// Copyright 2017 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 <iostream>
#include <memory>
#include <set>

#include <lib/async-loop/cpp/loop.h>
#include <lib/component/cpp/startup_context.h>
#include <lib/fit/function.h>
#include <lib/fsl/vmo/strings.h>
#include <lib/fxl/command_line.h>
#include <lib/fxl/files/scoped_temp_dir.h>
#include <lib/fxl/logging.h>
#include <lib/fxl/memory/ref_ptr.h>
#include <lib/fxl/strings/string_number_conversions.h>
#include <lib/zx/time.h>
#include <trace/event.h>

#include "peridot/bin/ledger/fidl/include/types.h"
#include "peridot/bin/ledger/testing/data_generator.h"
#include "peridot/bin/ledger/testing/get_ledger.h"
#include "peridot/bin/ledger/testing/get_page_ensure_initialized.h"
#include "peridot/bin/ledger/testing/page_data_generator.h"
#include "peridot/bin/ledger/testing/quit_on_error.h"
#include "peridot/bin/ledger/testing/run_with_tracing.h"
#include "peridot/lib/convert/convert.h"
#include "peridot/lib/rng/test_random.h"

namespace ledger {
namespace {

// Benchmark that measures performance of the Put() operation.
//
// Parameters:
//   --entry-count=<int> the number of entries to be put
//   --transaction-size=<int> the size of a single transaction in number of put
//     operations. If equal to 0, no explicit transactions will be made.
//   --key-size=<int> the size of a single key in bytes
//   --value-size=<int> the size of a single value in bytes
//   --refs=(on|off) the reference strategy: on if every value is inserted
//     as a reference, off if every value is inserted as a FIDL array.
//   --update whether operations will update existing entries (put with existing
//     keys and new values)
//   --seed=<int> (optional) the seed for key and value generation
class PutBenchmark : public PageWatcher {
 public:
  PutBenchmark(async::Loop* loop,
               std::unique_ptr<component::StartupContext> startup_context,
               int entry_count, int transaction_size, int key_size,
               int value_size, bool update,
               PageDataGenerator::ReferenceStrategy reference_strategy,
               uint64_t seed);

  void Run();

  // PageWatcher:
  void OnChange(PageChange page_change, ResultState result_state,
                OnChangeCallback callback) override;

 private:
  // Initilizes the keys to be used in the benchmark. In case the benchmark is
  // on updating entries, it also adds these keys in the ledger with some
  // initial values.
  void InitializeKeys(
      fit::function<void(std::vector<std::vector<uint8_t>>)> on_done);

  void BindWatcher(std::vector<std::vector<uint8_t>> keys);
  void RunSingle(int i, std::vector<std::vector<uint8_t>> keys);
  void CommitAndRunNext(int i, size_t key_number,
                        std::vector<std::vector<uint8_t>> keys);
  void PutEntry(std::vector<uint8_t> key, std::vector<uint8_t> value,
                fit::function<void()> on_done);

  void ShutDown();
  fit::closure QuitLoopClosure();

  async::Loop* const loop_;
  rng::TestRandom random_;
  DataGenerator generator_;
  PageDataGenerator page_data_generator_;

  files::ScopedTempDir tmp_dir_;
  std::unique_ptr<component::StartupContext> startup_context_;
  const int entry_count_;
  const int transaction_size_;
  const int key_size_;
  const int value_size_;
  const bool update_;

  fidl::Binding<PageWatcher> page_watcher_binding_;
  const PageDataGenerator::ReferenceStrategy reference_strategy_;

  fuchsia::sys::ComponentControllerPtr component_controller_;
  LedgerPtr ledger_;
  PagePtr page_;
  // Keys that we use to identify a change event. For transaction_size = 1 it
  // contains all the keys, otherwise only the last changed key for each
  // transaction.
  std::set<size_t> keys_to_receive_;

  FXL_DISALLOW_COPY_AND_ASSIGN(PutBenchmark);
};

}  // namespace
}  // namespace ledger

namespace ledger {
namespace {

constexpr fxl::StringView kStoragePath = "/data/benchmark/ledger/put";

