#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/types.h>

#include "etcd/Client.hpp"
#include "etcd/v3/Action.hpp"
#include "etcd/v3/AsyncDeleteRangeResponse.hpp"
#include "etcd/v3/AsyncLockResponse.hpp"
#include "etcd/v3/AsyncRangeResponse.hpp"
#include "etcd/v3/AsyncTxnResponse.hpp"
#include "etcd/v3/AsyncWatchResponse.hpp"
#include "etcd/v3/Transaction.hpp"
#include "etcd/v3/action_constants.hpp"
#include <iostream>
#include <limits>
#include <memory>

#include "etcd/v3/AsyncCompareAndDeleteAction.hpp"
#include "etcd/v3/AsyncCompareAndSwapAction.hpp"
#include "etcd/v3/AsyncDeleteAction.hpp"
#include "etcd/v3/AsyncGetAction.hpp"
#include "etcd/v3/AsyncLeaseGrantAction.hpp"
#include "etcd/v3/AsyncLeaseKeepAliveAction.hpp"
#include "etcd/v3/AsyncLeaseLeasesAction.hpp"
#include "etcd/v3/AsyncLeaseRevokeAction.hpp"
#include "etcd/v3/AsyncLeaseTimeToLiveAction.hpp"
#include "etcd/v3/AsyncLockAction.hpp"
#include "etcd/v3/AsyncSetAction.hpp"
#include "etcd/v3/AsyncTxnAction.hpp"
#include "etcd/v3/AsyncUpdateAction.hpp"
#include "etcd/v3/AsyncWatchAction.hpp"

#include <boost/algorithm/string.hpp>

using grpc::Channel;

namespace etcd {
namespace detail {

static bool dns_resolve(std::string const &target,
                        std::vector<std::string> &endpoints) {
  struct addrinfo hints = {}, *addrs;
  hints.ai_family = AF_INET;
  hints.ai_socktype = SOCK_STREAM;
  hints.ai_protocol = IPPROTO_TCP;

  std::vector<std::string> target_parts;
  boost::split(target_parts, target, boost::is_any_of(":"));
  if (target_parts.size() != 2) {
    std::cerr << "warn: invalid URL: " << target << std::endl;
    return false;
  }
  if (getaddrinfo(target_parts[0].c_str(), target_parts[1].c_str(), &hints,
                  &addrs) != 0) {
    std::cerr << "warn: getaddrinfo() failed for endpoint " << target
              << std::endl;
    return false;
  }

  char host[16] = {'\0'};
  for (struct addrinfo *addr = addrs; addr != nullptr; addr = addr->ai_next) {
    memset(host, '\0', sizeof(host));
    getnameinfo(addr->ai_addr, addr->ai_addrlen, host, sizeof(host), NULL, 0,
                NI_NUMERICHOST);
    endpoints.emplace_back(std::string(host) + ":" + target_parts[1]);
  }
  freeaddrinfo(addrs);
  return true;
}

const std::string strip_and_resolve_addresses(std::string const &address) {
  std::vector<std::string> addresses;
  boost::algorithm::split(addresses, address,
                          boost::algorithm::is_any_of(",;"));
  std::string stripped_address;
  {
    std::vector<std::string> stripped_addresses;
    std::string substr("://");
    for (auto const &addr : addresses) {
      std::string::size_type idx = addr.find(substr);
      std::string target =
          idx == std::string::npos ? addr : addr.substr(idx + substr.length());
      etcd::detail::dns_resolve(target, stripped_addresses);
    }
    stripped_address = boost::algorithm::join(stripped_addresses, ",");
  }
  return "ipv4:///" + stripped_address;
}

const bool authenticate(std::shared_ptr<grpc::Channel> const &channel,
                        std::string const &username,
                        std::string const &password,
                        std::string &token_or_message) {
  // run a round of auth
  auto auth_stub = Auth::NewStub(channel);
  ClientContext context;
  etcdserverpb::AuthenticateRequest auth_request;
  etcdserverpb::AuthenticateResponse auth_response;
  auth_request.set_name(username);
  auth_request.set_password(password);
  auto status = auth_stub->Authenticate(&context, auth_request, &auth_response);
  if (status.ok()) {
    token_or_message = auth_response.token();
    return true;
  } else {
    token_or_message = status.error_message();
    return false;
  }
}

