#!/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

die() {
        echo >&2 "$@"
        exit 1
}

usage() {
        die "Usage: $0 [--template=<template_directory>] [--reference <reference-repo>] [--bare] [-l [-s]] [-q] [-u <upload-pack>] [--origin <name>] [--depth <n>] [-n] <repo> [<dir>]"
}

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_DIR/clone-tmp" &&
        mkdir -p "$clone_tmp" || exit 1
        if [ -n "$GIT_CURL_FTP_NO_EPSV" -o \
                "`git-repo-config --bool http.noEPSV`" = true ]; then
                curl_extra_args="${curl_extra_args} --disable-epsv"
        fi
        http_fetch "$1/info/refs" "$clone_tmp/refs" ||
                die "Cannot get remote repository information.
Perhaps git-update-server-info needs to be run there?"
        while read sha1 refname
        do
                name=`expr "z$refname" : 'zrefs/\(.*\)'` &&
                case "$name" in
                *^*)    continue;;
                esac
                case "$bare,$name" in
                yes,* | ,heads/* | ,tags/*) ;;
                *)      continue ;;
                esac
                if test -n "$use_separate_remote" &&
                   branch_name=`expr "z$name" : 'zheads/\(.*\)'`
                then
                        tname="remotes/$origin/$branch_name"
                else
                        tname=$name
                fi
                git-http-fetch -v -a -w "$tname" "$name" "$1/" || exit 1
        done <"$clone_tmp/refs"
        rm -fr "$clone_tmp"
        http_fetch "$1/HEAD" "$GIT_DIR/REMOTE_HEAD" ||
        rm -f "$GIT_DIR/REMOTE_HEAD"
}

# Read git-fetch-pack -k output and store the remote branches.
copy_refs='
use File::Path qw(mkpath);
use File::Basename qw(dirname);
my $git_dir = $ARGV[0];
my $use_separate_remote = $ARGV[1];
my $origin = $ARGV[2];

my $branch_top = ($use_separate_remote ? "remotes/$origin" : "heads");
my $tag_top = "tags";

sub store {
        my ($sha1, $name, $top) = @_;
        $name = "$git_dir/refs/$top/$name";
        mkpath(dirname($name));
        open O, ">", "$name";
        print O "$sha1\n";
        close O;
}

open FH, "<", "$git_dir/CLONE_HEAD";
while (<FH>) {
        my ($sha1, $name) = /^([0-9a-f]{40})\s(.*)$/;
        next if ($name =~ /\^\173/);
        if ($name eq "HEAD") {
                open O, ">", "$git_dir/REMOTE_HEAD";
                print O "$sha1\n";
                close O;
                next;
        }
        if ($name =~ s/^refs\/heads\///) {
                store($sha1, $name, $branch_top);
                next;
        }
        if ($name =~ s/^refs\/tags\///) {
                store($sha1, $name, $tag_top);
                next;
        }
}
close FH;
'

quiet=
local=no
use_local=no
local_shared=no
unset template
no_checkout=
upload_pack=
bare=
reference=
origin=
origin_override=
use_separate_remote=t
depth=
while
        case "$#,$1" in
        0,*) break ;;
        *,-n|*,--no|*,--no-|*,--no-c|*,--no-ch|*,--no-che|*,--no-chec|\
        *,--no-check|*,--no-checko|*,--no-checkou|*,--no-checkout)
          no_checkout=yes ;;
        *,--na|*,--nak|*,--nake|*,--naked|\
        *,-b|*,--b|*,--ba|*,--bar|*,--bare) bare=yes ;;
        *,-l|*,--l|*,--lo|*,--loc|*,--loca|*,--local) use_local=yes ;;
        *,-s|*,--s|*,--sh|*,--sha|*,--shar|*,--share|*,--shared) 
          local_shared=yes; use_local=yes ;;
        1,--template) usage ;;
        *,--template)
                shift; template="--template=$1" ;;
        *,--template=*)
          template="$1" ;;
        *,-q|*,--quiet) quiet=-q ;;
        *,--use-separate-remote) ;;
        *,--no-separate-remote)
                die "clones are always made with separate-remote layout" ;;
        1,--reference) usage ;;
        *,--reference)
                shift; reference="$1" ;;
        *,--reference=*)
                reference=`expr "z$1" : 'z--reference=\(.*\)'` ;;
        *,-o|*,--or|*,--ori|*,--orig|*,--origi|*,--origin)
                case "$2" in
                '')
                    usage ;;
                */*)
                    die "'$2' is not suitable for an origin name"
                esac
                git-check-ref-format "heads/$2" ||
                    die "'$2' is not suitable for a branch name"
                test -z "$origin_override" ||
                    die "Do not give more than one --origin options."
                origin_override=yes
                origin="$2"; shift
                ;;
        1,-u|1,--upload-pack) usage ;;
        *,-u|*,--upload-pack)
                shift
                upload_pack="--exec=$1" ;;
        1,--depth) usage;;
        *,--depth)
                shift
                depth="--depth=$1";;
        *,-*) usage ;;
        *) break ;;
        esac
do
        shift
done

repo="$1"
test -n "$repo" ||
    die 'you must specify a repository to clone.'

