#!/bin/bash
DIR="$(dirname $1)"
FILE="$1"
BRANCH="${2:-$(git describe --contains --all HEAD)}"
git branch |grep ${BRANCH}- | xargs git branch -D
git tag |grep before-${BRANCH} | xargs git tag -d
git tag "before-$BRANCH"
(grep %patch "$FILE" || grep "^Patch.*:" "$FILE") | awk '{ print $1 " " $2 }' | sed -e 's/%p/P/' -e 's/:.*//' | while read patch_line patch_level
do
        if [ -z "$patch_level" ]; then
                patch_level="-p1"
        fi

        grep $(echo $patch_line:) "$FILE" | awk '{ print $2 }' | while read patch
        do
                git tag "before-$BRANCH-$patch"
                git checkout -b "$BRANCH-$patch"
                git am -3 --ignore-whitespace $patch_level "$DIR/$patch"
                cat "$DIR/$patch" | git am -3 --ignore-whitespace $patch_level -
                if [ $? != 0 ]; then
                        git am --abort
                        git reset --hard "before-$BRANCH-$patch"
                        echo "git-am failed, falling back to patch"
                        patch --fuzz=999 -l $patch_level < "$DIR/$patch" && git add -u
                        git commit -a -m "$patch"
                fi

                git checkout $BRANCH
                git rebase "$BRANCH-$patch"
        done
done