} // namespace detail
} // namespace etcd

etcd::Client::Client(std::string const &address,
                     std::string const &load_balancer) {
  // create channels
  std::string const addresses =
      etcd::detail::strip_and_resolve_addresses(address);
  grpc::ChannelArguments grpc_args;
  grpc_args.SetMaxSendMessageSize(std::numeric_limits<int>::max());
  grpc_args.SetMaxReceiveMessageSize(std::numeric_limits<int>::max());
  std::shared_ptr<grpc::ChannelCredentials> creds =
      grpc::InsecureChannelCredentials();
  grpc_args.SetLoadBalancingPolicyName(load_balancer);
  this->channel = grpc::CreateCustomChannel(addresses, creds, grpc_args);

  // create stubs
  kvServiceStub = KV::NewStub(this->channel);
  watchServiceStub = Watch::NewStub(this->channel);
  leaseServiceStub = Lease::NewStub(this->channel);
  lockServiceStub = Lock::NewStub(this->channel);
}

etcd::Client::Client(std::string const &address, std::string const &username,
                     std::string const &password,
                     std::string const &load_balancer) {
  // create channels
  std::string const addresses =
      etcd::detail::strip_and_resolve_addresses(address);
  grpc::ChannelArguments grpc_args;
  grpc_args.SetMaxSendMessageSize(std::numeric_limits<int>::max());
  grpc_args.SetMaxReceiveMessageSize(std::numeric_limits<int>::max());
  std::shared_ptr<grpc::ChannelCredentials> creds =
      grpc::InsecureChannelCredentials();
  grpc_args.SetLoadBalancingPolicyName(load_balancer);
  this->channel = grpc::CreateCustomChannel(addresses, creds, grpc_args);

  // auth
  std::string token_or_message;
  if (!etcd::detail::authenticate(this->channel, username, password,
                                  token_or_message)) {
    throw std::invalid_argument("Etcd authentication failed: " +
                                token_or_message);
  }
  this->auth_token = token_or_message;

  // setup stubs
  kvServiceStub = KV::NewStub(this->channel);
  watchServiceStub = Watch::NewStub(this->channel);
  leaseServiceStub = Lease::NewStub(this->channel);
  lockServiceStub = Lock::NewStub(this->channel);
}

pplx::task<etcd::Response> etcd::Client::get(std::string const &key) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.withPrefix = false;
  params.kv_stub = kvServiceStub.get();
  std::shared_ptr<etcdv3::AsyncGetAction> call(
      new etcdv3::AsyncGetAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response>
etcd::Client::set(std::string const &key, std::string const &value, int ttl) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.value.assign(value);
  params.kv_stub = kvServiceStub.get();

  if (ttl > 0) {
    auto res = leasegrant(ttl).get();
    if (!res.is_ok()) {
      return pplx::task<etcd::Response>([res]() {
        return etcd::Response(res.error_code(), res.error_message().c_str());
      });
    } else {
      params.lease_id = res.value().lease();
    }
  }

  std::shared_ptr<etcdv3::AsyncSetAction> call(
      new etcdv3::AsyncSetAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::set(std::string const &key,
                                             std::string const &value,
                                             int64_t leaseid) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.value.assign(value);
  params.lease_id = leaseid;
  params.kv_stub = kvServiceStub.get();
  std::shared_ptr<etcdv3::AsyncSetAction> call(
      new etcdv3::AsyncSetAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response>
etcd::Client::add(std::string const &key, std::string const &value, int ttl) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.value.assign(value);
  params.kv_stub = kvServiceStub.get();

