#define _LS_C

#include <pwd.h>
#include <grp.h>
#include <time.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include "mode_to_str.h"
#include "mu_strlen.h"
#include "make_path.h"
#include "get_stat.h"
#include "config.h"
#include "human.h"

static char O_flag;
static char a_flag;
static char l_flag;
static char F_flag;
static char c_flag;
static char R_flag;
static char d_flag;
static char L_flag;
static char h_flag;
static char s_flag;
static char i_flag;
static char p_flag;
static char nul_flag;

static int sortd(const void *p1, const void *p2);
static int (*sorter)(const void *p1, const void *p2) = sortd;

struct d_node {
	/* basename */
	char *name;

	/* For free */
	char *full_name;

	struct d_node *next;
	struct stat stats;
};

/* Work with dir */
static struct d_node *stat_file(char *filename, const int lfile) {
	/* lfile its flag. 1 if passed file from list_one() */
	struct d_node *file = malloc(sizeof(struct d_node));
	if (file == NULL) {
		fprintf(stderr, "ls: malloc: %s\n", strerror(errno));
		return NULL;
	}

	if (mu_get_stats("ls", !L_flag, filename, &file->stats)) {
		free(file);
		return NULL;
	}

	file->full_name = (lfile) ? strdup(filename) : filename;
	file->name = strrchr(filename, '/');
	if (file->name == NULL || lfile)
		file->name = filename;

	else
		file->name++;

	return file;
}

static void dfree(struct d_node **dir, const size_t files) {
	for (size_t i = 0; i < files; i++) {
		if (dir[i] != NULL && dir[i]->full_name != NULL)
			free(dir[i]->full_name);

		if (dir[i] != NULL)
			free(dir[i]);
	}

	free(dir);
}

static struct d_node **list(const char *path, off_t *total_size, size_t *nfiles, int *ret) {
	DIR *dp = opendir(path);
	if (dp == NULL) {
		fprintf(stderr, "ls: %s: %s\n", path, strerror(errno));
		return NULL;
	}

	struct d_node **dn = malloc(sizeof(struct d_node *));
	if (dn == NULL) {
		fprintf(stderr, "ls: malloc: %s\n", strerror(errno));
		return NULL;
	}

	struct dirent *ep;
	while ((ep = readdir(dp)) != NULL) {
		if (ep->d_name[0] == '.' && !a_flag)
			continue;

		char *full_path = mu_make_path("ls", path, ep->d_name);
		if (full_path == NULL)
			continue;

		struct d_node **bckp = realloc(dn, sizeof(struct d_node *) * (*nfiles + 1));
		if (bckp == NULL) {
			free(full_path);
			dfree(dn, *nfiles);
			closedir(dp);

			fprintf(stderr, "ls: realloc: %s\n", strerror(errno));
			return NULL;
		}

		dn = bckp;

		dn[*nfiles] = stat_file(full_path, 0);
		if (dn[*nfiles] == NULL) {
			*ret = 1;
			free(full_path);
			continue;
		}

		*total_size += dn[*nfiles]->stats.st_blocks;
		(*nfiles)++;
	}

	closedir(dp);
	return dn;
}

static char *get_date(const time_t mtime) {
	static char date[100];

	strftime(date, sizeof(date), "%b %d %H:%M", localtime(&mtime));

	return date;
}

/* Print */
static int print(const struct d_node *node) {
	char suf = ' ';
	char *color = "";

	char *mode = mu_mode_2_str(node->stats.st_mode);
	if (S_ISDIR(node->stats.st_mode)) {
		if (node->name[strlen(node->name) - 1] != '/')
			suf = '/';

		mode[0] = 'd';
		color = LS_DIR_COLOR;
	}

	else if (S_ISLNK(node->stats.st_mode)) {
		suf = '@';
		mode[0] = 'l';
		color = LS_LINK_COLOR;
	}

	else if (S_ISSOCK(node->stats.st_mode)) {
		suf = '=';
		mode[0] = 's';
		color = LS_SOCK_COLOR;
	}

	else if (S_ISBLK(node->stats.st_mode)) {
		mode[0] = 'b';
		color = LS_BLOCK_COLOR;
	}

