#!/bin/sh

# shellcheck source=conf/default.conf
. "${0%/*}/../conf/default.conf"

# TODO: enable email interface to delete packages

# TODO: read information from database (?)

if [ $# -ne 0 ]; then
  >&2 echo ''
  >&2 echo 'usage: interpret-mail'
  >&2 echo ' Read email from stdin and interpret / execute body.'
  >&2 echo ''
  >&2 echo ' The email needs a valid hashcash-stamp (>=20 bits)'
  >&2 echo ' and valid encryption to buildmaster@archlinux32.org,'
  >&2 echo ' as well as a valid gpg-signature from anyone on the'
  >&2 echo ' list in "conf/admin-gpg-keys". This entry also'
  >&2 echo ' determines what instructions are allowed.'
  >&2 echo ''
  >&2 echo ' Possible instructions are:'
  >&2 echo ''
  >&2 echo '  - "block: <state-file> <reason>":'
  >&2 echo '    Block the given packge for the given reason.'
  >&2 echo ''
  >&2 echo '  - "copy-to-build-support: <pkgname>":'
  >&2 echo '    Copy the given binary package into [build-support].'
  >&2 echo ''
  >&2 echo '  - "schedule: <pkgbase>":'
  >&2 echo '    Put the given package on the build list (again).'
  >&2 echo ''
  >&2 echo '  - "stabilize: <package-file>":'
  >&2 echo '    Mark the given package as tested.'
  >&2 echo ''
  >&2 echo '  - "unblock: <state-file>":'
  >&2 echo '    Unblock the given packge.'
  >&2 echo ''
  >&2 echo '  - ALL: all of the above (only valid in'
  >&2 echo '    "conf/admin-gpg-keys")'
  >&2 echo ''
  exit 1
fi

log() {
  # shellcheck disable=SC2059
  >&2 printf "$@"
  {
    cat "${webserver_directory}/mail-log.html"
    # shellcheck disable=SC2059
    printf "$@" | \
      sed '
        s|$|<br>|
        s|^|'"$(date)"': |
      '
  } | \
    tail -n "${max_mail_log_lines}" | \
    sponge "${webserver_directory}/mail-log.html"
}

log_from_file() {
  >&2 cat "$@"
  {
    cat "${webserver_directory}/mail-log.html"
    sed '
      s|$|<br>|
      s|^|'"$(date)"': |
    ' "$@"
  } | \
    tail -n "${max_mail_log_lines}" | \
    sponge "${webserver_directory}/mail-log.html"
}

run_and_log_on_error() {
  # shellcheck disable=SC2039
  local err
  err=0
  "$@" 2> "${tmp_dir}/stderr" > "${tmp_dir}/stdout" || \
    err=$?
  if [ "${err}" -eq 0 ]; then
    return 0
  fi
  log_from_file "${tmp_dir}/stderr" "${tmp_dir}/stdout"
  if [ "${err}" -eq 1 ]; then
    log '^ temporary error - I keep the message.\n'
    exit 1
  else
    return 1
  fi
}

tmp_dir=$(mktemp -d 'tmp.interpret-mail.XXXXXXXXXX' --tmpdir)
trap 'rm -rf --one-file-system "${tmp_dir}"' EXIT

cat > \
  "${tmp_dir}/mail"

if ! hashcash -qXc -b 20 \
  -d -f "${tmp_dir}/hashcash.db" \
  -r 'archlinux32-buildmaster@eckner.net' \
  -r 'buildmaster@archlinux32.org' < \
  "${tmp_dir}/mail"; then
  log 'Invalid stamp - ignoring this message.\n'
  exit
fi

if ! sed -n '
    /^-----BEGIN PGP MESSAGE-----\s*$/{
      :a
      /\n-----END PGP MESSAGE-----\s*$/!{
        N
        ba
      }
      p
    }
  ' "${tmp_dir}/mail" | \
    gpg --batch --status-file "${tmp_dir}/gpg-status" -q -d -o "${tmp_dir}/plain-content" > /dev/null 2>&1; then
  log 'Invalid encryption/signature - ignoring this message.\n'
  log_from_file "${tmp_dir}/gpg-status"
  exit
fi

grep '^\[GNUPG:] VALIDSIG ' "${tmp_dir}/gpg-status" | \
  cut -d' ' -f3 | \
  sort -u > \
  "${tmp_dir}/found-keys"

