/*
 * Copyright (C) 2024 The Android Open Source Project
 *
 * 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 "src/trace_processor/importers/proto/pixel_modem_module.h"

#include <cstdint>
#include <utility>

#include "perfetto/base/status.h"
#include "perfetto/protozero/field.h"
#include "perfetto/trace_processor/ref_counted.h"
#include "perfetto/trace_processor/trace_blob_view.h"
#include "src/trace_processor/importers/common/parser_types.h"
#include "src/trace_processor/importers/common/stats_tracker.h"
#include "src/trace_processor/importers/proto/blob_packet_writer.h"
#include "src/trace_processor/importers/proto/packet_sequence_state_generation.h"
#include "src/trace_processor/importers/proto/pixel_modem_parser.h"
#include "src/trace_processor/importers/proto/proto_importer_module.h"
#include "src/trace_processor/sorter/trace_sorter.h"
#include "src/trace_processor/storage/stats.h"

#include "protos/perfetto/trace/android/pixel_modem_events.pbzero.h"
#include "protos/perfetto/trace/trace_packet.pbzero.h"

namespace perfetto::trace_processor {

using perfetto::protos::pbzero::TracePacket;

PixelModemModule::PixelModemModule(ProtoImporterModuleContext* module_context,
                                   TraceProcessorContext* context)
    : ProtoImporterModule(module_context), context_(context), parser_(context) {
  RegisterForField(TracePacket::kPixelModemEventsFieldNumber);
  RegisterForField(TracePacket::kPixelModemTokenDatabaseFieldNumber);
}

ModuleResult PixelModemModule::TokenizePacket(
    const protos::pbzero::TracePacket_Decoder& decoder,
    TraceBlobView* /* packet */,
    int64_t packet_timestamp,
    RefPtr<PacketSequenceStateGeneration> state,
    uint32_t field_id) {
  // The database packet does not have a timestamp so needs to be handled at
  // the tokenization phase.
  if (field_id == TracePacket::kPixelModemTokenDatabaseFieldNumber) {
    auto db = decoder.pixel_modem_token_database();
    protos::pbzero::PixelModemTokenDatabase::Decoder database(db);

    base::Status status = parser_.SetDatabase(database.database());
    if (status.ok()) {
      return ModuleResult::Handled();
    }
    return ModuleResult::Error(status.message());
  }

  if (field_id != TracePacket::kPixelModemEventsFieldNumber) {
    return ModuleResult::Ignored();
  }

  // Pigweed events are similar to ftrace in that they have many events, each
  // with their own timestamp, packed inside a single TracePacket. This means
  // that, similar to ftrace, we need to unpack them and individually sort them.

  // However, as these events are not perf sensitive, it's not worth adding
  // a lot of machinery to shepherd these events through the sorting queues
  // in a special way. Therefore, we just forge new packets and sort them as if
  // they came from the underlying trace.
  auto events = decoder.pixel_modem_events();
  protos::pbzero::PixelModemEvents::Decoder evt(events.data, events.size);

  // To reduce overhead we store events and timestamps in parallel lists.
  // We also store timestamps within a packet as deltas.
  auto ts_it = evt.event_time_nanos();
  int64_t ts = 0;
  for (auto it = evt.events(); it && ts_it; ++it, ++ts_it) {
    protozero::ConstBytes event_bytes = *it;
    ts += *ts_it;
    if (ts < 0) {
      context_->stats_tracker->IncrementStats(
          stats::pixel_modem_negative_timestamp);
      continue;
    }

    TraceBlobView tbv =
        context_->blob_packet_writer->WritePacket([&](auto* data_packet) {
          // Keep the original timestamp to later extract as an arg; the sorter
          // does not read this.
          data_packet->set_timestamp(static_cast<uint64_t>(packet_timestamp));
          data_packet->set_pixel_modem_events()->add_events(event_bytes);
        });
    module_context_->trace_packet_stream->Push(
        ts, TracePacketData{std::move(tbv), state});
  }

  return ModuleResult::Handled();
}

void PixelModemModule::ParseTracePacketData(const TracePacket::Decoder& decoder,
                                            int64_t ts,
                                            const TracePacketData&,
                                            uint32_t field_id) {
  if (field_id != TracePacket::kPixelModemEventsFieldNumber) {
    return;
  }

  auto events = decoder.pixel_modem_events();
  protos::pbzero::PixelModemEvents::Decoder evt(events.data, events.size);
  auto it = evt.events();

  // We guarantee above there will be exactly one event.
  parser_.ParseEvent(ts, decoder.timestamp(), *it);
}

}  // namespace perfetto::trace_processor