  if (ttl > 0) {
    auto res = leasegrant(ttl).get();
    if (!res.is_ok()) {
      return pplx::task<etcd::Response>([res]() {
        return etcd::Response(res.error_code(), res.error_message().c_str());
      });
    } else {
      params.lease_id = res.value().lease();
    }
  }
  std::shared_ptr<etcdv3::AsyncSetAction> call(
      new etcdv3::AsyncSetAction(params, true));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::add(std::string const &key,
                                             std::string const &value,
                                             int64_t leaseid) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.value.assign(value);
  params.lease_id = leaseid;
  params.kv_stub = kvServiceStub.get();
  std::shared_ptr<etcdv3::AsyncSetAction> call(
      new etcdv3::AsyncSetAction(params, true));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::modify(std::string const &key,
                                                std::string const &value,
                                                int ttl) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.value.assign(value);
  params.kv_stub = kvServiceStub.get();

  if (ttl > 0) {
    auto res = leasegrant(ttl).get();
    if (!res.is_ok()) {
      return pplx::task<etcd::Response>([res]() {
        return etcd::Response(res.error_code(), res.error_message().c_str());
      });
    } else {
      params.lease_id = res.value().lease();
    }
  }
  std::shared_ptr<etcdv3::AsyncUpdateAction> call(
      new etcdv3::AsyncUpdateAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::modify(std::string const &key,
                                                std::string const &value,
                                                int64_t leaseid) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.value.assign(value);
  params.lease_id = leaseid;
  params.kv_stub = kvServiceStub.get();
  std::shared_ptr<etcdv3::AsyncUpdateAction> call(
      new etcdv3::AsyncUpdateAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::modify_if(std::string const &key,
                                                   std::string const &value,
                                                   std::string const &old_value,
                                                   int ttl) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.value.assign(value);
  params.old_value.assign(old_value);
  params.kv_stub = kvServiceStub.get();

