#!/usr/bin/env sh

# Name: dns_miab.sh
#
# Authors:
#    Darven Dissek 2018
#    William Gertz 2019
#
#     Thanks to Neil Pang and other developers here for code reused from acme.sh from DNS-01
#     used to communicate with the MailinaBox Custom DNS API
# Report Bugs here:
#    https://github.com/billgertz/MIAB_dns_api (for dns_miab.sh)
#    https://github.com/acmesh-official/acme.sh       (for acme.sh)
#
########  Public functions #####################

#Usage: dns_miab_add  _acme-challenge.www.domain.com  "XKrxpRBosdIKFzxW_CT3KLZNf6q0HG9i01zxXp5CPBs"
dns_miab_add() {
  fulldomain=$1
  txtvalue=$2
  _info "Using miab challange add"
  _debug fulldomain "$fulldomain"
  _debug txtvalue "$txtvalue"

  #retrieve MIAB environemt vars
  if ! _retrieve_miab_env; then
    return 1
  fi

  #check domain and seperate into doamin and host
  if ! _get_root "$fulldomain"; then
    _err "Cannot find any part of ${fulldomain} is hosted on ${MIAB_Server}"
    return 1
  fi

  _debug2 _sub_domain "$_sub_domain"
  _debug2 _domain "$_domain"

  #add the challenge record
  _api_path="custom/${fulldomain}/txt"
  _miab_rest "$txtvalue" "$_api_path" "POST"

  #check if result was good
  if _contains "$response" "updated DNS"; then
    _info "Successfully created the txt record"
    return 0
  else
    _err "Error encountered during record add"
    _err "$response"
    return 1
  fi
}

#Usage: dns_miab_rm  _acme-challenge.www.domain.com   "XKrxpRBosdIKFzxW_CT3KLZNf6q0HG9i01zxXp5CPBs"
dns_miab_rm() {
  fulldomain=$1
  txtvalue=$2

  _info "Using miab challage delete"
  _debug fulldomain "$fulldomain"
  _debug txtvalue "$txtvalue"

  #retrieve MIAB environemt vars
  if ! _retrieve_miab_env; then
    return 1
  fi

  #check domain and seperate into doamin and host
  if ! _get_root "$fulldomain"; then
    _err "Cannot find any part of ${fulldomain} is hosted on ${MIAB_Server}"
    return 1
  fi

  _debug2 _sub_domain "$_sub_domain"
  _debug2 _domain "$_domain"

  #Remove the challenge record
  _api_path="custom/${fulldomain}/txt"
  _miab_rest "$txtvalue" "$_api_path" "DELETE"

  #check if result was good
  if _contains "$response" "updated DNS"; then
    _info "Successfully removed the txt record"
    return 0
  else
    _err "Error encountered during record remove"
    _err "$response"
    return 1
  fi
}

####################  Private functions below ##################################
#
#Usage: _get_root  _acme-challenge.www.domain.com
#Returns:
# _sub_domain=_acme-challenge.www
# _domain=domain.com
_get_root() {
  _passed_domain=$1
  _debug _passed_domain "$_passed_domain"
  _i=2
  _p=1

  #get the zones hosed on MIAB server, must be a json stream
  _miab_rest "" "zones" "GET"

  if ! _is_json "$response"; then
    _err "ERROR fetching domain list"
    _err "$response"
    return 1
  fi

  #cycle through the passed domain seperating out a test domain discarding
  #   the subdomain by marching thorugh the dots
  while true; do
    _test_domain=$(printf "%s" "$_passed_domain" | cut -d . -f ${_i}-100)
    _debug _test_domain "$_test_domain"

    if [ -z "$_test_domain" ]; then
      return 1
    fi

    #report found if the test domain is in the json response and
    #   report the subdomain
    if _contains "$response" "\"$_test_domain\""; then
      _sub_domain=$(printf "%s" "$_passed_domain" | cut -d . -f 1-${_p})
      _domain=${_test_domain}
      return 0
    fi

    #cycle to the next dot in the passed domain
    _p=${_i}
    _i=$(_math "$_i" + 1)
  done

  return 1
}

#Usage: _retrieve_miab_env
#Returns (from store or environment variables):
# MIAB_Username
# MIAB_Password
# MIAB_Server
#retrieve MIAB environment variables, report errors and quit if problems
_retrieve_miab_env() {
  MIAB_Username="${MIAB_Username:-$(_readaccountconf_mutable MIAB_Username)}"
  MIAB_Password="${MIAB_Password:-$(_readaccountconf_mutable MIAB_Password)}"
  MIAB_Server="${MIAB_Server:-$(_readaccountconf_mutable MIAB_Server)}"

  #debug log the environmental variables
  _debug MIAB_Username "$MIAB_Username"
  _debug MIAB_Password "$MIAB_Password"
  _debug MIAB_Server "$MIAB_Server"

  #check if MIAB environemt vars set and quit if not
  if [ -z "$MIAB_Username" ] || [ -z "$MIAB_Password" ] || [ -z "$MIAB_Server" ]; then
    _err "You didn't specify one or more of MIAB_Username, MIAB_Password or MIAB_Server."
    _err "Please check these environment variables and try again."
    return 1
  fi

  #save the credentials to the account conf file.
  _saveaccountconf_mutable MIAB_Username "$MIAB_Username"
  _saveaccountconf_mutable MIAB_Password "$MIAB_Password"
  _saveaccountconf_mutable MIAB_Server "$MIAB_Server"
  return 0
}

#Useage: _miab_rest  "XKrxpRBosdIKFzxW_CT3KLZNf6q0HG9i01zxXp5CPBs"  "custom/_acme-challenge.www.domain.com/txt  "POST"
#Returns: "updated DNS: domain.com"
#rest interface MIAB dns
_miab_rest() {
  _data="$1"
  _api_path="$2"
  _httpmethod="$3"

  #encode username and password for basic authentication
  _credentials="$(printf "%s" "$MIAB_Username:$MIAB_Password" | _base64)"
  export _H1="Authorization: Basic $_credentials"
  _url="https://${MIAB_Server}/admin/dns/${_api_path}"

  _debug2 _data "$_data"
  _debug _api_path "$_api_path"
  _debug2 _url "$_url"
  _debug2 _credentails "$_credentials"
  _debug _httpmethod "$_httpmethod"

  if [ "$_httpmethod" = "GET" ]; then
    response="$(_get "$_url")"
  else
    response="$(_post "$_data" "$_url" "" "$_httpmethod")"
  fi

  _retcode="$?"

  if [ "$_retcode" != "0" ]; then
    _err "MIAB REST authentication failed on $_httpmethod"
    return 1
  fi

  _debug response "$response"
  return 0
}

#Usage: _is_json  "\[\n   "mydomain.com"\n]"
#Reurns "\[\n   "mydomain.com"\n]"
#returns the string if it begins and ends with square braces
_is_json() {
  _str="$(echo "$1" | _normalizeJson)"
  echo "$_str" | grep '^\[.*\]$' >/dev/null 2>&1
}