. "$BST_LIB"

# BST-TIMEOUT: 300   # measured 32s for 49 cases (==BST-SUITE, 2026-08-18, local
#                    # verify on a loaded build host); ~9x headroom. The suite
#                    # execs the probe eleven times and each run parses the whole
#                    # tree, so the cost is exec-bound rather than data-bound and
#                    # scales with cases added, not with fixture size.

# libdvdread 6.1.3 (meta-oe recipes-multimedia/libdvdread) -- VideoLAN's
# DVD-Video access library, shipped here as /usr/lib/libdvdread.a, the ten
# dvdread/ headers and dvdread.pc.  It is a LIBRARY port with no program of its
# own, so this suite is driven entirely by one consumer the bbappend builds
# against this image's own archive and packages as libdvdread-tests:
#
#   /usr/libexec/libdvdread-tests/libdvdread-probe
#
# THE ORACLE IS A STORED x86-64 REFERENCE, AND THE ARGUMENT FOR IT IS STRONGER
# HERE THAN FOR ANY DECODER ON THIS IMAGE.  57-libmad's reference needed a
# paragraph about fixed-point arithmetic; 57-libvorbis and 57-speexdsp refuse a
# cross-machine digest outright because they decode in floating point.
# libdvdread computes nothing.  It is a PARSER: every number it reports is a
# field lifted out of a byte at a fixed offset and byte-swapped, every structure
# is __attribute__((packed)) with fixed-width members, and there is not one
# floating-point operation and not one arithmetic kernel in the library.  Two
# machines that agree on what the bytes say MUST produce identical output, and a
# difference is a real defect -- a missed byte swap, a packed attribute the
# compiler dropped, a struct whose size moved -- rather than drift to be
# re-referenced.  Do not re-pin these references to whatever the arm printed.
#
# WHAT THE FIXTURE IS, AND WHY IT IS SYNTHESISED.  data/libdvdread-*.IFO/BUP/VOB
# are a minimal but STRUCTURALLY VALID DVD-Video tree written by
# src/libdvdread_mkfixtures.c: a VMGI with a First Play PGC, a title search
# pointer table and a title-set attribute table; a VTSI with a PTT search table,
# a program chain table with one PGC (program map, cell playback, cell position
# and a command table), a cell address table and a VOBU address map; and an
# 8-sector VOB whose blocks each carry a distinct deterministic pattern.  A real
# DVD-Video sample cannot be bundled -- the smallest is hundreds of megabytes and
# every one that exists is somebody's film -- and it would not be a better test:
# what this port has to get right is the NAVIGATION STRUCTURES, and those are
# exactly what the generator writes, field by field, out of libdvdread's own
# ifo_types.h through offsetof() and sizeof().  There is no video content and
# none is needed; libdvdread never looks inside a VOB.
#
# THE SUITE STAGES THE TREE INTO /tmp AND THAT IS NOT ONLY THE READ-ONLY ROOT.
# DVDOpen on a directory needs a VIDEO_TS/ subdirectory holding files with their
# real DVD names, and data/ is installed flat (the packager installs data/* with
# no recursion), so the five payloads ship under libdvdread- prefixed names and
# are copied into place here.  This also means the corruption controls below
# operate on copies and cannot damage the shipped payload.
#
# READING A RED.
#   * libdvdread/probe-present skip -> libdvdread-tests is not installed; every
#     case below is absent rather than failing, and the image entry is what to
#     fix.
#   * a libdvdread/size-* red -> the packed struct layout differs between the
#     machine that wrote the fixture and this one.  EVERY other case here is
#     explained by that and is not independent evidence; fix that first.
#   * libdvdread/self-block red with every size-* green -> a constant or an
#     offset moved: read the diff, it names the field.
#   * libdvdread/dvd-block red with the sizes green -> a genuine parse
#     difference.  The named cases below (discid, the per-block digests, the
#     cell and VOBU tables) narrow it; the block diff is authoritative.
#   * libdvdread/ifoprint-* red with dvd-block green -> ifo_print.c's rendering,
#     not the parse: a printf width or a formatting path, not a wrong value.
#   * libdvdread/no-css red -> the library did NOT take the non-CSS input path.
#     Either dlopen started working (which would be news, and good news) or a
#     libdvdcss appeared on the image.  Everything else here still holds; the
#     reference does not.
#   * libdvdread/mutation-detected or libdvdread/corrupt-both-rejected red ->
#     this suite's own controls are not discriminating and NOTHING above can be
#     trusted, whatever colour it is.

