#!/bin/sh
#
. git-sh-setup || die "Not a git archive"
. git-parse-remote
_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"

append=
force=
update_head_ok=
while case "$#" in 0) break ;; esac
do
        case "$1" in
        -a|--a|--ap|--app|--appe|--appen|--append)
                append=t
                ;;
        -f|--f|--fo|--for|--forc|--force)
                force=t
                ;;
        -u|--u|--up|--upd|--upda|--updat|--update|--update-|--update-h|\
        --update-he|--update-hea|--update-head|--update-head-|\
        --update-head-o|--update-head-ok)
                update_head_ok=t
                ;;
        *)
                break
                ;;
        esac
        shift
done

case "$#" in
0)
        test -f "$GIT_DIR/branches/origin" ||
                test -f "$GIT_DIR/remotes/origin" ||
                        die "Where do you want to fetch from today?"
        set origin ;;
esac

remote_nick="$1"
remote=$(get_remote_url "$@")
refs=
rref=
rsync_slurped_objects=

if test "" = "$append"
then
        : >$GIT_DIR/FETCH_HEAD
fi

append_fetch_head () {
    head_="$1"
    remote_="$2"
    remote_name_="$3"
    remote_nick_="$4"
    local_name_="$5"

    # remote-nick is the URL given on the command line (or a shorthand)
    # remote-name is the $GIT_DIR relative refs/ path we computed
    # for this refspec.
    case "$remote_name_" in
    HEAD)
        note_= ;;
    refs/heads/*)
        note_="$(expr "$remote_name_" : 'refs/heads/\(.*\)')"
        note_="branch '$note_' of " ;;
    refs/tags/*)
        note_="$(expr "$remote_name_" : 'refs/tags/\(.*\)')"
        note_="tag '$note_' of " ;;
    *)
        note_="$remote_name of " ;;
    esac
    remote_1_=$(expr "$remote_" : '\(.*\)\.git/*$') &&
        remote_="$remote_1_"
    note_="$note_$remote_"

    # 2.6.11-tree tag would not be happy to be fed to resolve.
    if git-cat-file commit "$head_" >/dev/null 2>&1
    then
        headc_=$(git-rev-parse --verify "$head_^0") || exit
        echo "$headc_   $note_" >>$GIT_DIR/FETCH_HEAD
        echo >&2 "* committish: $head_"
        echo >&2 "  $note_"
    else
        echo >&2 "* non-commit: $head_"
        echo >&2 "  $note_"
    fi
    if test "$local_name_" != ""
    then
        # We are storing the head locally.  Make sure that it is
        # a fast forward (aka "reverse push").
        fast_forward_local "$local_name_" "$head_" "$note_"
    fi
}

fast_forward_local () {
    mkdir -p "$(dirname "$GIT_DIR/$1")"
    case "$1" in
    refs/tags/*)
        # Tags need not be pointing at commits so there
        # is no way to guarantee "fast-forward" anyway.
        if test -f "$GIT_DIR/$1"
        then
                echo >&2 "* $1: updating with $3"
        else
                echo >&2 "* $1: storing $3"
        fi
        echo "$2" >"$GIT_DIR/$1" ;;

    refs/heads/*)
        # NEEDSWORK: use the same cmpxchg protocol here.
        echo "$2" >"$GIT_DIR/$1.lock"
        if test -f "$GIT_DIR/$1"
        then
            local=$(git-rev-parse --verify "$1^0") &&
            mb=$(git-merge-base "$local" "$2") &&
            case "$2,$mb" in
            $local,*)
                echo >&2 "* $1: same as $3"
                ;;
            *,$local)
                echo >&2 "* $1: fast forward to $3"
                ;;
            *)
                false
                ;;
            esac || {
                echo >&2 "* $1: does not fast forward to $3;"
                case "$force,$single_force" in
                t,* | *,t)
                        echo >&2 "  forcing update."
                        ;;
                *)
                        mv "$GIT_DIR/$1.lock" "$GIT_DIR/$1.remote"
                        echo >&2 "  leaving it in '$1.remote'"
                        ;;
                esac
            }
        else
                echo >&2 "* $1: storing $3"
        fi
        test -f "$GIT_DIR/$1.lock" &&
            mv "$GIT_DIR/$1.lock" "$GIT_DIR/$1"
        ;;
    esac
}

case "$update_head_ok" in
'')
        orig_head=$(cat "$GIT_DIR/HEAD" 2>/dev/null)
        ;;
esac

for ref in $(get_remote_refs_for_fetch "$@")
do
    refs="$refs $ref"

