// Copyright 2022 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "cdc_stream/local_assets_stream_manager_service_impl.h"

#include <iomanip>

#include "absl/strings/str_format.h"
#include "absl/strings/str_replace.h"
#include "absl/strings/str_split.h"
#include "cdc_stream/multi_session.h"
#include "cdc_stream/session_manager.h"
#include "common/grpc_status.h"
#include "common/log.h"
#include "common/path.h"
#include "common/process.h"
#include "common/sdk_util.h"
#include "common/status.h"
#include "google/protobuf/text_format.h"
#include "manifest/manifest_updater.h"

using TextFormat = google::protobuf::TextFormat;

namespace cdc_ft {
namespace {

std::string RequestToString(const google::protobuf::Message& request) {
  std::string str;
  google::protobuf::TextFormat::PrintToString(request, &str);
  if (!str.empty() && str.back() == '\n') str.pop_back();
  return absl::StrReplaceAll(str, {{"\n", ", "}});
}

// Parses |instance_name| of the form
// "organizations/{org-id}/projects/{proj-id}/pools/{pool-id}/gamelets/{gamelet-id}"
// into parts. The pool id is not returned.
bool ParseInstanceName(const std::string& instance_name,
                       std::string* instance_id, std::string* project_id,
                       std::string* organization_id) {
  std::string pool_id;
  std::vector<std::string> parts = absl::StrSplit(instance_name, '/');
  if (parts.size() != 10) return false;
  if (parts[0] != "organizations" || parts[1].empty()) return false;
  if (parts[2] != "projects" || parts[3].empty()) return false;
  if (parts[4] != "pools" || parts[5].empty()) return false;
  // Instance id is e.g.
  // edge/e-europe-west3-b/49d010c7be1845ac9a19a9033c64a460ces1
  if (parts[6] != "gamelets" || parts[7].empty() || parts[8].empty() ||
      parts[9].empty())
    return false;
  *organization_id = parts[1];
  *project_id = parts[3];
  *instance_id = absl::StrFormat("%s/%s/%s", parts[7], parts[8], parts[9]);
  return true;
}

// Parses |data| line by line for "|key|: value" and puts the first instance in
// |value| if present. Returns false if |data| does not contain "|key|: value".
// Trims whitespace.
bool ParseValue(const std::string& data, const std::string& key,
                std::string* value) {
  std::istringstream stream(data);

  std::string line;
  while (std::getline(stream, line)) {
    if (line.find(key + ":") == 0) {
      // Trim value.
      size_t start_pos = key.size() + 1;
      while (start_pos < line.size() && isspace(line[start_pos])) {
        start_pos++;
      }
      size_t end_pos = line.size();
      while (end_pos > start_pos && isspace(line[end_pos - 1])) {
        end_pos--;
      }
      *value = line.substr(start_pos, end_pos - start_pos);
      return true;
    }
  }
  return false;
}

// Why oh why?
std::string Quoted(const std::string& s) {
  std::ostringstream ss;
  ss << std::quoted(s);
  return ss.str();
}

}  // namespace

LocalAssetsStreamManagerServiceImpl::LocalAssetsStreamManagerServiceImpl(
    SessionManager* session_manager, ProcessFactory* process_factory,
    metrics::MetricsService* metrics_service)
    : session_manager_(session_manager),
      process_factory_(process_factory),
      metrics_service_(metrics_service) {}

LocalAssetsStreamManagerServiceImpl::~LocalAssetsStreamManagerServiceImpl() =
    default;

grpc::Status LocalAssetsStreamManagerServiceImpl::StartSession(
    grpc::ServerContext* /*context*/, const StartSessionRequest* request,
    StartSessionResponse* /*response*/) {
  LOG_INFO("RPC:StartSession(%s)", RequestToString(*request));

  MultiSession* ms = nullptr;
  metrics::DeveloperLogEvent evt;
  std::string instance_id;
  absl::Status status = StartSessionInternal(request, &instance_id, &ms, &evt);

  evt.as_manager_data->session_start_data->absl_status = status.code();
  if (ms) {
    evt.as_manager_data->session_start_data->concurrent_session_count =
        ms->GetSessionCount();
    if (!instance_id.empty() && ms->HasSession(instance_id)) {
      ms->RecordSessionEvent(std::move(evt), metrics::EventType::kSessionStart,
                             instance_id);
    } else {
      ms->RecordMultiSessionEvent(std::move(evt),
                                  metrics::EventType::kSessionStart);
    }
  } else {
    metrics_service_->RecordEvent(std::move(evt),
                                  metrics::EventType::kSessionStart);
  }

  if (status.ok()) {
    LOG_INFO("StartSession() succeeded");
  } else {
    LOG_ERROR("StartSession() failed: %s", status.ToString());
  }
  return ToGrpcStatus(status);
}

grpc::Status LocalAssetsStreamManagerServiceImpl::StopSession(
    grpc::ServerContext* /*context*/, const StopSessionRequest* request,
    StopSessionResponse* /*response*/) {
  LOG_INFO("RPC:StopSession(%s)", RequestToString(*request));

  std::string instance_id =
      !request->gamelet_id().empty()  // Stadia use case
          ? request->gamelet_id()
          : absl::StrCat(request->user_host(), ":", request->mount_dir());

  absl::Status status = session_manager_->StopSession(instance_id);
  if (status.ok()) {
    LOG_INFO("StopSession() succeeded");
  } else {
    LOG_ERROR("StopSession() failed: %s", status.ToString());
  }
  return ToGrpcStatus(status);
}