DVDDIR=/usr/libexec/libdvdread-tests
PROBE=$DVDDIR/libdvdread-probe

if [ ! -x "$PROBE" ]; then
  bst_skip libdvdread/probe-present "libdvdread-tests not installed on this image"
  exit 0
fi

tmp=${TMPDIR:-/tmp}/bst-libdvdread.$$
mkdir -p "$tmp" 2>/dev/null

# Pull one named section out of the x86-64 control.
want_section() {
  awk -v s="== $1" '$0==s{p=1;next} /^== /{p=0} p' "$BST_DATA/libdvdread-native.txt"
}

# Compare a probe run against its section of the control, byte for byte.  `D `
# lines are diagnostics whose value differs between the two machines by
# construction (sizeof(long) and friends) and are dropped on both sides -- the
# control was written with the same filter.
cmp_section() {
  _id=$1; _sec=$2; shift 2
  _got=$tmp/$_sec.got
  _wnt=$tmp/$_sec.want
  "$@" 2>&1 | grep -v '^D ' > "$_got"
  want_section "$_sec" > "$_wnt"
  if [ ! -s "$_wnt" ]; then
    bst_notok "$_id" "no '== $_sec' section in libdvdread-native.txt"
  elif cmp -s "$_got" "$_wnt"; then
    bst_ok "$_id"
  else
    bst_notok "$_id" "$(_bst_1line "$(diff "$_wnt" "$_got" 2>/dev/null || cat "$_got")")"
  fi
}

# ------------------------------------------------------------ what shipped ---
check libdvdread/lib-static  test -f /usr/lib/libdvdread.a
check libdvdread/header-main test -f /usr/include/dvdread/dvd_reader.h
check libdvdread/header-ifo  test -f /usr/include/dvdread/ifo_types.h
check libdvdread/header-udf  test -f /usr/include/dvdread/dvd_udf.h
check libdvdread/header-nav  test -f /usr/include/dvdread/nav_read.h
check libdvdread/pkgconfig   test -f /usr/lib/pkgconfig/dvdread.pc
check_out libdvdread/pkgconfig-version "Version: 6.1.3" cat /usr/lib/pkgconfig/dvdread.pc
# Shape, not absence: this arm converts to shared libraries per recipe
# (BRINTOS-1740), so a .so here is a conversion, not a policy breach.
bst_lib_shape libdvdread/no-shared "/usr/lib/libdvdread.so"
# 6.1.3 ships NO dvdread-config -- upstream deleted it in the 5.x build-system
# rewrite, so the stock recipe's `inherit binconfig` is vestigial and
# libdvdread-bin is an empty package.  Asserted rather than assumed: if a future
# version restores the script, the image entry has to gain libdvdread-bin, and
# this case is where that gets noticed instead of in a puzzled reading of
# lib_package.
check libdvdread/no-binconfig test ! -e /usr/bin/dvdread-config
check libdvdread/probe-present test -x "$PROBE"

# ------------------------------------------------- the identities, one by one --
# Every parse case below rests on these.  They are named individually so a red
# says WHICH structure moved rather than only that the block differs.
self=$("$PROBE" self 2>&1); rc=$?
if [ "$rc" -ne 0 ]; then
  if bst_execfail "$self"; then bst_unrun libdvdread/probe-self "$self"
  else bst_notok libdvdread/probe-self "rc=$rc $(_bst_1line "$self")"; fi
else
  bst_ok libdvdread/probe-self
fi
sfield() { printf '%s\n' "$self" | awk -v k="$1" -v f="$2" '$1==k && $2==f {print $3; exit}'; }

