#!/usr/bin/env bash
set -euo pipefail
export LC_ALL=C

root=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
cd "$root"

if [[ -n $(git status --porcelain --untracked-files=normal) ]]; then
  echo "refusing production build from a dirty worktree" >&2
  exit 1
fi

version=${GOCHAT_VERSION:-$(node -p "require('./package.json').version")}
[[ $version =~ ^[A-Za-z0-9][A-Za-z0-9._-]*$ ]] || {
  echo "invalid GOCHAT_VERSION: $version" >&2
  exit 1
}

commit=$(git rev-parse --short=12 HEAD)
build_date=$(git show -s --format=%cI HEAD)
source_date_epoch=$(git show -s --format=%ct HEAD)
tag="$version-$commit"
gochat_image="gochat/gochat:$tag"
connector_image="gochat/shangwutong:$tag"
output_dir=$(realpath -m "${GOCHAT_DIST_DIR:-$root/dist}")
[[ $output_dir != / && $output_dir != "$root" ]] || {
  echo "invalid GOCHAT_DIST_DIR: $output_dir" >&2
  exit 1
}
mkdir -p "$(dirname "$output_dir")"

stage=$(mktemp -d "$(dirname "$output_dir")/.gochat-dist.XXXXXX")
builder="gochat-dist-$$-$RANDOM"
buildkit_image='moby/buildkit:v0.13.2@sha256:9194b5ec1be368f41c516df7f93f7f540630ea06136056b2ffebb62226ed4ad6'
cleanup() {
  [[ -z $builder ]] || docker buildx rm "$builder" >/dev/null 2>&1 || true
  rm -rf "$stage"
}
trap cleanup EXIT HUP INT TERM

docker buildx create --name "$builder" --driver docker-container \
  --driver-opt "image=$buildkit_image" >/dev/null
build_args=(
  --build-arg "VERSION=$version"
  --build-arg "COMMIT_SHA=$commit"
  --build-arg "BUILD_DATE=$build_date"
  --build-arg "SOURCE_DATE_EPOCH=$source_date_epoch"
)
build_image() {
  local dockerfile=$1 image=$2 output=$3
  docker buildx build --builder "$builder" --platform linux/amd64 \
    "${build_args[@]}" --tag "$image" --file "$dockerfile" \
    --output "type=docker,rewrite-timestamp=true,dest=$output" .
  docker load --input "$output"
}

build_image deploy/docker/Dockerfile "$gochat_image" "$stage/gochat.image.tar"
build_image channels/shangwutong/Dockerfile "$connector_image" "$stage/shangwutong.image.tar"
docker image inspect "$gochat_image" "$connector_image" >/dev/null
docker buildx rm "$builder" >/dev/null
builder=
rm "$stage/gochat.image.tar" "$stage/shangwutong.image.tar"

archive="images/gochat-$tag-images.tgz"
mkdir -p "$stage/images"
docker save --output "$stage/images.tar" "$gochat_image" "$connector_image"
mkdir "$stage/.image-archive"
tar -xf "$stage/images.tar" -C "$stage/.image-archive"
mapfile -t image_archive_entries < <(find "$stage/.image-archive" -mindepth 1 -maxdepth 1 -printf '%f\n' | sort)
tar --sort=name --mtime=@0 --owner=0 --group=0 --numeric-owner \
  -cf "$stage/images.normalized.tar" -C "$stage/.image-archive" "${image_archive_entries[@]}"
rm -rf "$stage/.image-archive" "$stage/images.tar"
mv "$stage/images.normalized.tar" "$stage/images.tar"
gzip -n "$stage/images.tar"
mv "$stage/images.tar.gz" "$stage/$archive"

files=(
  deploy/docker/docker-compose.prod.yml
  deploy/docker/docker-compose.prod-smoke.yml
  deploy/docker/database_client_entrypoint.sh
  deploy/docker/database_host_rejection_cases.txt
  deploy/docker/preflight.sh
  deploy/docker/deploy.sh
  deploy/fluentd/fluent.conf
  deploy/prometheus/alertmanager.yml
  deploy/prometheus/blackbox.yml
  deploy/prometheus/postgres_queries.yml
  deploy/prometheus/prometheus.yml
  backend/configs/prometheus_alerts.yml
  docs/ops/01-rolling-upgrade.md
  docs/ops/02-production-operations.md
)
for file in "${files[@]}"; do
  mkdir -p "$stage/$(dirname "$file")"
  cp "$file" "$stage/$file"
done

sed \
  -e "s|^GOCHAT_IMAGE_REF=.*|GOCHAT_IMAGE_REF=$gochat_image|" \
  -e "s|^SHANGWUTONG_IMAGE_REF=.*|SHANGWUTONG_IMAGE_REF=$connector_image|" \
  .env.example >"$stage/.env.example"
cp deploy/docker/README.dist.md "$stage/README.md"
printf 'SOURCE_COMMIT=%s\nGOCHAT_IMAGE_REF=%s\nSHANGWUTONG_IMAGE_REF=%s\n' \
  "$(git rev-parse HEAD)" "$gochat_image" "$connector_image" >"$stage/MANIFEST"
(cd "$stage" && find . -type f ! -name SHA256SUMS -print | sort | xargs sha256sum >SHA256SUMS)

rm -rf "$output_dir"
mv "$stage" "$output_dir"
trap - EXIT HUP INT TERM
echo "Production bundle: $output_dir"