#!/bin/sh

# git-ls-remote could be called from outside a git managed repository;
# this would fail in that case and would issue an error message.
GIT_DIR=$(git-rev-parse --git-dir 2>/dev/null) || :;

get_data_source () {
        case "$1" in
        */*)
                # Not so fast.  This could be the partial URL shorthand...
                token=$(expr "z$1" : 'z\([^/]*\)/')
                remainder=$(expr "z$1" : 'z[^/]*/\(.*\)')
                if test -f "$GIT_DIR/branches/$token"
                then
                        echo branches-partial
                else
                        echo ''
                fi
                ;;
        *)
                if test -f "$GIT_DIR/remotes/$1"
                then
                        echo remotes
                elif test -f "$GIT_DIR/branches/$1"
                then
                        echo branches
                else
                        echo ''
                fi ;;
        esac
}

get_remote_url () {
        data_source=$(get_data_source "$1")
        case "$data_source" in
        '')
                echo "$1" ;;
        remotes)
                sed -ne '/^URL: */{
                        s///p
                        q
                }' "$GIT_DIR/remotes/$1" ;;
        branches)
                sed -e 's/#.*//' "$GIT_DIR/branches/$1" ;;
        branches-partial)
                token=$(expr "z$1" : 'z\([^/]*\)/')
                remainder=$(expr "z$1" : 'z[^/]*/\(.*\)')
                url=$(sed -e 's/#.*//' "$GIT_DIR/branches/$token")
                echo "$url/$remainder"
                ;;
        *)
                die "internal error: get-remote-url $1" ;;
        esac
}

get_remote_default_refs_for_push () {
        data_source=$(get_data_source "$1")
        case "$data_source" in
        '' | branches | branches-partial)
                ;; # no default push mapping, just send matching refs.
        remotes)
                sed -ne '/^Push: */{
                        s///p
                }' "$GIT_DIR/remotes/$1" ;;
        *)
                die "internal error: get-remote-default-ref-for-push $1" ;;
        esac
}

# Subroutine to canonicalize remote:local notation.
canon_refs_list_for_fetch () {
        # Leave only the first one alone; add prefix . to the rest
        # to prevent the secondary branches to be merged by default.
        dot_prefix=
        for ref
        do
                force=
                case "$ref" in
                +*)
                        ref=$(expr "z$ref" : 'z+\(.*\)')
                        force=+
                        ;;
                esac
                expr "z$ref" : 'z.*:' >/dev/null || ref="${ref}:"
                remote=$(expr "z$ref" : 'z\([^:]*\):')
                local=$(expr "z$ref" : 'z[^:]*:\(.*\)')
                case "$remote" in
                '') remote=HEAD ;;
                refs/heads/* | refs/tags/* | refs/remotes/*) ;;
                heads/* | tags/* | remotes/* ) remote="refs/$remote" ;;
                *) remote="refs/heads/$remote" ;;
                esac
                case "$local" in
                '') local= ;;
                refs/heads/* | refs/tags/* | refs/remotes/*) ;;
                heads/* | tags/* | remotes/* ) local="refs/$local" ;;
                *) local="refs/heads/$local" ;;
                esac

                if local_ref_name=$(expr "z$local" : 'zrefs/\(.*\)')
                then
                   git-check-ref-format "$local_ref_name" ||
                   die "* refusing to create funny ref '$local_ref_name' locally"
                fi
                echo "${dot_prefix}${force}${remote}:${local}"
                dot_prefix=.
        done
}

# Returns list of src: (no store), or src:dst (store)
get_remote_default_refs_for_fetch () {
        data_source=$(get_data_source "$1")
        case "$data_source" in
        '' | branches-partial)
                echo "HEAD:" ;;
        branches)
                remote_branch=$(sed -ne '/#/s/.*#//p' "$GIT_DIR/branches/$1")
                case "$remote_branch" in '') remote_branch=master ;; esac
                echo "refs/heads/${remote_branch}:refs/heads/$1"
                ;;
        remotes)
                # This prefixes the second and later default refspecs
                # with a '.', to signal git-fetch to mark them
                # not-for-merge.
                canon_refs_list_for_fetch $(sed -ne '/^Pull: */{
                                                s///p
                                        }' "$GIT_DIR/remotes/$1")
                ;;
        *)
                die "internal error: get-remote-default-ref-for-push $1" ;;
        esac
}

get_remote_refs_for_push () {
        case "$#" in
        0) die "internal error: get-remote-refs-for-push." ;;
        1) get_remote_default_refs_for_push "$@" ;;
        *) shift; echo "$@" ;;
        esac
}

get_remote_refs_for_fetch () {
        case "$#" in
        0)
            die "internal error: get-remote-refs-for-fetch." ;;
        1)
            get_remote_default_refs_for_fetch "$@" ;;
        *)
            shift
            tag_just_seen=
            for ref
            do
                if test "$tag_just_seen"
                then
                    echo "refs/tags/${ref}:refs/tags/${ref}"
                    tag_just_seen=
                    continue
                else
                    case "$ref" in
                    tag)
                        tag_just_seen=yes
                        continue
                        ;;
                    esac
                fi
                canon_refs_list_for_fetch "$ref"
            done
            ;;
        esac
}

resolve_alternates () {
        # original URL (xxx.git)
        top_=`expr "z$1" : 'z\([^:]*:/*[^/]*\)/'`
        while read path
        do
                case "$path" in
                \#* | '')
                        continue ;;
                /*)
                        echo "$top_$path/" ;;
                ../*)
                        # relative -- ugly but seems to work.
                        echo "$1/objects/$path/" ;;
                *)
                        # exit code may not be caught by the reader.
                        echo "bad alternate: $path"
                        exit 1 ;;
                esac
        done
}