#include <psemek/audio/duplicate.hpp>
#include <psemek/audio/recorder.hpp>

#include <atomic>

namespace psemek::audio
{

	namespace
	{

		struct duplicate_impl
			: stream
		{
			duplicate_impl(std::shared_ptr<audio::recorder> recorder)
				: recorder_(std::move(recorder))
			{}

			std::optional<std::size_t> length() const override
			{
				return recorder_->length();
			}

			std::size_t played() const override
			{
				return played_.load();
			}

			std::size_t read(float * data, std::size_t sample_count) override
			{
				auto buffer = recorder_->buffer();
				auto played = played_.load();
				if (buffer.size() < played + sample_count)
				{
					recorder_->request(sample_count);
					buffer = recorder_->buffer();
				}

				auto count = std::min<std::size_t>(sample_count, buffer.size() - played);
				std::copy(buffer.data() + played, buffer.data() + played + count, data);
				played_.fetch_add(count);
				return count;
			}

		private:
			std::shared_ptr<recorder> recorder_;
			std::atomic<std::size_t> played_{0};
		};

	}

	duplicator make_duplicator(stream_ptr stream)
	{
		auto recorder = make_recorder(std::move(stream));
		return [recorder]{
			return std::make_shared<duplicate_impl>(recorder);
		};
	}

}