#!/bin/sh

if [ "x$1" = 'x-m' ]; then
  machine_readable=true
  shift
else
  machine_readable=false
fi

if [ $# -eq 0 ]; then
  git -C "$(dirname "$0")/../packages" pull --ff-only >/dev/null 2>&1
#  curl -Ss 'http://packages.archlinux32.local/?uses_upstream=Does+Not+Use+Upstream&fuzzy&tsv' | \
  curl -Ss 'https://www.archlinux32.org/packages/?uses_upstream=Does+Not+Use+Upstream&fuzzy&tsv' | \
    {
      read -r headers
      pkgbase_column=$(
        printf '%s\n' "${headers}" | \
          tr '\t' '\n' | \
          grep -nxF 'pkgbase' | \
          cut -d: -f1
      )
      cut -f${pkgbase_column}
    } | \
    sort -u | \
    parallel -j0 "$0"
  exit $?
elif [ $# -gt 1 ]; then
  >&2 echo 'I need zero or one argument.'
  exit 1
fi

pkgbase="$1"
unset pkgver
unset epoch

oldver=$(
  git -C "$(dirname "$0")/../packages" remote | \
    while read -r remote; do
      eval "$(
        git -C "$(dirname "$0")/../packages" archive "${remote}/master" -- 2>/dev/null | \
          tar -Ox --wildcards '*/'"${pkgbase}"'/PKGBUILD' 2>/dev/null | \
          sed -n '
            /^epoch=/p
            /^pkgver=/p
          '
      )"
      printf '%s %s\n' "${epoch-0}" "${pkgver}"
    done | \
    sort -k1n,1 -k2V,2 | \
    tail -n1 | \
    sed '
      s/^0\s\+//
      s/\s\+/:/
    '
)

case "${pkgbase}" in
  'linux-pae')
    url=$(
      curl -LSs 'https://www.kernel.org/pub/linux/kernel' \
        | sed '
          s,^<a href="\(v[0-9]\+\.x/\)">\1</a>.*$,\1,
          t
          d
        ' \
        | sort -Vr \
        | while read -r sub; do
          if curl -ILs "https://www.kernel.org/pub/linux/kernel/${sub}/sha256sums.asc" \
            | grep -qFw 'HTTP/1.1 200 OK'; then
            echo "https://www.kernel.org/pub/linux/kernel/${sub}"
            break
          fi
        done
    )
    regex='<a href="linux-\([0-9.]\+\)\.tar\.sign">'
  ;;
  'pcmciautils')
    url='https://kernel.org/pub/linux/utils/kernel/pcmcia/'
    regex='<a href="pcmciautils-\([0-9.]\+\)\.tar\.sign">'
  ;;
  'archlinux32-keyring'|'archlinux32-keyring-transition')
    url='https://sources.archlinux32.org/sources/'
    regex='<a href="archlinux32-keyring-v\([0-9.]\+\)\.tar\.gz">'
  ;;
  'python-pip-bootstrap')
    url='https://bootstrap.pypa.io/get-pip.py'
    regex=' entire copy of pip (version \([0-9.]\+\))\.'
  ;;
  *'-dummy'|*'-bootstrap')
    rem_pkgbase="${pkgbase%-*}"
    rem_pkgbase="${rem_pkgbase//+/%2B}"
    url='https://www.archlinux.org/packages/?q='"${rem_pkgbase}"
    range='/^<div id="exact-matches"/,/^<\/div>/'
    regex='<td>\([^-<>]\+\)-[0-9]\+<\/td>'
    regex_b='<td><span class="flagged">\([^-<>]\+\)-[0-9]\+<\/span><\/td>'
  ;;
  *)
    # It might be a (slightly modified) copy of an upstream package:
    # Then we simply take the upstream pkgver.
    if [ "${pkgbase}" = 'linux-olpc-xo1' ] \
    || [ "${pkgbase}" = 'linux-galileo-gen2' ]; then
      _pkgbase='linux'
    else
      _pkgbase="${pkgbase}"
    fi
    newver=$(
      for repository in /var/lib/pacman/sync/*.db; do
        bsdtar -tf "${repository}"
      done \
      | sed '
        s@^'"${_pkgbase//./\.}"'-\([^-]\+\)-[0-9.]\+/desc$@\1@
        t
        d
      ' \
      | sort -V \
      | tail -n1
    )
    if [ -z "${newver}" ]; then
      >&2 printf 'Checking the version of package "%s" is not yet implemented!\n' "${pkgbase}"
      exit 1
    fi
  ;;
esac

if [ -z "${newver}" ]; then
  if [ -z "${regex_b}" ]; then
    regex_b="${regex}"
  fi

  newver=$(
    curl -LSs "${url}" | \
      sed '
        '"${range}"' s/^.*'"${regex}"'.*$/\1/
        t
        '"${range}"' s/^.*'"${regex_b}"'.*$/\1/
        t
        d
      ' | \
      sort -V | \
      tail -n1
  )
fi

if [ "${newver}" != "${oldver}" ]; then
  if ${machine_readable}; then
    printf '%s="%s";\n' \
      'pkgbase' "${pkgbase}" \
      'newver' "${newver}" \
      'oldver' "${oldver}"
  else
    printf '%s: %s vs. %s\n' \
      "${pkgbase}" \
      "${newver}" \
      "${oldver}"
  fi
fi