#!/bin/sh
# This file is a part of Julia. License is MIT: https://julialang.org/license

# build-time mini version of WinRPM, usage:
# ./winrpm.sh http://download.opensuse.org/repositories/windows:/mingw:/win64/openSUSE_13.2/ mingw64-zlib1
# depends on curl, xmllint, gunzip, sort -V, sha256sum, and p7zip

set -e
setglobal url = $1
setglobal toinstall = $2

for i in [curl xmllint gunzip sort sha256sum 7z] {
  if test -z $[which $i !2 >/dev/null] {
    echo "error: this script requires having $i installed" > !2
    exit 1
  }
}

# there is a curl --retry flag but it wasn't working here for some reason
proc retry_curl {
  for i in [$[seq 10]] {
    curl -fLsS $1 && return
    #sleep 2
  }
  echo "error: failed to download $1" > !2
  exit 1
}

setglobal xp = '"xmllint --xpath'"
# the local-name() complication here is due to xml namespaces
setglobal loc = '"local-name()='"
eval $[retry_curl $url/repodata/repomd.xml | $xp "/*[$loc'repomd'] \
  /*[$loc'data'][@type='primary']/*[$loc'location']/@href" -]

match $href {
  with *.gz
    setglobal primary = $[retry_curl $url/$href | gunzip]
  with *
    setglobal primary = $[retry_curl $url/$href]
}

# outputs <package> xml string for newest version
# don't include arch=src packages, those will list build-time dependencies
proc rpm_select {
  setglobal candidates = ""<c>$[echo $primary | $xp "//*[$loc'package'] \
    [./*[$loc'name' and .='$1']][./*[$loc'arch' and .='noarch']]" - \
    !2 >/dev/null | sed -e 's|<rpm:|<|g' -e 's|</rpm:|</|g]</c>""
  # remove rpm namespacing so output can be parsed by xmllint later
  if test $candidates = "<c></c>" {
    echo "error: no package candidates found for $1" > !2
    exit 1
  }
  setglobal epochs = ''""
  for i in [$[echo $candidates | $xp "/c/package/version/@epoch" -]] {
    eval $i
    setglobal epochs = ""$epochs $epoch""
  }
  setglobal maxepoch = $[echo $epochs | sed 's/ /\n/g' | sort -V -u | tail -n 1]
  setglobal vers = ''""
  for i in [$[echo $candidates | $xp "/c/package/version \
      [@epoch='$maxepoch']/@ver" -]] {
    eval $i
    setglobal vers = ""$vers $ver""
  }
  setglobal maxver = $[echo $vers | sed 's/ /\n/g' | sort -V -u | tail -n 1]
  setglobal rels = ''""
  for i in [$[echo $candidates | $xp "/c/package/version \
      [@epoch='$maxepoch'][@ver='$maxver']/@rel" -]] {
    eval $i
    setglobal rels = ""$rels $rel""
  }
  setglobal maxrel = $[echo $rels | sed 's/ /\n/g' | sort -V -u | tail -n 1]
  setglobal repeats = $[echo $rels | sed 's/ /\n/g' | sort -V | uniq -d | tail -n 1]
  if test $repeats = $maxrel {
    echo "warning: multiple candidates found for $1 with same version:" > !2
    echo "epoch $maxepoch, ver $maxver, rel $maxrel, picking at random" > !2
  }
  echo $candidates | $xp "/c/package[version[@epoch='$maxepoch'] \
    [@ver='$maxver'][@rel='$maxrel']][1]" -
}

for i in [$toinstall] {
  # fail if no available candidates for requested packages
  if test -z $[rpm_select $i] {
    exit 1
  }
}

# outputs package and dll names, e.g. mingw64(zlib1.dll)
proc rpm_requires {
  for i in [$[rpm_select $1 | \
      $xp "/package/format/requires/entry/@name" - !2 >/dev/null]] {
    eval $i
    echo $name
  }
}

# outputs package name, warns if multiple providers with different names
proc rpm_provides {
  setglobal providers = $[echo $primary | $xp "//*[$loc'package'][./*[$loc'format'] \
    /*[$loc'provides']/*[$loc'entry'][@name='$1']]/*[$loc'name']" - | \
    sed -e 's|<name>||g' -e 's|</name>|\n|g' | sort -u]
  if test $[echo $providers | wc -w] -gt 1 {
    echo "warning: found multiple providers $providers for $1, adding all" > !2
  }
  echo $providers
}

setglobal newpkgs = $toinstall
setglobal allrequires = ''""
while test -n $newpkgs {
  setglobal newrequires = ''""
  for i in [$newpkgs] {
    for j in [$[rpm_requires $i]] {
      # leading and trailing spaces to ensure word match
      match " $allrequires $newrequires " {
        with *" $j "* # already on list
          
        with *
          setglobal newrequires = ""$newrequires $j""
      }
    }
  }
  setglobal allrequires = ""$allrequires $newrequires""
  setglobal newpkgs = ''""
  for i in [$newrequires] {
    setglobal provides = $[rpm_provides $i]
    match " $toinstall $newpkgs " {
      with *" $provides "* # already on list
        
      with *
        setglobal newpkgs = ""$newpkgs $provides""
    }
  }
  setglobal toinstall = ""$toinstall $newpkgs""
}

mkdir -p noarch
for i in [$toinstall] {
  setglobal pkgi = $[rpm_select $i]
  setglobal checksum = $[echo $pkgi | $xp "/package/checksum/text()" -]
  eval $[echo $pkgi | $xp "/package/location/@href" -]
  echo "downloading $href"
  $[dirname $0]/../../deps/tools/jldownload $href $url/$href
  echo "$checksum *$href" | sha256sum -c
  7z x -y $href
  setglobal cpiofile = $[basename $href | sed 's/.rpm$/.cpio/]
  rm $href
  7z x -y $cpiofile
  rm $cpiofile
}
rmdir --ignore-fail-on-non-empty noarch