#!/usr/bin/env bash
set -euo pipefail

# Keep readelf and ldd output stable for the runtime dependency checks below.
export LC_ALL=C

if [[ $# -lt 3 || $# -gt 4 ]]; then
    echo "Usage: $0 <debian-arch> <xmake-arch> <version> [extra-recommendation]" >&2
    exit 2
fi

DEBIAN_ARCH="$1"
XMAKE_ARCH="$2"
INPUT_VERSION="$3"
EXTRA_RECOMMENDATION="${4:-}"

PKG_NAME="crossdesk"
VIRTUAL_PACKAGE_NAME="crossdesk-virtual-desktop-xfce"
APP_NAME="CrossDesk"
MAINTAINER="Junkun Di <junkun.di@hotmail.com>"
DESCRIPTION="A simple cross-platform remote desktop client."
ALSA_RUNTIME_DEP="libasound2 | libasound2t64"
PORTAL_RUNTIME_RECOMMENDS="xdg-desktop-portal, xdg-desktop-portal-gtk | xdg-desktop-portal-kde | xdg-desktop-portal-wlr"
TRAY_RUNTIME_RECOMMENDS="libayatana-appindicator3-1 | libappindicator3-1"
# Only the virtual desktop package installs a desktop environment. Both packages
# contain the same application, including headless support. Older Ubuntu releases ship
# dbus-run-session in dbus; newer releases split it into dbus-daemon.
HEADLESS_RUNTIME_DEPS="xvfb, xfce4, dbus-daemon | dbus"

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

normalize_app_version() {
    local input="$1"
    local prefix=""
    local body="$input"

    if [[ "$body" == v* ]]; then
        prefix="v"
        body="${body#v}"
    fi

    if [[ "$body" =~ ^([0-9]+(\.[0-9]+){1,3})-([0-9]{8})-([0-9]+)$ ]]; then
        echo "${prefix}${BASH_REMATCH[1]}-${BASH_REMATCH[4]}-${BASH_REMATCH[3]}"
    else
        echo "$input"
    fi
}

APP_VERSION="$(normalize_app_version "$INPUT_VERSION")"
DEB_VERSION="${APP_VERSION#v}"
if [[ ! "$DEB_VERSION" =~ ^[0-9][0-9A-Za-z.+:~_-]*$ ]]; then
    echo "Invalid Debian version: $DEB_VERSION" >&2
    exit 2
fi

BUILD_BINARY="$PROJECT_ROOT/build/linux/$XMAKE_ARCH/release/crossdesk"
if [[ ! -x "$BUILD_BINARY" ]]; then
    echo "Missing release binary: $BUILD_BINARY" >&2
    echo "Build it first with: xmake f -m release -y && xmake b -vy crossdesk" >&2
    exit 1
fi

for command_name in readelf ldd dpkg-deb strip; do
    if ! command -v "$command_name" >/dev/null 2>&1; then
        echo "Required packaging command is missing: $command_name" >&2
        exit 1
    fi
done

WORK_DIR="$(mktemp -d "${TMPDIR:-/tmp}/crossdesk-deb.XXXXXX")"
trap 'rm -rf "$WORK_DIR"' EXIT

DEB_DIR="$WORK_DIR/${PKG_NAME}-${DEB_VERSION}"
DEBIAN_DIR="$DEB_DIR/DEBIAN"
BIN_DIR="$DEB_DIR/usr/bin"
PRIVATE_DIR="$DEB_DIR/usr/lib/$PKG_NAME"
ICON_BASE_DIR="$DEB_DIR/usr/share/icons/hicolor"
DESKTOP_DIR="$DEB_DIR/usr/share/applications"

install -d "$DEBIAN_DIR" "$BIN_DIR" "$PRIVATE_DIR" "$DESKTOP_DIR"
install -m 0755 "$BUILD_BINARY" "$PRIVATE_DIR/crossdesk-bin"
install -m 0755 "$(dirname "$BUILD_BINARY")/crossdesk_updater" "$PRIVATE_DIR/crossdesk_updater"

