#include <stdio.h>
#include <time.h>
#include <pthread.h>
#include "benchmark.h"
#include "structs.h"
#include "algorithms.h"

#define NUM_SIZES 5
#define NUM_CONFIGS 5
#define TOTAL_GRAPHS 5

static int graph_sizes[NUM_SIZES] = { 5, 10, 20, 100, 500 };

typedef struct {
	int n;
	double p;
	double q;
	int k;
	int graph_index;
	int config_index;
	// results
	double time_kclique;
	double time_louvain;
	double time_cbla;
	int kclique_communities;
	int louvain_communities;
	int cbla_communities;
	int done;
	char error[128];
} bench_task_t;

static double elapsed_ms(struct timespec start, struct timespec end)
{
	return ((end.tv_sec - start.tv_sec) * 1000.0) +
	       ((end.tv_nsec - start.tv_nsec) / 1e6);
}

static void *benchmark_thread(void *arg)
{
	bench_task_t *task = (bench_task_t *)arg;
	struct timespec t0, t1;

	printf("[thread] config=%d graph=%d n=%-7d p=%.2f q=%.2f — generating...\n",
	       task->config_index + 1, task->graph_index + 1, task->n, task->p,
	       task->q);

	graph_t *graph = generate_graph(task->n, task->p, task->q, 122);
	if (!graph) {
		snprintf(task->error, sizeof(task->error),
			 "generate_graph failed");
		task->done = 1;
		return NULL;
	}

	clock_gettime(CLOCK_MONOTONIC, &t0);
	community_result_t *kc = find_k_clique_communities(graph, task->k);
	clock_gettime(CLOCK_MONOTONIC, &t1);
	task->time_kclique = elapsed_ms(t0, t1);
	task->kclique_communities = kc ? kc->count : 0;
	free_community_result(kc);

	clock_gettime(CLOCK_MONOTONIC, &t0);
	louvain_result_t *lv = compute_louvain(graph);
	clock_gettime(CLOCK_MONOTONIC, &t1);
	task->time_louvain = elapsed_ms(t0, t1);
	task->louvain_communities = lv ? lv->count : 0;
	free_louvain_result(lv);

	clock_gettime(CLOCK_MONOTONIC, &t0);
	cbla_result_t *hy = cbla_community_detection(graph, task->k);
	clock_gettime(CLOCK_MONOTONIC, &t1);
	task->time_cbla = elapsed_ms(t0, t1);
	task->cbla_communities = hy ? hy->count : 0;
	free_cbla_result(hy);

	free_graph(graph);

	printf("[thread] config=%d graph=%d n=%-7d — done "
	       "(kclique=%.1fms louvain=%.1fms cbla=%.1fms)\n",
	       task->config_index + 1, task->graph_index + 1, task->n,
	       task->time_kclique, task->time_louvain, task->time_cbla);

	task->done = 1;
	return NULL;
}

void run_benchmark(void)
{
	// p/q configurations
	double configs[NUM_CONFIGS][3] = {
		{ 1.0, 0.15, 3 }, { 1.0, 0.15, 3 },   { 0.8, 0.05, 3 },
		{ 0.4, 0.02, 5 }, { 0.10, 0.005, 6 },
	};

	bench_task_t tasks[TOTAL_GRAPHS];
	pthread_t threads[TOTAL_GRAPHS];
	int task_idx = 0;

	// Initialize all tasks
	for (int c = 0; c < TOTAL_GRAPHS; c++) {
		bench_task_t *t = &tasks[task_idx++];
		t->n = graph_sizes[c];
		t->p = configs[c][0];
		t->q = configs[c][1];
		t->k = configs[c][2];
		t->config_index = c;
		t->graph_index = c;
		t->done = 0;
		t->error[0] = '\0';
		t->time_kclique = 0;
		t->time_louvain = 0;
		t->time_cbla = 0;
	}

	printf("[benchmark] launching %d threads...\n", TOTAL_GRAPHS);

	// Launch one thread per task
	for (int i = 0; i < TOTAL_GRAPHS; i++)
		pthread_create(&threads[i], NULL, benchmark_thread, &tasks[i]);

	// Wait for all threads
	for (int i = 0; i < TOTAL_GRAPHS; i++)
		pthread_join(threads[i], NULL);

	printf("[benchmark] all threads done — writing CSV...\n");

	// ── Build timestamped filename ────────────────────────────────────────────
	time_t now = time(NULL);
	struct tm *tm = localtime(&now);
	char filename[64];
	strftime(filename, sizeof(filename), "benchmark_%Y%m%d_%H%M%S.csv", tm);

	// ── Write CSV ─────────────────────────────────────────────────────────────
	FILE *f = fopen(filename, "w");
	if (!f) {
		perror("fopen");
		return;
	}

	// Header
	fprintf(f, "config,p,q,graph_size,"
		   "kclique_time_ms,kclique_communities,"
		   "louvain_time_ms,louvain_communities,"
		   "cbla_time_ms,cbla_communities\n");

	char config_names[NUM_CONFIGS][32] = {
		"very_dense", "dense", "medium", "sparse", "very_sparse",
	};

	task_idx = 0;
	for (int i = 0; i < TOTAL_GRAPHS; i++) {
		bench_task_t *t = &tasks[i];

		char kclique_time[16], kclique_comm[16];
		char cbla_time[16], cbla_comm[16];

		if (t->time_kclique < 0) {
			snprintf(kclique_time, sizeof(kclique_time), "N/A");
			snprintf(kclique_comm, sizeof(kclique_comm), "N/A");
		} else {
			snprintf(kclique_time, sizeof(kclique_time), "%.4f",
				 t->time_kclique);
			snprintf(kclique_comm, sizeof(kclique_comm), "%d",
				 t->kclique_communities);
		}

		if (t->time_cbla < 0) {
			snprintf(cbla_time, sizeof(cbla_time), "N/A");
			snprintf(cbla_comm, sizeof(cbla_comm), "N/A");
		} else {
			snprintf(cbla_time, sizeof(cbla_time), "%.4f",
				 t->time_cbla);
			snprintf(cbla_comm, sizeof(cbla_comm), "%d",
				 t->cbla_communities);
		}

		fprintf(f, "%s,%.4f,%.6f,%d,%s,%s,%.4f,%d,%s,%s\n",
			config_names[i], t->p, t->q, t->n, kclique_time,
			kclique_comm, t->time_louvain, t->louvain_communities,
			cbla_time, cbla_comm);
	}

	fclose(f);
	printf("[benchmark] results written to %s\n", filename);
}