#!/bin/bash
# build-full-image.sh — sbo-full:{ver} FROM sbo-base:{ver}, all series.
# Adapted from forge slackware/docker-images. No root needed.
set -euo pipefail
HERE="$(cd "$(dirname "$0")" && pwd)"
source "${HERE}/config"
LOG_TAG=full
source "${HERE}/lib.sh"

BASE_IMAGE="${REGISTRY}/sbo-base"
FULL_IMAGE="${REGISTRY}/sbo-full"
DIGEST_LABEL="sbo.full.base-digest"

# ============================================================================
# Argument parsing
# ============================================================================

FORCE=false
OPT_VERSION=""
while [[ $# -gt 0 ]]; do
    case "$1" in
        --version) OPT_VERSION="$2"; shift 2 ;;
        --force)   FORCE=true;       shift   ;;
        *) _err "unknown argument: $1" ;;
    esac
done
if [[ -n "${OPT_VERSION}" ]]; then
    BUILD_VARIANTS=("${OPT_VERSION}")
else
    BUILD_VARIANTS=("${VARIANTS[@]}")
fi

# ============================================================================
# Tag derivation
# ============================================================================

# derive_tags VERSION
# Sets globals BASE_TAG and FULL_TAG for the given variant.
derive_tags() {
    local VERSION="$1"
    BASE_TAG="${BASE_IMAGE}:${VERSION}"
    FULL_TAG="${FULL_IMAGE}:${VERSION}"
}

# ============================================================================
# Rebuild detection
#
# After pulling the latest base image, its digest is compared with the
# digest stored in the DIGEST_LABEL on the current full image.  If
# they differ the base image has been updated and the full must be
# rebuilt to incorporate slackpkg package updates shipped with the new base.
# ============================================================================

needs_rebuild() {
    local BASE_TAG="$1" FULL_TAG="$2"

    if [[ "${FORCE}" == "true" ]]; then
        _log "  --force specified; rebuilding unconditionally."
        return 0
    fi

    # Digest of the base image we just pulled
    local BASE_DIGEST
    BASE_DIGEST=$(docker inspect --format '{{index .RepoDigests 0}}' \
                  "${BASE_TAG}" 2>/dev/null || echo "")
    if [[ -z "${BASE_DIGEST}" ]]; then
        _warn "  Could not determine base image digest; rebuilding to be safe."
        return 0
    fi

    # Digest recorded in the full image's label (empty if image doesn't exist)
    local RECORDED_DIGEST
    RECORDED_DIGEST=$(docker inspect \
                      --format "{{index .Config.Labels \"${DIGEST_LABEL}\"}}" \
                      "${FULL_TAG}" 2>/dev/null || echo "")

    if [[ "${BASE_DIGEST}" == "${RECORDED_DIGEST}" ]]; then
        _log "  Base image unchanged (${BASE_DIGEST:0:40}...); skipping."
        return 1
    fi

    _log "  Base image changed; rebuilding."
    _log "    Was : ${RECORDED_DIGEST:0:60}..."
    _log "    Now : ${BASE_DIGEST:0:60}..."
    return 0
}

# ============================================================================
# Build one variant
# ============================================================================

build_variant() {
    local VERSION="$1"
    derive_tags "${VERSION}"

    _log "=== ${FULL_TAG} ==="

    # Pull the latest base image so digest comparison is against the current
    # state of the registry, not a stale local cache.
    _log "  Pulling base image ${BASE_TAG}..."
    docker pull "${BASE_TAG}"

    if ! needs_rebuild "${BASE_TAG}" "${FULL_TAG}"; then
        return 0
    fi

    # Record the base image digest for the label
    local BASE_DIGEST
    BASE_DIGEST=$(docker inspect --format '{{index .RepoDigests 0}}' "${BASE_TAG}")

    local WORKDIR
    WORKDIR="$(mktemp -d /tmp/slackware-full.XXXXXX)"
    # shellcheck disable=SC2064
    trap "rm -rf '${WORKDIR}'" EXIT

    # Generate the Dockerfile for this variant
    cat > "${WORKDIR}/Dockerfile" <<DOCKERFILE
FROM ${BASE_TAG}
LABEL maintainer="Eric Hameleers <alien@slackware.com>"

# Update the slackpkg package list before installing so that we always
# get the versions current at build time, not the versions cached in the
# base image.
RUN LC_ALL=C slackpkg -batch=on -default_answer=y update

# Download and install each individual package (thanks aclemons):
RUN sed -i 's/DOWNLOAD_ALL=on/DOWNLOAD_ALL=off/' /etc/slackpkg/slackpkg.conf

# We don't care about a big firmware package:
RUN mv /etc/slackpkg/blacklist{,.keep} && \\
  echo kernel-firmware > /etc/slackpkg/blacklist

# Install the full Slackware:
# All packages are installed in a single RUN layer to keep the image lean.
RUN export LC_ALL=C && \\
  for series in a ap d e f k kde l n t tcl x xap xfce y ; do \\
  slackpkg -delall=on -batch=on -default_answer=y install "\$series"/* ; done

# And back to defaults:
RUN sed -i 's/DOWNLOAD_ALL=off/DOWNLOAD_ALL=on/' /etc/slackpkg/slackpkg.conf
RUN mv /etc/slackpkg/blacklist{.keep,}


# Delete package cache:
RUN rm -rf /var/cache/packages/*

# Rebuild the linker cache after adding new libraries
RUN /sbin/ldconfig

LABEL org.opencontainers.image.created="$(date -u +%Y-%m-%dT%H:%M:%SZ)"
LABEL org.opencontainers.image.title="Slackware Linux ${VERSION} full (x86_64)"
LABEL org.opencontainers.image.description="Slackware Linux ${VERSION} full image with all packages installed (x86_64)"
LABEL org.opencontainers.image.vendor="Slackware Linux"
LABEL org.opencontainers.image.licenses="GPL-2.0-or-later AND LGPL-2.1-or-later"
LABEL org.opencontainers.image.url="http://www.slackware.com"
LABEL org.opencontainers.image.source="https://forge.slackware.nl/slackware/docker-images"
LABEL org.opencontainers.image.revision="${VERSION}"
LABEL slackware.version="${VERSION}"
LABEL slackware.arch="x86_64"
LABEL ${DIGEST_LABEL}="${BASE_DIGEST}"
CMD ["/bin/bash"]
DOCKERFILE

    local BUILD_FLAGS=()
    [[ "${FORCE}" == "true" ]] && BUILD_FLAGS+=(--no-cache)

    _log "  Building ${FULL_TAG}..."
    docker build "${BUILD_FLAGS[@]}" \
        -t "${FULL_TAG}" \
        "${WORKDIR}"

    _log "  Pushing ${FULL_TAG}..."
    docker push "${FULL_TAG}"

    _log "=== Done: ${FULL_TAG} ==="
}

# ============================================================================
# Main
# ============================================================================

for VERSION in "${BUILD_VARIANTS[@]}"; do
    build_variant "${VERSION}"
done