// Copyright 2018 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 <cobalt-client/cpp/collector.h>
#include <cobalt-client/cpp/counter-internal.h>
#include <cobalt-client/cpp/histogram-internal.h>
#include <cobalt-client/cpp/metric-options.h>
#include <cobalt-client/cpp/types-internal.h>

#ifdef __Fuchsia__
#include <cobalt-client/cpp/collector-internal.h>

#include <fuchsia/cobalt/c/fidl.h>
#include <lib/fdio/util.h>
#include <lib/fidl/cpp/vector_view.h>
#include <lib/zx/channel.h>
#endif

#include <utility>

namespace cobalt_client {
namespace internal {
namespace {

#ifdef __Fuchsia__
internal::CobaltOptions MakeCobaltOptions(CollectorOptions options) {
    ZX_DEBUG_ASSERT_MSG(options.load_config, "Must define a load_config function.");
    internal::CobaltOptions cobalt_options;
    cobalt_options.logger_deadline_first_attempt = options.initial_response_deadline;
    cobalt_options.logger_deadline = options.response_deadline;
    cobalt_options.config_reader = std::move(options.load_config);
    cobalt_options.service_connect = [](const char* service_path,
                                        zx::channel service) -> zx_status_t {
        return fdio_service_connect(service_path, service.release());
    };
    cobalt_options.service_path.AppendPrintf("/svc/%s", fuchsia_cobalt_LoggerFactory_Name);
    cobalt_options.release_stage = static_cast<internal::ReleaseStage>(options.release_stage);
    return cobalt_options;
}
#else
// Host side implementation, which does nothing, just provides safety that all methods wont
// fault.
class HostLogger : public internal::Logger {
public:
    ~HostLogger() override = default;

    bool Log(const RemoteMetricInfo& remote_info, const HistogramBucket* buckets,
             size_t num_buckets) override {
        return true;
    };

    bool Log(const RemoteMetricInfo& remote_info, int64_t count) override { return true; };
};
#endif // __Fuchsia__
} // namespace
} // namespace internal

#ifdef __Fuchsia__
Collector::Collector(CollectorOptions options)
    : logger_(std::make_unique<internal::CobaltLogger>(
          internal::MakeCobaltOptions(std::move(options)))) {
    flushing_.store(false);
}
#else
Collector::Collector(CollectorOptions options) : logger_(std::make_unique<internal::HostLogger>()) {
    flushing_.store(false);
}
#endif // __Fuchsia__

Collector::Collector(std::unique_ptr<internal::Logger> logger) : logger_(std::move(logger)) {
    flushing_.store(false);
}

Collector::~Collector() {
    if (logger_ != nullptr) {
        Flush();
    }
};

void Collector::Flush() {
    // If we are already flushing we just return and do nothing.
    // First come first serve.
    if (flushing_.exchange(true)) {
        return;
    }

    for (internal::FlushInterface* flushable : flushables_) {
        if (!flushable->Flush(logger_.get())) {
            flushable->UndoFlush();
        }
    }

    // Once we are finished we allow flushing again.
    flushing_.store(false);
}

void Collector::UnSubscribe(internal::FlushInterface* flushable) {
    // TODO(gevalentino): Replace the vector for an unordered_map/hash_map.
    for (size_t i = 0; i < flushables_.size(); ++i) {
        if (flushable == flushables_[i]) {
            flushables_.erase(i);
            break;
        }
    }
}

CollectorOptions CollectorOptions::GeneralAvailability() {
    CollectorOptions options;
    options.release_stage = static_cast<uint32_t>(internal::ReleaseStage::kGa);
    return options;
}

CollectorOptions CollectorOptions::Dogfood() {
    CollectorOptions options;
    options.release_stage = static_cast<uint32_t>(internal::ReleaseStage::kDogfood);
    return options;
}

CollectorOptions CollectorOptions::Fishfood() {
    CollectorOptions options;
    options.release_stage = static_cast<uint32_t>(internal::ReleaseStage::kFishfood);
    return options;
}

CollectorOptions CollectorOptions::Debug() {
    CollectorOptions options;
    options.release_stage = static_cast<uint32_t>(internal::ReleaseStage::kDebug);
    return options;
}

} // namespace cobalt_client