check_eq libdvdread/version          "6.1.3" "$(sfield V version)"
check_eq libdvdread/size-vmgi_mat    "510"   "$(sfield Z vmgi_mat)"
check_eq libdvdread/size-vtsi_mat    "984"   "$(sfield Z vtsi_mat)"
check_eq libdvdread/size-vts_attrs   "542"   "$(sfield Z vts_attributes)"
check_eq libdvdread/size-title_info  "12"    "$(sfield Z title_info)"
check_eq libdvdread/size-cell_pb     "24"    "$(sfield Z cell_playback)"
check_eq libdvdread/size-cell_adr    "12"    "$(sfield Z cell_adr)"
check_eq libdvdread/size-audio_attr  "8"     "$(sfield Z audio_attr)"
check_eq libdvdread/off-tt_srpt      "196"   "$(sfield O vmgi.tt_srpt)"
check_eq libdvdread/off-vts_pgcit    "204"   "$(sfield O vtsi.vts_pgcit)"
check_eq libdvdread/lb-len           "2048"  "$(sfield C DVD_VIDEO_LB_LEN)"

cmp_section libdvdread/self-block self "$PROBE" self

# ---------------------------------------------------------- stage the tree ---
dvd=$tmp/dvd
mkdir -p "$dvd/VIDEO_TS" 2>/dev/null
staged=1
for f in VIDEO_TS.IFO VIDEO_TS.BUP VTS_01_0.IFO VTS_01_0.BUP VTS_01_1.VOB; do
  if [ ! -f "$BST_DATA/libdvdread-$f" ]; then
    bst_notok libdvdread/payload "missing $BST_DATA/libdvdread-$f"
    staged=0
    break
  fi
  cp "$BST_DATA/libdvdread-$f" "$dvd/VIDEO_TS/$f" 2>/dev/null || staged=0
done
if [ "$staged" -ne 1 ]; then
  bst_notok libdvdread/stage "cannot stage the VIDEO_TS tree under $tmp"
  rm -rf "$tmp"
  exit 0
fi
bst_ok libdvdread/stage

# ------------------------------------------------------------- the parse ----
out=$tmp/dvd.out
"$PROBE" dvd "$dvd" > "$out" 2>&1; prc=$?
if [ "$prc" -ne 0 ]; then
  if bst_execfail "$(cat "$out")"; then bst_unrun libdvdread/probe-dvd "$(cat "$out")"
  else bst_notok libdvdread/probe-dvd "rc=$prc $(_bst_1line "$(cat "$out")")"; fi
else
  bst_ok libdvdread/probe-dvd
fi
pfield() { awk -v k="$1" -v f="$2" '$1==k && $2==f {print $3; exit}' "$out"; }

# The three things the ticket named, each its own case.
check_out libdvdread/open        "R open ok"        cat "$out"
check_out libdvdread/ifo-vmg-id  "M id DVDVIDEO-VMG" cat "$out"
check_out libdvdread/ifo-vts-id  "S id DVDVIDEO-VTS" cat "$out"
# DVDDiscID is the only exported path through libdvdread's own md5.c, and it
# hashes the IFO files whole -- so it is a single value that goes wrong if any
# byte of either navigation file is read differently.
check_eq  libdvdread/discid "84d89516efa6740e1ac63b3f83a86ab7" "$(pfield R discid)"
# The navigation tables, read back as values rather than as a block.
check_eq  libdvdread/tt-srpts       "1"  "$(pfield T nr_of_srpts)"
check_eq  libdvdread/vts-atrt-count "1"  "$(pfield A nr_of_vtss)"
check_eq  libdvdread/pgci-count     "1"  "$(pfield G nr_of_pgci_srp)"
check_eq  libdvdread/vob-filesize   "8"  "$(pfield B filesize)"
check_out libdvdread/cell-address   "C cell0 vob 1 cell 1 start 0 last 7" cat "$out"
check_out libdvdread/vobu-admap     "U vobu 1 4"                          cat "$out"
# DVDReadBlocks, one block and then a run: a reader that ignores its count
# argument passes the single-block case and fails this pair.
check_out libdvdread/block-0    "B block 0 BRINTOS-DVD-BLOCK-00 fnv 2ec6e34fa69af218" cat "$out"
check_out libdvdread/block-7    "B block 7 BRINTOS-DVD-BLOCK-07 fnv 77faea10a1540d34" cat "$out"
check_out libdvdread/block-run  "B run 0-7 got 8 fnv bb61806375973b1b"                cat "$out"
# A read entirely past the end must return 0, not invent data.
check_out libdvdread/block-past-end "B past-end got 0" cat "$out"
# DVDFileSeek + DVDReadBytes is the other access path -- it is what ifoRead_*
# uses internally -- and seeking to 4096 must land in block 2.
check_out libdvdread/seek-bytes "B seek4096 got 64 BRINTOS-DVD-BLOCK-02" cat "$out"
# The input backend, in the library's own words.  dvd_input.c says this exactly
# when dlopen("libdvdcss.so.2") returned NULL and it installed its own file_*
# readers -- the unencrypted path this port is scoped to.
check_out libdvdread/no-css "Encrypted DVD support unavailable." cat "$out"

