# squashfs-tools -- mksquashfs packs a directory tree into a compressed
# read-only .sqfs image, unsquashfs reads and extracts one. Like
# dosfstools/mtools/e2fsprogs it works on a plain FILE, which is what makes it
# usable on a machine with no block layer.
#
# THE READ SIDE IS GREEN AND IT IS REAL WORK. unsquashfs reads the superblock
# and lists the tree of data/squashfs-sample.sqfs -- an image built by UPSTREAM
# mksquashfs on the build host, not by us -- so those cases prove on-disk-format
# compatibility and gzip metadata decompression on target, independently of
# whether our own mksquashfs can write. mksquashfs itself reports its version
# and its compiled-in compressor set, which is this image's only on-target proof
# that the recipe's PACKAGECONFIG took.
#
# THE WRITE SIDE IS RED, IS NOT EXECUTED BY DEFAULT, AND MUST STAY RED.
# Packing and extracting both need the reader/inflator/deflator thread pool, and
# pthread_create traps on this arm (brintos/linux-in-the-browser#85 -- the
# coroutinized thread-start frame parks under the native spawn machinery and the
# orphaned handle trips "set-over-set" at the next park). Unlike md5deep and
# zstd there is no threadless build mode to select: upstream has no such knob
# and the thread pipeline is the program.
#
# They are reported without being run because running them does not just fail
# -- it takes the whole selftest run down with it. The trap poisons a lane that
# a later, unrelated exec then hits inside the kernel
# (wasm32_user_exec_load -> __hwjs_clear_parked), and because the runner buffers
# each suite's output and prints it only on completion, a machine death here
# discards every result from this file AND every suite after it. Set
# BST_SQUASHFS_WRITE=1 to actually exercise them (expect the run to die); the
# default reports them as the known blocker instead of destroying the capture.
. "$BST_LIB"
require unsquashfs squashfs-tools/unsquashfs-present
require mksquashfs squashfs-tools/mksquashfs-present

T=${TMPDIR:-/tmp}/bst-sqfs.$$
mkdir -p "$T" || exit 0
trap 'rm -rf "$T"' EXIT

FIX=$BST_DATA/squashfs-sample.sqfs
# BRINTOS-WORKAROUND: linux-in-the-browser#85 remove — the cases skipped with this reason are MASKED, so they will never flip green by themselves; drop the skip and let them run once the issue closes.
B85="blocked: pthread_create traps (hwjs-user-rt set-over-set) -- brintos/linux-in-the-browser#85"

# assert on OUTPUT only: the compressor list is printed on the error path of an
# unknown -comp, which exits non-zero by design, so check_out (which also
# demands rc 0) would conflate the two.
has()   { case "$3" in *"$2"*) bst_ok "$1" ;;
                       *) bst_notok "$1" "want '$2' in compressor list, got: $(_bst_1line "$3")" ;; esac; }
# assert on OUTPUT only, ignoring rc: unsquashfs -version prints its banner and
# then exits 1, so check_out would report a working binary as broken.
msg()   { _i=$1; _n=$2; shift 2; _o=$("$@" 2>&1)
          case "$_o" in *"$_n"*) bst_ok "$_i" ;;
                        *) bst_notok "$_i" "want '$_n' got: $(_bst_1line "$_o")" ;; esac; }
hasnt() { case "$3" in *"$2"*) bst_notok "$1" "'$2' is compiled in, but this image does not build it" ;;
                       *) bst_ok "$1" ;; esac; }

# ------------------------------------------------- both binaries load and run
# mksquashfs sizes its queues from sysconf(_SC_PHYS_PAGES) before it even
# handles -version; sysinfo(2) is ENOSYS here so that reads 0 and upstream
# aborts with "requires more physical memory than is available". The recipe
# patches it to read /proc/meminfo, so this case is also the on-target check
# that the patch is present and working (brintos/linux/issues/26).
check_out squashfs-tools/mksquashfs-version "mksquashfs version 4.6.1" mksquashfs -version
msg       squashfs-tools/unsquashfs-version "unsquashfs version 4.6.1" unsquashfs -version

# ------------------------------------------------------- compiled-in backends
# An unknown -comp makes mksquashfs print the compressors it was built with,
# inside the option-parse loop. The two negative cases are the point: without
# them a stock PACKAGECONFIG (which also builds lzo and zstd) would pass the
# positive four and the recipe's restriction would go unverified.
COMP=$(mksquashfs "$T" "$T/x.sqfs" -comp no-such-compressor 2>&1)
has   squashfs-tools/comp-gzip    "gzip" "$COMP"
has   squashfs-tools/comp-lz4     "lz4"  "$COMP"
has   squashfs-tools/comp-xz      "xz"   "$COMP"
has   squashfs-tools/comp-lzma    "lzma" "$COMP"
hasnt squashfs-tools/comp-no-lzo  "lzo"  "$COMP"
hasnt squashfs-tools/comp-no-zstd "zstd" "$COMP"
rm -f "$T/x.sqfs"

