#ifndef PERF_H

#define PERF_H

#include <stdint.h>

#include <stddef.h>

typedef enum {

PERF_OFF = 0,

PERF_BENCH,

PERF_AMBIENT

} PerfMode;

/* Initialize the perf subsystem.

* PERF_OFF - no-op; all probes short-circuit on one branch.

* PERF_BENCH - collect samples into per-label arrays for aggregation.

* PERF_AMBIENT - stream one EDN map per sample to out_path.

* out_path is copied. For BENCH it is used later by perf_write_bench_edn;

* for AMBIENT it is opened immediately and streamed to. */

void perf_init(PerfMode mode, const char *out_path);

/* Flush pending ambient samples, close files, free per-label buffers. */

void perf_shutdown(void);

/* Monotonic nanosecond clock. Safe to call even when perf is off. */

uint64_t perf_now_ns(void);

/* Record a single sample. One-branch no-op when PERF_OFF. */

void perf_record(const char *label, uint64_t ns);

/* Current mode (used by callers that want to skip sample-prep work). */

PerfMode perf_get_mode(void);

/* BENCH mode: write the aggregate EDN map to out_path (NULL or "-" = stdout).

* Emits {:version :host :mode :bench :timestamp :samples [{...}]}. */

void perf_write_bench_edn(const char *out_path);

#endif /* PERF_H */