#!/bin/bash
# Build libva-v4l2-request-fourier_<ver>_arm64.deb.
#
# Compiles the libva ICD from the marfrit/libva-v4l2-request-fourier
# tip pinned in PKGVER below.  Mirrors arch/libva-v4l2-request-fourier
# (Arch Linux build).  Output is a single arm64 .deb that ships the
# VA-API driver as /usr/lib/aarch64-linux-gnu/dri/v4l2_request_drv_video.so.
#
# Sibling Arch package: ../../arch/libva-v4l2-request-fourier/PKGBUILD
# Upstream fork: https://git.reauktion.de/marfrit/libva-v4l2-request-fourier
set -euo pipefail

# Same pin as the Arch PKGBUILD.  c332d34 = LIBVA-1 close — per-codec
# dispatch on Pi 5: rpi-hevc-dec + daedalus_v4l2 both probe each other
# as alts, VP9/AV1/H.264 route to daedalus via new 'd' kind, HEVC stays
# on 'p' (rpi-hevc-dec).
UPSTREAM_COMMIT=c332d34643be29e88012e30878d2fbeb255b20ab
PKGVER=1.0.0+r378+gc332d34
PKGREL=2  # rebuild against pinned trixie libva-dev (2.22) for __vaDriverInit_1_22 ABI

HERE=$(dirname "$(readlink -f "$0")")

# Reproducible build.  2026-05-18 23:00 UTC — Phase 8.13 close.
export SOURCE_DATE_EPOCH=1779231600

work=$(mktemp -d)
trap "rm -rf $work" EXIT

cd "$work"

# ---------------------------------------------------------------------------
# Pin libva ABI to Debian trixie's version (libva 2.22.0 -> VA-API 1.22).
#
# Without this, when the CI runner is Arch (libva 2.23.0 currently) the
# driver compiles in __vaDriverInit_1_23 from Arch's <va/va.h> — but the
# Debian trixie libva runtime on the install target looks up
# __vaDriverInit_1_22 and the dlsym() returns NULL.  libva then reports
# "has no function __vaDriverInit_1_0" (its fallback search name) and
# vaInitialize() fails with -1.
#
# The driver itself doesn't link against libva.so — only the symbol NAME
# matters, and the name is computed at compile time from VA_MAJOR /
# VA_MINOR macros in <va/va.h>.  So all we have to do is point pkg-config
# at trixie's libva-dev headers; the link step still resolves -lva
# against the runner's libva (any version is fine — it's just for the
# linker to be happy, the result has no NEEDED entry for libva).
# ---------------------------------------------------------------------------
LIBVA_TRIXIE_VER="2.22.0-3"
TRIXIE_SYSROOT="$work/trixie-sysroot"
mkdir -p "$TRIXIE_SYSROOT"
for pkg in libva-dev libva2 libva-drm2; do
    curl -sSLfo "$work/${pkg}.deb" \
        "https://deb.debian.org/debian/pool/main/libv/libva/${pkg}_${LIBVA_TRIXIE_VER}_arm64.deb"
    dpkg-deb -x "$work/${pkg}.deb" "$TRIXIE_SYSROOT"
done

# Rewrite the prefix in the .pc files so pkg-config returns -I/-L pointing
# inside the sysroot (Debian's pkg-config files default to /usr).
for pc in "$TRIXIE_SYSROOT"/usr/lib/aarch64-linux-gnu/pkgconfig/libva*.pc; do
    sed -i "s|^prefix=/usr|prefix=$TRIXIE_SYSROOT/usr|" "$pc"
done

# Symlink libva.so -> libva.so.2 inside the sysroot so the linker can
# resolve `-lva` against trixie's shipped runtime (no -dev symlink in
# the libva2 .deb).  Same for libva-drm.
ln -sf libva.so.2     "$TRIXIE_SYSROOT/usr/lib/aarch64-linux-gnu/libva.so"
ln -sf libva-drm.so.2 "$TRIXIE_SYSROOT/usr/lib/aarch64-linux-gnu/libva-drm.so"

export PKG_CONFIG_PATH="$TRIXIE_SYSROOT/usr/lib/aarch64-linux-gnu/pkgconfig:${PKG_CONFIG_PATH:-}"

curl -sSLfo libva-fourier.tar.gz \
    "https://git.reauktion.de/marfrit/libva-v4l2-request-fourier/archive/${UPSTREAM_COMMIT}.tar.gz"
tar xzf libva-fourier.tar.gz
SRCDIR=$(echo libva-v4l2-request-fourier)

cd "$SRCDIR"
meson setup build \
    --buildtype=release \
    --prefix=/usr \
    --libdir=lib/aarch64-linux-gnu \
    -Db_lto=false
meson compile -C build

# Sanity check: the produced .so MUST export __vaDriverInit_1_22 (not 1_23).
# Fail loud if it doesn't — otherwise the .deb installs but refuses to load
# on trixie and the bug is invisible until someone runs vainfo.
SO=$(find build -name 'v4l2_request_drv_video.so' | head -1)
if ! nm -D --defined-only "$SO" | grep -q '__vaDriverInit_1_22'; then
    echo "FATAL: built driver does not export __vaDriverInit_1_22"
    nm -D --defined-only "$SO" | grep -i vadriverinit || true
    exit 1
fi
echo "ABI check: $SO exports __vaDriverInit_1_22 (matches trixie libva 2.22)"

ROOT="$work/pkgroot"
DESTDIR="$ROOT" meson install -C build

# Strip any non-package debug, then drop dependencies + control.
install -Dm644 "$HERE/debian/copyright" "$ROOT/usr/share/doc/libva-v4l2-request-fourier/copyright"
install -Dm644 "$HERE/debian/changelog" "$ROOT/usr/share/doc/libva-v4l2-request-fourier/changelog.Debian"
gzip -9 -n "$ROOT/usr/share/doc/libva-v4l2-request-fourier/changelog.Debian"

mkdir -p "$ROOT/DEBIAN"
cat > "$ROOT/DEBIAN/control" <<EOF
Package: libva-v4l2-request-fourier
Version: ${PKGVER}-${PKGREL}
Section: libs
Priority: optional
Architecture: arm64
Depends: libva2, libdrm2
Conflicts: libva-v4l2-request
Replaces: libva-v4l2-request
Provides: libva-driver, libva-v4l2-request (= ${PKGVER}-${PKGREL})
Maintainer: Markus Fritsche <mfritsche@reauktion.de>
Homepage: https://git.reauktion.de/marfrit/libva-v4l2-request-fourier
Description: VA-API backend for V4L2 stateless decoders (fourier fork)
 LibVA implementation for the Linux Video4Linux2 Request API, multiplanar
 fork of bootlin/libva-v4l2-request.  Drives rkvdec / hantro / cedrus /
 rpi-hevc-dec / daedalus_v4l2 stateless decoders for H.264, HEVC, VP8,
 VP9, AV1, and MPEG-2.
 .
 Auto-detected by VAAPI consumers (ffmpeg -hwaccel vaapi, mpv --hwdec=vaapi,
 Firefox VAAPI accel) when LIBVA_DRIVER_NAME=v4l2_request is set.
EOF

DEB_OUT="libva-v4l2-request-fourier_${PKGVER}-${PKGREL}_arm64.deb"
dpkg-deb --root-owner-group --build "$ROOT" "$HERE/$DEB_OUT"
echo "built: $HERE/$DEB_OUT"