/*
 *
 * Copyright 2015-2016, 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 <grpc/grpc.h>

#include "src/core/channel/http_server_filter.h"
#include "src/core/iomgr/resolve_address.h"
#include "src/core/iomgr/tcp_server.h"
#include "src/core/surface/api_trace.h"
#include "src/core/surface/server.h"
#include "src/core/transport/chttp2_transport.h"
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/useful.h>

static void setup_transport(grpc_exec_ctx *exec_ctx, void *server,
                            grpc_transport *transport) {
  static grpc_channel_filter const *extra_filters[] = {
      &grpc_http_server_filter};
  grpc_server_setup_transport(exec_ctx, server, transport, extra_filters,
                              GPR_ARRAY_SIZE(extra_filters),
                              grpc_server_get_channel_args(server));
}

static void new_transport(grpc_exec_ctx *exec_ctx, void *server,
                          grpc_endpoint *tcp,
                          grpc_tcp_server_acceptor *acceptor) {
  /*
   * Beware that the call to grpc_create_chttp2_transport() has to happen before
   * grpc_tcp_server_destroy(). This is fine here, but similar code
   * asynchronously doing a handshake instead of calling grpc_tcp_server_start()
   * (as in server_secure_chttp2.c) needs to add synchronization to avoid this
   * case.
   */
  grpc_transport *transport = grpc_create_chttp2_transport(
      exec_ctx, grpc_server_get_channel_args(server), tcp, 0);
  setup_transport(exec_ctx, server, transport);
  grpc_chttp2_transport_start_reading(exec_ctx, transport, NULL, 0);
}

/* Server callback: start listening on our ports */
static void start(grpc_exec_ctx *exec_ctx, grpc_server *server, void *tcpp,
                  grpc_pollset **pollsets, size_t pollset_count) {
  grpc_tcp_server *tcp = tcpp;
  grpc_tcp_server_start(exec_ctx, tcp, pollsets, pollset_count, new_transport,
                        server);
}

/* Server callback: destroy the tcp listener (so we don't generate further
   callbacks) */
static void destroy(grpc_exec_ctx *exec_ctx, grpc_server *server, void *tcpp,
                    grpc_closure *destroy_done) {
  grpc_tcp_server *tcp = tcpp;
  grpc_tcp_server_unref(exec_ctx, tcp);
  grpc_exec_ctx_enqueue(exec_ctx, destroy_done, true, NULL);
}

int grpc_server_add_insecure_http2_port(grpc_server *server, const char *addr) {
  grpc_resolved_addresses *resolved = NULL;
  grpc_tcp_server *tcp = NULL;
  size_t i;
  unsigned count = 0;
  int port_num = -1;
  int port_temp;
  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;

  GRPC_API_TRACE("grpc_server_add_insecure_http2_port(server=%p, addr=%s)", 2,
                 (server, addr));

  resolved = grpc_blocking_resolve_address(addr, "http");
  if (!resolved) {
    goto error;
  }

  tcp = grpc_tcp_server_create(NULL);
  GPR_ASSERT(tcp);

  for (i = 0; i < resolved->naddrs; i++) {
    port_temp = grpc_tcp_server_add_port(
        tcp, (struct sockaddr *)&resolved->addrs[i].addr,
        resolved->addrs[i].len);
    if (port_temp > 0) {
      if (port_num == -1) {
        port_num = port_temp;
      } else {
        GPR_ASSERT(port_num == port_temp);
      }
      count++;
    }
  }
  if (count == 0) {
    gpr_log(GPR_ERROR, "No address added out of total %d resolved",
            resolved->naddrs);
    goto error;
  }
  if (count != resolved->naddrs) {
    gpr_log(GPR_ERROR, "Only %d addresses added out of total %d resolved",
            count, resolved->naddrs);
  }
  grpc_resolved_addresses_destroy(resolved);

  /* Register with the server only upon success */
  grpc_server_add_listener(&exec_ctx, server, tcp, start, destroy);
  goto done;

/* Error path: cleanup and return */
error:
  if (resolved) {
    grpc_resolved_addresses_destroy(resolved);
  }
  if (tcp) {
    grpc_tcp_server_unref(&exec_ctx, tcp);
  }
  port_num = 0;

done:
  grpc_exec_ctx_finish(&exec_ctx);
  return port_num;
}