#define _POSIX_C_SOURCE 199309L
#include "benchmark.h"
#include "resource_usage.h"
#include <stdio.h>

#if defined(_WIN32) || defined(_WIN64)
#include <windows.h>
#else
#include <time.h>
#endif

/* ANSI color codes */
const char* COLOR_RED = "\033[31m";
const char* COLOR_GREEN = "\033[32m";
const char* COLOR_YELLOW = "\033[33m";
const char* COLOR_RESET = "\033[0m";

/* Maximum allowed average execution time per call in milliseconds */
const double MAX_ALLOWED_MS = 0.05;

/* Default benchmark iteration counts */
const size_t DEFAULT_BENCHMARKS = 100;
const size_t ITERATIONS_FAST = 1000;
const size_t ITERATIONS_SLOW = 10;

/* Volatile sink to prevent compiler optimizations removing the function call */
static volatile int sink;

/**
 * @brief Cross-platform monotonic time in milliseconds
 */
static double now_ms(void)
{
#if defined(_WIN32) || defined(_WIN64)
	LARGE_INTEGER freq, counter;
	QueryPerformanceFrequency(&freq);
	QueryPerformanceCounter(&counter);
	return (double)counter.QuadPart * 1000.0 / (double)freq.QuadPart;
#else
	struct timespec ts;
	clock_gettime(CLOCK_MONOTONIC, &ts);
	return ts.tv_sec * 1000.0 + ts.tv_nsec / 1e6;
#endif
}

double benchmark_func(const function_to_benchmark func,
		      const char* arg,
		      size_t benchmarks)
{
	if (!func)
		return 0.0;
	if (benchmarks == 0)
		benchmarks = DEFAULT_BENCHMARKS;
	size_t warmup = benchmarks / 10;
	if (warmup > 1000)
		warmup = 1000;
	for (size_t i = 0; i < warmup; ++i)
		sink = func(arg);
	const double start = now_ms();
	for (size_t i = 0; i < benchmarks; ++i)
		sink = func(arg);
	const double end = now_ms();
	return (end - start) / benchmarks;
}

void report_result(const char* test_name,
		   const int passed,
		   const double avg_ms,
		   const double max_allowed_ms)
{
	const int is_pass = passed && (avg_ms <= max_allowed_ms);
	const char* status_color = is_pass ? COLOR_GREEN : COLOR_RED;
	const char* status_text = is_pass ? "PASS" : "FAIL";

	if (!is_pass && avg_ms > max_allowed_ms)
		status_text = "SLOW";

	printf("[avg %.6f ms] %s%s: %s%s\n",
	       avg_ms,
	       status_color,
	       status_text,
	       test_name,
	       COLOR_RESET);

	if (!is_pass && avg_ms > max_allowed_ms) {
		printf("  %sReason:%s exceeded %.3f ms limit\n",
		       COLOR_YELLOW,
		       COLOR_RESET,
		       max_allowed_ms);
	}
}

void benchmark_func_with_resources(const function_to_benchmark func,
				   const char* arg,
				   const size_t benchmarks,
				   const char* label)
{
	const double avg_ms = benchmark_func(func, arg, benchmarks);
	printf("[Benchmark] %s avg %.6f ms\n", label, avg_ms);
	print_resource_usage(label);
}