PutBenchmark::PutBenchmark(
    async::Loop* loop,
    std::unique_ptr<component::StartupContext> startup_context, int entry_count,
    int transaction_size, int key_size, int value_size, bool update,
    PageDataGenerator::ReferenceStrategy reference_strategy, uint64_t seed)
    : loop_(loop),
      random_(seed),
      generator_(&random_),
      page_data_generator_(&random_),
      tmp_dir_(kStoragePath),
      startup_context_(std::move(startup_context)),
      entry_count_(entry_count),
      transaction_size_(transaction_size),
      key_size_(key_size),
      value_size_(value_size),
      update_(update),
      page_watcher_binding_(this),
      reference_strategy_(reference_strategy) {
  FXL_DCHECK(loop_);
  FXL_DCHECK(entry_count > 0);
  FXL_DCHECK(transaction_size >= 0);
  FXL_DCHECK(key_size > 0);
  FXL_DCHECK(value_size > 0);
}

void PutBenchmark::Run() {
  FXL_LOG(INFO) << "--entry-count=" << entry_count_
                << " --transaction-size=" << transaction_size_
                << " --key-size=" << key_size_
                << " --value-size=" << value_size_ << " --refs="
                << (reference_strategy_ ==
                            PageDataGenerator::ReferenceStrategy::INLINE
                        ? "off"
                        : "on")
                << (update_ ? " --update" : "");
  Status status = GetLedger(
      startup_context_.get(), component_controller_.NewRequest(), nullptr, "",
      "put", DetachedPath(tmp_dir_.path()), QuitLoopClosure(), &ledger_);
  if (QuitOnError(QuitLoopClosure(), status, "GetLedger")) {
    return;
  }

  GetPageEnsureInitialized(
      &ledger_, nullptr, DelayCallback::YES, QuitLoopClosure(),
      [this](Status status, PagePtr page, PageId id) mutable {
        if (QuitOnError(QuitLoopClosure(), status,
                        "GetPageEnsureInitialized")) {
          return;
        }
        page_ = std::move(page);

        InitializeKeys(
            [this](std::vector<std::vector<uint8_t>> keys) mutable {
              if (transaction_size_ > 0) {
                page_->StartTransaction(
                    [this, keys = std::move(keys)](Status status) mutable {
                      if (QuitOnError(QuitLoopClosure(), status,
                                      "Page::StartTransaction")) {
                        return;
                      }
                      TRACE_ASYNC_BEGIN("benchmark", "transaction", 0);
                      BindWatcher(std::move(keys));
                    });
              } else {
                BindWatcher(std::move(keys));
              }
            });
      });
}

void PutBenchmark::OnChange(PageChange page_change,
                            ResultState /*result_state*/,
                            OnChangeCallback callback) {
  for (auto const& change : page_change.changed_entries) {
    size_t key_number = std::stoul(convert::ToString(change.key));
    if (keys_to_receive_.find(key_number) != keys_to_receive_.end()) {
      TRACE_ASYNC_END("benchmark", "local_change_notification", key_number);
      keys_to_receive_.erase(key_number);
    }
  }
  if (keys_to_receive_.empty()) {
    ShutDown();
  }
  callback(nullptr);
}

void PutBenchmark::InitializeKeys(
    fit::function<void(std::vector<std::vector<uint8_t>>)> on_done) {
  std::vector<std::vector<uint8_t>> keys =
      generator_.MakeKeys(entry_count_, key_size_, entry_count_);
  std::vector<std::vector<uint8_t>> keys_cloned;
  for (int i = 0; i < entry_count_; ++i) {
    keys_cloned.push_back(keys[i]);
    if (transaction_size_ == 0 ||
        i % transaction_size_ == transaction_size_ - 1) {
      keys_to_receive_.insert(std::stoul(convert::ToString(keys[i])));
    }
  }
  // Last key should always be recorded so the last transaction is not lost.
  size_t last_key_number = std::stoul(convert::ToString(keys.back()));
  keys_to_receive_.insert(last_key_number);
  if (!update_) {
    on_done(std::move(keys));
    return;
  }
  page_data_generator_.Populate(
      &page_, std::move(keys_cloned), value_size_, keys_cloned.size(),
      reference_strategy_, Priority::EAGER,
      [this, keys = std::move(keys),
       on_done = std::move(on_done)](Status status) mutable {
        if (QuitOnError(QuitLoopClosure(), status,
                        "PageDataGenerator::Populate")) {
          return;
        }
        on_done(std::move(keys));
      });
}

void PutBenchmark::BindWatcher(std::vector<std::vector<uint8_t>> keys) {
  PageSnapshotPtr snapshot;
  page_->GetSnapshot(
      snapshot.NewRequest(), fidl::VectorPtr<uint8_t>::New(0),
      page_watcher_binding_.NewBinding(),
      [this, keys = std::move(keys)](Status status) mutable {
        if (QuitOnError(QuitLoopClosure(), status, "GetSnapshot")) {
          return;
        }
        RunSingle(0, std::move(keys));
      });
}

