#!/bin/sh
#
# Copyright (c) 2005, 2006 Junio C Hamano

USAGE='[--signoff] [--dotest=<dir>] [--utf8] [--binary] [--3way]
  [--interactive] [--whitespace=<option>] <mbox>...
  or, when resuming [--skip | --resolved]'
. git-sh-setup

git var GIT_COMMITTER_IDENT >/dev/null || exit

stop_here () {
    echo "$1" >"$dotest/next"
    exit 1
}

stop_here_user_resolve () {
    if [ -n "$resolvemsg" ]; then
            echo "$resolvemsg"
            stop_here $1
    fi
    cmdline=$(basename $0)
    if test '' != "$interactive"
    then
        cmdline="$cmdline -i"
    fi
    if test '' != "$threeway"
    then
        cmdline="$cmdline -3"
    fi
    if test '.dotest' != "$dotest"
    then
        cmdline="$cmdline -d=$dotest"
    fi
    echo "When you have resolved this problem run \"$cmdline --resolved\"."
    echo "If you would prefer to skip this patch, instead run \"$cmdline --skip\"."

    stop_here $1
}

go_next () {
        rm -f "$dotest/$msgnum" "$dotest/msg" "$dotest/msg-clean" \
                "$dotest/patch" "$dotest/info"
        echo "$next" >"$dotest/next"
        this=$next
}

fall_back_3way () {
    O_OBJECT=`cd "$GIT_OBJECT_DIRECTORY" && pwd`

    rm -fr "$dotest"/patch-merge-*
    mkdir "$dotest/patch-merge-tmp-dir"

    # First see if the patch records the index info that we can use.
    if git-apply -z --index-info "$dotest/patch" \
        >"$dotest/patch-merge-index-info" 2>/dev/null &&
        GIT_INDEX_FILE="$dotest/patch-merge-tmp-index" \
        git-update-index -z --index-info <"$dotest/patch-merge-index-info" &&
        GIT_INDEX_FILE="$dotest/patch-merge-tmp-index" \
        git-write-tree >"$dotest/patch-merge-base+" &&
        # index has the base tree now.
        GIT_INDEX_FILE="$dotest/patch-merge-tmp-index" \
        git-apply $binary --cached <"$dotest/patch"
    then
        echo Using index info to reconstruct a base tree...
        mv "$dotest/patch-merge-base+" "$dotest/patch-merge-base"
        mv "$dotest/patch-merge-tmp-index" "$dotest/patch-merge-index"
    fi

    test -f "$dotest/patch-merge-index" &&
    his_tree=$(GIT_INDEX_FILE="$dotest/patch-merge-index" git-write-tree) &&
    orig_tree=$(cat "$dotest/patch-merge-base") &&
    rm -fr "$dotest"/patch-merge-* || exit 1

    echo Falling back to patching base and 3-way merge...

    # This is not so wrong.  Depending on which base we picked,
    # orig_tree may be wildly different from ours, but his_tree
    # has the same set of wildly different changes in parts the
    # patch did not touch, so resolve ends up canceling them,
    # saying that we reverted all those changes.

    git-merge-resolve $orig_tree -- HEAD $his_tree || {
            if test -d "$GIT_DIR/rr-cache"
            then
                git-rerere
            fi
            echo Failed to merge in the changes.
            exit 1
    }
}

prec=4
rloga=am
dotest=.dotest sign= utf8= keep= skip= interactive= resolved= binary= ws= resolvemsg=

while case "$#" in 0) break;; esac
do
        case "$1" in
        -d=*|--d=*|--do=*|--dot=*|--dote=*|--dotes=*|--dotest=*)
        dotest=`expr "z$1" : 'z-[^=]*=\(.*\)'`; shift ;;
        -d|--d|--do|--dot|--dote|--dotes|--dotest)
        case "$#" in 1) usage ;; esac; shift
        dotest="$1"; shift;;

        -i|--i|--in|--int|--inte|--inter|--intera|--interac|--interact|\
        --interacti|--interactiv|--interactive)
        interactive=t; shift ;;

        -b|--b|--bi|--bin|--bina|--binar|--binary)
        binary=t; shift ;;

        -3|--3|--3w|--3wa|--3way)
        threeway=t; shift ;;
        -s|--s|--si|--sig|--sign|--signo|--signof|--signoff)
        sign=t; shift ;;
        -u|--u|--ut|--utf|--utf8)
        utf8=t; shift ;;
        -k|--k|--ke|--kee|--keep)
        keep=t; shift ;;

