#!/bin/bash

set -o pipefail

readonly program="$(basename "${0}")"
skip_curl_verify=0
verbose=0

syntax_error() {
  echo "${program}: ${1}" >&2
  echo "Try \`${program} --help\` for more information." >&2
  exit 1
}

depends_on() {
  formula="${1}"
  [[ "$#" -eq 2 ]] && cmd="${2}" || cmd=$(basename "${formula}")

  if [[ ! $(which "${cmd}") ]]; then
    echo -e "$(tput setaf 1)
      This script depends on '${cmd}'.
      If you have [Homebrew](http://brew.sh), you can install it with 'brew install ${formula}'.
    $(tput sgr0)" | sed -E 's/ {6}//' >&2
    exit 1
  fi
}

depends_on 'tsparber/tiny-scripts/curl-check-url'

usage() {
  echo "
    This script changes the url, appcast and homepage stanzas to https

    After changing to https a HTTP GET request is performed to verify if the url is reachable.
    If the https url is not reachable it is reverted to the previous version.

    Known Issues: If multiple url/appcast stanzas are present, all urls are changed but only
                  those for the current os are verified.

    If no cask name is given the current work directory is scanned with the given options.

    usage: $program [options] [<cask_name>]
    options:
      -s, --skip-verify  Skip checking for a HTTP 200 Status Code using curl.
      --verbose          Show more verbose output.
      -h, --help         Show this help.

    Based on: https://github.com/vitorgalvao/tiny-scripts/blob/master/cask-repair
  " | sed -E 's/^ {4}//'
}

# available flags
while [[ "${1}" ]]; do
  case "${1}" in
    -h | --help)
      usage
      exit 0
      ;;
    -s | --skip-verify)
      skip_curl_verify=1
      ;;
    --verbose)
      verbose=1
      ;;
    -*)
      syntax_error "unrecognized option: ${1}"
      ;;
    *)
      break
      ;;
  esac
  shift
done

# define function to check if given URL exists and is reachable using HTTPS
check_url_for_https() {
  cask_url="${1}"
  verbose_option=''

  [[ "${verbose}" -ne 0 ]] && verbose_option="-v "

  # check if the URL sends a 200 HTTP code, else abort
  curl-check-url "${verbose_option}" "${cask_url}" > /dev/null
  exit_code="$?"

  if [[ "${exit_code}" -ne 0 ]]; then
    echo "curl returned ${exit_code}: FAIL for ${cask_url}"
    return 1
  fi

  return 0
}

# define function to modify part of stanza
replace_protocol_of_stanza() {
  cask_file="${1}"
  stanza="${2}"
  old_value="${3}"
  new_value="${4}"

  sed "s|${stanza} \(['\"]\)${old_value}://|${stanza} \1${new_value}://|g" "${cask_file}" > tmpfile
  mv tmpfile "${cask_file}"
}

# define abort function, that will reset the state
finish() {
  # show message
  if [[ "${1}" == 'abort' ]]; then
    echo -e "$(tput setaf 1)${2}$(tput sgr0)\n"
    [[ ! -z "${cask_file}" ]] && git checkout -- "${cask_file}"
    exit 1
  elif [[ "${1}" == 'success' ]]; then
    echo -e "$(tput setaf 2)Updated: ${cask_name} is now using HTTPS$(tput sgr0)\n"
    exit 0
  fi
}

# cleanup if aborted with ⌃C
trap 'finish abort "You aborted"' SIGINT

# exit if not inside a 'homebrew-*/Casks' directory
casks_dir=$(pwd | perl -ne 'print m{homebrew-[^/]+/Casks}')
if [[ -z "${casks_dir}" ]]; then
  echo -e "\n$(tput setaf 1)You need to be inside a '/homebrew-*/Casks' directory$(tput sgr0)\n"
  exit 1
fi

# exit if no argument was given: Run in current directory
if [[ -z "${1}" ]]; then
  options=""
  [[ ${skip_curl_verify} -ne 0 ]] && options+=" --skip-verify"
  [[ ${verbose} -ne 0 ]] && options+=" --verbose"

  for file in *.rb;
  do
    "${0}" "${options}" "${file}"
  done

  exit 0
fi

# clean the cask's name, and check if it is valid
cask_name="${1%.rb}" # remove '.rb' extension, if present
cask_file="./${cask_name}.rb"
[[ ! -f "${cask_file}" ]] && finish abort 'There is no such cask'

# initial tasks
git checkout -- "${cask_file}"

# check if a http url exists
cask_contains_http=$(grep "['\"]http://" "${cask_file}")
if [[ -z ${cask_contains_http} ]]; then
  echo -e "Skipped ${cask_name} no http found\n"
  exit 0
fi

updated_stanzas=0
for stanza in url appcast homepage; do
  # Check if the stanza exists
  stanza_contained=$(grep "${stanza} ['\"]" "${cask_file}")
  [[ -z ${stanza_contained} ]] && continue

  stanza_contains_https=$(grep "${stanza} ['\"]http://" "${cask_file}")
  if [[ -z ${stanza_contains_https} ]]; then
#    echo "Skipped stanza ${stanza} in ${cask_name} no http url found"
    continue
  fi

  replace_protocol_of_stanza "${cask_file}" "${stanza}" "http" "https"

  if [[ ${skip_curl_verify} -eq 0 ]]; then
    check_url_for_https "$(brew cask _stanza "${stanza}" "${cask_name}")"
  else
    true
  fi

  if [[ $? -ne 0 ]]; then
    echo "Restored original value for stanza ${stanza} as curl check failed"
    replace_protocol_of_stanza "${cask_file}" "${stanza}" "https" "http"
  else
    updated_stanzas=$((updated_stanzas+1))
  fi
done

if [[ ${updated_stanzas} -ne 0 ]]; then
  finish success
else
  finish abort "no updated stanzas after verify for ${cask_name}"
fi