#!/usr/bin/env bash
# Usage: tools/build-rootfs [-h] [--base]
#
# Builds the werkrevisor image and exports its file system
# as werkrevisor-rootfs-<version>.tar.zst for hosts without Docker (werkdock).
# Run it from the repository root.
# It runs with docker, else podman; CONTAINER_ENGINE overrides the choice.
# The archive does not keep image metadata; run it with
#   PATH=/app/.venv/bin:/usr/local/bin:/usr/bin:/bin PYTHONPATH=/werkrevisor:/app PYTHONNOUSERSITE=1 python -s -m werkrevisor
# After a successful build it keeps only the two newest archives in the repository directory
# and the two newest image tags; each release adds about 183 MB.
# With --base it exports only the stage `base` of the Dockerfile (PR-Agent, Node.js and PR Lens),
# as werkrevisor-base-<hash>.tar.zst, from which tools/release_rootfs.py assembles a release
# on a host without a container engine.
set -euo pipefail

if [[ "${1:-}" =~ ^(-h|-\?|--help)$ ]]; then
    awk 'NR > 1 && /^#/ { sub(/^# ?/, ""); print; next } NR > 1 { exit }' "$0"
    exit 0
fi

version=$(sed -n 's/^__version__ = "\(.*\)"$/\1/p' werkrevisor/__init__.py)
image="werkrevisor:${version}"
archive="werkrevisor-rootfs-${version}.tar.zst"
container_engine="${CONTAINER_ENGINE:-$(command -v docker || command -v podman || true)}"
[[ -n "$container_engine" ]] || { echo "tools/build-rootfs: neither docker nor podman found; set CONTAINER_ENGINE" >&2; exit 2; }

if [[ "${1:-}" == "--base" ]]; then
    base=$(python3 tools/release_rootfs.py base-name)
    "$container_engine" build --target base -t werkrevisor-base:latest .
    container=$("$container_engine" create werkrevisor-base:latest)
    trap '"$container_engine" rm -f "$container" >/dev/null' EXIT
    "$container_engine" export "$container" | zstd -q -T0 -10 -f -o "$base"
    echo "archive: $base ($(du -h "$base" | cut -f1))"
    sha256sum "$base"
    exit 0
fi

"$container_engine" build -t "$image" .
container=$("$container_engine" create "$image")
trap '"$container_engine" rm -f "$container" >/dev/null' EXIT
"$container_engine" export "$container" | zstd -q -T0 -10 -f -o "$archive"
echo "image:   $image"
echo "archive: $archive ($(du -h "$archive" | cut -f1))"
sha256sum "$archive"

for old in $(python3 tools/release_files.py 2 -- werkrevisor-rootfs-*.tar.zst); do
    rm -f -- "$old"
    echo "removed: $old"
done
for old in $(python3 tools/release_files.py 2 -- $("$container_engine" images werkrevisor --format 'werkrevisor:{{.Tag}}')); do
    "$container_engine" rmi "$old" >/dev/null
    echo "removed: $old"
done