#!/bin/bash
set -euo pipefail

# Usage:
#   ./build.bash [app]                              build an in-tree app (default: lilush)
#   ./build.bash --pack <git-url> --ref <tag|sha> --name <binary>
#                                                   build an external LILPACK repo into a
#                                                   custom static binary
#
# In-tree builds use buildgen/apps/<app>.lua. Pack builds clone <git-url> at
# <tag|sha> inside the container and build from the pack's build/<name>.lua
# descriptor. <name> is the descriptor's `binary` value and the output filename.

PACK_URL=""
PACK_REF=""
APP="lilush"

if [ "${1:-}" = "--pack" ]; then
    while [ $# -gt 0 ]; do
        case "$1" in
            --pack) PACK_URL="$2"; shift 2 ;;
            --ref)  PACK_REF="$2"; shift 2 ;;
            --name) APP="$2";      shift 2 ;;
            *) echo "unknown option: $1" >&2; exit 1 ;;
        esac
    done
    if [ -z "$PACK_URL" ] || [ -z "$PACK_REF" ] || [ -z "$APP" ]; then
        echo "pack build requires --pack <git-url> --ref <tag|sha> --name <binary>" >&2
        exit 1
    fi
else
    APP=${1:-lilush}
fi

if [ -n "$PACK_URL" ]; then
    # --no-cache so a re-pushed tag can't serve a stale cloned layer.
    docker build --no-cache \
        --build-arg APP="${APP}" \
        --build-arg PACK_URL="${PACK_URL}" \
        --build-arg PACK_REF="${PACK_REF}" \
        -t lilush-build .
else
    docker build --build-arg APP="${APP}" -t lilush-build .
fi

docker cp $(docker create --name lilush-build lilush-build):/build/${APP} ./${APP}
docker rm lilush-build