#!/bin/bash

# Usage:

#    ./otp-get-patches.sh /path/to/otp OTP_R14B01 fedora-R14B01

#

# Note:

#    We do NOT update erlang.spec or the git index at all.

#    For now, take a look at the patch-list-*.txt files

#    generated in the tmpdir manually copy and adapt them

#    to erlang.spec. Then handle the otp-*.patch files:

#

#        git rm -f otp-00*.patch

#        mv tmp.foobar/otp-00*.patch .

#        git add otp-00*.patch

#

#    We could only automate this if we added the required patch

#    specific spec file conditionals to the commit message somehow,

#    and then had this script transfer the conditionals into erlang.spec.

otp_dir="${1:?'Fatal: otp git repo dir required'}"

otp_upstream="${2:?'Fatal: git ref to upstream release required'}"

otp_fedora="${3:?'Fatal: git ref to branch with fedora patches required'}"

set -e

# set -x

tmpdir="$(mktemp -d --tmpdir="$PWD")"

pushd "$otp_dir"

git format-patch -o "$tmpdir" "${otp_upstream}..${otp_fedora}" > "$tmpdir/patch-list.txt"

popd

test -s "$tmpdir/patch-list.txt"

echo "# start of autogenerated patch tag list" > "$tmpdir/patch-list-tags.txt"

echo "# start of autogenerated prep patch list" > "$tmpdir/patch-list-prep.txt"

n=1

while read patch

do

	otppatch="$(dirname "$patch")/otp-$(basename "$patch")"

	mv -f "$patch" "$otppatch"

	echo "Patch$n: $(basename "$otppatch")" >> "$tmpdir/patch-list-tags.txt"

	base="$(basename "$patch" ".patch" | sed 's/^00[0-9][0-9]-//')"

	backupext=".$(echo -n "$base" | tr -c -s '[:alnum:]' '_')"

	echo "%patch$n -p1 -b ${backupext}" >> "$tmpdir/patch-list-prep.txt"

	n=$(($n + 1))

done < "$tmpdir/patch-list.txt"

echo "# end of autogenerated patch tag list" >> "$tmpdir/patch-list-tags.txt"

echo "# end of autogenerated prep patch list" >> "$tmpdir/patch-list-prep.txt"

echo "Results in tmp dir \`$tmpdir':"

echo

cat "$tmpdir/patch-list-tags.txt"

echo

cat "$tmpdir/patch-list-prep.txt"

echo

echo "Run \`rm -rf \"$(basename "$tmpdir")\"' when you are finished with the files."

# End of file.