// Copyright 2020 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/local_aggregation_1_1/local_aggregate_storage/immediate_local_aggregate_storage.h"

#include "absl/strings/numbers.h"
#include "absl/strings/str_cat.h"
#include "src/local_aggregation_1_1/local_aggregate_storage/local_aggregate_storage.h"
#include "src/logger/project_context_factory.h"
#include "src/logging.h"

namespace cobalt::local_aggregation {

ImmediateLocalAggregateStorage::ImmediateLocalAggregateStorage(
    std::string base_directory, util::FileSystem *fs,
    const logger::ProjectContextFactory *global_project_context_factory)
    : base_directory_(std::move(base_directory)),
      fs_(fs),
      proto_store_(fs_),
      global_project_context_factory_(global_project_context_factory) {
  CHECK(global_project_context_factory_)
      << "No global_project_context_factory provided. Cannot initialize store!";

  DeleteOutdatedMetrics();
  InitializePersistentStore();
}

void ImmediateLocalAggregateStorage::DeleteData() {
  for (const auto &customer_folder : fs_->ListFiles(base_directory_).ConsumeValueOr({})) {
    fs_->DeleteRecursive(absl::StrCat(base_directory_, "/", customer_folder));
  }
  aggregates_.clear();
}

void ImmediateLocalAggregateStorage::DeleteOutdatedMetrics() {
  for (const auto &customer_folder : fs_->ListFiles(base_directory_).ConsumeValueOr({})) {
    auto customer_dir = absl::StrCat(base_directory_, "/", customer_folder);

    uint32_t customer_id;
    if (!absl::SimpleAtoi(customer_folder, &customer_id)) {
      LOG(WARNING) << "Found bad customer folder name: " << customer_folder;
      continue;
    }

    for (const auto &project_folder : fs_->ListFiles(customer_dir).ConsumeValueOr({})) {
      auto project_dir = absl::StrCat(customer_dir, "/", project_folder);

      uint32_t project_id;
      if (!absl::SimpleAtoi(project_folder, &project_id)) {
        LOG(WARNING) << "Found bad project folder name: " << project_folder;
        continue;
      }

      auto project_context =
          global_project_context_factory_->NewProjectContext(customer_id, project_id);
      if (!project_context) {
        LOG(WARNING) << "Found customer/project that is not present in the registry: ("
                     << customer_id << ", " << project_id << "): Deleting it.";
        if (!fs_->DeleteRecursive(project_dir)) {
          LOG(ERROR) << "Unable to delete project folder";
        }
        continue;
      }

      for (const auto &metric_file : fs_->ListFiles(project_dir).ConsumeValueOr({})) {
        auto metric_filename = absl::StrCat(project_dir, "/", metric_file);

        uint32_t metric_id;
        if (!absl::SimpleAtoi(metric_file, &metric_id)) {
          LOG(WARNING) << "Unable to parse metric file name `" << metric_file << "` as an integer";
          continue;
        }

        if (!project_context->GetMetric(metric_id)) {
          LOG(WARNING) << "Found metric that is not present in the registry: (" << customer_id
                       << ", " << project_id << ", " << metric_id << "): Deleting it.";
          if (!fs_->Delete(metric_filename)) {
            LOG(ERROR) << "Unable to delete metric file";
          }
        }
      }
    }
  }
}

void ImmediateLocalAggregateStorage::InitializePersistentStore() {
  if (!fs_->FileExists(base_directory_)) {
    fs_->MakeDirectory(base_directory_);
  }
  for (const auto &project : global_project_context_factory_->ListProjects()) {
    auto customer_id = std::get<0>(project);
    auto project_id = std::get<1>(project);

    auto customer_dir = absl::StrCat(base_directory_, "/", customer_id);
    if (!fs_->FileExists(customer_dir)) {
      fs_->MakeDirectory(customer_dir);
    }

    auto project_dir = absl::StrCat(customer_dir, "/", project_id);
    if (!fs_->FileExists(project_dir)) {
      fs_->MakeDirectory(project_dir);
    }

    auto ctx = global_project_context_factory_->NewProjectContext(customer_id, project_id);
    for (const auto &metric_id : ctx->ListMetrics()) {
      auto metric_file = absl::StrCat(project_dir, "/", metric_id);
      if (!fs_->FileExists(metric_file)) {
        aggregates_[std::make_tuple(customer_id, project_id, metric_id)] = MetricAggregate();
      }
    }
  }
}

lib::statusor::StatusOr<LocalAggregateStorage::MetricAggregateRef>
ImmediateLocalAggregateStorage::GetMetricAggregate(const uint32_t customer_id,
                                                   const uint32_t project_id,
                                                   const uint32_t metric_id) {
  // Check if the file has already been read
  auto tuple = std::make_tuple(customer_id, project_id, metric_id);
  auto aggregate = aggregates_.find(tuple);
  if (aggregate != aggregates_.end()) {
    return MetricAggregateRef(customer_id, project_id, metric_id, &aggregate->second, this, mutex_);
  }

  // Try to read the file (if the customer_id/project_id/metric_id tuple actually exists in the
  // registry)
  auto ctx = global_project_context_factory_->NewProjectContext(customer_id, project_id);
  if (ctx) {
    if (ctx->GetMetric(metric_id)) {
      auto status = proto_store_.Read(
          absl::StrCat(base_directory_, "/", customer_id, "/", project_id, "/", metric_id),
          &aggregates_[tuple]);

      if (!status.ok()) {
        LOG(WARNING) << "Failed to load aggregate file: " << customer_id << "/" << project_id << "/"
                     << metric_id << ": " << status.error_message();
      }

      return MetricAggregateRef(customer_id, project_id, metric_id, &aggregates_[tuple], this,
                                mutex_);
    }
    return util::Status(
        util::StatusCode::NOT_FOUND,
        absl::StrCat("Metric id `", metric_id, "` not found in registry for project (", customer_id,
                     ", ", project_id, ")"));
  }

  return util::Status(
      util::StatusCode::NOT_FOUND,
      absl::StrCat("Project (", customer_id, ", ", project_id, ") not found in registry"));
}

util::Status ImmediateLocalAggregateStorage::SaveMetricAggregate(const uint32_t customer_id,
                                                                 const uint32_t project_id,
                                                                 const uint32_t metric_id) {
  auto aggregate = aggregates_.find(std::make_tuple(customer_id, project_id, metric_id));
  if (aggregate != aggregates_.end()) {
    return proto_store_.Write(
        absl::StrCat(base_directory_, "/", customer_id, "/", project_id, "/", metric_id),
        aggregate->second);
  }
  return util::Status(util::StatusCode::NOT_FOUND, "No matching metric aggregate found");
}

}  // namespace cobalt::local_aggregation