    # These are relative path from $GIT_DIR, typically starting at refs/
    # but may be HEAD
    if expr "$ref" : '\+' >/dev/null
    then
        single_force=t
        ref=$(expr "$ref" : '\+\(.*\)')
    else
        single_force=
    fi
    remote_name=$(expr "$ref" : '\([^:]*\):')
    local_name=$(expr "$ref" : '[^:]*:\(.*\)')

    rref="$rref $remote_name"

    # There are transports that can fetch only one head at a time...
    case "$remote" in
    http://* | https://*)
        if [ -n "$GIT_SSL_NO_VERIFY" ]; then
            curl_extra_args="-k"
        fi
        head=$(curl -nsf $curl_extra_args "$remote/$remote_name") &&
        expr "$head" : "$_x40\$" >/dev/null ||
                die "Failed to fetch $remote_name from $remote"
        echo >&2 Fetching "$remote_name from $remote" using http
        git-http-fetch -v -a "$head" "$remote/" || exit
        ;;
    rsync://*)
        TMP_HEAD="$GIT_DIR/TMP_HEAD"
        rsync -L -q "$remote/$remote_name" "$TMP_HEAD" || exit 1
        head=$(git-rev-parse TMP_HEAD)
        rm -f "$TMP_HEAD"
        test "$rsync_slurped_objects" || {
            rsync -av --ignore-existing --exclude info \
                "$remote/objects/" "$GIT_OBJECT_DIRECTORY/" || exit

            # Look at objects/info/alternates for rsync -- http will
            # support it natively and git native ones will do it on the remote
            # end.  Not having that file is not a crime.
            rsync -q "$remote/objects/info/alternates" \
                "$GIT_DIR/TMP_ALT" 2>/dev/null ||
                rm -f "$GIT_DIR/TMP_ALT"
            if test -f "$GIT_DIR/TMP_ALT"
            then
                resolve_alternates "$remote" <"$GIT_DIR/TMP_ALT" |
                while read alt
                do
                    case "$alt" in 'bad alternate: '*) die "$alt";; esac
                    echo >&2 "Getting alternate: $alt"
                    rsync -av --ignore-existing --exclude info \
                    "$alt" "$GIT_OBJECT_DIRECTORY/" || exit
                done
                rm -f "$GIT_DIR/TMP_ALT"
            fi
            rsync_slurped_objects=t
        }
        ;;
    *)
        # We will do git native transport with just one call later.
        continue ;;
    esac

    append_fetch_head "$head" "$remote" "$remote_name" "$remote_nick" "$local_name"

done

case "$remote" in
http://* | https://* | rsync://* )
    ;; # we are already done.
*)
    (
        git-fetch-pack "$remote" $rref || echo failed "$remote"
    ) |
    while read sha1 remote_name
    do
        case "$sha1" in
        failed)
                echo >&2 "Fetch failure: $remote"
                exit 1 ;;
        esac
        found=
        single_force=
        for ref in $refs
        do
            case "$ref" in
            +$remote_name:*)
                single_force=t
                found="$ref"
                break ;;
            $remote_name:*)
                found="$ref"
                break ;;
            esac
        done

        local_name=$(expr "$found" : '[^:]*:\(.*\)')
        append_fetch_head "$sha1" "$remote" "$remote_name" "$remote_nick" "$local_name"
    done || exit
    ;;
esac

# If the original head was empty (i.e. no "master" yet), or
# if we were told not to worry, we do not have to check.
case ",$update_head_ok,$orig_head," in
*,, | t,* )
        ;;
*)
        curr_head=$(cat "$GIT_DIR/HEAD" 2>/dev/null)
        if test "$curr_head" != "$orig_head"
        then
                echo "$orig_head" >$GIT_DIR/HEAD
                die "Cannot fetch into the current branch."
        fi
        ;;
esac