# --------------------------------------------- reading an image we did not write
check_out squashfs-tools/superblock-valid "Found a valid SQUASHFS 4:0 superblock" unsquashfs -s "$FIX"
check_out squashfs-tools/superblock-comp  "Compression gzip"                      unsquashfs -s "$FIX"

# Listing walks the directory table, which is itself gzip-compressed ("Inodes
# are compressed"), so this is what proves the zlib backend decompresses on
# target rather than merely being linked in.
check_out squashfs-tools/list-root   "squashfs-root"             unsquashfs -l "$FIX"
check_out squashfs-tools/list-nested "squashfs-root/fixture.txt" unsquashfs -l "$FIX"

# A control: a non-squashfs file must be rejected. Without it, a reader that
# answered plausibly for any input would sweep every case above.
#
# Match the full "Found a valid ..." phrase, not "valid SQUASHFS" -- the
# REJECTION reads "Can't find a valid SQUASHFS superblock on ...", which
# contains the shorter substring, so the loose form asserted the opposite of
# what it looks like it asserts.
dd if=/dev/zero of="$T/zeroes" bs=1024 count=64 2>/dev/null
case "$(unsquashfs -s "$T/zeroes" 2>&1)" in
  *"Found a valid SQUASHFS"*) bst_notok squashfs-tools/reject-non-sqfs "64 KiB of zeroes accepted as a filesystem" ;;
  *)                          bst_ok    squashfs-tools/reject-non-sqfs ;;
esac

# --------------------------------------------------------------- the write side
if [ "${BST_SQUASHFS_WRITE:-0}" = 1 ]; then
  blocked() {   # <id> <rc> <output> -- name #85 only when its signature is present
    case "$3" in
      *set-over-set*|*"hwjs-user-rt VIOLATION"*|*"Illegal instruction"*|*unreachable*|*"futex facility"*)
        bst_notok "$1" "$B85 (rc=$2)" ;;
      *) bst_notok "$1" "rc=$2 $(_bst_1line "$3")" ;;
    esac
  }

  OUT=$(unsquashfs -d "$T/ext" "$FIX" 2>&1); RC=$?
  if [ "$RC" -eq 0 ] && [ -f "$T/ext/fixture.txt" ]; then
    check_eq squashfs-tools/extract "brintos squashfs fixture" "$(cat "$T/ext/fixture.txt" 2>/dev/null)"
  else
    blocked squashfs-tools/extract "$RC" "$OUT"
  fi

  SRC=$T/src; mkdir -p "$SRC/sub"
  printf 'hello squashfs\n' > "$SRC/a.txt"
  printf 'second file\n'    > "$SRC/sub/b.txt"
  ln -s a.txt "$SRC/link"

  OUT=$(mksquashfs "$SRC" "$T/tree.sqfs" -comp gzip -no-progress -all-root 2>&1); RC=$?
  if [ "$RC" -eq 0 ] && [ -s "$T/tree.sqfs" ]; then bst_ok squashfs-tools/pack
  else blocked squashfs-tools/pack "$RC" "$OUT"; fi

  if [ -s "$T/tree.sqfs" ] && unsquashfs -d "$T/back" "$T/tree.sqfs" >/dev/null 2>&1; then
    a=$(cat "$T/back/a.txt" 2>/dev/null); b=$(cat "$T/back/sub/b.txt" 2>/dev/null)
    l=$(readlink "$T/back/link" 2>/dev/null)
    if [ "$a" = "hello squashfs" ] && [ "$b" = "second file" ] && [ "$l" = "a.txt" ]; then
      bst_ok squashfs-tools/roundtrip
    else
      bst_notok squashfs-tools/roundtrip "a='$a' b='$b' link='$l'"
    fi
  else
    bst_notok squashfs-tools/roundtrip "$B85 (no image to read back -- pack blocked)"
  fi
else
  bst_notok squashfs-tools/extract   "$B85 (not executed: it kills the run -- BST_SQUASHFS_WRITE=1 to exercise)"
  bst_notok squashfs-tools/pack      "$B85 (not executed: it kills the run -- BST_SQUASHFS_WRITE=1 to exercise)"
  bst_notok squashfs-tools/roundtrip "$B85 (not executed: it kills the run -- BST_SQUASHFS_WRITE=1 to exercise)"
fi