	else if (S_ISFIFO(node->stats.st_mode)) {
		suf = '|';
		mode[0] = 'p';
		color = LS_FIFO_COLOR;
	}

	else if ((node->stats.st_mode & S_IXUSR) || (node->stats.st_mode & S_IXGRP) || (node->stats.st_mode & S_IXOTH)) {
		suf = '*';
		color = LS_EXE_COLOR;
	}

	int ret = 0;
	if (i_flag)
		ret += printf("%7ju ", (uintmax_t)node->stats.st_ino);

	if (s_flag) {
		off_t size = 512 * node->stats.st_blocks;
		if (h_flag)
			ret += printf("%7s ", mu_humansize(size, 1024));

		else
			ret += printf("%7jd ", size / 1024);
	}

	if (l_flag) {
		printf("%s", mode);

		struct passwd *pw = getpwuid(node->stats.st_uid);
		struct group *gr = getgrgid(node->stats.st_gid);
		if (pw == NULL || gr == NULL) {
			fprintf(stderr, "ls: print: %s\n", strerror(errno));
			return -1;
		}

		if (h_flag)
			ret += printf(" %4ju %4s %6s %6s %s ", (uintmax_t)node->stats.st_nlink, pw->pw_name, gr->gr_name, mu_humansize(node->stats.st_size, 1024), get_date(node->stats.st_mtime));

		else
			ret += printf(" %4ju %4s %6s %10ld %s ", (uintmax_t)node->stats.st_nlink, pw->pw_name, gr->gr_name, node->stats.st_size, get_date(node->stats.st_mtime));
	}

	if (c_flag && p_flag)
		printf("%s", color);

	printf("%s", node->name);
	ret += mu_strlen(node->name);

	if (c_flag && p_flag)
		printf("\033[0m");

	if (F_flag)
		printf("%c", suf);

	return ret;
}

static int col_print(struct d_node **node, const size_t files, const struct winsize w) {
	/* Get max len */
	size_t maxlen = 0;
	for (size_t i = 0; i < files; i++) {
		size_t len = mu_strlen(node[i]->name);
		if (len > maxlen)
			maxlen = len;
	}

	/* Calc */
	maxlen += 3;
	if (i_flag)
		maxlen += 10;

	if (s_flag)
		maxlen += 10;

	size_t ncols = w.ws_col / maxlen;
	size_t nrows = files;
	if (ncols > 1) {
		nrows = files / ncols;
		if (nrows * ncols < files)
			nrows++;
	}

	else
		ncols = 1;

	int col = 0;
	int nexttab = 0;

	/* Mc print */
	for (size_t i = 0; i < nrows; i++) {
		for (size_t j = 0; j < ncols; j++) {
			size_t index = j * nrows + i;
			if (index < files) {
				if (col > 0) {
					nexttab -= col;
					col += nexttab;
					for (int k = 0; k < nexttab; k++)
						putchar(' ');
				}

				nexttab = col + (int)maxlen;
				int ret = print(node[index]);
				if (ret == -1)
					return 1;

				col += ret;
			}
		}

		putchar((nul_flag) ? '\0' : '\n');
		col = 0;
	}

	return 0;
}

static int struct_print(struct d_node **dir, const size_t files, const struct winsize w) {
	int ret = 0;

	/* pipe print */
	if (!p_flag || l_flag || O_flag) {
		for (size_t i = 0; i < files; i++) {
			if (print(dir[i]) == -1)
				ret = 1;

			putchar((nul_flag) ? '\0' : '\n');
		}
	}

	else
		if (col_print(dir, files, w))
			ret = 1;

	return ret;
}

/* Sort */
static int sortt(const void *p1, const void *p2) {
	return (*(struct d_node **)p2)->stats.st_mtime - (*(struct d_node **)p1)->stats.st_mtime;
}

static int sorts(const void *p1, const void *p2) {
	return (*(struct d_node **)p2)->stats.st_size - (*(struct d_node **)p1)->stats.st_size;
}

static int sortd(const void *p1, const void *p2) {
	return strcmp((*(struct d_node **)p1)->full_name, (*(struct d_node **)p2)->full_name);
}

/* Ls */
static int ls_dir(const char *dir_name, const int label, const struct winsize w) {
	if (dir_name == NULL)
		return 0;

	int ret = 0;

	size_t files = 0;
	off_t total_size = 0;
	struct d_node **dir = list(dir_name, &total_size, &files, &ret);

