#!/bin/bash
# build-deb.sh — stage and build the jray-server Debian package.
#
# Built with dpkg-deb from an explicit staging tree rather than with cargo-deb.
# The reason is debconf: its `config` script and `templates` live in the control
# archive alongside the maintainer scripts, and controlling that archive directly
# is simpler than discovering what a wrapper will and will not copy into it.
# dpkg-dev is present on any Debian builder, so this adds no build dependency.
#
# Usage:
#   scripts/build-deb.sh                          # build the binary, then package
#   scripts/build-deb.sh --binary path/to/bin     # package an existing binary
#   scripts/build-deb.sh --version 1.2.3          # override the computed version
#   scripts/build-deb.sh --out dist               # output directory
set -euo pipefail

REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
cd "$REPO_ROOT"

TARGET="x86_64-unknown-linux-musl"
BINARY=""
VERSION=""
OUT="$REPO_ROOT/dist"

while [ $# -gt 0 ]; do
    case "$1" in
        --binary)  BINARY="${2:?--binary needs a path}"; shift ;;
        --version) VERSION="${2:?--version needs a value}"; shift ;;
        --out)     OUT="${2:?--out needs a path}"; shift ;;
        -h|--help) sed -n '2,16p' "${BASH_SOURCE[0]}"; exit 0 ;;
        *) echo "error: unknown argument '$1'" >&2; exit 2 ;;
    esac
    shift
done

# ── Version ─────────────────────────────────────────────────────────────────
#
# A tagged commit packages as that tag. Anything else packages as a PRE-release
# of the version in Cargo.toml: `0.1.0~git20260905.9bcc765` sorts BELOW `0.1.0`
# in dpkg's ordering, because `~` sorts before everything including the empty
# string. That is what makes a master build upgradeable to the eventual release
# rather than blocking it — the mistake would be `0.1.0+git...`, which sorts
# above and would leave apt refusing the real 0.1.0.
if [ -z "$VERSION" ]; then
    if tag=$(git describe --exact-match --tags HEAD 2>/dev/null); then
        VERSION="${tag#v}"
    else
        cargo_version=$(sed -n 's/^version *= *"\(.*\)"/\1/p' Cargo.toml | head -1)
        VERSION="${cargo_version}~git$(date -u +%Y%m%d).$(git rev-parse --short HEAD)"
    fi
fi

# ── Binary ──────────────────────────────────────────────────────────────────
if [ -z "$BINARY" ]; then
    echo "=== building $TARGET"
    cargo build --release --target "$TARGET"
    BINARY="target/$TARGET/release/jray-server"
fi

[ -f "$BINARY" ] || { echo "error: no binary at $BINARY" >&2; exit 1; }

# The package claims no libc dependency, which is only honest if the binary
# genuinely has none. Asserted with `file` rather than `ldd`: a musl static-PIE
# makes ldd print the musl loader path, so an ldd check calls a static binary
# dynamic. Same reasoning as the Dockerfile and the CI musl job.
if command -v file >/dev/null 2>&1; then
    linkage=$(file -b "$BINARY")
    case "$linkage" in
        *"static-pie linked"*|*"statically linked"*) ;;
        *) echo "error: $BINARY is not static ($linkage)." >&2
           echo "       The package declares no libc dependency, so a dynamic" >&2
           echo "       binary here would install cleanly and then fail to run." >&2
           exit 1 ;;
    esac
fi

# ── Stage ───────────────────────────────────────────────────────────────────
STAGE="$(mktemp -d)"
trap 'rm -rf "$STAGE"' EXIT

install -d -m 0755 "$STAGE/DEBIAN"
install -d -m 0755 "$STAGE/usr/bin"
install -d -m 0755 "$STAGE/lib/systemd/system"
install -d -m 0755 "$STAGE/usr/share/doc/jray-server/examples"

install -m 0755 "$BINARY"                                "$STAGE/usr/bin/jray-server"
install -m 0644 packaging/jray-server.service            "$STAGE/lib/systemd/system/jray-server.service"
install -m 0644 packaging/examples/nginx-jray-server.conf \
                "$STAGE/usr/share/doc/jray-server/examples/nginx-jray-server.conf"
install -m 0644 SPEC.md    "$STAGE/usr/share/doc/jray-server/SPEC.md"
install -m 0644 README.md  "$STAGE/usr/share/doc/jray-server/README.md"

# Licences. LICENSE-DATA is not the code licence: contributed manifests are CC0
# while the server itself is GPLv3, and shipping only one of them would misstate
# what the operator is redistributing.
install -m 0644 LICENSE      "$STAGE/usr/share/doc/jray-server/LICENSE"
install -m 0644 LICENSE-DATA "$STAGE/usr/share/doc/jray-server/LICENSE-DATA"

install -m 0755 packaging/debian/config   "$STAGE/DEBIAN/config"
install -m 0755 packaging/debian/postinst "$STAGE/DEBIAN/postinst"
install -m 0755 packaging/debian/prerm    "$STAGE/DEBIAN/prerm"
install -m 0755 packaging/debian/postrm   "$STAGE/DEBIAN/postrm"
install -m 0644 packaging/debian/templates "$STAGE/DEBIAN/templates"

SIZE=$(du -ks "$STAGE" | cut -f1)

# No libc, no libsqlite3, no CA bundle: SQLite is compiled in (`rusqlite`
# bundled), the TLS roots are compiled in (`reqwest` rustls-tls uses
# webpki-roots), and the target is musl static. The only dependencies are the
# two the maintainer scripts themselves call.
cat > "$STAGE/DEBIAN/control" <<EOF
Package: jray-server
Version: $VERSION
Section: net
Priority: optional
Architecture: amd64
Depends: debconf (>= 0.5) | debconf-2.0, init-system-helpers (>= 1.54)
Installed-Size: $SIZE
Maintainer: Duncan Tourolle <duncan@tourolle.paris>
Homepage: https://gitea.tourolle.paris/dtourolle/JRay-public-server
Description: JRay public server - community manifest exchange
 Serves and accepts JRay manifests: per-actor scene windows contributed by
 media-centre users and matched to a cut by runtime and audio signature.
 .
 One static binary and one SQLite file, behind a reverse proxy the operator
 provides. The server stores no binary content by design - no images, no
 embeddings, no opaque blobs - which is what makes it safe for a volunteer to
 run.
 .
 An example nginx site is installed under
 /usr/share/doc/jray-server/examples/, to be copied to whichever host runs
 your proxy.
EOF

mkdir -p "$OUT"
DEB="$OUT/jray-server_${VERSION}_amd64.deb"
dpkg-deb --root-owner-group --build "$STAGE" "$DEB" >/dev/null

echo "=== built $DEB"
dpkg-deb --info "$DEB" | sed 's/^/    /'
echo "=== contents"
dpkg-deb --contents "$DEB" | sed 's/^/    /'