#!/usr/bin/env bash

# usage
usage() {
USAGE=$(cat <<EOF
Usage: docker_compose_update

Utility to batch update docker-compose deployments residing in sub folders of a base directory. Please see man docker_compose_update.
EOF
)
	echo "$USAGE";
}

set -e;

declare -A DOCKER_COMPOSE_UPDATE_COMMANDS;

# check for config file
apply_config() {
  local config=$1;

  if [[ ! -f "$config" ]]; then
      echo "No config file specified";
      echo "";
      usage;
      exit 1;
  fi

  set -a;
  # shellcheck disable=SC1090
  source "$config";
  set +a;
}

source_config() {
  local configFallback=$1;
  local configGlobalFallback=$2;

  if [[ -f "$configFallback" ]]; then
    apply_config "$configFallback";
    return;
  fi

  if [[ -f "$configGlobalFallback" ]]; then
    apply_config "$configGlobalFallback";
    return;
  fi
}

apply_defaults() {
    [[ -z ${DOCKER_COMPOSE_UPDATE_IGNORES} ]] && DOCKER_COMPOSE_UPDATE_IGNORES=();
	[[ -z ${DOCKER_COMPOSE_UPDATE_COMMAND} ]] && DOCKER_COMPOSE_UPDATE_COMMAND="docker-compose down; docker-compose pull; docker-compose up -d;"
	[[ -z ${DOCKER_COMPOSE_UPDATE_FAIL_ON_UPDATE_ERROR} ]] && DOCKER_COMPOSE_UPDATE_FAIL_ON_UPDATE_ERROR="false";
}
check_required() {
    if [[ -z ${DOCKER_COMPOSE_UPDATE_BASEDIR} ]]; then
    	echo "DOCKER_COMPOSE_UPDATE_BASEDIR is required"
        exit 1;
    fi
    if [[ -z ${DOCKER_COMPOSE_UPDATE_COMMAND} ]]; then
    	echo "DOCKER_COMPOSE_UPDATE_COMMAND is required"
        exit 1;
    fi

	type docker-compose &> /dev/null || { echo "Requiring 'docker-compose' but it's not installed"; exit 1; }
}

# check requirements
FALLBACK_CONFIG_FILE="${HOME}/.docker_compose_update.conf";
FALLBACK_CONFIG_GLOBAL_FILE="/etc/docker_compose_update.conf";
source_config "${FALLBACK_CONFIG_FILE}" "${FALLBACK_CONFIG_GLOBAL_FILE}";
apply_defaults;
check_required;

# DO NOT TOUCH BELOW
currentDir=$(pwd)
echo "Current directory is '${currentDir}'"
cd "${DOCKER_COMPOSE_UPDATE_BASEDIR}";

for dir in *; do
    if [ -d "${dir}" ]; then
    	basename=$(basename "${dir}")

    	ignore=false;
    	for ignorePattern in "${DOCKER_COMPOSE_UPDATE_IGNORES[@]}"; do
    		if [[ "${basename}" == *"${ignorePattern}"* ]]; then
    			ignore=true;
			fi
		done

		if [[ "${ignore}" == "true" ]]; then
			echo "Ignoring '${basename}'";
			continue;
		fi

    	echo "Handling '${basename}'";

		updateCommand=""
    	for cmd in "${!DOCKER_COMPOSE_UPDATE_COMMANDS[@]}"; do
    		if [[ "${cmd}" == "${basename}" ]]; then
    			updateCommand="${DOCKER_COMPOSE_UPDATE_COMMANDS[$cmd]}";
			fi
    	done
        
        if [[ -n "${updateCommand}" ]]; then
        	echo "Using custom command '${updateCommand}'";
    	else
    		updateCommand="${DOCKER_COMPOSE_UPDATE_COMMAND}";
    		echo "Using command '${DOCKER_COMPOSE_UPDATE_COMMAND}'";
    	fi

    	cd "${basename}";

    	if [[ "${DOCKER_COMPOSE_UPDATE_FAIL_ON_UPDATE_ERROR}" == "false" ]]; then
    		set +e;
		fi
    	
		# shellcheck disable=SC2034
    	res=$(eval "${updateCommand}")

    	if [[ "${DOCKER_COMPOSE_UPDATE_FAIL_ON_UPDATE_ERROR}" == "false" ]]; then
    		set -e;
		fi
    	cd "../";
    	echo "";
    fi
done