	/* Title */
	if ((label || R_flag) && !d_flag)
		printf("\n%s:\n", dir_name);

	if (l_flag) {
		if (h_flag)
			printf("total: %s\n", mu_humansize(total_size * 512, 1024));

		else
			printf("total: %jd\n", (intmax_t)total_size / 2);
	}

	if (dir == NULL)
		return 1;

	qsort(dir, files, sizeof(struct d_node *), sorter);
	if (struct_print(dir, files, w))
		ret = 1;

	if (R_flag)
		for (size_t i = 0; i < files; i++)
			if (S_ISDIR(dir[i]->stats.st_mode) && strcmp(dir[i]->name, "..") && strcmp(dir[i]->name, "."))
				ls_dir(dir[i]->full_name, 1, w);

	dfree(dir, files);
	return ret;
}

static int ls_files(int argc, char **argv, const struct winsize w) {
	size_t files = 0;
	struct d_node **file = malloc(sizeof(struct d_node *));
	if (file == NULL) {
		fprintf(stderr, "ls: malloc: %s\n", strerror(errno));
		return 1;
	}

	int ret = 0;
	for (int i = 0; i < argc; i++) {
		struct stat sb;
		if (mu_get_lstat("ls", argv[i], &sb)) {
			ret = 1;
			argv[i] = NULL;
			continue;
		}

		if (S_ISDIR(sb.st_mode))
			continue;

		struct d_node **tmp = realloc(file, sizeof(struct d_node *) * (files + 2));
		if (tmp == NULL) {
			dfree(file, files);
			argv[i] = NULL;
			return 1;
		}
		file = tmp;

		file[files] = stat_file(argv[i], 1);
		if (file[files] == NULL) {
			argv[i] = NULL;
			continue;
		}

		files++;
		argv[i] = NULL;
	}

	if (files) {
		qsort(file, files, sizeof(struct d_node *), sorter);
		if (struct_print(file, files, w))
			ret = 1;
	}

	dfree(file, files);
	return ret;
}

int main(int argc, char **argv) {
	int opt;
	while ((opt = getopt(argc, argv, "1alFcRdLhistS0")) != -1) {
		switch (opt) {
			case '1':
				O_flag = 1;
				break;

			case 'a':
				a_flag = 1;
				break;

			case 'l':
				l_flag = 1;
				break;

			case 'F':
				F_flag = 1;
				break;

			case 'c':
				c_flag = 1;
				break;

			case 'R':
				d_flag = 0;
				R_flag = 1;
				break;

			case 'd':
				R_flag = 0;
				d_flag = 1;
				break;

			case 'L':
				L_flag = 1;
				break;

			case 'h':
				h_flag = 1;
				break;

			case 'i':
				i_flag = 1;
				break;

			case 's':
				s_flag = 1;
				break;

			case 't':
				sorter = sortt;
				break;

			case 'S':
				sorter = sorts;
				break;

			case '0':
				nul_flag = 1;
				break;

			default:
				puts("ls [1alFcRdLhistS0] [dir1 file2...]\n\t-a Show hidden files\n\t-l Use a long listing format\n\t-F Append indicator to names\n\t-c Color mode\n\t-R Recursive\n\t-1 One column\n\t-d Print only dir names\n\t-L Follow symlinks\n\t-h Sizes in human readable format\n\t-i Listen inodes\n\t-t Sort by mtime\n\t-S Sort by size\n\t-s Print file size\n\t-0 End line with \\0");
				return 0;
		}
	}

	argv += optind;
	argc -= optind;

	struct winsize w;
	ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);

	/* Check if programm piped, 1 - false, 0 - true */
	p_flag = isatty(STDOUT_FILENO);

	int ret = 0;
	if (ls_files(argc, argv, w))
		ret = 1;

	if (argc == 0) {
		if (ls_dir(".", 0, w))
			ret = 1;
	}

	else if (argc == 1) {
		if (ls_dir(argv[0], 0, w))
			ret = 1;
	}

	else {
		for (int i = 0; i < argc; i++)
			if (ls_dir(argv[i], 1, w))
				ret = 1;
	}

	return ret;
}