#!/usr/bin/env bash

if [[ ! -f "/.dockerenv" ]]; then
	repo_root="$(git rev-parse --show-toplevel)";
else
	repo_root="/srv";
fi

lantern_path="${repo_root}/lantern-build-engine";

IMAGEBUILDER_REGISTRY="${IMAGEBUILDER_REGISTRY:-registry.service.mooncarrot.space:5000}";
export IMAGEBUILDER_REGISTRY;

###############################################################################

#shellcheck disable=SC1090
source "${lantern_path}/lantern.sh";

if [[ -z "${BASE_PATH}" ]]; then
	subtask_begin "BASE_PATH environment variable not found - setting base path to ${HC}${repo_root}/images${RS}";
	BASE_PATH="${repo_root}/images";
	subtask_end "$?";
fi
if [[ ! -d "${BASE_PATH}" ]]; then
	echo "Error: The specified base path '${BASE_PATH}' doesn't exist.";
	exit 1;
fi

# Make sure the current directory is the location of this script to simplify matters
cd "$(dirname "$(readlink -f "$0")")" || { echo "Error: Failed to cd"; exit 1; };

# Check out the lantern git submodule if needed
if [ ! -f "${lantern_path}/lantern.sh" ]; then git submodule update --init "${lantern_path}"; fi

# Create temporary directory
temp_dir="$(mktemp --tmpdir -d "imagebuilder-XXXXXXX")";
on_exit() {
	task_begin "Cleaning up temporary directory";
	rm -rf "${temp_dir}";
	task_end "$?";
}
trap on_exit EXIT;


###############################################################################

subcommand="${1}";
shift;

if [[ -z "${subcommand}" ]]; then
	CHEADING="${HC}${FCYN}";
	CACTION="${FYEL}";#
	CARG="${FMAG}"
	echo -e "${HC}imagebuilder: Docker image (re)builder${RS}" >&2;
	echo -e "	By Starbeamrainbowlabs" >&2;
	echo -e "" >&2;
	echo -e "${CHEADING}Usage:${RS}" >&2;
	echo -e "	${HC}${FGRN}./imagebuilder.sh${RS} ${CACTION}{action}${RS} ${LC}[${RS}${CARG}{arguments}${RS}${LC}]${RS}" >&2;
	echo -e "" >&2;
	echo -e "${CHEADING}Actions:${RS}" >&2;
	echo -e "	${CACTION}build${RS} ${CARG}{imagename}${RS} [${CARG}{imagetag}${RS}]" >&2;
	echo -e "		Build the given image and upload it to the docker registry, optionally assigning a custom tag name" >&2;
	echo -e "	${CACTION}list${RS}" >&2;
	echo -e "		List available images" >&2;
	echo -e "" >&2;
	echo -e "${CHEADING}Environment Variables:${RS}" >&2;
	echo -e "	${CACTION}IMAGEBUILDER_REGISTRY${RS}" >&2;
	echo -e "		Set the url of the Docker registry (default: ${HC}registry.service.mooncarrot.space:5000${RS})" >&2;
	echo -e "	${CACTION}BASE_PATH${RS}" >&2;
	echo -e "		Base path in which to look for image directories (defaults to the current working directory)" >&2;
	echo -e "" >&2;
	exit 0;
fi

###############################################################################

case "${subcommand}" in
	# ██      ██ ███████ ████████
	# ██      ██ ██         ██
	# ██      ██ ███████    ██
	# ██      ██      ██    ██
	# ███████ ██ ███████    ██
	list)
		while read -r filepath; do
			filepath_stripped="${filepath#"${BASE_PATH}"}";
			if [[ -z "${filepath_stripped}" ]] || [[ ! -f "${filepath}/type.txt" ]]; then
				continue;
			fi
			
			echo "${filepath_stripped}";
		done < <(find "${BASE_PATH}" -maxdepth 1 -type d);
		;;
	
	
	# ██████  ██    ██ ██ ██      ██████
	# ██   ██ ██    ██ ██ ██      ██   ██
	# ██████  ██    ██ ██ ██      ██   ██
	# ██   ██ ██    ██ ██ ██      ██   ██
	# ██████   ██████  ██ ███████ ██████
	build)
		imagename="${1}";
		imagetag="${2}";
		
		if [[ -z "${imagename}" ]]; then
			echo "Error: No image name specified.":
			exit 1;
		fi
		
		imagedir="${BASE_PATH}/${imagename}";
		
		if [[ ! -d "${imagedir}" ]]; then
			echo -e "Error: An image with the name ${HC}${imagename}${RS} doesn't exist.";
			exit 2;
		fi
		
		if [[ ! -f "${imagedir}/type.txt" ]]; then
			echo -e "Error: No type.txt file was found for the image with the name ${HC}${imagename}${RS}.";
			exit 3;
		fi
		
