#!/bin/bash

set -eu

# cd to location of script
cd "$(dirname "$(realpath "$0")")"

# Builds the docker images.
# Usage: ./build {COMPONENTS}, or just ./build to build all.
# The resulting images are named wubloader-COMPONENT.
# Pass PUSH=true to also push the resulting images, or PUSH=latest to push them as :latest tag

# The different images we can build
COMPONENTS=(downloader restreamer backfiller thrimshim cutter sheetsync nginx postgres segment_coverage playlist_manager)

# Define push if not already defined
PUSH=${PUSH:-}

# Base is the repository namespace information, not including the wubloader-component part.
BASE="ghcr.io/ekimekim"

# The docker image tag, derived from the git commit + whether working tree is clean
TAG=$(./get-build-tag)

if [ "$#" -gt 0 ]; then
	COMPONENTS=("$@")
fi

# If CACHE_FROM is set, explicitly pull and re-use specified image versions
CACHE_IMAGES=()
CACHE_ARGS=()
if [ -n "${CACHE_FROM:-}" ]; then
	# Note lack of quotes here - we want to word split
	for commit in $CACHE_FROM; do
		tag=$(git rev-parse --short "$commit")
		for component in "${COMPONENTS[@]}"; do
			CACHE_IMAGES+=("$BASE/wubloader-$component:$tag")
			CACHE_ARGS+=("--cache-from" "$BASE/wubloader-$component:$tag")
		done
	done
	echo "Trying to pull images for commits $CACHE_FROM if they exist, to re-use layers if possible"
	for image in "${CACHE_IMAGES[@]}"; do
		echo "Pulling $image"
		docker pull "$image" || true # don't exit on failure
	done
fi

for component in "${COMPONENTS[@]}"; do
	echo "Building image for $component"
	latest="$BASE/wubloader-$component:latest"
	specific="$BASE/wubloader-$component:$TAG"
	docker build \
		-f "$component/Dockerfile" \
		-t "$latest" \
		-t "$specific" \
		"${CACHE_ARGS[@]}" \
		.
	echo "Built image wubloader-$component:$TAG"
	if [ -n "$PUSH" ]; then
		echo "Pushing tag $specific"
		docker push "$specific"
	fi
	if [ "$PUSH" == "latest" ]; then
		echo "Pushing tag $latest"
		docker push "$latest"
	fi
done