/*
 *
 * Copyright 2015, Google Inc.
 * All rights reserved.
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 * 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.
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 * 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,
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */

#include "src/core/lib/client_config/resolvers/dns_resolver.h"

#include <string.h>

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

#include "src/core/lib/iomgr/resolve_address.h"
#include "src/core/lib/iomgr/timer.h"
#include "test/core/util/test_config.h"

static void subchannel_factory_ref(grpc_subchannel_factory *scv) {}
static void subchannel_factory_unref(grpc_exec_ctx *exec_ctx,
                                     grpc_subchannel_factory *scv) {}
static grpc_subchannel *subchannel_factory_create_subchannel(
    grpc_exec_ctx *exec_ctx, grpc_subchannel_factory *factory,
    grpc_subchannel_args *args) {
  return NULL;
}

static const grpc_subchannel_factory_vtable sc_vtable = {
    subchannel_factory_ref, subchannel_factory_unref,
    subchannel_factory_create_subchannel};

static grpc_subchannel_factory sc_factory = {&sc_vtable};

static gpr_mu g_mu;
static bool g_fail_resolution = true;

static grpc_resolved_addresses *my_resolve_address(const char *name,
                                                   const char *addr) {
  gpr_mu_lock(&g_mu);
  GPR_ASSERT(0 == strcmp("test", name));
  if (g_fail_resolution) {
    g_fail_resolution = false;
    gpr_mu_unlock(&g_mu);
    return NULL;
  } else {
    gpr_mu_unlock(&g_mu);
    grpc_resolved_addresses *addrs = gpr_malloc(sizeof(*addrs));
    addrs->naddrs = 1;
    addrs->addrs = gpr_malloc(sizeof(*addrs->addrs));
    addrs->addrs[0].len = 123;
    return addrs;
  }
}

static grpc_resolver *create_resolver(const char *name) {
  grpc_resolver_factory *factory = grpc_dns_resolver_factory_create();
  grpc_uri *uri = grpc_uri_parse(name, 0);
  GPR_ASSERT(uri);
  grpc_resolver_args args;
  memset(&args, 0, sizeof(args));
  args.uri = uri;
  args.subchannel_factory = &sc_factory;
  grpc_resolver *resolver =
      grpc_resolver_factory_create_resolver(factory, &args);
  grpc_resolver_factory_unref(factory);
  grpc_uri_destroy(uri);
  return resolver;
}

static void on_done(grpc_exec_ctx *exec_ctx, void *ev, bool success) {
  gpr_event_set(ev, (void *)1);
}

// interleave waiting for an event with a timer check
static bool wait_loop(int deadline_seconds, gpr_event *ev) {
  while (deadline_seconds) {
    gpr_log(GPR_DEBUG, "Test: waiting for %d more seconds", deadline_seconds);
    if (gpr_event_wait(ev, GRPC_TIMEOUT_SECONDS_TO_DEADLINE(1))) return true;
    deadline_seconds--;

    grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
    grpc_timer_check(&exec_ctx, gpr_now(GPR_CLOCK_MONOTONIC), NULL);
    grpc_exec_ctx_finish(&exec_ctx);
  }
  return false;
}

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

  grpc_init();
  gpr_mu_init(&g_mu);
  grpc_blocking_resolve_address = my_resolve_address;

  grpc_resolver *resolver = create_resolver("dns:test");

  grpc_client_config *config = (grpc_client_config *)1;

  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
  gpr_event ev1;
  gpr_event_init(&ev1);
  grpc_resolver_next(&exec_ctx, resolver, &config,
                     grpc_closure_create(on_done, &ev1));
  grpc_exec_ctx_flush(&exec_ctx);
  GPR_ASSERT(wait_loop(5, &ev1));
  GPR_ASSERT(config == NULL);

  gpr_event ev2;
  gpr_event_init(&ev2);
  grpc_resolver_next(&exec_ctx, resolver, &config,
                     grpc_closure_create(on_done, &ev2));
  grpc_exec_ctx_flush(&exec_ctx);
  GPR_ASSERT(wait_loop(30, &ev2));
  GPR_ASSERT(config != NULL);

  grpc_client_config_unref(&exec_ctx, config);
  GRPC_RESOLVER_UNREF(&exec_ctx, resolver, "test");
  grpc_exec_ctx_finish(&exec_ctx);

  grpc_shutdown();
  gpr_mu_destroy(&g_mu);
}