cmp_section libdvdread/dvd-block dvd "$PROBE" dvd "$dvd"

# ifo_print.c is roughly a thousand lines that render the same structures a
# second time through a completely separate code path, and nothing else on this
# image reaches it.  Compared as two blocks rather than named case by case.
cmp_section libdvdread/ifoprint-vmg ifoprint-0 "$PROBE" print "$dvd" 0
cmp_section libdvdread/ifoprint-vts ifoprint-1 "$PROBE" print "$dvd" 1

# The one line in those two blocks worth naming on its own, because it is the
# only place this port carries a patch. Stock ifoPrint_C_ADT() sizes the cell
# address table by sizeof(c_adt_t) -- a struct ending in a pointer -- instead of
# sizeof(cell_adr_t), so on a 64-bit build it prints three quarters of the
# entries and, for a table this small, none. wasm32's 4-byte pointer makes the
# two sizes equal, so THIS TARGET was always right and the patch changes nothing
# here: what it fixes is the machine the reference is generated on. The case is
# named anyway so that a red reads as "the cell entry stopped rendering" rather
# than as an unexplained block diff, and so that a future reference taken from an
# unpatched tree is caught by a case that says why.
#
# THE NEEDLE IS "Sector (first)", AND THE OBVIOUS ONE WAS WRONG. The first cut
# grepped for "VOB ID:   1, Cell ID:   1" and PASSED against an unpatched 64-bit
# library -- because the PGC's cell-position printer emits "Cell:   1 has VOB
# ID:   1, Cell ID:   1" twenty lines earlier, and a substring match cannot tell
# the two apart. The case was asserting the presence of a line the bug does not
# touch. "Sector (first)" is printed by ifoPrint_C_ADT and by nothing else in
# either dump, which is what makes this a guard rather than decoration.
check_out libdvdread/ifoprint-cell-entry \
          "VOB ID:   1, Cell ID:   1   Sector (first): 0x00000000   (last): 0x00000007" \
          "$PROBE" print "$dvd" 1

# ------------------------------------------------------- negative controls ---
# A guard adopted because it passes is not evidence.  These four establish that
# the comparisons above would actually go red if the library were wrong, and
# that the failure paths mean what the cases assume.

