/*
 *
 * 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 "test/core/end2end/cq_verifier.h"

#include <stdarg.h>
#include <stdio.h>
#include <string.h>

#include "src/core/surface/event_string.h"
#include "src/core/support/string.h"
#include <grpc/byte_buffer.h>
#include <grpc/byte_buffer_reader.h>
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>
#include <grpc/support/time.h>
#include <grpc/support/useful.h>

#define ROOT_EXPECTATION 1000

/* a set of metadata we expect to find on an event */
typedef struct metadata
{
  size_t count;
  size_t cap;
  char **keys;
  char **values;
} metadata;

/* details what we expect to find on a single event - and forms a linked
   list to detail other expectations */
typedef struct expectation
{
  struct expectation *next;
  struct expectation *prev;
  grpc_completion_type type;
  void *tag;
  int success;
} expectation;

/* the verifier itself */
struct cq_verifier
{
  /* bound completion queue */
  grpc_completion_queue *cq;
  /* the root/sentinal expectation */
  expectation expect;
};

cq_verifier *
cq_verifier_create (grpc_completion_queue * cq)
{
  cq_verifier *v = gpr_malloc (sizeof (cq_verifier));
  v->expect.type = ROOT_EXPECTATION;
  v->expect.tag = NULL;
  v->expect.next = &v->expect;
  v->expect.prev = &v->expect;
  v->cq = cq;
  return v;
}

void
cq_verifier_destroy (cq_verifier * v)
{
  cq_verify (v);
  gpr_free (v);
}

static int
has_metadata (const grpc_metadata * md, size_t count, const char *key, const char *value)
{
  size_t i;
  for (i = 0; i < count; i++)
    {
      if (0 == strcmp (key, md[i].key) && strlen (value) == md[i].value_length && 0 == memcmp (md[i].value, value, md[i].value_length))
	{
	  return 1;
	}
    }
  return 0;
}

int
contains_metadata (grpc_metadata_array * array, const char *key, const char *value)
{
  return has_metadata (array->metadata, array->count, key, value);
}

static gpr_slice
merge_slices (gpr_slice * slices, size_t nslices)
{
  size_t i;
  size_t len = 0;
  gpr_uint8 *cursor;
  gpr_slice out;

  for (i = 0; i < nslices; i++)
    {
      len += GPR_SLICE_LENGTH (slices[i]);
    }

  out = gpr_slice_malloc (len);
  cursor = GPR_SLICE_START_PTR (out);

  for (i = 0; i < nslices; i++)
    {
      memcpy (cursor, GPR_SLICE_START_PTR (slices[i]), GPR_SLICE_LENGTH (slices[i]));
      cursor += GPR_SLICE_LENGTH (slices[i]);
    }

  return out;
}

static int
byte_buffer_eq_slice (grpc_byte_buffer * bb, gpr_slice b)
{
  gpr_slice a;
  int ok;

  if (!bb)
    return 0;

  a = merge_slices (bb->data.raw.slice_buffer.slices, bb->data.raw.slice_buffer.count);
  ok = GPR_SLICE_LENGTH (a) == GPR_SLICE_LENGTH (b) && 0 == memcmp (GPR_SLICE_START_PTR (a), GPR_SLICE_START_PTR (b), GPR_SLICE_LENGTH (a));
  gpr_slice_unref (a);
  gpr_slice_unref (b);
  return ok;
}

int
byte_buffer_eq_string (grpc_byte_buffer * bb, const char *str)
{
  grpc_byte_buffer_reader reader;
  grpc_byte_buffer *rbb;
  int res;

  grpc_byte_buffer_reader_init (&reader, bb);
  rbb = grpc_raw_byte_buffer_from_reader (&reader);
  res = byte_buffer_eq_slice (rbb, gpr_slice_from_copied_string (str));
  grpc_byte_buffer_reader_destroy (&reader);
  grpc_byte_buffer_destroy (rbb);

  return res;
}

static void
verify_matches (expectation * e, grpc_event * ev)
{
  GPR_ASSERT (e->type == ev->type);
  switch (e->type)
    {
    case GRPC_QUEUE_SHUTDOWN:
      gpr_log (GPR_ERROR, "premature queue shutdown");
      abort ();
      break;
    case GRPC_OP_COMPLETE:
      GPR_ASSERT (e->success == ev->success);
      break;
    case GRPC_QUEUE_TIMEOUT:
      gpr_log (GPR_ERROR, "not implemented");
      abort ();
      break;
    }
}

