#!/usr/bin/env sh

set -u

usage() {
  cat <<EOF
Usage: $0 [options]

Environment-backed options (CLI flags are optional):
  --owner VALUE            (default: \$IMAGE_LABEL_OWNER)
  --repository VALUE       (default: \$IMAGE_LABEL_REPO)
  --slug VALUE             (default: catthehacker/ubuntu)
  --tags TAG [TAG ...]     Multiple destination tags
  --tag TAG                Single destination tag
  --node VALUE             (default: \$NODE)
  --distro VALUE           (default: ubuntu)
  --type VALUE             (default: \$TYPE)
  --runner VALUE           (default: \$RUNNER)
  --platforms CSV          (default: \$PLATFORMS, comma-separated)
  --build-tag VALUE        (default: \$BUILD_TAG)
  --build-tag-version VAL  (default: \$BUILD_TAG_VERSION)
  --build-ref VALUE        (default: \$BUILD_REF)
  --from-image VALUE       (default: \$FROM_IMAGE)
  --from-tag VALUE         (default: \$FROM_TAG)
  --push                   Push manifest to remote registries
  -h, --help               Show this help and exit
EOF
}

# Defaults from environment (mirrors build.ps1 parameter defaults), with safe fallbacks
owner=${IMAGE_LABEL_OWNER:-actions}
repository=${IMAGE_LABEL_REPO:-ubuntu}
tags=""
tag=""
node=${NODE:-"20 24"}
distro='ubuntu'
type=${TYPE:-act}
runner=${RUNNER:-root}
platforms=${PLATFORMS:-linux/amd64,linux/arm64}
build_tag=${BUILD_TAG:-act-24.04}
build_tag_version=${BUILD_TAG_VERSION:-dev}
build_ref=${BUILD_REF:-local}
from_image=${FROM_IMAGE:-buildpack-deps}
from_tag=${FROM_TAG:-24.04}
push=false

# Argument parsing (simple long options, designed to be close to build.ps1 semantics)
while [ "$#" -gt 0 ]; do
  case "$1" in
    --owner)
      owner=$2
      shift 2
      ;;
    --repository)
      repository=$2
      shift 2
      ;;
    --tags)
      shift
      # Collect all following non-option arguments as tags
      while [ "$#" -gt 0 ] && [ "${1#-}" = "$1" ]; do
        if [ -z "$tags" ]; then
          tags=$1
        else
          tags="$tags $1"
        fi
        shift
      done
      ;;
    --tag)
      tag=$2
      shift 2
      ;;
    --node)
      node=$2
      shift 2
      ;;
    --distro)
      distro=$2
      shift 2
      ;;
    --type)
      type=$2
      shift 2
      ;;
    --runner)
      runner=$2
      shift 2
      ;;
    --platforms)
      platforms=$2
      shift 2
      ;;
    --build-tag)
      build_tag=$2
      shift 2
      ;;
    --build-tag-version)
      build_tag_version=$2
      shift 2
      ;;
    --build-ref)
      build_ref=$2
      shift 2
      ;;
    --from-image)
      from_image=$2
      shift 2
      ;;
    --from-tag)
      from_tag=$2
      shift 2
      ;;
    --push)
      push=true
      shift
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      printf 'Unknown argument: %s\n' "$1" >&2
      usage
      exit 1
      ;;
  esac
done

# Helper to run a command and fail with a useful message (equivalent to exec in build.ps1)
exec_cmd() {
  if ! "$@"; then
    status=$?
    printf '%s failed with exit code %s\n' "$*" "$status" >&2
    exit "$status"
  fi
}

if [ -z "$platforms" ]; then
  printf 'Error: PLATFORMS is empty. Set PLATFORMS or pass --platforms.\n' >&2
  exit 1
fi

if [ -z "$from_image" ] || [ -z "$from_tag" ]; then
  printf 'Error: FROM_IMAGE/FROM_TAG are empty. Set env vars or pass --from-image/--from-tag.\n' >&2
  exit 1
fi

if [ "$push" = true ]; then
  # Combine tags and tag (if provided)
  all_tags=$tags
  if [ -n "$tag" ]; then
    if [ -z "$all_tags" ]; then
      all_tags=$tag
    else
      all_tags="$all_tags $tag"
    fi
  fi
else
  # Even when not pushing, honor --tag so the local image is named.
  all_tags=$tags
  if [ -n "$tag" ]; then
    if [ -z "$all_tags" ]; then
      all_tags=$tag
    else
      all_tags="$all_tags $tag"
    fi
  fi
fi

# Buildx expects comma-separated --platform list; reuse platforms as-is.

tag_args=""
for t in $all_tags; do
  tag_args="$tag_args -t $t"
done

build_date=$(date -u +"%Y-%m-%d %H:%M:%SZ")

# Build argument vector to preserve spacing/quoting (e.g. NODE_VERSION="20 24")
set -- docker buildx build \
  --ulimit "nofile=4096:4096" \
  --platform "$platforms" \
  --build-arg "TARGETARCH=\$TARGETARCH" \
  --build-arg "NODE_VERSION=$node" \
  --build-arg "DISTRO=$distro" \
  --build-arg "TYPE=$type" \
  --build-arg "RUNNER=$runner" \
  --build-arg "BUILD_DATE=$build_date" \
  --build-arg "BUILD_OWNER=$owner" \
  --build-arg "BUILD_OWNER_MAIL=$owner" \
  --build-arg "BUILD_REPO=$repository" \
  --build-arg "BUILD_TAG=$build_tag" \
  --build-arg "BUILD_TAG_VERSION=$build_tag_version" \
  --build-arg "BUILD_REF=$build_ref" \
  --build-arg "FROM_IMAGE=$from_image" \
  --build-arg "FROM_TAG=$from_tag" \
  --file "./Dockerfile"

# Append tag flags
# shellcheck disable=SC2086
set -- "$@" $tag_args

# Append push/load and final PATH argument
if [ "$push" = true ]; then
  set -- "$@" --push .
else
  set -- "$@" --load .
fi

exec_cmd "$@"