absl::Status LocalAssetsStreamManagerServiceImpl::StartSessionInternal(
    const StartSessionRequest* request, std::string* instance_id,
    MultiSession** ms, metrics::DeveloperLogEvent* evt) {
  instance_id->clear();
  *ms = nullptr;
  evt->as_manager_data = std::make_unique<metrics::AssetStreamingManagerData>();
  evt->as_manager_data->session_start_data =
      std::make_unique<metrics::SessionStartData>();
  evt->as_manager_data->session_start_data->absl_status = absl::StatusCode::kOk;
  evt->as_manager_data->session_start_data->status =
      metrics::SessionStartStatus::kOk;
  evt->as_manager_data->session_start_data->origin =
      ConvertOrigin(request->origin());

  if (!(request->gamelet_name().empty() ^ request->user_host().empty())) {
    return absl::InvalidArgumentError(
        "Must set either gamelet_name or user_host.");
  }

  if (request->mount_dir().empty()) {
    return absl::InvalidArgumentError("mount_dir cannot be empty.");
  }

  SessionTarget target;
  if (!request->gamelet_name().empty()) {
    ASSIGN_OR_RETURN(target,
                     GetTargetForStadia(*request, instance_id, &evt->project_id,
                                        &evt->organization_id));
  } else {
    target = GetTarget(*request, instance_id);
  }

  return session_manager_->StartSession(
      *instance_id, request->workstation_directory(), target, evt->project_id,
      evt->organization_id, ms,
      &evt->as_manager_data->session_start_data->status);
}

absl::StatusOr<SessionTarget>
LocalAssetsStreamManagerServiceImpl::GetTargetForStadia(
    const StartSessionRequest& request, std::string* instance_id,
    std::string* project_id, std::string* organization_id) {
  SessionTarget target;
  target.mount_dir = request.mount_dir();
  target.ssh_command = request.ssh_command();
  target.sftp_command = request.sftp_command();

  // Parse instance/project/org id.
  if (!ParseInstanceName(request.gamelet_name(), instance_id, project_id,
                         organization_id)) {
    return absl::InvalidArgumentError(absl::StrFormat(
        "Failed to parse instance name '%s'", request.gamelet_name()));
  }

  // Run 'ggp ssh init' to determine IP (host) and port.
  std::string instance_ip;
  ASSIGN_OR_RETURN(instance_ip,
                   InitSsh(*instance_id, *project_id, *organization_id));

  target.user_host = "cloudcast@" + instance_ip;
  // Note: Port must be set with ssh_command (-p) and sftp_command (-P).
  return target;
}

SessionTarget LocalAssetsStreamManagerServiceImpl::GetTarget(
    const StartSessionRequest& request, std::string* instance_id) {
  SessionTarget target;
  target.user_host = request.user_host();
  target.mount_dir = request.mount_dir();
  target.ssh_command = request.ssh_command();
  target.sftp_command = request.sftp_command();

  *instance_id = absl::StrCat(target.user_host, ":", target.mount_dir);
  return target;
}

metrics::RequestOrigin LocalAssetsStreamManagerServiceImpl::ConvertOrigin(
    StartSessionRequestOrigin origin) const {
  switch (origin) {
    case StartSessionRequest::ORIGIN_UNKNOWN:
      return metrics::RequestOrigin::kUnknown;
    case StartSessionRequest::ORIGIN_CLI:
      return metrics::RequestOrigin::kCli;
    case StartSessionRequest::ORIGIN_PARTNER_PORTAL:
      return metrics::RequestOrigin::kPartnerPortal;
    default:
      return metrics::RequestOrigin::kUnknown;
  }
}

absl::StatusOr<std::string> LocalAssetsStreamManagerServiceImpl::InitSsh(
    const std::string& instance_id, const std::string& project_id,
    const std::string& organization_id) {
  SdkUtil sdk_util;

  ProcessStartInfo start_info;
  start_info.command = absl::StrFormat(
      "%s ssh init", path::Join(sdk_util.GetDevBinPath(), "ggp"));
  start_info.command += absl::StrFormat(" --instance %s", Quoted(instance_id));
  if (!project_id.empty()) {
    start_info.command += absl::StrFormat(" --project %s", Quoted(project_id));
  }
  if (!organization_id.empty()) {
    start_info.command +=
        absl::StrFormat(" --organization %s", Quoted(organization_id));
  }
  start_info.name = "ggp ssh init";
  start_info.flags = ProcessFlags::kNoWindow;

  std::string output;
  start_info.stdout_handler = [&output, this](const char* data,
                                              size_t data_size) {
    // Note: This is called from a background thread!
    output.append(data, data_size);
    return absl::OkStatus();
  };
  start_info.forward_output_to_log = true;

  std::unique_ptr<Process> process = process_factory_->Create(start_info);
  absl::Status status = process->Start();
  if (!status.ok()) {
    return WrapStatus(status, "Failed to start ggp process");
  }

  status = process->RunUntilExit();
  if (!status.ok()) {
    return WrapStatus(status, "Failed to run ggp process");
  }

  uint32_t exit_code = process->ExitCode();
  if (exit_code != 0) {
    return MakeStatus("ggp process exited with code %u", exit_code);
  }

  // Parse gamelet IP. Should be "Host: <instance_ip ip>".
  std::string instance_ip;
  if (!ParseValue(output, "Host", &instance_ip)) {
    return MakeStatus("Failed to parse host from ggp ssh init response\n%s",
                      output);
  }

  return instance_ip;
}

}  // namespace cdc_ft