  if (ttl > 0) {
    auto res = leasegrant(ttl).get();
    if (!res.is_ok()) {
      return pplx::task<etcd::Response>([res]() {
        return etcd::Response(res.error_code(), res.error_message().c_str());
      });
    } else {
      params.lease_id = res.value().lease();
    }
  }
  std::shared_ptr<etcdv3::AsyncCompareAndSwapAction> call(
      new etcdv3::AsyncCompareAndSwapAction(
          params, etcdv3::Atomicity_Type::PREV_VALUE));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::modify_if(std::string const &key,
                                                   std::string const &value,
                                                   std::string const &old_value,
                                                   int64_t leaseid) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.value.assign(value);
  params.old_value.assign(old_value);
  params.lease_id = leaseid;
  params.kv_stub = kvServiceStub.get();
  std::shared_ptr<etcdv3::AsyncCompareAndSwapAction> call(
      new etcdv3::AsyncCompareAndSwapAction(
          params, etcdv3::Atomicity_Type::PREV_VALUE));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::modify_if(std::string const &key,
                                                   std::string const &value,
                                                   int old_index, int ttl) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.value.assign(value);
  params.old_revision = old_index;
  params.kv_stub = kvServiceStub.get();
  if (ttl > 0) {
    auto res = leasegrant(ttl).get();
    if (!res.is_ok()) {
      return pplx::task<etcd::Response>([res]() {
        return etcd::Response(res.error_code(), res.error_message().c_str());
      });
    } else {
      params.lease_id = res.value().lease();
    }
  }
  std::shared_ptr<etcdv3::AsyncCompareAndSwapAction> call(
      new etcdv3::AsyncCompareAndSwapAction(
          params, etcdv3::Atomicity_Type::PREV_INDEX));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::modify_if(std::string const &key,
                                                   std::string const &value,
                                                   int old_index,
                                                   int64_t leaseid) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.value.assign(value);
  params.lease_id = leaseid;
  params.old_revision = old_index;
  params.kv_stub = kvServiceStub.get();
  std::shared_ptr<etcdv3::AsyncCompareAndSwapAction> call(
      new etcdv3::AsyncCompareAndSwapAction(
          params, etcdv3::Atomicity_Type::PREV_INDEX));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::rm(std::string const &key) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.withPrefix = false;
  params.kv_stub = kvServiceStub.get();
  std::shared_ptr<etcdv3::AsyncDeleteAction> call(
      new etcdv3::AsyncDeleteAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::rm_if(std::string const &key,
                                               std::string const &old_value) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.old_value.assign(old_value);
  params.kv_stub = kvServiceStub.get();
  std::shared_ptr<etcdv3::AsyncCompareAndDeleteAction> call(
      new etcdv3::AsyncCompareAndDeleteAction(
          params, etcdv3::Atomicity_Type::PREV_VALUE));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::rm_if(std::string const &key,
                                               int old_index) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.old_revision = old_index;
  params.kv_stub = kvServiceStub.get();
  std::shared_ptr<etcdv3::AsyncCompareAndDeleteAction> call(
      new etcdv3::AsyncCompareAndDeleteAction(
          params, etcdv3::Atomicity_Type::PREV_INDEX));
  ;
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::rmdir(std::string const &key,
                                               bool recursive) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.withPrefix = recursive;
  params.kv_stub = kvServiceStub.get();
  std::shared_ptr<etcdv3::AsyncDeleteAction> call(
      new etcdv3::AsyncDeleteAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::ls(std::string const &key) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.withPrefix = true;
  params.limit = 0; // default no limit.
  params.kv_stub = kvServiceStub.get();
  std::shared_ptr<etcdv3::AsyncGetAction> call(
      new etcdv3::AsyncGetAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::ls(std::string const &key,
                                            size_t const limit) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.withPrefix = true;
  params.limit = limit;
  params.kv_stub = kvServiceStub.get();
  std::shared_ptr<etcdv3::AsyncGetAction> call(
      new etcdv3::AsyncGetAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::watch(std::string const &key,
                                               bool recursive) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.withPrefix = recursive;
  params.watch_stub = watchServiceStub.get();
  std::shared_ptr<etcdv3::AsyncWatchAction> call(
      new etcdv3::AsyncWatchAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::watch(std::string const &key,
                                               int fromIndex, bool recursive) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key.assign(key);
  params.withPrefix = recursive;
  params.revision = fromIndex;
  params.watch_stub = watchServiceStub.get();
  std::shared_ptr<etcdv3::AsyncWatchAction> call(
      new etcdv3::AsyncWatchAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::leasegrant(int ttl) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.ttl = ttl;
  params.lease_stub = leaseServiceStub.get();
  std::shared_ptr<etcdv3::AsyncLeaseGrantAction> call(
      new etcdv3::AsyncLeaseGrantAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::listleases() {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.lease_stub = leaseServiceStub.get();
  std::shared_ptr<etcdv3::AsyncLeaseLeasesAction> call(
      new etcdv3::AsyncLeaseLeasesAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::leasekeepalive(int64_t lease_id) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.lease_id = lease_id;
  params.lease_stub = leaseServiceStub.get();
  std::shared_ptr<etcdv3::AsyncLeaseKeepAliveAction> call(
      new etcdv3::AsyncLeaseKeepAliveAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::leaserevoke(int64_t lease_id) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.lease_id = lease_id;
  params.lease_stub = leaseServiceStub.get();
  std::shared_ptr<etcdv3::AsyncLeaseRevokeAction> call(
      new etcdv3::AsyncLeaseRevokeAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::leasettl(int64_t lease_id, bool keys) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.lease_id = lease_id;
  params.keys = keys;
  params.lease_stub = leaseServiceStub.get();
  std::shared_ptr<etcdv3::AsyncLeaseTimeToLiveAction> call(
      new etcdv3::AsyncLeaseTimeToLiveAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::lock(std::string const &key) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key = key;
  params.lock_stub = lockServiceStub.get();
  std::shared_ptr<etcdv3::AsyncLockAction> call(
      new etcdv3::AsyncLockAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::unlock(std::string const &key) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.key = key;
  params.lock_stub = lockServiceStub.get();
  std::shared_ptr<etcdv3::AsyncUnlockAction> call(
      new etcdv3::AsyncUnlockAction(params));
  return Response::create(call);
}

pplx::task<etcd::Response> etcd::Client::txn(etcdv3::Transaction const &txn) {
  etcdv3::ActionParameters params;
  params.auth_token.assign(this->auth_token);
  params.kv_stub = kvServiceStub.get();
  std::shared_ptr<etcdv3::AsyncTxnAction> call(
      new etcdv3::AsyncTxnAction(params, txn));
  return Response::create(call);
}