void PutBenchmark::RunSingle(int i,
                             std::vector<std::vector<uint8_t>> keys) {
  if (i == entry_count_) {
    // All sent, waiting for watcher notification before shutting down.
    return;
  }

  fidl::VectorPtr<uint8_t> value = generator_.MakeValue(value_size_);
  size_t key_number = std::stoul(convert::ToString(keys[i]));
  if (transaction_size_ == 0) {
    TRACE_ASYNC_BEGIN("benchmark", "local_change_notification", key_number);
  }
  PutEntry(std::move(keys[i]), std::move(value),
           [this, i, key_number, keys = std::move(keys)]() mutable {
             if (transaction_size_ > 0 &&
                 (i % transaction_size_ == transaction_size_ - 1 ||
                  i + 1 == entry_count_)) {
               CommitAndRunNext(i, key_number, std::move(keys));
             } else {
               RunSingle(i + 1, std::move(keys));
             }
           });
}

void PutBenchmark::PutEntry(std::vector<uint8_t> key,
                            std::vector<uint8_t> value,
                            fit::function<void()> on_done) {
  auto trace_event_id = TRACE_NONCE();
  TRACE_ASYNC_BEGIN("benchmark", "put", trace_event_id);
  if (reference_strategy_ == PageDataGenerator::ReferenceStrategy::INLINE) {
    page_->Put(
        std::move(key), std::move(value),
        [this, trace_event_id, on_done = std::move(on_done)](Status status) {
          if (QuitOnError(QuitLoopClosure(), status, "Page::Put")) {
            return;
          }
          TRACE_ASYNC_END("benchmark", "put", trace_event_id);
          on_done();
        });
    return;
  }
  fsl::SizedVmo vmo;
  FXL_CHECK(fsl::VmoFromString(convert::ToStringView(value), &vmo));
  TRACE_ASYNC_BEGIN("benchmark", "create_reference", trace_event_id);
  page_->CreateReferenceFromBuffer(
      std::move(vmo).ToTransport(),
      [this, trace_event_id, key = std::move(key),
       on_done = std::move(on_done)](Status status,
                                     ReferencePtr reference) mutable {
        if (QuitOnError(QuitLoopClosure(), status,
                        "Page::CreateReferenceFromBuffer")) {
          return;
        }
        TRACE_ASYNC_END("benchmark", "create_reference", trace_event_id);
        TRACE_ASYNC_BEGIN("benchmark", "put_reference", trace_event_id);
        page_->PutReference(
            std::move(key), std::move(*reference), Priority::EAGER,
            [this, trace_event_id,
             on_done = std::move(on_done)](Status status) {
              if (QuitOnError(QuitLoopClosure(), status,
                              "Page::PutReference")) {
                return;
              }
              TRACE_ASYNC_END("benchmark", "put_reference", trace_event_id);
              TRACE_ASYNC_END("benchmark", "put", trace_event_id);
              on_done();
            });
      });
}

void PutBenchmark::CommitAndRunNext(
    int i, size_t key_number, std::vector<std::vector<uint8_t>> keys) {
  TRACE_ASYNC_BEGIN("benchmark", "local_change_notification", key_number);
  TRACE_ASYNC_BEGIN("benchmark", "commit", i / transaction_size_);
  page_->Commit([this, i, keys = std::move(keys)](Status status) mutable {
    if (QuitOnError(QuitLoopClosure(), status, "Page::Commit")) {
      return;
    }
    TRACE_ASYNC_END("benchmark", "commit", i / transaction_size_);
    TRACE_ASYNC_END("benchmark", "transaction", i / transaction_size_);

    if (i == entry_count_ - 1) {
      RunSingle(i + 1, std::move(keys));
      return;
    }
    page_->StartTransaction([this, i = i + 1,
                             keys = std::move(keys)](Status status) mutable {
      if (QuitOnError(QuitLoopClosure(), status, "Page::StartTransaction")) {
        return;
      }
      TRACE_ASYNC_BEGIN("benchmark", "transaction", i / transaction_size_);
      RunSingle(i, std::move(keys));
    });
  });
}

void PutBenchmark::ShutDown() {
  // Shut down the Ledger process first as it relies on |tmp_dir_| storage.
  KillLedgerProcess(&component_controller_);
  loop_->Quit();
}

fit::closure PutBenchmark::QuitLoopClosure() {
  return [this] { loop_->Quit(); };
}

