#!/usr/bin/env sh

########
# Custom cyon.ch DNS API for use with [acme.sh](https://github.com/Neilpang/acme.sh)
#
# Usage: acme.sh --issue --dns dns_cyon -d www.domain.com
#
# Dependencies:
# -------------
# - jq (get it here: https://stedolan.github.io/jq/download)
# - oathtool (When using 2 Factor Authentication)
#
# Author: Armando Lüscher <armando@noplanman.ch>
########

########
# Define cyon.ch login credentials:
#
# Either set them here: (uncomment these lines)
#
# cyon_username='your_cyon_username'
# cyon_password='your_cyon_password'
# cyon_otp_secret='your_otp_secret' # Only required if using 2FA
#
# ...or export them as environment variables in your shell:
#
# $ export cyon_username='your_cyon_username'
# $ export cyon_password='your_cyon_password'
# $ export cyon_otp_secret='your_otp_secret' # Only required if using 2FA
#
# *Note:*
# After the first run, the credentials are saved in the "account.conf"
# file, so any hard-coded or environment variables can then be removed.
########

dns_cyon_add() {
  if ! _exists jq; then
    _fail "Please install jq to use cyon.ch DNS API."
  fi

  _load_credentials
  _load_parameters "$@"

  _info_header "add"
  _login
  _domain_env
  _add_txt
  _cleanup

  return 0
}

dns_cyon_rm() {
  _load_credentials
  _load_parameters "$@"

  _info_header "delete"
  _login
  _domain_env
  _delete_txt
  _cleanup

  return 0
}

#########################
### PRIVATE FUNCTIONS ###
#########################

_load_credentials() {
  # Convert loaded password to/from base64 as needed.
  if [ "${cyon_password_b64}" ]; then
    cyon_password="$(echo "${cyon_password_b64}" | _dbase64)"
  elif [ "${cyon_password}" ]; then
    cyon_password_b64="$(echo "${cyon_password}" | _base64)"
  fi

  if [ -z "${cyon_username}" ] || [ -z "${cyon_password}" ]; then
    cyon_username=""
    cyon_password=""
    cyon_otp_secret=""
    _err ""
    _err "You haven't set your cyon.ch login credentials yet."
    _err "Please set the required cyon environment variables."
    _err ""
    exit 1
  fi

  # Save the login credentials to the account.conf file.
  _debug "Save credentials to account.conf"
  _saveaccountconf cyon_username "${cyon_username}"
  _saveaccountconf cyon_password_b64 "$cyon_password_b64"
  if [ ! -z "${cyon_otp_secret}" ]; then
    _saveaccountconf cyon_otp_secret "$cyon_otp_secret"
  fi
}

_is_idn() {
  _idn_temp=$(printf "%s" "$1" | tr -d "[0-9a-zA-Z.,-]")
  _idn_temp2="$(printf "%s" "$1" | grep -o "xn--")"
  [ "$_idn_temp" ] || [ "$_idn_temp2" ]
}

_load_parameters() {
  # Read the required parameters to add the TXT entry.
  fulldomain="$(echo "$1" | tr '[:upper:]' '[:lower:]')"
  fulldomain_idn="${fulldomain}"

  # Special case for IDNs, as cyon needs a domain environment change,
  # which uses the "pretty" instead of the punycode version.
  if _is_idn "$1"; then
    if ! _exists idn; then
      _fail "Please install idn to process IDN names."
    fi

    fulldomain="$(idn -u "${fulldomain}")"
    fulldomain_idn="$(idn -a "${fulldomain}")"
  fi

  _debug fulldomain "$fulldomain"
  _debug fulldomain_idn "$fulldomain_idn"

  txtvalue="$2"
  _debug txtvalue "$txtvalue"

  # Cookiejar required for login session, as cyon.ch has no official API (yet).
  cookiejar=$(tempfile)
  _debug cookiejar "$cookiejar"
}

_info_header() {
  if [ "$1" = "add" ]; then
    _info ""
    _info "+---------------------------------------------+"
    _info "| Adding DNS TXT entry to your cyon.ch domain |"
    _info "+---------------------------------------------+"
    _info ""
    _info "  * Full Domain: ${fulldomain}"
    _info "  * TXT Value:   ${txtvalue}"
    _info "  * Cookie Jar:  ${cookiejar}"
    _info ""
  elif [ "$1" = "delete" ]; then
    _info ""
    _info "+-------------------------------------------------+"
    _info "| Deleting DNS TXT entry from your cyon.ch domain |"
    _info "+-------------------------------------------------+"
    _info ""
    _info "  * Full Domain: ${fulldomain}"
    _info "  * Cookie Jar:  ${cookiejar}"
    _info ""
  fi
}

_login() {
  _info "  - Logging in..."
  login_response=$(curl \
    "https://my.cyon.ch/auth/index/dologin-async" \
    -s \
    -c "${cookiejar}" \
    -H "X-Requested-With: XMLHttpRequest" \
    --data-urlencode "username=${cyon_username}" \
    --data-urlencode "password=${cyon_password}" \
    --data-urlencode "pathname=/")

  _debug login_response "${login_response}"

  # Bail if login fails.
  if [ "$(echo "${login_response}" | jq -r '.onSuccess')" != "success" ]; then
    _fail "    $(echo "${login_response}" | jq -r '.message')"
  fi

  _info "    success"

  # NECESSARY!! Load the main page after login, before the OTP check.
  curl "https://my.cyon.ch/" -s --compressed -b "${cookiejar}" >/dev/null

  # todo: instead of just checking if the env variable is defined, check if we actually need to do a 2FA auth request.

  # 2FA authentication with OTP?
  if [ ! -z "${cyon_otp_secret}" ]; then
    _info "  - Authorising with OTP code..."

    if ! _exists oathtool; then
      _fail "Please install oathtool to use 2 Factor Authentication."
    fi

