#!/bin/sh
# shellcheck source=./lib/lib.sh

. "$(dirname "$(realpath "$0")")/lib/lib.sh"

BASE_DIR="$(dirname "$(realpath "$0")")"

KB=1024
MB=$((1024 * KB))

TARGET=
IMAGE=
MOUNTPOINT="$(mktemp -d)"

usage() {
    cat >&2 <<EOF
Usage: $0 -t <TARGET> -o <OUTPUT> [-h]

Options
    -t          The target building image for
                    [available: riscv64 x86 loongarch64]
    -o          Output image path
    -h          Show help message
EOF

    exit "$1"
}

ensure_mount_macos() {
    hdiutil detach "$MOUNTPOINT" > /dev/null 2>&1 || :
    hdiutil attach "$IMAGE" -mountpoint "$MOUNTPOINT"
}

ensure_mount_linux() {
    DEV=$(sudo losetup -f "$IMAGE" --show)
    sudo mount "$DEV" "$MOUNTPOINT"
}

ensure_mount() {
    if [ "$OS" = Darwin ]; then
        ensure_mount_macos
        return
    fi

    ensure_mount_linux
}

unmount_macos() {
    hdiutil detach "$MOUNTPOINT"
}

unmount_linux() {
    sudo umount "$MOUNTPOINT"
    sudo losetup -d "$DEV"
}

cleanup() {
    case "$OS" in
        Darwin)
            unmount_macos
            ;;
        *)
            unmount_linux
            ;;
    esac
}

set -eu

while getopts "t:o:h" opt; do
    case "$opt" in
        t) TARGET="$OPTARG";;
        o) IMAGE="$OPTARG";;
        h) usage 0;;
        ?) usage 1;;
    esac
done

shift $((OPTIND - 1))

[ -z "$TARGET" ] && die "ARCH is not set"
[ -z "$IMAGE" ] && die "output image path is not set"

echo "Build image with ARCH=$TARGET OUTPUT=$IMAGE MOUNTPOINT=$MOUNTPOINT"

dd if=/dev/zero of="$IMAGE" bs=$((1 * MB)) count=$((1024 - 4))
mkfs.fat -n SYSTEM "$IMAGE"

ensure_mount
trap cleanup EXIT

for name in $(iter_files_sorted "$BASE_DIR/platform/$TARGET"); do
    ( . "$name" )
done