#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/mman.h>
#include "make_path.h"
#include "get_stat.h"

unsigned int s_flag;

int write_buffer(int mode, int ifd, int ofd, const char *dst) {
	off_t len = lseek(ifd, 0, SEEK_END);
	if (len <= 0) {
		if (len < 0)
			return 1;

		int fd = open(dst, O_CREAT | O_RDONLY, mode);
		if (fd < 0)
			return 1;

		close(fd);
		return 0;
	}

	if (ftruncate(ofd, len) < 0)
		return 1;

	void *buf_in = mmap(NULL, len, PROT_READ, MAP_SHARED, ifd, 0);
	if (buf_in == MAP_FAILED)
		return 1;

	void *buf_out = mmap(NULL, len, PROT_WRITE, MAP_SHARED, ofd, 0);
	if (buf_out == MAP_FAILED)
		return 1;

	memcpy(buf_out, buf_in, len);

	if (munmap(buf_in, len) || munmap(buf_out, len))
		return 1;

	return 0;

}

int copy(int mode, const char *src, const char *dst) {
	int ifd = open(src, O_RDONLY);
	if (ifd < 0)
		return 1;

	/* test ./testdir/ -> test ./testdir/test */
	char *dup = NULL;
	char *new_path = (char *)dst;
	int flag = 0;
	int ret = 0;

	int ofd = open(dst, O_CREAT | O_TRUNC | O_RDWR, mode);
	if (ofd < 0) {
		ret = 1;

		dup = strdup(src);
		if (dup == NULL)
			goto CLOSE;

		flag = 1;
		new_path = NULL;

		new_path = mu_make_path("cp", dst, basename(dup));
		if (new_path == NULL)
			goto CLOSE;

		if (!strcmp(new_path, src) || !strcmp(new_path + 2, src))
			goto CLOSE;

		ofd = open(new_path, O_CREAT | O_TRUNC | O_RDWR, mode);
		if (ofd < 0)
			goto CLOSE;

		ret = 0;
	}

	if (write_buffer(mode, ifd, ofd, new_path))
		if (!s_flag)
			fprintf(stderr, "cp: (%s %s) %s\n", src, dst, strerror(errno));


	close(ofd);

CLOSE:
	close(ifd);
	if (flag) {
		if (dup != NULL)
			free(dup);

		if (new_path != NULL)
			free(new_path);
	}

	return ret;
}

int cptree(const char *src, const char *dst) {
	struct stat stat_path;
	if (mu_get_lstat("cp", src, &stat_path))
		return 1;

	if (!S_ISDIR(stat_path.st_mode)) {
		if (copy(stat_path.st_mode, src, dst)) {
			if (!s_flag)
				fprintf(stderr, "cp: (%s %s): copy() failed (%s)\n", src, dst, strerror(errno));

			return 1;
		}

		return 0;
	}

	else if (mkdir(dst, 0777) < 0)
		if (!s_flag)
			fprintf(stderr, "cp: %s\n", strerror(errno));

	DIR *dir = opendir(src);
	if (dir == NULL) {
		fprintf(stderr, "cp: %s: Can`t open directory\n", src);
		return 1;
        }

	int ret = 0;

	struct dirent *ep;
	while ((ep = readdir(dir)) != NULL) {
		if (!strcmp(ep->d_name, ".") || !strcmp(ep->d_name, "..") || !strcmp(dst, ep->d_name))
			continue;

		char *src_path = mu_make_path("cp", src, ep->d_name);
		if (src_path == NULL)
			continue;

		char *dst_path = mu_make_path("cp", dst, ep->d_name);
		if (dst_path == NULL) {
			free(src_path);
			continue;
		}

		if (cptree(src_path, dst_path))
			ret = 1;

		free(src_path);
		free(dst_path);
	}

	closedir(dir);
	return ret;
}

int main(int argc, char **argv) {
	int opt;
	while ((opt = getopt(argc, argv, "frR")) != -1) {
		switch (opt) {
			case 'f':
				s_flag = 1;
				break;

			case 'r':
			case 'R':
				break;

			default:
				printf("chmod [src1 src2...] [dst]\n\t[-f Silent]\n");
				return 0;
		}
	}

	if (argv[optind] == NULL) {
		fprintf(stderr, "cp: missing operand\n");
		return 1;
	}

	argv += optind;
	argc -= optind;

	int ret = 0;
	if (argc == 2)
		ret = cptree(argv[0], argv[argc - 1]);

	else {
		for (int i = 1; i < argc - 1; i++) {
			char *new_path = mu_make_path("cp", argv[argc - 1], basename(argv[i]));
			if (new_path == NULL)
				return 1;

			if (cptree(argv[i], new_path))
				ret = 1;

			free(new_path);
		}
	}

	return ret;
}