#!/bin/bash

# Wrapper for various setup scripts
# included in the docker-mailserver

set -euEo pipefail
trap '_report_err $_ $LINENO $?' ERR

function _report_err()
{
  echo "ERROR occured :: source (hint) $1 ; line $2 ; exit code $3 ;;" >&2
  _unset_vars
}

function _unset_vars()
{
  unset CDIR CRI INFO IMAGE_NAME CONTAINER_NAME DEFAULT_CONFIG_PATH
  unset USE_CONTAINER WISHED_CONFIG_PATH CONFIG_PATH VOLUME USE_TTY
}

CDIR="$(cd "$(dirname "$(readlink -f "$0")")" && pwd)"
CRI=
INFO=
IMAGE_NAME=
CONTAINER_NAME='mail'
DEFAULT_CONFIG_PATH="$CDIR/config"
USE_CONTAINER=false
WISHED_CONFIG_PATH=
CONFIG_PATH=
VOLUME=
USE_TTY=

function _check_root()
{
  if [[ $EUID -ne 0 ]]
  then
    echo "Curently docker-mailserver doesn't support podman's rootless mode, please run this script as root user."
    return 1
  fi
}

function _update_config_path()
{
  if [[ -n $CONTAINER_NAME ]]
  then
    VOLUME=$(docker inspect "$CONTAINER_NAME" \
      --format="{{range .Mounts}}{{ println .Source .Destination}}{{end}}" | \
      grep "/tmp/docker-mailserver$" 2>/dev/null)
  fi

  if [[ -n $VOLUME ]]
  then
    CONFIG_PATH=$(echo "$VOLUME" | awk '{print $1}')
  fi
}

function _inspect()
{
  if _docker_image_exists "$IMAGE_NAME"
  then
    echo "Image: $IMAGE_NAME"
  else
    echo "Image: '$IMAGE_NAME' can’t be found."
  fi

  if [[ -n $CONTAINER_NAME ]]
  then
    echo "Container: $CONTAINER_NAME"
    echo "Config mount: $CONFIG_PATH"
  else
    echo "Container: Not running, please start docker-mailserver."
  fi
}

function _usage()
{
  echo "Usage: $0 [-i IMAGE_NAME] [-c CONTAINER_NAME] <subcommand> <subcommand> [args]

OPTIONS:

  -i IMAGE_NAME     The name of the docker-mailserver image, by default
                    'tvial/docker-mailserver:latest' for docker, and
                    'docker.io/tvial/docker-mailserver:latest' for podman.

  -c CONTAINER_NAME The name of the running container.

  -p PATH           config folder path (default: $(pwd)/config)

SUBCOMMANDS:

  email:

    $0 email add <email> [<password>]
    $0 email update <email> [<password>]
    $0 email del <email>
    $0 email restrict <add|del|list> <send|receive> [<email>]
    $0 email list

  alias:
    $0 alias add <email> <recipient>
    $0 alias del <email> <recipient>
    $0 alias list

  quota:
    $0 quota set <email> [<quota>]
    $0 quota del <email>

  config:

    $0 config dkim <keysize> (default: 2048)
    $0 config ssl <fqdn>

  relay:

    $0 relay add-domain <domain> <host> [<port>]
    $0 relay add-auth <domain> <username> [<password>]
    $0 relay exclude-domain <domain>

  debug:

    $0 debug fetchmail
    $0 debug fail2ban [<unban> <ip-address>]
    $0 debug show-mail-logs
    $0 debug inspect
    $0 debug login <commands>
"

  return 1
}

function _docker_image_exists()
{
  if $CRI history -q "$1" >/dev/null 2>&1
  then
    return 0
  else
    return 1
  fi
}

function _docker_image()
{
  if $USE_CONTAINER
  then
    # reuse existing container specified on command line
    $CRI exec "$USE_TTY" "$CONTAINER_NAME" "$@"
  else
    # start temporary container with specified image
    if ! _docker_image_exists "$IMAGE_NAME"
    then
      echo "Image '$IMAGE_NAME' not found. Pulling ..."
      $CRI pull "$IMAGE_NAME"
    fi

