/* vi: set sw=4 ts=4:
 *
 * ls.c - list files
 *
 * Copyright 2012 Andre Renaud <andre@bluewatersys.com>
 * Copyright 2012 Rob Landley <rob@landley.net>
 *
 * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/ls.html

// "[-Cl]"
USE_LS(NEWTOY(ls, "goACFHLRSacdfiklmnpqrstux1", TOYFLAG_BIN))

config LS
	bool "ls"
	default y
	help
	  usage: ls [-ACFHLRSacdfiklmnpqrstux1] [directory...]
	  list files

	  what to show:
	  -a    all files including .hidden
	  -c	use ctime for timestamps
	  -d	directory, not contents
	  -i	inode number
	  -k	block sizes in kilobytes
	  -p	put a '/' after directory names
	  -q	unprintable chars as '?'
	  -s	size (in blocks)
	  -u	use access time for timestamps
	  -A	list all files except . and ..
	  -H	follow command line symlinks
	  -L	follow symlinks
	  -R	recursively list files in subdirectories
	  -F    append file type indicator (/=dir, *=exe, @=symlink, |=FIFO)

	  output formats:
	  -1    list one file per line
	  -C	columns (sorted vertically)
	  -g	like -l but no owner
	  -l	long (show full details for each file)
	  -m	comma separated
	  -n	like -l but numeric uid/gid
	  -o	like -l but no group
	  -x	columns (sorted horizontally)

	  sorting (default is alphabetical):
	  -f	unsorted
	  -r	reverse
	  -t	timestamp
	  -S	size
*/

#include "toys.h"

#define FLAG_1 (1<<0)
#define FLAG_x (1<<1)
#define FLAG_u (1<<2)
#define FLAG_t (1<<3)
#define FLAG_s (1<<4)
#define FLAG_r (1<<5)
#define FLAG_q (1<<6)
#define FLAG_p (1<<7)
#define FLAG_n (1<<8)
#define FLAG_m (1<<9)
#define FLAG_l (1<<10)
#define FLAG_k (1<<11)
#define FLAG_i (1<<12)
#define FLAG_f (1<<13)
#define FLAG_d (1<<14)
#define FLAG_c (1<<15)
#define FLAG_a (1<<16)
#define FLAG_S (1<<17)
#define FLAG_R (1<<18)
#define FLAG_L (1<<19)
#define FLAG_H (1<<20)
#define FLAG_F (1<<21)
#define FLAG_C (1<<22)
#define FLAG_A (1<<23)
#define FLAG_o (1<<24)
#define FLAG_g (1<<25)

// test sst output (suid/sticky in ls flaglist)

// ls -lR starts .: then ./subdir:

DEFINE_GLOBALS(
    struct dirtree *files;

    unsigned screen_width;
    int nl_title;
)

#define TT this.ls

void dlist_to_dirtree(struct dirtree *parent)
{
    // Turn double_list into dirtree
    struct dirtree *dt = parent->child;
    if (dt) {
        dt->parent->next = NULL;
        while (dt) {
            dt->parent = parent;
            dt = dt->next;
        }
    }
}

static char endtype(struct stat *st)
{
    mode_t mode = st->st_mode;
    if ((toys.optflags&(FLAG_F|FLAG_p)) && S_ISDIR(mode)) return '/';
    if (toys.optflags & FLAG_F) {
        if (S_ISLNK(mode)) return '@';
        if (S_ISREG(mode) && (mode&0111)) return '*';
        if (S_ISFIFO(mode)) return '|';
        if (S_ISSOCK(mode)) return '=';
    }
    return 0;
}

static char *getusername(uid_t uid)
{
    struct passwd *pw = getpwuid(uid);
    return pw ? pw->pw_name : utoa(uid);
}

static char *getgroupname(gid_t gid)
{
    struct group *gr = getgrgid(gid);
    return gr ? gr->gr_name : utoa(gid);
}

// Figure out size of printable entry fields for display indent/wrap

static void entrylen(struct dirtree *dt, unsigned *len)
{
    struct stat *st = &(dt->st);
    unsigned flags = toys.optflags;