# 1. Corrupt the VTSI's identifier.  ifoOpen must fall back to VTS_01_0.BUP and
#    still succeed -- the backup path is a real feature of the format and is
#    otherwise never taken on a healthy tree.
bup=$tmp/bup
mkdir -p "$bup/VIDEO_TS" 2>/dev/null
cp "$dvd"/VIDEO_TS/* "$bup/VIDEO_TS/" 2>/dev/null
if printf 'XXXXXXXXXXXX' | dd of="$bup/VIDEO_TS/VTS_01_0.IFO" bs=1 count=12 \
       conv=notrunc 2>/dev/null; then
  bupout=$("$PROBE" open "$bup" 2>&1)
  case "$bupout" in
    *"R vtsi ok"*) bst_ok libdvdread/bup-fallback ;;
    *) bst_notok libdvdread/bup-fallback "a corrupt VTS_01_0.IFO did not fall back to the BUP: $(_bst_1line "$bupout")" ;;
  esac
else
  bst_notok libdvdread/bup-fallback "cannot stage the corrupted copy"
fi

# 2. Corrupt BOTH.  ifoOpen must now report failure -- cleanly, with the process
#    still alive to say so.  This is what proves case 1 was the BUP being read
#    and not the corruption being ignored.
if printf 'XXXXXXXXXXXX' | dd of="$bup/VIDEO_TS/VTS_01_0.BUP" bs=1 count=12 \
       conv=notrunc 2>/dev/null; then
  bothout=$("$PROBE" open "$bup" 2>&1)
  case "$bothout" in
    *"R vtsi FAILED"*) bst_ok libdvdread/corrupt-both-rejected ;;
    *) bst_notok libdvdread/corrupt-both-rejected "a VTSI corrupt in both copies still parsed -- the identifier check is not running, and libdvdread/bup-fallback proves nothing: $(_bst_1line "$bothout")" ;;
  esac
else
  bst_notok libdvdread/corrupt-both-rejected "cannot stage the corrupted copy"
fi

# 3. Mutate one VOB block.  Every block digest above must then differ -- if a
#    mutated payload still hashes to the reference, the digests are asserting
#    nothing.  Byte 100 of block 3 is inside the pattern, not inside the ASCII
#    tag, so the tag still prints and only the digest moves.
mut=$tmp/mut
mkdir -p "$mut/VIDEO_TS" 2>/dev/null
cp "$dvd"/VIDEO_TS/* "$mut/VIDEO_TS/" 2>/dev/null
printf '\125' | dd of="$mut/VIDEO_TS/VTS_01_1.VOB" bs=1 seek=6244 count=1 \
     conv=notrunc 2>/dev/null
if cmp -s "$mut/VIDEO_TS/VTS_01_1.VOB" "$dvd/VIDEO_TS/VTS_01_1.VOB"; then
  # Distinguished from a wrong digest on purpose: the copy being IDENTICAL means
  # either dd did not write or byte 6244 already held 0x55, and a control that
  # mutates nothing would pass forever while asserting nothing. If the fixture is
  # ever regenerated this offset has to be re-checked against it.
  bst_notok libdvdread/mutation-detected "the mutated copy is byte-identical to the fixture -- dd did not write, or offset 6244 already held 0x55; this control is asserting nothing"
else
  mutfnv=$("$PROBE" dvd "$mut" 2>&1 | awk '$1=="B" && $2=="block" && $3=="3" {print $6; exit}')
  reffnv=$(awk '$1=="B" && $2=="block" && $3=="3" {print $6; exit}' "$out")
  if [ -z "$mutfnv" ]; then
    bst_notok libdvdread/mutation-detected "the probe printed no digest for the mutated block"
  elif [ "$mutfnv" = "$reffnv" ]; then
    bst_notok libdvdread/mutation-detected "a mutated VOB block hashed to the reference ($mutfnv) -- the block digests above prove nothing"
  else
    bst_ok libdvdread/mutation-detected
  fi
fi

# 4. A directory with no VIDEO_TS at all.  DVDOpen returns a reader for any
#    directory -- it is only when a file is asked for that the absence shows --
#    so the assertion is that the IFO open FAILS rather than that the open does.
empty=$tmp/empty
mkdir -p "$empty" 2>/dev/null
emptyout=$("$PROBE" open "$empty" 2>&1)
case "$emptyout" in
  *"R vmgi FAILED"*) bst_ok libdvdread/empty-tree-rejected ;;
  *) bst_notok libdvdread/empty-tree-rejected "an empty directory yielded a VMGI: $(_bst_1line "$emptyout")" ;;
esac

rm -rf "$tmp"