}  // namespace
}  // namespace ledger

namespace ledger {
namespace {
constexpr fxl::StringView kBinaryPath =
    "fuchsia-pkg://fuchsia.com/ledger_benchmarks#meta/put.cmx";
constexpr fxl::StringView kEntryCountFlag = "entry-count";
constexpr fxl::StringView kTransactionSizeFlag = "transaction-size";
constexpr fxl::StringView kKeySizeFlag = "key-size";
constexpr fxl::StringView kValueSizeFlag = "value-size";
constexpr fxl::StringView kRefsFlag = "refs";
constexpr fxl::StringView kUpdateFlag = "update";
constexpr fxl::StringView kSeedFlag = "seed";

constexpr fxl::StringView kRefsOnFlag = "on";
constexpr fxl::StringView kRefsOffFlag = "off";

void PrintUsage() {
  std::cout << "Usage: trace record "
            << kBinaryPath
            // Comment to make clang format not break formatting.
            << " --" << kEntryCountFlag << "=<int>"
            << " --" << kTransactionSizeFlag << "=<int>"
            << " --" << kKeySizeFlag << "=<int>"
            << " --" << kValueSizeFlag << "=<int>"
            << " --" << kRefsFlag << "=(" << kRefsOnFlag << "|" << kRefsOffFlag
            << ")"
            << " [--" << kSeedFlag << "=<int>]"
            << " [--" << kUpdateFlag << "]" << std::endl;
}

bool GetPositiveIntValue(const fxl::CommandLine& command_line,
                         fxl::StringView flag, int* value) {
  std::string value_str;
  int found_value;
  if (!command_line.GetOptionValue(flag.ToString(), &value_str) ||
      !fxl::StringToNumberWithError(value_str, &found_value) ||
      found_value <= 0) {
    return false;
  }
  *value = found_value;
  return true;
}

int Main(int argc, const char** argv) {
  fxl::CommandLine command_line = fxl::CommandLineFromArgcArgv(argc, argv);
  async::Loop loop(&kAsyncLoopConfigAttachToThread);
  auto startup_context = component::StartupContext::CreateFromStartupInfo();

  int entry_count;
  std::string transaction_size_str;
  int transaction_size;
  int key_size;
  int value_size;
  bool update = command_line.HasOption(kUpdateFlag.ToString());
  if (!GetPositiveIntValue(command_line, kEntryCountFlag, &entry_count) ||
      !command_line.GetOptionValue(kTransactionSizeFlag.ToString(),
                                   &transaction_size_str) ||
      !fxl::StringToNumberWithError(transaction_size_str, &transaction_size) ||
      transaction_size < 0 ||
      !GetPositiveIntValue(command_line, kKeySizeFlag, &key_size) ||
      !GetPositiveIntValue(command_line, kValueSizeFlag, &value_size)) {
    PrintUsage();
    return -1;
  }

  std::string ref_strategy_str;
  if (!command_line.GetOptionValue(kRefsFlag.ToString(), &ref_strategy_str)) {
    PrintUsage();
    return -1;
  }
  PageDataGenerator::ReferenceStrategy ref_strategy;
  if (ref_strategy_str == kRefsOnFlag) {
    ref_strategy = PageDataGenerator::ReferenceStrategy::REFERENCE;
  } else if (ref_strategy_str == kRefsOffFlag) {
    ref_strategy = PageDataGenerator::ReferenceStrategy::INLINE;
  } else {
    std::cerr << "Unknown option " << ref_strategy_str << " for "
              << kRefsFlag.ToString() << std::endl;
    PrintUsage();
    return -1;
  }

  int seed;
  std::string seed_str;
  if (command_line.GetOptionValue(kSeedFlag.ToString(), &seed_str)) {
    if (!fxl::StringToNumberWithError(seed_str, &seed)) {
      PrintUsage();
      return -1;
    }
  } else {
    seed = 0;
  }

  PutBenchmark app(&loop, std::move(startup_context), entry_count,
                   transaction_size, key_size, value_size, update, ref_strategy,
                   seed);

  return RunWithTracing(&loop, [&app] { app.Run(); });
}

}  // namespace
}  // namespace ledger

int main(int argc, const char** argv) { return ledger::Main(argc, argv); }