    *len = strlen(dt->name);
    if (endtype(st)) ++*len;
    if (flags & FLAG_m) ++*len;

    if (flags & FLAG_i) *len += (len[1] = numlen(st->st_ino));
    if (flags & (FLAG_l|FLAG_o|FLAG_n|FLAG_g)) {
        unsigned fn = flags & FLAG_n;
        len[2] = numlen(st->st_nlink);
        len[3] = strlen(fn ? utoa(st->st_uid) : getusername(st->st_uid));
        len[4] = strlen(fn ? utoa(st->st_gid) : getgroupname(st->st_gid));
        len[5] = numlen(st->st_size);
    }
    if (flags & FLAG_s) *len += (len[6] = numlen(st->st_blocks));
}

static int compare(void *a, void *b)
{
    struct dirtree *dta = *(struct dirtree **)a;
    struct dirtree *dtb = *(struct dirtree **)b;
    int ret = 0, reverse = (toys.optflags & FLAG_r) ? -1 : 1;

    if (toys.optflags & FLAG_S) {
        if (dta->st.st_size > dtb->st.st_size) ret = -1;
        else if (dta->st.st_size < dtb->st.st_size) ret = 1;
    }
    if (toys.optflags & FLAG_t) {
        if (dta->st.st_mtime > dtb->st.st_mtime) ret = -1;
        else if (dta->st.st_mtime < dtb->st.st_mtime) ret = 1;
    }
    if (!ret) ret = strcmp(dta->name, dtb->name);
    return ret * reverse;
}

// callback from dirtree_recurse() determining how to handle this entry.

static int filter(struct dirtree *new)
{
    int flags = toys.optflags;

    // Special case to handle enormous dirs without running out of memory.
    if (flags == (FLAG_1|FLAG_f)) {
        xprintf("%s\n", new->name);
        return 0;
    }

    if (!(flags&FLAG_f)) { 
        if (flags & FLAG_a) return 0;
        if (!(flags & FLAG_A) && new->name[0]=='.') return 0;
    }

    if (flags & FLAG_u) new->st.st_mtime = new->st.st_atime;
    if (flags & FLAG_c) new->st.st_mtime = new->st.st_ctime;
    if (flags & FLAG_k) new->st.st_blocks = (new->st.st_blocks + 1) / 2;
    return dirtree_notdotdot(new);
}

// For column view, calculate horizontal position (for padding) and return
// index of next entry to display.

static unsigned long next_column(unsigned long ul, unsigned long dtlen,
    unsigned columns, unsigned *xpos)
{
    unsigned long transition;
    unsigned height, widecols;

    // Horizontal sort is easy
    if (!(toys.optflags & FLAG_C)) {
        *xpos = ul % columns;
        return ul;
    }

    // vertical sort

    // For -x, calculate height of display, rounded up
    height = (dtlen+columns-1)/columns;

    // Sanity check: does wrapping render this column count impossible
    // due to the right edge wrapping eating a whole row?
    if (height*columns - dtlen >= height) {
        *xpos = columns;
        return 0;
    }

    // Uneven rounding goes along right edge
    widecols = dtlen % height;
    if (!widecols) widecols = height;
    transition = widecols * columns;
    if (ul < transition) {
        *xpos =  ul % columns;
        return (*xpos*height) + (ul/columns);
    }

    ul -= transition;
    *xpos = ul % (columns-1);

    return (*xpos*height) + widecols + (ul/(columns-1));
}

// Display a list of dirtree entries, according to current format
// Output types -1, -l, -C, or stream

static void listfiles(int dirfd, struct dirtree *indir)
{
    struct dirtree *dt, **sort = 0;
    unsigned long dtlen = 0, ul = 0;
    unsigned width, flags = toys.optflags, totals[7], len[7],
        *colsizes = (unsigned *)(toybuf+260), columns = (sizeof(toybuf)-260)/4;
    
    memset(totals, 0, sizeof(totals));

    // Silently descend into single directory listed by itself on command line.
    // In this case only show dirname/total header when given -R.
    if (!indir->parent) {
        if (!(dt = indir->child)) return;
        if (S_ISDIR(dt->st.st_mode) && !dt->next && !(flags & FLAG_d)) {
            dt->extra = 1;
            listfiles(open(dt->name, 0), dt);
            return;
        }
    } else {
        // Read directory contents. We dup() the fd because this will close it.
        indir->data = dup(dirfd);
        dirtree_recurse(indir, filter, (flags&FLAG_L));
    }