printf '%s\n' "${admin_gpg_keys}" | \
  sort -k1,1 -u > \
  "${tmp_dir}/admin-gpg-keys"

join -j 1 -o 2.2 \
  "${tmp_dir}/found-keys" \
  "${tmp_dir}/admin-gpg-keys" | \
  tr ',' '\n' | \
  sed 's|^ALL$|'"${possible_email_actions}"'|' | \
  tr ' ,' '\n' | \
  sort -u > \
  "${tmp_dir}/allowed-actions"

if [ ! -s "${tmp_dir}/allowed-actions" ]; then
  log 'No known signature found - I found:\n'
  grep '^\[GNUPG:] VALIDSIG ' "${tmp_dir}/gpg-status" | \
    cut -d' ' -f3 | \
    sort -u | \
    sed 's|^|> |' > \
    "${tmp_dir}/log"
  log_from_file "${tmp_dir}/log"
  log 'ignoring this message.\n'
  exit
fi

printf '\n\n' >> "${tmp_dir}/plain-content"

sed -n '
  /^$/!b
  N
  s/^\n//
  /^--/b
  :a
  N
  /\n$/!ba
  s/\n$//
  p
' "${tmp_dir}/plain-content" | \
  sed '
    :start_loop
      $!{
        N
        bstart_loop
      }
    s/[=\]\s*\n//g
    s/:\s*\n/: /g
    s/\n\(\S\+[^: ]\(\s\|\n\|$\)\)/ \1/g
  ' > \
  "${tmp_dir}/raw-content"

sed -n "$(
  while read -r action; do
    if [ -z "${action}" ]; then
      continue
    fi
    printf \
      '/^%s:/{ s/^%s:\s*//; w %s/%s\n b; }\n' \
      "${action}" \
      "${action}" \
      "${tmp_dir}" \
      "${action}"
  done < \
    "${tmp_dir}/allowed-actions"
)" "${tmp_dir}/raw-content"

if [ -s "${tmp_dir}/block" ]; then
  if run_and_log_on_error "${base_dir}/bin/modify-package-state" --wait --block "${tmp_dir}/block"; then
    log 'Successfully blocked %s packages.\n' "$(wc -l < "${tmp_dir}/block")"
  else
    log 'There was an error while blocking the packages - ignoring this message.\n'
  fi
fi

if [ -s "${tmp_dir}/stabilize" ]; then
  sed -i '
    /\.pkg\.tar\.xz$/!s/$/.pkg.tar.xz/
  ' "${tmp_dir}/stabilize"
  if run_and_log_on_error "${base_dir}/bin/modify-package-state" --wait --tested "${tmp_dir}/stabilize"; then
    log 'Successfully marked %s packages as tested.\n' "$(wc -l < "${tmp_dir}/stabilize")"
  else
    log 'There was an error while marking the packages as tested - ignoring this message.\n'
  fi
fi

if [ -s "${tmp_dir}/unblock" ]; then
  if run_and_log_on_error "${base_dir}/bin/modify-package-state" --wait --unblock "${tmp_dir}/unblock"; then
    log 'Successfully unblocked %s packages.\n' "$(wc -l < "${tmp_dir}/unblock")"
  else
    log 'There was an error while unblocking the packages - ignoring this message.\n'
  fi
fi

if [ -s "${tmp_dir}/schedule" ]; then
  # shellcheck disable=SC2046
  "${base_dir}/bin/seed-build-list" --wait $(
    tr '[:space:]' '\n' < \
      "${tmp_dir}/schedule" | \
      grep -vxF '' | \
      while read -r package; do
        printf -- '-p ^%s$\n' "$(str_to_regex "${package}")"
      done
  ) | \
    sponge "${tmp_dir}/schedule"
  log 'Successfully (re)scheduled %s packages.\n' "$(wc -l < "${tmp_dir}/schedule")"
fi

if [ -s "${tmp_dir}/copy-to-build-support" ]; then
  sed -i '
    /\.pkg\.tar\.xz$/!s/$/.pkg.tar.xz/
  ' "${tmp_dir}/copy-to-build-support"
  if run_and_log_on_error "${base_dir}/bin/copy-to-build-support" --wait "${tmp_dir}/copy-to-build-support"; then
    log 'Successfully copied %s packages to [build-support].\n' "$(wc -l < "${tmp_dir}/copy-to-build-support")"
  else
    log 'There was an error while copying the packages to [build-support] - ignoring this message.\n'
  fi
fi