

#include "heap-inl.h"

#include <limits.h>

static struct heap *timer_heap(const uv_loop_t* loop) {

#ifdef _WIN32

  return (struct heap*) loop->timer_heap;

#else

  return (struct heap*) &loop->timer_heap;

#endif

}

static int timer_less_than(const struct heap_node* ha,

                           const struct heap_node* hb) {

  const uv_timer_t* a;

  const uv_timer_t* b;

  a = container_of(ha, uv_timer_t, node.heap);

  b = container_of(hb, uv_timer_t, node.heap);

  if (a->timeout < b->timeout)

    return 1;

  if (b->timeout < a->timeout)

    return 0;

  /* Compare start_id when both have the same timeout. start_id is

   * allocated with loop->timer_counter in uv_timer_start().

   */

  return a->start_id < b->start_id;

}

int uv_timer_init(uv_loop_t* loop, uv_timer_t* handle) {

  uv__handle_init(loop, (uv_handle_t*)handle, UV_TIMER);

  handle->timer_cb = NULL;

  handle->timeout = 0;

  handle->repeat = 0;

  uv__queue_init(&handle->node.queue);

  return 0;

}

int uv_timer_start(uv_timer_t* handle,

                   uv_timer_cb cb,

                   uint64_t timeout,

                   uint64_t repeat) {

  uint64_t clamped_timeout;

  if (uv__is_closing(handle) || cb == NULL)

    return UV_EINVAL;

  uv_timer_stop(handle);

  clamped_timeout = handle->loop->time + timeout;

  if (clamped_timeout < timeout)

    clamped_timeout = (uint64_t) -1;

  handle->timer_cb = cb;

  handle->timeout = clamped_timeout;

  handle->repeat = repeat;

  /* start_id is the second index to be compared in timer_less_than() */

  handle->start_id = handle->loop->timer_counter++;

  heap_insert(timer_heap(handle->loop),

              (struct heap_node*) &handle->node.heap,

              timer_less_than);

  uv__handle_start(handle);

  return 0;

}

int uv_timer_stop(uv_timer_t* handle) {

  if (uv__is_active(handle)) {

    heap_remove(timer_heap(handle->loop),

                (struct heap_node*) &handle->node.heap,

                timer_less_than);

    uv__handle_stop(handle);

  } else {

    uv__queue_remove(&handle->node.queue);

  }

  uv__queue_init(&handle->node.queue);

  return 0;

}

int uv_timer_again(uv_timer_t* handle) {

  if (handle->timer_cb == NULL)

    return UV_EINVAL;

  if (handle->repeat) {

    uv_timer_stop(handle);

    uv_timer_start(handle, handle->timer_cb, handle->repeat, handle->repeat);

  }

  return 0;

}

void uv_timer_set_repeat(uv_timer_t* handle, uint64_t repeat) {

  handle->repeat = repeat;

}

uint64_t uv_timer_get_repeat(const uv_timer_t* handle) {

  return handle->repeat;

}

uint64_t uv_timer_get_due_in(const uv_timer_t* handle) {

  if (handle->loop->time >= handle->timeout)

    return 0;

  return handle->timeout - handle->loop->time;

}

int uv__next_timeout(const uv_loop_t* loop) {

  const struct heap_node* heap_node;

  const uv_timer_t* handle;

  uint64_t diff;

  heap_node = heap_min(timer_heap(loop));

  if (heap_node == NULL)

    return -1; /* block indefinitely */

  handle = container_of(heap_node, uv_timer_t, node.heap);

  if (handle->timeout <= loop->time)

    return 0;

  diff = handle->timeout - loop->time;

  if (diff > INT_MAX)

    diff = INT_MAX;

  return (int) diff;

}

void uv__run_timers(uv_loop_t* loop) {

  struct heap_node* heap_node;

  uv_timer_t* handle;

  struct uv__queue* queue_node;

  struct uv__queue ready_queue;

  uv__queue_init(&ready_queue);

  for (;;) {

    heap_node = heap_min(timer_heap(loop));

    if (heap_node == NULL)

      break;

    handle = container_of(heap_node, uv_timer_t, node.heap);

    if (handle->timeout > loop->time)

      break;

    uv_timer_stop(handle);

    uv__queue_insert_tail(&ready_queue, &handle->node.queue);

  }

  while (!uv__queue_empty(&ready_queue)) {

    queue_node = uv__queue_head(&ready_queue);

    uv__queue_remove(queue_node);

    uv__queue_init(queue_node);

    handle = container_of(queue_node, uv_timer_t, node.queue);

    uv_timer_again(handle);

    handle->timer_cb(handle);

  }

}

void uv__timer_close(uv_timer_t* handle) {

  uv_timer_stop(handle);

}