#!/bin/bash
#
#This script will initialise the required files and directories for automatic backup of Docker data.
#

helpFunction()
{
   echo ""
   echo "Usage: $0 -i INPUT -c CONFIG_DIR -l LOG_DIR"
   echo -e "\t-i Input folder to create a repository for."
   echo -e "\t-c Location of config directory where the repository, password and uuid files are stored."
   echo -e "\t-n Name of the Docker container. Required to stop the container and restart it before backing up."
   exit 1 # Exit script after printing help
}

while getopts "i:c:n:f" opt
do
   case "$opt" in
      i ) INPUT="$OPTARG" ;;
      c ) CONFIG_DIR="$OPTARG" ;;
      n ) CONTAINER_NAME="$OPTARG" ;;
      f ) FORCE=true ;;
      ? ) helpFunction ;; # Print helpFunction in case parameter is non-existent
   esac
done

# Verify that required parameters are present

set -a && source .env && set +a

REQUIRED_PARAMS=(
	INPUT
	CONFIG_DIR
	CONTAINER_NAME
	EXTERNAL_STORAGE_URL
	EXTERNAL_STORAGE_USER
	EXTERNAL_STORAGE_PORT
	EXTERNAL_STORAGE_ROOT_DIR
	INTERNAL_STORAGE_ROOT_DIR
)

for variable in "${REQUIRED_PARAMS[@]}" ; do
	if [ -z "${!variable+x}" ]; then
		echo "$variable is not set. Make sure your .env file is complete, and you have passed in all required flags.";
		exit;
	fi
done

echo $FORCE

# Parse the input to create the SERVICE variable (lower case)
SERVICE=${INPUT##*/}
SERVICE=${SERVICE,,}

# Set the location of the internal repo
INTERNAL_REPO_LOCATION=$INTERNAL_STORAGE_ROOT_DIR/$SERVICE


# Generate random password and UUID
PASSWORD=$(tr -dc 'A-Za-z0-9!?%=' < /dev/urandom | head -c 50)
UUID=$(uuidgen)

# Set filenames 
REPO_FILE_PATH="$CONFIG_DIR/${SERVICE}_repository"
PWD_FILE_PATH="$CONFIG_DIR/${SERVICE}_password"
UUID_FILE_PATH="$CONFIG_DIR/${SERVICE}_uuid"
CONTAINER_NAME_FILE_PATH="$CONFIG_DIR/${SERVICE}_container_name"


# Make the config directory if it does not already exist
if [ ! -d "$CONFIG_DIR" ]; then
	mkdir $CONFIG_DIR
fi

# Run the code only if the config files for the service does not already exist, or if force overwrite is specified
if [[ ! -f "$CONFIG_DIR/${SERVICE}_repository" ]] ||  [[ $FORCE == true ]]; then 
	# Prompt user if they are sure whether to force overwrite
	if [[ $FORCE == true ]]; then
		while true; do
			read -p "The config for ${INPUT} already exists, but you specified to force overwrite. This will also delete what is already in the restic repository and recreate an empty repo. Are you sure? [y/n] " yn
			case $yn in
				[Yy]* ) break;;
				[Nn]* ) echo "Exiting without overwriting..."; exit;;
				* ) echo "Please anser yes or no."
			esac
		done
	fi

	# Write the config files
	echo $INTERNAL_REPO_LOCATION > $REPO_FILE_PATH
	echo $PASSWORD > $PWD_FILE_PATH
	echo $UUID > $UUID_FILE_PATH
	echo $CONTAINER_NAME > $CONTAINER_NAME_FILE_PATH

	echo "Created required backup directories for $INPUT"
	echo "Password: $PASSWORD"
	echo "UUID: $UUID"
	echo "Make sure to note this down in your password manager to be able to decrypt the repositories, and to map the repositories on the external storage" 

	# Make the internal restic repository
	if [ -d "$INTERNAL_REPO_LOCATION" ]; then
		cp -r $INTERNAL_REPO_LOCATION ${INTERNAL_REPO_LOCATION}_old_$(date +%Y%m%d_%H%M%S)
		rm -r $INTERNAL_REPO_LOCATION
	fi

	restic init --repository-file $REPO_FILE_PATH -p $PWD_FILE_PATH
	
	

else
	echo "Repository config already exists for the service you specified. You can override this by passing the -f flag."

fi