    // Copy linked list to array and sort it. Directories go in array because
    // we visit them in sorted order.

    for (;;) {
        for (dt = indir->child; dt; dt = dt->next) {
            if (sort) sort[dtlen] = dt;
            dtlen++;
        }
        if (sort) break;
        sort = xmalloc(dtlen * sizeof(void *));
        dtlen = 0;
        continue;
    }

    // Label directory if not top of tree, or if -R
    if (indir->parent && (!indir->extra || (flags & FLAG_R)))
    {
        char *path = dirtree_path(indir, 0);

        if (TT.nl_title++) xputc('\n');
        xprintf("%s:\n", path);
        free(path);
    }

    if (!(flags & FLAG_f)) qsort(sort, dtlen, sizeof(void *), (void *)compare);

    // Find largest entry in each field for display alignment
    if (flags & (FLAG_C|FLAG_x)) {

        // columns can't be more than toybuf can hold, or more than files,
        // or > 1/2 screen width (one char filename, one space).
        if (columns > TT.screen_width/2) columns = TT.screen_width/2;
        if (columns > dtlen) columns = dtlen;

        // Try to fit as many columns as we can, dropping down by one each time
        for (;columns > 1; columns--) {
            unsigned c, totlen = columns;

            memset(colsizes, 0, columns*sizeof(unsigned));
            for (ul=0; ul<dtlen; ul++) {
                entrylen(sort[next_column(ul, dtlen, columns, &c)], len);
                if (c == columns) break;
                // Does this put us over budget?
                if (*len > colsizes[c]) {
                    totlen += *len-colsizes[c];
                    colsizes[c] = *len;
                    if (totlen > TT.screen_width) break;
                }
            }
            // If it fit, stop here
            if (ul == dtlen) break;
        }
    } else if (flags & (FLAG_l|FLAG_o|FLAG_n|FLAG_g|FLAG_s)) {
        unsigned long blocks = 0;

        for (ul = 0; ul<dtlen; ul++)
        {
            entrylen(sort[ul], len);
            for (width=0; width<6; width++)
                if (len[width] > totals[width]) totals[width] = len[width];
            blocks += sort[ul]->st.st_blocks;
        }

        if (indir->parent) xprintf("total %lu\n", blocks);
    }

    // Loop through again to produce output.
    memset(toybuf, ' ', 256);
    width = 0;
    for (ul = 0; ul<dtlen; ul++) {
        unsigned curcol;
        unsigned long next = next_column(ul, dtlen, columns, &curcol);
        struct stat *st = &(sort[next]->st);
        mode_t mode = st->st_mode;
        char et = endtype(st);

        // Skip directories at the top of the tree when -d isn't set
        if (S_ISDIR(mode) && !indir->parent && !(flags & FLAG_d)) continue;
        TT.nl_title=1;

        // Handle padding and wrapping for display purposes
        entrylen(sort[next], len);
        if (ul) {
            if (flags & FLAG_m) xputc(',');
            if (flags & (FLAG_C|FLAG_x)) {
                if (!curcol) xputc('\n');
            } else if ((flags & FLAG_1) || width+1+*len > TT.screen_width) {
                xputc('\n');
                width = 0;
            } else {
                xputc(' ');
                width++;
            }
        }
        width += *len;

        if (flags & FLAG_i)
            xprintf("% *lu ", len[1], (unsigned long)st->st_ino);
        if (flags & FLAG_s)
            xprintf("% *lu ", len[6], (unsigned long)st->st_blocks);

        if (flags & (FLAG_l|FLAG_o|FLAG_n|FLAG_g)) {
            struct tm *tm;
            char perm[11], thyme[64], c, d, *usr, *upad, buf[12], *grp, *grpad;
            int i, bit;

            perm[10]=0;
            for (i=0; i<9; i++) {
                bit = mode & (1<<i);
                c = i%3;
                if (!c && (mode & (1<<((d=i/3)+9)))) {
                    c = "tss"[d];
                    if (!bit) c &= 0x20;
                } else c = bit ? "xwr"[c] : '-';
                perm[9-i] = c;
            }