        -r|--r|--re|--res|--reso|--resol|--resolv|--resolve|--resolved)
        resolved=t; shift ;;

        --sk|--ski|--skip)
        skip=t; shift ;;

        --whitespace=*)
        ws=$1; shift ;;

        --resolvemsg=*)
        resolvemsg=$(echo "$1" | sed -e "s/^--resolvemsg=//"); shift ;;

        --reflog-action=*)
        rloga=`expr "z$1" : 'z-[^=]*=\(.*\)'`; shift ;;

        --)
        shift; break ;;
        -*)
        usage ;;
        *)
        break ;;
        esac
done

# If the dotest directory exists, but we have finished applying all the
# patches in them, clear it out.
if test -d "$dotest" &&
   last=$(cat "$dotest/last") &&
   next=$(cat "$dotest/next") &&
   test $# != 0 &&
   test "$next" -gt "$last"
then
   rm -fr "$dotest"
fi

if test -d "$dotest"
then
        test ",$#," = ",0," ||
        die "previous dotest directory $dotest still exists but mbox given."
        resume=yes
else
        # Make sure we are not given --skip nor --resolved
        test ",$skip,$resolved," = ,,, ||
                die "Resolve operation not in progress, we are not resuming."

        # Start afresh.
        mkdir -p "$dotest" || exit

        git-mailsplit -d"$prec" -o"$dotest" -b -- "$@" > "$dotest/last" ||  {
                rm -fr "$dotest"
                exit 1
        }

        # -b, -s, -u, -k and --whitespace flags are kept for the
        # resuming session after a patch failure.
        # -3 and -i can and must be given when resuming.
        echo "$binary" >"$dotest/binary"
        echo " $ws" >"$dotest/whitespace"
        echo "$sign" >"$dotest/sign"
        echo "$utf8" >"$dotest/utf8"
        echo "$keep" >"$dotest/keep"
        echo 1 >"$dotest/next"
fi

case "$resolved" in
'')
        files=$(git-diff-index --cached --name-only HEAD) || exit
        if [ "$files" ]; then
           echo "Dirty index: cannot apply patches (dirty: $files)" >&2
           exit 1
        fi
esac

if test "$(cat "$dotest/binary")" = t
then
        binary=--allow-binary-replacement
fi
if test "$(cat "$dotest/utf8")" = t
then
        utf8=-u
fi
if test "$(cat "$dotest/keep")" = t
then
        keep=-k
fi
ws=`cat "$dotest/whitespace"`
if test "$(cat "$dotest/sign")" = t
then
        SIGNOFF=`git-var GIT_COMMITTER_IDENT | sed -e '
                        s/>.*/>/
                        s/^/Signed-off-by: /'
                `
else
        SIGNOFF=
fi

last=`cat "$dotest/last"`
this=`cat "$dotest/next"`
if test "$skip" = t
then
        this=`expr "$this" + 1`
        resume=
fi

if test "$this" -gt "$last"
then
        echo Nothing to do.
        rm -fr "$dotest"
        exit
fi

while test "$this" -le "$last"
do
        msgnum=`printf "%0${prec}d" $this`
        next=`expr "$this" + 1`
        test -f "$dotest/$msgnum" || {
                resume=
                go_next
                continue
        }

        # If we are not resuming, parse and extract the patch information
        # into separate files:
        #  - info records the authorship and title
        #  - msg is the rest of commit log message
        #  - patch is the patch body.
        #
        # When we are resuming, these files are either already prepared
        # by the user, or the user can tell us to do so by --resolved flag.
        case "$resume" in
        '')
                git-mailinfo $keep $utf8 "$dotest/msg" "$dotest/patch" \
                        <"$dotest/$msgnum" >"$dotest/info" ||
                        stop_here $this
                git-stripspace < "$dotest/msg" > "$dotest/msg-clean"
                ;;
        esac

