#pragma once

#include <cstdint>
#include <deque>
#include <vector>

namespace cvmmap_streamer::metrics {

struct LatencySummary {
	std::uint64_t samples{0};
	std::uint64_t min_us{0};
	std::uint64_t max_us{0};
	std::uint64_t avg_us{0};
	std::uint64_t p50_us{0};
	std::uint64_t p95_us{0};
	std::uint64_t p99_us{0};
};

class IngestEmitLatencyTracker {
public:
	void note_ingest();
	void note_emit();
	void note_emit_stall();

	[[nodiscard]]
	std::uint64_t emit_stall_events() const;

	[[nodiscard]]
	std::uint64_t pending_frames() const;

	[[nodiscard]]
	LatencySummary summarize() const;

private:
	std::deque<std::uint64_t> ingest_queue_ns_{};
	std::vector<std::uint64_t> samples_us_{};
	std::uint64_t emit_stall_events_{0};
};

}