#define _XOPEN_SOURCE 500
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <inttypes.h>
#include <unistd.h>

#include "video_decode.h"
#include "util.h"

static void
start_new_szene(int64_t prev_szene_end, int64_t start)
{
	static int prev_dts_start = 0;

	print_time(prev_dts_start);
	printf(" ");
	print_time(prev_szene_end - prev_dts_start);
	prev_dts_start = start;
}

static void
usage(void)
{
	fprintf(stderr,
		"cuttime [-adDfhsT] FILE\n"
		"\n"
		"OPTIONS\n"
		"\t-a\tcalculate average color of a frame\n"
		"\t-d\tcalculate difference between prev and next frame and\n"
		"\t\tslope of this value\n"
		"\t-D\tprint diff and slope of diff (implies -d)\n"
		"\t-f\tprint frame number of every frame\n"
		"\t-h\tprint this help message\n"
		"\t-s\tsave frame from detected cut\n"
		"\t-T\tprint timestamp of every frame\n");

	exit(EXIT_FAILURE);
}

int
main(int argc, char **argv)
{
	struct video_decode *vd;
	struct video_frame *frame_a = NULL, *frame_b = NULL;
	int ret, ch;
	int diff_flag = 0, average_flag = 0, frame_flag = 0, showcut_flag = 0;
	int print_diff_flag = 0, time_flag = 0;
	int64_t timestamp = 0;
	double diff = 0.0, prev_diff = 0.0, diff_slope = 0.0;
	char filename[BUFSIZ];

	while ((ch = getopt(argc, argv, "adDfsTh")) != -1) {
		switch (ch) {
		case 'a':
			average_flag = 1;
			break;
		case 'd':
			diff_flag = 1;
			break;
		case 'D':
			print_diff_flag = 1;
			diff_flag = 1;		/* implies -d */
			break;
		case 'f':
			frame_flag = 1;
			break;
		case 's':
			showcut_flag = 1;
			break;
		case 'T':
			time_flag = 1;
			break;
		case 'h':
		default:
			usage();
			/* NOTREACHED */
		}
	}
	argc -= optind;
	argv += optind;

	if (argc < 1)
		usage();

	if (argc == 2 && strtol(argv[1], NULL, 10) > 0)
		timestamp = strtol(argv[1], NULL, 10);

	ret = video_decode_init(&vd, argv[0], timestamp);
	if (ret < 0)
		return -ret;

	ret = video_decode_get_frame(vd, &frame_a);
	if (ret < 0)
		return -ret;

	for (int i = 0; video_decode_get_frame(vd, &frame_b) > 0; ++i) {

		if (frame_flag)		/* print frame number */
			printf("%d\t", i);

		if (time_flag)
			printf("%" PRId64 "\t", frame_b->dts);

		if (average_flag)	/* print frame average */
			printf("%f", frame_average(frame_a));

		if (average_flag && diff_flag)
			printf("\t");

		if (diff_flag) {
			diff = frame_diff(frame_a, frame_b);
			diff_slope = diff - prev_diff;
			prev_diff = diff;

			if (print_diff_flag)
				printf("%f\t%f\t", diff, diff_slope);
		}

		if (diff_slope > 20.0) {
			start_new_szene(frame_a->dts, frame_b->dts);

			if (!frame_flag && !average_flag) {
				printf("\n");
				fflush(stdout);
			}

			if (showcut_flag == 1) {
				snprintf(filename, BUFSIZ, "img/%04i.pgm", i);
				frame_mix(frame_a, frame_b);

				if (pgm_save(frame_a->data, frame_a->stride,
					     frame_a->width, frame_a->height,
					     filename) < 0)
					exit(EXIT_FAILURE);
			}
		}

		if (frame_flag || average_flag) {
			printf("\n");
			fflush(stdout);
		}

		pswap((void **)&frame_a, (void **)&frame_b);
	}

	if (diff_flag) {
		/* acutally we just finalize the last frame here */
		start_new_szene(frame_a->dts, 0);
		printf("\n");
	}

	video_decode_free_frame(&frame_a);
	if (frame_b)
		video_decode_free_frame(&frame_b);
	video_decode_uninit(&vd);
	return EXIT_SUCCESS;
}