    ${CRI} run --rm \
      -v "$CONFIG_PATH":/tmp/docker-mailserver \
      "$USE_TTY" "$IMAGE_NAME" "$@"
  fi
}

function _docker_container()
{
  if [[ -n $CONTAINER_NAME ]]
  then
    $CRI exec "$USE_TTY" "$CONTAINER_NAME" "$@"
  else
    echo "The docker-mailserver is not running!"
    exit 1
  fi
}

function _main()
{
  if [[ -n $(command -v docker) ]]
  then
    CRI=docker
  elif [[ -n $(command -v podman) ]]
  then
    CRI=podman
    _check_root
  else
    echo "No supported Container Runtime Interface detected."
    exit 10
  fi

  INFO=$($CRI ps \
    --no-trunc \
    --format "{{.Image}};{{.Names}}" \
    --filter label=org.label-schema.name="docker-mailserver" | \
    tail -1)

  IMAGE_NAME=${INFO%;*}
  CONTAINER_NAME=${INFO#*;}

  if [[ -z $IMAGE_NAME ]]
  then
    if [[ $CRI == "docker" ]]
    then
      IMAGE_NAME=tvial/docker-mailserver:latest
    elif [[ $CRI == "podman" ]]
    then
      IMAGE_NAME=docker.io/tvial/docker-mailserver:latest
    fi
  fi

  if tty -s
  then
    USE_TTY="-ti"
  fi

  local OPTIND
  while getopts ":c:i:p:" OPT
  do
    case $OPT in
      c) CONTAINER_NAME="$OPTARG" ; USE_CONTAINER=true ;; # container specified, connect to running instance
      i) IMAGE_NAME="$OPTARG" ;;
      p)
        case "$OPTARG" in
          /*) WISHED_CONFIG_PATH="$OPTARG" ;;
          * ) WISHED_CONFIG_PATH="$CDIR/$OPTARG" ;;
        esac

        if [[ ! -d $WISHED_CONFIG_PATH ]]
        then
          echo "Directory doesn't exist"
          _usage
          exit 1
        fi
        ;;
     *) echo "Invalid option: -$OPTARG" >&2 ;;
    esac
  done
  shift $((OPTIND-1))

  if [[ -z $WISHED_CONFIG_PATH ]]
  then
    # no wished config path
    _update_config_path

    if [[ -z $CONFIG_PATH ]]
    then
      CONFIG_PATH=$DEFAULT_CONFIG_PATH
    fi
  else
    CONFIG_PATH=$WISHED_CONFIG_PATH
  fi


  case ${1:-} in

    email)
      shift ; case ${1:-} in
        add      ) shift ; _docker_image addmailuser "$@" ;;
        update   ) shift ; _docker_image updatemailuser "$@" ;;
        del      ) shift ; _docker_image delmailuser "$@" ;;
        restrict ) shift ; _docker_container restrict-access "$@" ;;
        list     ) _docker_image listmailuser ;;
        *        ) _usage ;;
      esac
      ;;

    alias)
      shift ; case ${1:-} in
        add      ) shift ; _docker_image addalias "$@" ;;
        del      ) shift ; _docker_image delalias "$@" ;;
        list     ) shift ; _docker_image listalias "$@" ;;
        *        ) _usage ;;
      esac
      ;;

    quota)
      shift ; case ${1:-} in
        set      ) shift ; _docker_image setquota "$@" ;;
        del      ) shift ; _docker_image delquota "$@" ;;
        *        )   _usage ;;
      esac
      ;;

    config)
      shift ; case ${1:-} in
        dkim     ) _docker_image generate-dkim-config "${2:-2048}" ;;
        ssl      ) _docker_image generate-ssl-certificate "$2" ;;
        *        ) _usage ;;
      esac
      ;;

    relay)
      shift ; case ${1:-} in
        add-domain     ) shift ; _docker_image addrelayhost "$@" ;;
        add-auth       ) shift ; _docker_image addsaslpassword "$@" ;;
        exclude-domain ) shift ; _docker_image excluderelaydomain "$@" ;;
        *              ) _usage ;;
      esac
      ;;

    debug)
      shift ; case ${1:-} in
        fetchmail      ) _docker_image debug-fetchmail ;;
        fail2ban       ) shift ; _docker_container fail2ban "$@" ;;
        show-mail-logs ) _docker_container cat /var/log/mail/mail.log ;;
        inspect        ) _inspect ;;
        login          )
          shift
          if [[ -z ${1:-''} ]]
          then
            _docker_container /bin/bash
          else
            _docker_container /bin/bash -c "$@"
          fi
          ;;
        *        ) _usage ;;
      esac
      ;;

    *            ) _usage ;;
  esac
}

_main "$@"
_unset_vars