# PipeWire is deliberately optional. The Wayland capturer resolves PipeWire
# 0.3 with dlopen() so the same package can run on Ubuntu 20.04 without the
# runtime while using the host runtime on newer Ubuntu releases.
if readelf -d "$BUILD_BINARY" \
    | grep -qE 'Shared library: \[libpipewire-0\.3\.so'; then
    echo "CrossDesk must not link directly to the optional PipeWire runtime" >&2
    exit 1
fi

# Slint is intentionally built as a shared library. Keep that runtime private
# to CrossDesk instead of relying on a non-existent distribution package.
SLINT_NEEDED="$(readelf -d "$BUILD_BINARY" | sed -n \
    's/.*Shared library: \[\(libslint_cpp[^]]*\)\].*/\1/p' | head -n 1)"
if [[ -n "$SLINT_NEEDED" ]]; then
    # The build rule copies the exact linked package beside the executable.
    # Never search global caches or trust the packager's LD_LIBRARY_PATH: an
    # unpatched runtime can share both the version and SONAME of the linked one.
    SLINT_LIBRARY="$(dirname "$BUILD_BINARY")/$SLINT_NEEDED"
    if [[ ! -f "$SLINT_LIBRARY" ]]; then
        echo "Missing build-matched Slint runtime: $SLINT_LIBRARY" >&2
        echo "Build it first with: xmake b -vy crossdesk" >&2
        exit 1
    fi
    install -m 0755 "$SLINT_LIBRARY" "$PRIVATE_DIR/$SLINT_NEEDED"
    # Keep dynamic exports/relocations while removing unneeded symbols from the
    # staged copy. Never strip Xmake's cached runtime in place.
    strip --strip-unneeded "$PRIVATE_DIR/$SLINT_NEEDED"
fi

# Check the staged files with only their private runtime directory available.
# ldd -r can exit successfully even when it reports unresolved symbols, so its
# diagnostics must also be checked. This does not start the GUI or updater.
for executable in crossdesk-bin crossdesk_updater; do
    dependency_report="$WORK_DIR/$executable.ldd"
    if ! env -u LD_PRELOAD -u LD_AUDIT LD_LIBRARY_PATH="$PRIVATE_DIR" \
        ldd -r "$PRIVATE_DIR/$executable" > "$dependency_report" 2>&1 || \
        grep -Eq 'not found|undefined symbol:' "$dependency_report"; then
        echo "Packaged runtime dependency check failed: $executable" >&2
        cat "$dependency_report" >&2
        exit 1
    fi
done
if [[ -n "$SLINT_NEEDED" ]]; then
    if ! grep -Fq "$SLINT_NEEDED => $PRIVATE_DIR/$SLINT_NEEDED (" "$WORK_DIR/crossdesk-bin.ldd"; then
        echo "Packaged executable does not load its private Slint runtime" >&2
        cat "$WORK_DIR/crossdesk-bin.ldd" >&2
        exit 1
    fi
fi

cat > "$BIN_DIR/$PKG_NAME" <<'EOF'
#!/bin/sh
private_lib_dir="/usr/lib/crossdesk"
if [ -n "${LD_LIBRARY_PATH:-}" ]; then
    export LD_LIBRARY_PATH="$private_lib_dir:$LD_LIBRARY_PATH"
else
    export LD_LIBRARY_PATH="$private_lib_dir"
fi
exec /usr/lib/crossdesk/crossdesk-bin "$@"
EOF
chmod 0755 "$BIN_DIR/$PKG_NAME"
ln -s "$PKG_NAME" "$BIN_DIR/$APP_NAME"

for size in 16 24 32 48 64 96 128 256; do
    install -d "$ICON_BASE_DIR/${size}x${size}/apps"
    install -m 0644 "$PROJECT_ROOT/apps/desktop/resources/linux/crossdesk_${size}x${size}.png" \
        "$ICON_BASE_DIR/${size}x${size}/apps/${PKG_NAME}.png"
done

