#!/bin/bash

notify_err() {
  say "errexit on line $(caller)"
  say "Error messages can be found at the end of setup.log"
  exit 1
}

trap notify_err ERR

# Message
function say() {
  echo "TALER: " "$@" >> setup.log
  echo "TALER: " "$@"
}

# Check user if the user is root
function check_user() {
  if [ "$(whoami)" != "root" ]; then
    say "Please run this script as root"
    exit 1
  fi
}

function ask_questions() {
  if test -z "${CURRENCY:-}"; then
    read -r -p "Enter the name of the regional currency (e.g. 'NETZBON'): " CURRENCY
    CURRENCY=$(normalize_currency "${CURRENCY}")
    echo "CURRENCY=${CURRENCY}" >>config/user.conf
  fi
  if test -z "${FIAT_CURRENCY:-}"; then
    read -r -p "Enter the name of the fiat currency (e.g. 'CHF'): " FIAT_CURRENCY
    FIAT_CURRENCY=$(normalize_currency "${FIAT_CURRENCY}")
    echo "FIAT_CURRENCY=${FIAT_CURRENCY}" >>config/user.conf
  fi
  if test -z "${BANK_NAME:-}"; then
    read -r -p "Enter the human-readable name of the bank (e.g. 'Taler Bank'): " BANK_NAME
    echo "BANK_NAME=\"${BANK_NAME}\"" >>config/user.conf
  fi
  if test -z "${DOMAIN_NAME:-}"; then
    read -r -p "Enter the domain name: " DOMAIN_NAME
    # convert to lower-case
    DOMAIN_NAME=$(echo "${DOMAIN_NAME}" | tr A-Z a-z)
    check_dns
    echo "DOMAIN_NAME=${DOMAIN_NAME}" >>config/user.conf
  fi
  if test -z "${ENABLE_TLS:-}"; then
    read -r -p "Setup TLS using Let's Encrypt? (y/n): " ENABLE_TLS
    echo "ENABLE_TLS=${ENABLE_TLS}" >>config/user.conf
  fi
  if test -z "${TLS_EMAIL:-}"; then
    if test "${ENABLE_TLS:-}" == y; then
      read -r -p "Enter an email address for Let's Encrypt: " TLS_EMAIL
      echo "TLS_EMAIL=${TLS_EMAIL}" >>config/user.conf
    fi
  fi
  if test -z "${TLS_TOS:-}"; then
    if test "${ENABLE_TLS:-}" == y; then
      echo "Please read the Terms of Service at https://letsencrypt.org/documents/LE-SA-v1.3-September-21-2022.pdf."
      read -r -p "You must agree in order to register with the ACME server. Do you agree? (y/n): " TLS_TOS
      if test "${TLS_TOS:-y}" != y; then
        say "You must agree in order to register with the ACME server"
        exit 1
      fi
      echo "TLS_TOS=${TLS_TOS}" >>config/user.conf
    fi
  fi
  if test -z "${DO_OFFLINE:-}"; then
    read -r -p "Run taler-exchange-offline? (y/n): " DO_OFFLINE
    echo "DO_OFFLINE=${DO_OFFLINE}" >>config/user.conf
  fi
  if test -z "${MASTER_PUBLIC_KEY:-}"; then
    if test "${DO_OFFLINE:-y}" == n; then
      read -r -p "Enter the exchange-offline master public key: " MASTER_PUBLIC_KEY
      echo "MASTER_PUBLIC_KEY=${MASTER_PUBLIC_KEY}" >>config/user.conf
    fi
  fi
  if test -z "${BANK_ADMIN_PASSWORD:-}"; then
    read -r -s -p "Enter the admin password for the bank (or press enter to autogenerate password): " BANK_ADMIN_PASSWORD
    echo "BANK_ADMIN_PASSWORD=$(printf '%q' "${BANK_ADMIN_PASSWORD}")" >>config/user.conf
    echo "" # force new line
  fi
  if test -z "${DO_TELESIGN:-}"; then
    read -r -p "Setup sms two-factor authentication using Telesign https://www.telesign.com? (y/n): " DO_TELESIGN
    if test "${DO_TELESIGN:-y}" != n; then
      read -r -p "Enter your Telesign Customer ID: " TELESIGN_CUSTOMER_ID
      read -r -s -p "Enter your Telesign API Key: " TELESIGN_API_KEY
      echo "" # force new line
      read -r -p "Enter a phone number to test: " TELESIGN_PHONE
      TELESIGN_AUTH_TOKEN=$(echo "$TELESIGN_CUSTOMER_ID:$TELESIGN_API_KEY" | base64 -w 0)
      export AUTH_TOKEN=$TELESIGN_AUTH_TOKEN
      echo "12345" | libeufin-tan-sms.sh $TELESIGN_PHONE
      read -r -s -p "Enter the code received by $TELESIGN_PHONE : " TELESIGN_TEST_CODE
      if test "${TELESIGN_TEST_CODE:-y}" != "12345"; then
        say "Wrong code, rerun this script to enter the right Telesign auth info"
        exit 1
      fi
      echo "TELESIGN_AUTH_TOKEN=\"${TELESIGN_AUTH_TOKEN}\"" >>config/user.conf
    fi
    echo "DO_TELESIGN=${DO_TELESIGN}" >>config/user.conf
    echo "" # force new line
  fi
}