		# Determine the fully qualified tag that we're going to push to
		docker_tag="${IMAGEBUILDER_REGISTRY}/${imagename}";
		if [[ ! -z "${imagetag}" ]]; then
			docker_tag="${docker_tag}:${imagetag}";
		fi
		
		echo -e "[${HOSTNAME}:imagebuilder] Fully qualified tag name: ${HC}${FGRN}${docker_tag}${RS}";
		
		imagetype="$(tr -d "[:blank:]" <"${imagedir}/type.txt")";
		
		case "${imagetype}" in
			# ██████   ██████   ██████ ██   ██ ███████ ██████
			# ██   ██ ██    ██ ██      ██  ██  ██      ██   ██
			# ██   ██ ██    ██ ██      █████   █████   ██████
			# ██   ██ ██    ██ ██      ██  ██  ██      ██   ██
			# ██████   ██████   ██████ ██   ██ ███████ ██   ██
			docker)
				if [[ ! -f "${imagedir}/Dockerfile" ]]; then
					echo -e "Error: Failed to find a Dockerfile at ${HC}${imagedir}/Dockerfile${RS}.";
					exit 7;
				fi
				
				cd "${imagedir}" || { echo -e "Error: Failed to cd into ${HC}${imagedir}${RS}"; exit 1; };
				
				if [[ -x "./pre.sh" ]]; then
					task_begin "Executing pre-build hook";
					execute ./pre.sh;
					task_end "$?";
				fi
				
				task_begin "Building docker image";
				echo "Tag: ${docker_tag}";
				execute docker build --no-cache --pull --tag "${docker_tag}" --build-arg "REPO_LOCATION=${IMAGEBUILDER_REGISTRY}/" .;
				task_end "$?";
				
				task_begin "Pushing resulting docker image";
				execute docker push "${docker_tag}";
				task_end "$?";
				
				if [[ -x "./post.sh" ]]; then
					task_begin "Executing post-build hook";
					execute ./post.sh;
					task_end "$?";
				fi
				;;
			
			
			# ██████   █████  ███████ ███████
			# ██   ██ ██   ██ ██      ██
			# ██████  ███████ ███████ █████
			# ██   ██ ██   ██      ██ ██
			# ██████  ██   ██ ███████ ███████
			base|base-nopush)
				builderscript="${imagedir}/${imagename}.sh";
				if [[ ! -x "${builderscript}" ]]; then
					echo -e "Error: Failed to find the base image builder script at ${HC}${builderscript}${RS} (is it executable?).";
					exit 5;
				fi
				
				output_dir="${temp_dir}/${imagename}";
				mkdir -p "${output_dir}";
				
				task_begin "Building base image";
				if [[ "${UID}" -ne 0 ]] && which fakeroot && which fakechroot; then
					echo "Non-root user detected - using fakeroot & fakechroot";
					execute fakechroot fakeroot "${builderscript}" "${output_dir}";
				else
					echo "root user or fakeroot & fakechroot not detected";
					execute "${builderscript}" "${output_dir}";
				fi
				task_end "$?";
				
				if [[ "${imagetype}" == "base-nopush" ]]; then
					echo -e "${HC}Nopush mode invoked, not checking output directory or pushing to docker registry${RS}";
					exit 0;
				fi
				
				if [[ ! -d "${output_dir}" ]]; then
					echo -e "${FRED}${HC}Error: The builder script failed to create the output directory (expecting directory at ${FBLE}${output_dir}${FRED}, but found nothing).${RS}";
					exit 6;
				fi
				
				task_begin "Importing resulting image into Docker";
				image_filepath="$(find "${output_dir}" -iname "*.tar.gz" -printf '%p' -quit)";
				docker_tag_local="$(docker import - <"${image_filepath}")";
				task_end "$?";
				
				task_begin "Tagging and pushing to registry";
				execute docker tag "${docker_tag_local}" "${docker_tag}";
				execute docker push "${docker_tag}";
				task_end "$?";
				;;
			
			import)
				task_begin "Finding remote image name";
				if [[ ! -r "${imagedir}/imagename.txt" ]]; then
					echo "Error: 'import' image type specified, but no imagename.txt file was found containing the (fully qualified) image name to pull from.";
					exit 8;
				fi
				
				imagename_remote="$(tr -d "[:blank:]" <"${imagedir}/imagename.txt")"
				
				if [[ -z "${imagename_remote}" ]]; then
					echo "Error: An empty image name to pull isn't valid.";
					exit 7;
				fi
				
				echo -e "[${HOSTNAME}:imagebuilder] Remote image name is ${FGRN}${HC}${imagename_remote}${RS}";
				task_end "$?";
				
				task_begin "Downloading image";
				execute docker pull "${imagename_remote}";
				task_end "$?" "Error: Failed to download image";
				
				task_begin "Retagging image";
				execute docker tag "${imagename_remote}" "${docker_tag}";
				task_end "$?";
				
				task_begin "Pushing image";
				execute docker push "${docker_tag}";
				task_end "$?";
				
				;;
			
			
			# ██    ██ ███    ██ ██   ██ ███    ██  ██████  ██     ██ ███    ██
			# ██    ██ ████   ██ ██  ██  ████   ██ ██    ██ ██     ██ ████   ██
			# ██    ██ ██ ██  ██ █████   ██ ██  ██ ██    ██ ██  █  ██ ██ ██  ██
			# ██    ██ ██  ██ ██ ██  ██  ██  ██ ██ ██    ██ ██ ███ ██ ██  ██ ██
			#  ██████  ██   ████ ██   ██ ██   ████  ██████   ███ ███  ██   ████
			*)
				echo -e "Error: The image type ${HC}${imagetype}${RS} was not recognised. Currently recognised types: base, base-nopush, docker";
				exit 4;
				;;
			esac
		;;
	
	*)
		echo -e "Unknown subcommand '${HC}${subcommand}${RS}' (try calling imagebuilder.sh without any arguments)";
		;;
esac