#!/bin/bash

set -euo pipefail

usage() {
    echo "Usage: $0 GUI.AppImage-or-AppDir SERVER_BINARY SERVER_DB_MODE OUTPUT.AppImage" >&2
}

if [[ $# -ne 4 ]]; then
    usage
    exit 2
fi

script_dir="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
gui_bundle="$(realpath -- "$1")"
server_binary="$(realpath -- "$2")"
server_db_mode="$3"
output_parent="$(dirname -- "$4")"
mkdir -p "$output_parent"
output="$(cd -- "$output_parent" && pwd)/$(basename -- "$4")"

if [[ "$server_db_mode" != embedded && "$server_db_mode" != external ]]; then
    echo "SERVER_DB_MODE must be embedded or external, got: $server_db_mode" >&2
    exit 2
fi

if [[ ! -d "$gui_bundle" && ! -x "$gui_bundle" ]]; then
    echo "GUI bundle is neither an AppDir nor an executable AppImage: $gui_bundle" >&2
    exit 1
fi
if [[ ! -x "$server_binary" ]]; then
    echo "Server binary is not executable: $server_binary" >&2
    exit 1
fi

work_dir="$(mktemp -d /tmp/komp-ac-appimage.XXXXXX)"
cleanup() {
    case "$work_dir" in
        /tmp/komp-ac-appimage.*)
            rm -rf -- "$work_dir"
            ;;
        *)
            echo "Refusing to remove unexpected temporary directory: $work_dir" >&2
            ;;
    esac
}
trap cleanup EXIT INT TERM HUP

app_dir="$work_dir/squashfs-root"
if [[ -d "$gui_bundle" ]]; then
    mkdir "$app_dir"
    cp -a -- "$gui_bundle/." "$app_dir/"
else
    (
        cd -- "$work_dir"
        "$gui_bundle" --appimage-extract >/dev/null
    )
fi

if [[ ! -e "$app_dir/AppRun" ]]; then
    echo "The GUI AppImage did not contain an AppRun entry point" >&2
    exit 1
fi

mv -- "$app_dir/AppRun" "$app_dir/AppRun.gui"
install -Dm755 "$script_dir/AppRun" "$app_dir/AppRun"
install -Dm755 "$server_binary" "$app_dir/usr/bin/komp-ac-server"
install -d "$app_dir/usr/share/komp-ac"
printf '%s\n' "$server_db_mode" > "$app_dir/usr/share/komp-ac/server-db-mode"

# Tauri names the root icon after productName (`komp_ac.png`) while its desktop
# entry names the Rust binary (`Icon=client-gui2`). AppImage packers require the
# desktop icon name to resolve at the AppDir root.
if [[ -f "$app_dir/komp_ac.png" && ! -e "$app_dir/client-gui2.png" ]]; then
    ln -s komp_ac.png "$app_dir/client-gui2.png"
fi

if [[ -n "${APPIMAGETOOL:-}" ]]; then
    ARCH=x86_64 "$APPIMAGETOOL" "$app_dir" "$output"
elif command -v appimagetool >/dev/null 2>&1; then
    ARCH=x86_64 appimagetool "$app_dir" "$output"
else
    cache_home="${XDG_CACHE_HOME:-${HOME:?HOME is not set}/.cache}"
    appimage_plugin="$cache_home/tauri/linuxdeploy-plugin-appimage.AppImage"
    if [[ ! -x "$appimage_plugin" ]]; then
        echo "No AppImage packer found; set APPIMAGETOOL to appimagetool's executable path" >&2
        exit 1
    fi
    ARCH=x86_64 \
    LDAI_NO_APPSTREAM=1 \
    LDAI_OUTPUT="$output" \
    "$appimage_plugin" --appimage-extract-and-run --appdir="$app_dir"
fi
echo "Created $output"