function normalize_currency() {
  # convert to all-caps
  local CURRENCY=$(echo "$1" | tr a-z A-Z)
  # libeufin currenly doesn't like currency names less than 3 letters.
  if [[ ${#CURRENCY} -lt 3 || ${#CURRENCY} -gt 11 ]]; then
    say "Currency name must be between 3 and 10 letters"
    exit 1
  fi
  echo "${CURRENCY}"
}

function check_currency_spec() {
  return 0
  # TODO fix when 'taler-harness deployment setup-currency' works
  # Convert to lowercase
  local CURRENCY=$(echo "$1" | tr A-Z a-z)
  local HAS_SPEC=$(taler-config -S 2>/dev/null | grep --count "^currency-$CURRENCY$")
  if test "${HAS_SPEC}" != "1"; then
    say "Missing currency specification for $1, creating one"
    read -r -p "Enter the currency name (e.g. 'US Dollar' for USD): " CURRENCY_SPEC_NAME
    read -r -p "Enter the currency unit name (e.g. '$' for USD): " CURRENCY_SPEC_UNIT_NAME
    cat << EOF > /usr/share/taler/config.d/$CURRENCY.conf
[currency-$CURRENCY]
ENABLED=YES
name="$CURRENCY_SPEC_NAME"
code="$1"
fractional_input_digits=2
fractional_normal_digits=2
fractional_trailing_zero_digits=2
alt_unit_names = {"0":"$CURRENCY_SPEC_UNIT_NAME"}
EOF
    chmod a+r /usr/share/taler/config.d/$CURRENCY.conf
    ln -s /usr/share/taler/config.d/$CURRENCY.conf /usr/share/libeufin/config.d/$CURRENCY.conf
    say "Currency specification for $1 have been created at /usr/share/taler/config.d/$CURRENCY.conf"
  fi
}

function check_dns() {
  for prefix in "exchange" "bank" "backend"; do
    if ! ping -c1 "${prefix}.${DOMAIN_NAME}" &>>setup.log; then
      say "Could not ping ${prefix}.${DOMAIN_NAME}."
      say "Please make sure your DNS/network are working."
      exit 1
    fi
  done
}

# Set DISTRO to the detected distro or return non-zero
# status if distro not supported.
function detect_distro() {
  unset DISTRO
  # shellcheck disable=SC2034
  uname -a | grep Ubuntu >/dev/null && DISTRO=ubuntu && return 0
  # shellcheck disable=SC2034
  uname -a | grep Debian >/dev/null && DISTRO=debian && return 0
  echo "Unsupported distro, should be either ubuntu or debian" >&2
  return 1
}