#!/bin/sh
#
# Copyright (c) 2005, Linus Torvalds
# Copyright (c) 2005, Junio C Hamano
# 
# Clone a repository into a different directory that does not yet exist.

# See git-sh-setup why.
unset CDPATH

usage() {
        echo >&2 "Usage: $0 [-l [-s]] [-q] [-u <upload-pack>] [-o <name>] [-n] <repo> [<dir>]"
        exit 1
}

get_repo_base() {
        (cd "$1" && (cd .git ; pwd)) 2> /dev/null
}

if [ -n "$GIT_SSL_NO_VERIFY" ]; then
    curl_extra_args="-k"
fi

http_fetch () {
        # $1 = Remote, $2 = Local
        curl -nsfL $curl_extra_args "$1" >"$2"
}

clone_dumb_http () {
        # $1 - remote, $2 - local
        cd "$2" &&
        clone_tmp='.git/clone-tmp' &&
        mkdir -p "$clone_tmp" || exit 1
        http_fetch "$1/info/refs" "$clone_tmp/refs" || {
                echo >&2 "Cannot get remote repository information.
Perhaps git-update-server-info needs to be run there?"
                exit 1;
        }
        while read sha1 refname
        do
                name=`expr "$refname" : 'refs/\(.*\)'` &&
                case "$name" in
                *^*)    ;;
                *)
                        git-http-fetch -v -a -w "$name" "$name" "$1/" || exit 1
                esac
        done <"$clone_tmp/refs"
        rm -fr "$clone_tmp"
}

quiet=
use_local=no
local_shared=no
no_checkout=
upload_pack=
origin=origin
while
        case "$#,$1" in
        0,*) break ;;
        *,-n) no_checkout=yes ;;
        *,-l|*,--l|*,--lo|*,--loc|*,--loca|*,--local) use_local=yes ;;
        *,-s|*,--s|*,--sh|*,--sha|*,--shar|*,--share|*,--shared) 
          local_shared=yes; use_local=yes ;;
        *,-q|*,--quiet) quiet=-q ;;
        1,-o) usage;;
        *,-o)
                git-check-ref-format "$2" || {
                    echo >&2 "'$2' is not suitable for a branch name"
                    exit 1
                }
                origin="$2"; shift
                ;;
        1,-u|1,--upload-pack) usage ;;
        *,-u|*,--upload-pack)
                shift
                upload_pack="--exec=$1" ;;
        *,-*) usage ;;
        *) break ;;
        esac
do
        shift
done

# Turn the source into an absolute path if
# it is local
repo="$1"
local=no
if base=$(get_repo_base "$repo"); then
        repo="$base"
        local=yes
fi

dir="$2"
# Try using "humanish" part of source repo if user didn't specify one
[ -z "$dir" ] && dir=$(echo "$repo" | sed -e 's|/$||' -e 's|:*/*\.git$||' -e 's|.*/||g')
[ -e "$dir" ] && echo "$dir already exists." && usage
mkdir -p "$dir" &&
D=$(
        (cd "$dir" && git-init-db && pwd)
) &&
test -d "$D" || usage

# We do local magic only when the user tells us to.
case "$local,$use_local" in
yes,yes)
        ( cd "$repo/objects" ) || {
                echo >&2 "-l flag seen but $repo is not local."
                exit 1
        }

        case "$local_shared" in
        no)
            # See if we can hardlink and drop "l" if not.
            sample_file=$(cd "$repo" && \
                          find objects -type f -print | sed -e 1q)

            # objects directory should not be empty since we are cloning!
            test -f "$repo/$sample_file" || exit

            l=
            if ln "$repo/$sample_file" "$D/.git/objects/sample" 2>/dev/null
            then
                    l=l
            fi &&
            rm -f "$D/.git/objects/sample" &&
            cd "$repo" &&
            find objects -depth -print | cpio -puamd$l "$D/.git/" || exit 1
            ;;
        yes)
            mkdir -p "$D/.git/objects/info"
            {
                test -f "$repo/objects/info/alternates" &&
                cat "$repo/objects/info/alternates";
                echo "$repo/objects"
            } >"$D/.git/objects/info/alternates"
            ;;
        esac

        # Make a duplicate of refs and HEAD pointer
        HEAD=
        if test -f "$repo/HEAD"
        then
                HEAD=HEAD
        fi
        (cd "$repo" && tar cf - refs $HEAD) |
        (cd "$D/.git" && tar xf -) || exit 1
        ;;
*)
        case "$repo" in
        rsync://*)
                rsync $quiet -av --ignore-existing  \
                        --exclude info "$repo/objects/" "$D/.git/objects/" &&
                rsync $quiet -av --ignore-existing  \
                        --exclude info "$repo/refs/" "$D/.git/refs/" || 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 "$repo/objects/info/alternates" \
                        "$D/.git/TMP_ALT" 2>/dev/null ||
                        rm -f "$D/.git/TMP_ALT"
                if test -f "$D/.git/TMP_ALT"
                then
                    ( cd "$D" &&
                      . git-parse-remote &&
                      resolve_alternates "$repo" <"./.git/TMP_ALT" ) |
                    while read alt
                    do
                        case "$alt" in 'bad alternate: '*) die "$alt";; esac
                        case "$quiet" in
                        '')     echo >&2 "Getting alternate: $alt" ;;
                        esac
                        rsync $quiet -av --ignore-existing  \
                            --exclude info "$alt" "$D/.git/objects" || exit
                    done
                    rm -f "$D/.git/TMP_ALT"
                fi
                ;;
        http://*)
                clone_dumb_http "$repo" "$D"
                ;;
        *)
                cd "$D" && case "$upload_pack" in
                '') git-clone-pack $quiet "$repo" ;;
                *) git-clone-pack $quiet "$upload_pack" "$repo" ;;
                esac || {
                        echo >&2 "clone-pack from '$repo' failed."
                        exit 1
                }
                ;;
        esac
        ;;
esac

cd "$D" || exit

if test -f ".git/HEAD"
then
        head_points_at=`git-symbolic-ref HEAD`
        case "$head_points_at" in
        refs/heads/*)
                head_points_at=`expr "$head_points_at" : 'refs/heads/\(.*\)'`
                mkdir -p .git/remotes &&
                echo >.git/remotes/origin \
                "URL: $repo
Pull: $head_points_at:$origin" &&
                git-update-ref "refs/heads/$origin" $(git-rev-parse HEAD) &&
                find .git/refs/heads -type f -print |
                while read ref
                do
                        head=`expr "$ref" : '.git/refs/heads/\(.*\)'` &&
                        test "$head_points_at" = "$head" ||
                        test "$origin" = "$head" ||
                        echo "Pull: ${head}:${head}"
                done >>.git/remotes/origin
        esac

        case "$no_checkout" in
        '')
                git checkout
        esac
fi