RECOMMENDS="$PORTAL_RUNTIME_RECOMMENDS, $TRAY_RUNTIME_RECOMMENDS, policykit-1"
if [[ -n "$EXTRA_RECOMMENDATION" ]]; then
    RECOMMENDS="$RECOMMENDS, $EXTRA_RECOMMENDATION"
fi

cat > "$DESKTOP_DIR/$PKG_NAME.desktop" <<EOF
[Desktop Entry]
Version=1.0
Name=$APP_NAME
Comment=$DESCRIPTION
Exec=/usr/bin/$PKG_NAME
Icon=$PKG_NAME
StartupWMClass=$PKG_NAME
Terminal=false
Type=Application
Categories=Utility;
EOF

# Give shells a desktop entry for the remote window's separate app id. Without
# it, some shells fall back to the process's main launcher and merge the groups;
# Wayland also uses this entry to resolve the icon. Hide it from app menus: a
# fresh launch can open CrossDesk, but cannot recreate a live remote session.
cat > "$DESKTOP_DIR/$PKG_NAME-remote-control.desktop" <<EOF
[Desktop Entry]
Version=1.0
Name=$APP_NAME Remote Control
Comment=Active CrossDesk remote control sessions
Exec=/usr/bin/$PKG_NAME
Icon=$PKG_NAME
StartupWMClass=$PKG_NAME-remote-control
Terminal=false
Type=Application
NoDisplay=true
EOF

# Stage and strip the application once, then package it with two dependency sets.
# Keep the executable, launcher and configuration paths identical when switching.
for package_name in "$PKG_NAME" "$VIRTUAL_PACKAGE_NAME"; do
    extra_depends=""
    description="$DESCRIPTION"
    other_package="$VIRTUAL_PACKAGE_NAME"
    if [[ "$package_name" == "$VIRTUAL_PACKAGE_NAME" ]]; then
        extra_depends=", $HEADLESS_RUNTIME_DEPS"
        description="CrossDesk with Xfce and Xvfb for independent virtual desktops."
        other_package="$PKG_NAME"
    fi
    cat > "$DEBIAN_DIR/control" <<EOF
Package: $package_name
Version: $DEB_VERSION
Architecture: $DEBIAN_ARCH
Maintainer: $MAINTAINER
Description: $description
Depends: libc6 (>= 2.31), libstdc++6 (>= 10), libx11-6, libxext6,
 libxrender1, libxft2, libxrandr2, libxfixes3, libxcursor1, libxi6, libxcb1, libxcb-randr0,
 libxcb-xtest0, libxcb-xinerama0, libxcb-shape0, libxcb-xkb1,
 libxcb-xfixes0, libxv1, libxtst6, $ALSA_RUNTIME_DEP, libsndio7.0,
 libxcb-shm0, libpulse0, libdrm2, libdbus-1-3, libgl1$extra_depends
Recommends: $RECOMMENDS
Conflicts: $other_package
Replaces: $other_package
Priority: optional
Section: utils
EOF
    if [[ "$package_name" == "$VIRTUAL_PACKAGE_NAME" ]]; then
        echo "Provides: $PKG_NAME (= $DEB_VERSION)" >> "$DEBIAN_DIR/control"
    fi
    # Read beside the executable by the updater; never store this in user config.
    echo "$package_name" > "$PRIVATE_DIR/package-name"
    chmod 0644 "$PRIVATE_DIR/package-name"
    OUTPUT_FILE="$PROJECT_ROOT/${package_name}-linux-${DEBIAN_ARCH}-${APP_VERSION}.deb"
    rm -f "$OUTPUT_FILE"
    dpkg-deb --root-owner-group --build "$DEB_DIR" "$OUTPUT_FILE"
    dpkg-deb --info "$OUTPUT_FILE" >/dev/null
    dpkg-deb --contents "$OUTPUT_FILE" > "$WORK_DIR/package-contents.txt"

    if [[ -n "$SLINT_NEEDED" ]] && \
       ! grep -q "usr/lib/$PKG_NAME/$SLINT_NEEDED" "$WORK_DIR/package-contents.txt"; then
        echo "Packaged artifact is missing $SLINT_NEEDED" >&2
        exit 1
    fi

    echo "Deb package created: $OUTPUT_FILE"
done