    # Get OTP code with the defined secret.
    otp_code=$(oathtool --base32 --totp "${cyon_otp_secret}" 2>/dev/null)

    otp_response=$(curl \
      "https://my.cyon.ch/auth/multi-factor/domultifactorauth-async" \
      -s \
      --compressed \
      -b "${cookiejar}" \
      -c "${cookiejar}" \
      -H "X-Requested-With: XMLHttpRequest" \
      -d "totpcode=${otp_code}&pathname=%2F&rememberme=0")

    _debug otp_response "${otp_response}"

    # Bail if OTP authentication fails.
    if [ "$(echo "${otp_response}" | jq -r '.onSuccess')" != "success" ]; then
      _fail "    $(echo "${otp_response}" | jq -r '.message')"
    fi

    _info "    success"
  fi

  _info ""
}

_domain_env() {
  _info "  - Changing domain environment..."

  # Get the "example.com" part of the full domain name.
  domain_env=$(echo "${fulldomain}" | sed -E -e 's/.*\.(.*\..*)$/\1/')
  _debug "Changing domain environment to ${domain_env}"

  domain_env_response=$(curl \
    "https://my.cyon.ch/user/environment/setdomain/d/${domain_env}/gik/domain%3A${domain_env}" \
    -s \
    --compressed \
    -b "${cookiejar}" \
    -H "X-Requested-With: XMLHttpRequest")

  _debug domain_env_response "${domain_env_response}"

  _check_2fa_miss "${domain_env_response}"

  domain_env_success=$(echo "${domain_env_response}" | jq -r '.authenticated')

  # Bail if domain environment change fails.
  if [ "${domain_env_success}" != "true" ]; then
    _fail "    $(echo "${domain_env_response}" | jq -r '.message')"
  fi

  _info "    success"
  _info ""
}

_add_txt() {
  _info "  - Adding DNS TXT entry..."
  addtxt_response=$(curl \
    "https://my.cyon.ch/domain/dnseditor/add-record-async" \
    -s \
    --compressed \
    -b "${cookiejar}" \
    -H "X-Requested-With: XMLHttpRequest" \
    -d "zone=${fulldomain_idn}.&ttl=900&type=TXT&value=${txtvalue}")

  _debug addtxt_response "${addtxt_response}"

  _check_2fa_miss "${addtxt_response}"

  addtxt_message=$(echo "${addtxt_response}" | jq -r '.message')
  addtxt_status=$(echo "${addtxt_response}" | jq -r '.status')

  # Bail if adding TXT entry fails.
  if [ "${addtxt_status}" != "true" ]; then
    if [ "${addtxt_status}" = "null" ]; then
      addtxt_message=$(echo "${addtxt_response}" | jq -r '.error.message')
    fi
    _fail "    ${addtxt_message}"
  fi

  _info "    success"
  _info ""
}

_delete_txt() {
  _info "  - Deleting DNS TXT entry..."

  list_txt_response=$(curl \
    "https://my.cyon.ch/domain/dnseditor/list-async" \
    -s \
    -b "${cookiejar}" \
    --compressed \
    -H "X-Requested-With: XMLHttpRequest")

  _debug list_txt_response "${list_txt_response}"

  _check_2fa_miss "${list_txt_response}"

  # Find and delete all acme challenge entries for the $fulldomain.
  _dns_entries=$(echo "$list_txt_response" | jq -r --arg fulldomain_idn "${fulldomain_idn}." '
    .rows[] |
      label $out|
      if .[0] != $fulldomain_idn then
        break $out
      else
        .[4]|
        capture("data-hash=\"(?<hash>[^\"]*)\" data-identifier=\"(?<identifier>[^\"]*)\"";"g")|
        .hash + " " + .identifier
    end')
  _dns_entries_cnt=$(echo "${_dns_entries}" | wc -l | grep -o '\d')

  _info "    (entries found: ${_dns_entries_cnt})"

  _dns_entry_num=0

  echo "${_dns_entries}" | while read -r _hash _identifier; do
    _dns_entry_num=$((_dns_entry_num + 1))

    delete_txt_response=$(curl \
      "https://my.cyon.ch/domain/dnseditor/delete-record-async" \
      -s \
      --compressed \
      -b "${cookiejar}" \
      -H "X-Requested-With: XMLHttpRequest" \
      --data-urlencode "hash=${_hash}" \
      --data-urlencode "identifier=${_identifier}")

    _debug delete_txt_response "${delete_txt_response}"

    _check_2fa_miss "${delete_txt_response}"

    delete_txt_message=$(echo "${delete_txt_response}" | jq -r '.message')
    delete_txt_status=$(echo "${delete_txt_response}" | jq -r '.status')

    # Skip if deleting TXT entry fails.
    if [ "${delete_txt_status}" != "true" ]; then
      if [ "${delete_txt_status}" = "null" ]; then
        delete_txt_message=$(echo "${delete_txt_response}" | jq -r '.error.message')
      fi
      _err "    [${_dns_entry_num}/${_dns_entries_cnt}] ${delete_txt_message} (${_identifier})"
    else
      _info "    [${_dns_entry_num}/${_dns_entries_cnt}] success (${_identifier})"
    fi
  done

  _info "    done"
  _info ""
}

_check_2fa_miss() {
  # Did we miss the 2FA?
  if test "${1#*multi_factor_form}" != "$1"; then
    _fail "    Missed OTP authentication!"
  fi
}

_fail() {
  _err "$1"
  _err ""
  _cleanup
  exit 1
}

_cleanup() {
  _info "  - Cleanup."
  _debug "Remove cookie jar: ${cookiejar}"
  rm "${cookiejar}" 2>/dev/null
  _info ""
}