#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 <limits.h>
#include <sys/mman.h>
#include "make_path.h"
#include "get_stat.h"
#include "config.h"

static char *f_flag = "cp";
static char r_flag;
static char v_flag;
static char L_flag;

static char copy_reg(int mode, const char *src, const char *dst) {
	int ret = 1;

	int ifd = open(src, O_RDONLY);
	if (ifd < 0)
		return 1;

	int ofd = open(dst, O_WRONLY | O_TRUNC | O_CREAT, mode);
	if (ofd < 0)
		goto CLOSE_OFD;

	char buf[BUF_SIZE + 1];
	while (1) {
		ssize_t n = read(ifd, buf, sizeof(buf));
		if (n <= 0) {
			if (n < 0)
				goto CLOSE;

			break;
		}

		if (write(ofd, buf, n) != n)
			goto CLOSE;
	}

	ret = 0;

CLOSE:
	close(ofd);

CLOSE_OFD:
	close(ifd);
	return ret;
}

static char copy_lnk(const char *src, const char *dst) {
	char path[PATH_MAX + 1];
	ssize_t ret = readlink(src, path, sizeof(path));
	if (ret < 0)
		return 1;

	path[ret] = '\0';
	if (symlink(path, dst) < 0)
		return 1;

	return 0;
}

static char copy(struct stat st, const char *src, const char *dst) {
	if (v_flag)
		printf("Copying '%s' to '%s'\n", src, dst);

	if (S_ISLNK(st.st_mode))
		return copy_lnk(src, dst);

	else if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode) || S_ISFIFO(st.st_mode)) {
		if (mknod(dst, st.st_mode, st.st_dev) < 0)
			return 1;
	}

	else
		return copy_reg(st.st_mode, src, dst);

	return 0;
}

static int cptree(const char *src, const char *dst) {
	struct stat src_stat;
	if (mu_get_stats(f_flag, !L_flag, src, &src_stat))
		return 1;

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

			return 1;
		}

		return 0;
	}

	else if (!r_flag) {
		if (f_flag)
			fprintf(stderr, "cp: omitting directory: %s\n", dst);

		return 1;
	}

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

		return 1;
	}

	DIR *dir = opendir(src);
	if (dir == NULL) {
		if (f_flag)
			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;

		/* Copy */
		char *src_path = mu_make_path(f_flag, src, ep->d_name);
		if (src_path == NULL)
			continue;

		char *dst_path = mu_make_path(f_flag, 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);
		if (ret)
			break;
	}

	closedir(dir);
	return ret;
}

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

			case 'r':
				r_flag = 1;
				break;

			case 'v':
				v_flag = 1;
				break;

			case 'L':
				L_flag = 1;
				break;

			default:
				printf("cp [frvL] [src1 src2...] [dst]\n\t-f Silent\n\t-r Recursive\n\t-v Verbose\n\t-L Follow all symlinks\n");
				return 0;
		}
	}

	argv += optind;
	argc -= optind;

	if (argc < 2) {
		fprintf(stderr, "cp: missing operand\n");
		return 1;
	}

	int ret = 0;
	struct stat sb;
	if (!mu_get_stat(NULL, argv[argc - 1], &sb))
		if (S_ISDIR(sb.st_mode))
			goto IF_EXSIST;

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

	else {
IF_EXSIST:
		for (int i = 0; i < argc - 1; i++) {
			char *new_path = mu_make_path(f_flag, 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;
}