            if (S_ISDIR(mode)) c = 'd';
            else if (S_ISBLK(mode)) c = 'b';
            else if (S_ISCHR(mode)) c = 'c';
            else if (S_ISLNK(mode)) c = 'l';
            else if (S_ISFIFO(mode)) c = 'p';
            else if (S_ISSOCK(mode)) c = 's';
            else c = '-';
            *perm = c;

            tm = localtime(&(st->st_mtime));
            strftime(thyme, sizeof(thyme), "%F %H:%M", tm);

            if (flags&FLAG_o) grp = grpad = toybuf+256;
            else {
                grp = (flags&FLAG_n) ? utoa(st->st_gid)
                      : getgroupname(st->st_gid);
                grpad = toybuf+256-(totals[4]-len[4]);
            }

            if (flags&FLAG_g) usr = upad = toybuf+256;
            else {
                upad = toybuf+255-(totals[3]-len[3]);
                if (flags&FLAG_n) {
                    usr = buf;
                    utoa_to_buf(st->st_uid, buf, 12);
                } else usr = getusername(st->st_uid);
            }

            // Coerce the st types into something we know we can print.
            xprintf("%s% *ld %s%s%s%s% *"PRId64" %s ", perm, totals[2]+1,
                (long)st->st_nlink, usr, upad, grp, grpad, totals[5]+1,
                (int64_t)st->st_size, thyme);
        }

        if (flags & FLAG_q) {
            char *p;
            for (p=sort[next]->name; *p; p++) xputc(isprint(*p) ? *p : '?');
        } else xprintf("%s", sort[next]->name);
        if ((flags & (FLAG_l|FLAG_o|FLAG_n|FLAG_g)) && S_ISLNK(mode))
            xprintf(" -> %s", sort[next]->symlink);

        if (et) xputc(et);

        // Pad columns
        if (flags & (FLAG_C|FLAG_x)) {
            curcol = colsizes[curcol] - *len;
            if (curcol >= 0) xprintf("%s", toybuf+255-curcol);
        }
    }

    if (width) xputc('\n');

    // Free directory entries, recursing first if necessary.

    for (ul = 0; ul<dtlen; free(sort[ul++])) {
        if ((flags & FLAG_d) || !S_ISDIR(sort[ul]->st.st_mode)
            || !dirtree_notdotdot(sort[ul])) continue;

        // Recurse into dirs if at top of the tree or given -R
        if (!indir->parent || (flags & FLAG_R))
            listfiles(openat(dirfd, sort[ul]->name, 0), sort[ul]);
    }
    free(sort);
    if (dirfd != AT_FDCWD) close(indir->data);
}

void ls_main(void)
{
    char **s, *noargs[] = {".", 0};
    struct dirtree *dt;

    // Do we have an implied -1
    if (!isatty(1) || (toys.optflags&(FLAG_l|FLAG_o|FLAG_n|FLAG_g)))
        toys.optflags |= FLAG_1;
    else {
        TT.screen_width = 80;
        terminal_size(&TT.screen_width, NULL);
    }
    // The optflags parsing infrastructure should really do this for us,
    // but currently it has "switch off when this is set", so "-dR" and "-Rd"
    // behave differently
    if (toys.optflags & FLAG_d) toys.optflags &= ~FLAG_R;

    // Iterate through command line arguments, collecting directories and files.
    // Non-absolute paths are relative to current directory.
    TT.files = dirtree_add_node(0, 0, 0);
    for (s = *toys.optargs ? toys.optargs : noargs; *s; s++) {
        dt = dirtree_add_node(AT_FDCWD, *s,
            (toys.optflags & (FLAG_L|FLAG_H|FLAG_l))^FLAG_l);

        if (!dt) {
            toys.exitval = 1;
            continue;
        }

        // Typecast means double_list->prev temporarirly goes in dirtree->parent
        dlist_add_nomalloc((struct double_list **)&TT.files->child,
                           (struct double_list *)dt);
    }

    // Turn double_list into dirtree
    dlist_to_dirtree(TT.files);

    // Display the files we collected
    listfiles(AT_FDCWD, TT.files);

    if (CFG_TOYBOX_FREE) free(TT.files);
}