static void
expectation_to_strvec (gpr_strvec * buf, expectation * e)
{
  char *tmp;

  gpr_asprintf (&tmp, "%p ", e->tag);
  gpr_strvec_add (buf, tmp);

  switch (e->type)
    {
    case GRPC_OP_COMPLETE:
      gpr_asprintf (&tmp, "GRPC_OP_COMPLETE result=%d", e->success);
      gpr_strvec_add (buf, tmp);
      break;
    case GRPC_QUEUE_TIMEOUT:
    case GRPC_QUEUE_SHUTDOWN:
      gpr_log (GPR_ERROR, "not implemented");
      abort ();
      break;
    }
}

static void
expectations_to_strvec (gpr_strvec * buf, cq_verifier * v)
{
  expectation *e;

  for (e = v->expect.next; e != &v->expect; e = e->next)
    {
      expectation_to_strvec (buf, e);
      gpr_strvec_add (buf, gpr_strdup ("\n"));
    }
}

static void
fail_no_event_received (cq_verifier * v)
{
  gpr_strvec buf;
  char *msg;
  gpr_strvec_init (&buf);
  gpr_strvec_add (&buf, gpr_strdup ("no event received, but expected:\n"));
  expectations_to_strvec (&buf, v);
  msg = gpr_strvec_flatten (&buf, NULL);
  gpr_log (GPR_ERROR, "%s", msg);
  gpr_strvec_destroy (&buf);
  gpr_free (msg);
  abort ();
}

void
cq_verify (cq_verifier * v)
{
  gpr_timespec deadline = GRPC_TIMEOUT_SECONDS_TO_DEADLINE (10);
  grpc_event ev;
  expectation *e;
  char *s;
  gpr_strvec have_tags;

  gpr_strvec_init (&have_tags);

  while (v->expect.next != &v->expect)
    {
      ev = grpc_completion_queue_next (v->cq, deadline, NULL);
      if (ev.type == GRPC_QUEUE_TIMEOUT)
	{
	  fail_no_event_received (v);
	  break;
	}

      for (e = v->expect.next; e != &v->expect; e = e->next)
	{
	  gpr_asprintf (&s, " %p", e->tag);
	  gpr_strvec_add (&have_tags, s);
	  if (e->tag == ev.tag)
	    {
	      verify_matches (e, &ev);
	      e->next->prev = e->prev;
	      e->prev->next = e->next;
	      gpr_free (e);
	      break;
	    }
	}
      if (e == &v->expect)
	{
	  s = grpc_event_string (&ev);
	  gpr_log (GPR_ERROR, "event not found: %s", s);
	  gpr_free (s);
	  s = gpr_strvec_flatten (&have_tags, NULL);
	  gpr_log (GPR_ERROR, "have tags:%s", s);
	  gpr_free (s);
	  gpr_strvec_destroy (&have_tags);
	  abort ();
	}
    }

  gpr_strvec_destroy (&have_tags);
}

void
cq_verify_empty (cq_verifier * v)
{
  gpr_timespec deadline = gpr_time_add (gpr_now (GPR_CLOCK_REALTIME),
					gpr_time_from_seconds (1, GPR_TIMESPAN));
  grpc_event ev;

  GPR_ASSERT (v->expect.next == &v->expect && "expectation queue must be empty");

  ev = grpc_completion_queue_next (v->cq, deadline, NULL);
  if (ev.type != GRPC_QUEUE_TIMEOUT)
    {
      char *s = grpc_event_string (&ev);
      gpr_log (GPR_ERROR, "unexpected event (expected nothing): %s", s);
      gpr_free (s);
      abort ();
    }
}

static expectation *
add (cq_verifier * v, grpc_completion_type type, void *tag)
{
  expectation *e = gpr_malloc (sizeof (expectation));
  e->type = type;
  e->tag = tag;
  e->next = &v->expect;
  e->prev = e->next->prev;
  e->next->prev = e->prev->next = e;
  return e;
}

void
cq_expect_completion (cq_verifier * v, void *tag, int success)
{
  add (v, GRPC_OP_COMPLETE, tag)->success = success;
}