#!/usr/bin/env bash

# usage
usage() {
USAGE=$(cat <<EOF
Usage: docker_compose_update [CONFIG_FILE (absolute path)]

If no CONFIG_FILE is given, HOME/.docker_compose_update.conf or /etc/docker_compose_update.conf is used. This fallback option
has to exist or the script will exit.

Configuration can be done in any file and any pre-defined variable can be overwritten.

The following are at least required for the script to work:
- DOCKER_COMPOSE_UPDATE_BASEDIR="/root/deployments" // where all docker stacks are located in their own sub-folders
- DOCKER_COMPOSE_UPDATE_IGNORES=("mailcow") // folder names which will be ignored and not be updated, at least () is required
- DOCKER_COMPOSE_UPDATE_COMMANDS[aDirectoryName]="./callFancyScriptInDirectory" // use another command to update, multiple possible. 
Example: accessor has to match the folder, e.g. <baseDir>/aDirectoryName will use command "./callFancyScriptInDirectory" when changing directory into it.
- DOCKER_COMPOSE_UPDATE_COMMAND="sudo docker-compose down; sudo docker-compose pull; sudo docker-compose up -d;" // the default update command for deployments
- DOCKER_COMPOSE_UPDATE_FAIL_ON_UPDATE_ERROR="false" // if set to true, script fails if at least one update procedure failed

You can copy this script to '/usr/local/bin' and use create a custom CONFIG_FILE as user. Examples can be found in '/usr/share/doc/<scriptname>'.
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;
  source "$config";
  set +a;
}

source_config() {
  local config=$1;
  local configFallback=$2;
  local configGlobalFallback=$3;

  if [[ -f "$config" ]]; then
    apply_config "$config";
    exit 0;
  fi

  if [[ -f "$configFallback" ]]; then
    apply_config "$configFallback";
    exit 0;
  fi

  if [[ -f "$configGlobalFallback" ]]; then
    apply_config "$configGlobalFallback";
    exit 0;
  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
}

# check requirements
CONFIG_FILE="$1";
FALLBACK_CONFIG_FILE="${HOME}/.docker_compose_update.conf";
FALLBACK_CONFIG_GLOBAL_FILE="/etc/docker_compose_update.conf";
source_config "${CONFIG_FILE}" "${FALLBACK_CONFIG_FILE}" "${FALLBACK_CONFIG_GLOBAL_FILE}";
apply_defaults;
check_required;

# DO NOT TOUCH BELOW
currentDir=$(pwd)
cd "${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
    	
    	res=$(eval "${updateCommand}")

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