/*
 *
 * 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 <vector>

#include <node.h>
#include <nan.h>
#include "grpc/grpc.h"
#include "grpc/grpc_security.h"
#include "channel.h"
#include "credentials.h"

namespace grpc {
namespace node {

using v8::Array;
using v8::Exception;
using v8::Function;
using v8::FunctionTemplate;
using v8::Handle;
using v8::HandleScope;
using v8::Integer;
using v8::Local;
using v8::Object;
using v8::Persistent;
using v8::String;
using v8::Value;

NanCallback *Channel::constructor;
Persistent<FunctionTemplate> Channel::fun_tpl;

Channel::Channel(grpc_channel *channel, NanUtf8String *host)
    : wrapped_channel(channel), host(host) {}

Channel::~Channel() {
  if (wrapped_channel != NULL) {
    grpc_channel_destroy(wrapped_channel);
  }
  delete host;
}

void Channel::Init(Handle<Object> exports) {
  NanScope();
  Local<FunctionTemplate> tpl = NanNew<FunctionTemplate>(New);
  tpl->SetClassName(NanNew("Channel"));
  tpl->InstanceTemplate()->SetInternalFieldCount(1);
  NanSetPrototypeTemplate(tpl, "close",
                          NanNew<FunctionTemplate>(Close)->GetFunction());
  NanAssignPersistent(fun_tpl, tpl);
  Handle<Function> ctr = tpl->GetFunction();
  constructor = new NanCallback(ctr);
  exports->Set(NanNew("Channel"), ctr);
}

bool Channel::HasInstance(Handle<Value> val) {
  NanScope();
  return NanHasInstance(fun_tpl, val);
}

grpc_channel *Channel::GetWrappedChannel() { return this->wrapped_channel; }

char *Channel::GetHost() { return **this->host; }

NAN_METHOD(Channel::New) {
  NanScope();

  if (args.IsConstructCall()) {
    if (!args[0]->IsString()) {
      return NanThrowTypeError("Channel expects a string and an object");
    }
    grpc_channel *wrapped_channel;
    // Owned by the Channel object
    NanUtf8String *host = new NanUtf8String(args[0]);
    NanUtf8String *host_override = NULL;
    if (args[1]->IsUndefined()) {
      wrapped_channel = grpc_channel_create(**host, NULL);
    } else if (args[1]->IsObject()) {
      grpc_credentials *creds = NULL;
      Handle<Object> args_hash(args[1]->ToObject()->Clone());
      if (args_hash->HasOwnProperty(NanNew(GRPC_SSL_TARGET_NAME_OVERRIDE_ARG))) {
        host_override = new NanUtf8String(args_hash->Get(NanNew(GRPC_SSL_TARGET_NAME_OVERRIDE_ARG)));
      }
      if (args_hash->HasOwnProperty(NanNew("credentials"))) {
        Handle<Value> creds_value = args_hash->Get(NanNew("credentials"));
        if (!Credentials::HasInstance(creds_value)) {
          return NanThrowTypeError(
              "credentials arg must be a Credentials object");
        }
        Credentials *creds_object =
            ObjectWrap::Unwrap<Credentials>(creds_value->ToObject());
        creds = creds_object->GetWrappedCredentials();
        args_hash->Delete(NanNew("credentials"));
      }
      Handle<Array> keys(args_hash->GetOwnPropertyNames());
      grpc_channel_args channel_args;
      channel_args.num_args = keys->Length();
      channel_args.args = reinterpret_cast<grpc_arg *>(
          calloc(channel_args.num_args, sizeof(grpc_arg)));
      /* These are used to keep all strings until then end of the block, then
         destroy them */
      std::vector<NanUtf8String *> key_strings(keys->Length());
      std::vector<NanUtf8String *> value_strings(keys->Length());
      for (unsigned int i = 0; i < channel_args.num_args; i++) {
        Handle<String> current_key(keys->Get(i)->ToString());
        Handle<Value> current_value(args_hash->Get(current_key));
        key_strings[i] = new NanUtf8String(current_key);
        channel_args.args[i].key = **key_strings[i];
        if (current_value->IsInt32()) {
          channel_args.args[i].type = GRPC_ARG_INTEGER;
          channel_args.args[i].value.integer = current_value->Int32Value();
        } else if (current_value->IsString()) {
          channel_args.args[i].type = GRPC_ARG_STRING;
          value_strings[i] = new NanUtf8String(current_value);
          channel_args.args[i].value.string = **value_strings[i];
        } else {
          free(channel_args.args);
          return NanThrowTypeError("Arg values must be strings");
        }
      }
      if (creds == NULL) {
        wrapped_channel = grpc_channel_create(**host, &channel_args);
      } else {
        wrapped_channel =
            grpc_secure_channel_create(creds, **host, &channel_args);
      }
      free(channel_args.args);
    } else {
      return NanThrowTypeError("Channel expects a string and an object");
    }
    Channel *channel;
    if (host_override == NULL) {
      channel = new Channel(wrapped_channel, host);
    } else {
      channel = new Channel(wrapped_channel, host_override);
    }
    channel->Wrap(args.This());
    NanReturnValue(args.This());
  } else {
    const int argc = 2;
    Local<Value> argv[argc] = {args[0], args[1]};
    NanReturnValue(constructor->GetFunction()->NewInstance(argc, argv));
  }
}

NAN_METHOD(Channel::Close) {
  NanScope();
  if (!HasInstance(args.This())) {
    return NanThrowTypeError("close can only be called on Channel objects");
  }
  Channel *channel = ObjectWrap::Unwrap<Channel>(args.This());
  if (channel->wrapped_channel != NULL) {
    grpc_channel_destroy(channel->wrapped_channel);
    channel->wrapped_channel = NULL;
  }
  NanReturnUndefined();
}

}  // namespace node
}  // namespace grpc