        GIT_AUTHOR_NAME="$(sed -n '/^Author/ s/Author: //p' "$dotest/info")"
        GIT_AUTHOR_EMAIL="$(sed -n '/^Email/ s/Email: //p' "$dotest/info")"
        GIT_AUTHOR_DATE="$(sed -n '/^Date/ s/Date: //p' "$dotest/info")"

        if test -z "$GIT_AUTHOR_EMAIL"
        then
                echo "Patch does not have a valid e-mail address."
                stop_here $this
        fi

        export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE

        SUBJECT="$(sed -n '/^Subject/ s/Subject: //p' "$dotest/info")"
        case "$keep_subject" in -k)  SUBJECT="[PATCH] $SUBJECT" ;; esac

        case "$resume" in
        '')
            if test '' != "$SIGNOFF"
            then
                LAST_SIGNED_OFF_BY=`
                    sed -ne '/^Signed-off-by: /p' \
                    "$dotest/msg-clean" |
                    tail -n 1
                `
                ADD_SIGNOFF=`
                    test "$LAST_SIGNED_OFF_BY" = "$SIGNOFF" || {
                    test '' = "$LAST_SIGNED_OFF_BY" && echo
                    echo "$SIGNOFF"
                }`
            else
                ADD_SIGNOFF=
            fi
            {
                echo "$SUBJECT"
                if test -s "$dotest/msg-clean"
                then
                        echo
                        cat "$dotest/msg-clean"
                fi
                if test '' != "$ADD_SIGNOFF"
                then
                        echo "$ADD_SIGNOFF"
                fi
            } >"$dotest/final-commit"
            ;;
        *)
                case "$resolved$interactive" in
                tt)
                        # This is used only for interactive view option.
                        git-diff-index -p --cached HEAD >"$dotest/patch"
                        ;;
                esac
        esac

        resume=
        if test "$interactive" = t
        then
            test -t 0 ||
            die "cannot be interactive without stdin connected to a terminal."
            action=again
            while test "$action" = again
            do
                echo "Commit Body is:"
                echo "--------------------------"
                cat "$dotest/final-commit"
                echo "--------------------------"
                printf "Apply? [y]es/[n]o/[e]dit/[v]iew patch/[a]ccept all "
                read reply
                case "$reply" in
                [yY]*) action=yes ;;
                [aA]*) action=yes interactive= ;;
                [nN]*) action=skip ;;
                [eE]*) "${VISUAL:-${EDITOR:-vi}}" "$dotest/final-commit"
                       action=again ;;
                [vV]*) action=again
                       LESS=-S ${PAGER:-less} "$dotest/patch" ;;
                *)     action=again ;;
                esac
            done
        else
            action=yes
        fi

        if test $action = skip
        then
                go_next
                continue
        fi

        if test -x "$GIT_DIR"/hooks/applypatch-msg
        then
                "$GIT_DIR"/hooks/applypatch-msg "$dotest/final-commit" ||
                stop_here $this
        fi

        echo
        echo "Applying '$SUBJECT'"
        echo

        case "$resolved" in
        '')
                git-apply $binary --index $ws "$dotest/patch"
                apply_status=$?
                ;;
        t)
                # Resolved means the user did all the hard work, and
                # we do not have to do any patch application.  Just
                # trust what the user has in the index file and the
                # working tree.
                resolved=
                changed="$(git-diff-index --cached --name-only HEAD)"
                if test '' = "$changed"
                then
                        echo "No changes - did you forget update-index?"
                        stop_here_user_resolve $this
                fi
                unmerged=$(git-ls-files -u)
                if test -n "$unmerged"
                then
                        echo "You still have unmerged paths in your index"
                        echo "did you forget update-index?"
                        stop_here_user_resolve $this
                fi
                apply_status=0
                ;;
        esac

        if test $apply_status = 1 && test "$threeway" = t
        then
                if (fall_back_3way)
                then
                    # Applying the patch to an earlier tree and merging the
                    # result may have produced the same tree as ours.
                    changed="$(git-diff-index --cached --name-only HEAD)"
                    if test '' = "$changed"
                    then
                            echo No changes -- Patch already applied.
                            go_next
                            continue
                    fi
                    # clear apply_status -- we have successfully merged.
                    apply_status=0
                fi
        fi
        if test $apply_status != 0
        then
                echo Patch failed at $msgnum.
                stop_here_user_resolve $this
        fi

        if test -x "$GIT_DIR"/hooks/pre-applypatch
        then
                "$GIT_DIR"/hooks/pre-applypatch || stop_here $this
        fi

        tree=$(git-write-tree) &&
        echo Wrote tree $tree &&
        parent=$(git-rev-parse --verify HEAD) &&
        commit=$(git-commit-tree $tree -p $parent <"$dotest/final-commit") &&
        echo Committed: $commit &&
        git-update-ref -m "$rloga: $SUBJECT" HEAD $commit $parent ||
        stop_here $this

        if test -x "$GIT_DIR"/hooks/post-applypatch
        then
                "$GIT_DIR"/hooks/post-applypatch
        fi

        go_next
done

rm -fr "$dotest"