# --bare implies --no-checkout and --no-separate-remote
if test yes = "$bare"
then
        if test yes = "$origin_override"
        then
                die '--bare and --origin $origin options are incompatible.'
        fi
        no_checkout=yes
        use_separate_remote=
fi

if test -z "$origin"
then
        origin=origin
fi

# Turn the source into an absolute path if
# it is local
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 "$dir" ] && die "destination directory '$dir' already exists."
mkdir -p "$dir" &&
D=$(cd "$dir" && pwd) &&
trap 'err=$?; cd ..; rm -rf "$D"; exit $err' 0
case "$bare" in
yes)
        GIT_DIR="$D" ;;
*)
        GIT_DIR="$D/.git" ;;
esac && export GIT_DIR && git-init ${template+"$template"} || usage

if test -n "$reference"
then
        if test -d "$reference"
        then
                if test -d "$reference/.git/objects"
                then
                        reference="$reference/.git"
                fi
                reference=$(cd "$reference" && pwd)
                echo "$reference/objects" >"$GIT_DIR/objects/info/alternates"
                (cd "$reference" && tar cf - refs) |
                (cd "$GIT_DIR/refs" &&
                 mkdir reference-tmp &&
                 cd reference-tmp &&
                 tar xf -)
        else
                die "reference repository '$reference' is not a local directory."
        fi
fi

rm -f "$GIT_DIR/CLONE_HEAD"

# We do local magic only when the user tells us to.
case "$local,$use_local" in
yes,yes)
        ( cd "$repo/objects" ) ||
                die "-l flag seen but repository '$repo' is not local."

        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" "$GIT_DIR/objects/sample" 2>/dev/null
            then
                    l=l
            fi &&
            rm -f "$GIT_DIR/objects/sample" &&
            cd "$repo" &&
            find objects -depth -print | cpio -pumd$l "$GIT_DIR/" || exit 1
            ;;
        yes)
            mkdir -p "$GIT_DIR/objects/info"
            echo "$repo/objects" >> "$GIT_DIR/objects/info/alternates"
            ;;
        esac
        git-ls-remote "$repo" >"$GIT_DIR/CLONE_HEAD" || exit 1
        ;;
*)
        case "$repo" in
        rsync://*)
                case "$depth" in
                "") ;;
                *) die "shallow over rsync not supported" ;;
                esac
                rsync $quiet -av --ignore-existing  \
                        --exclude info "$repo/objects/" "$GIT_DIR/objects/" ||
                exit
                # Look at objects/info/alternates for rsync -- http will
                # support it natively and git native ones will do it on the
                # remote end.  Not having that file is not a crime.
                rsync -q "$repo/objects/info/alternates" \
                        "$GIT_DIR/TMP_ALT" 2>/dev/null ||
                        rm -f "$GIT_DIR/TMP_ALT"
                if test -f "$GIT_DIR/TMP_ALT"
                then
                    ( cd "$D" &&
                      . git-parse-remote &&
                      resolve_alternates "$repo" <"$GIT_DIR/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" "$GIT_DIR/objects" || exit
                    done
                    rm -f "$GIT_DIR/TMP_ALT"
                fi
                git-ls-remote "$repo" >"$GIT_DIR/CLONE_HEAD" || exit 1
                ;;
        https://*|http://*|ftp://*)
                case "$depth" in
                "") ;;
                *) die "shallow over http or ftp not supported" ;;
                esac
                if test -z "@@NO_CURL@@"
                then
                        clone_dumb_http "$repo" "$D"
                else
                        die "http transport not supported, rebuild Git with curl support"
                fi
                ;;
        *)
                case "$upload_pack" in
                '') git-fetch-pack --all -k $quiet $depth "$repo" ;;
                *) git-fetch-pack --all -k $quiet "$upload_pack" $depth "$repo" ;;
                esac >"$GIT_DIR/CLONE_HEAD" ||
                        die "fetch-pack from '$repo' failed."
                ;;
        esac
        ;;
esac
test -d "$GIT_DIR/refs/reference-tmp" && rm -fr "$GIT_DIR/refs/reference-tmp"

if test -f "$GIT_DIR/CLONE_HEAD"
then
        # Read git-fetch-pack -k output and store the remote branches.
        @@PERL@@ -e "$copy_refs" "$GIT_DIR" "$use_separate_remote" "$origin" ||
        exit
fi

cd "$D" || exit

if test -z "$bare" && test -f "$GIT_DIR/REMOTE_HEAD"
then
        # a non-bare repository is always in separate-remote layout
        remote_top="refs/remotes/$origin"
        head_sha1=`cat "$GIT_DIR/REMOTE_HEAD"`
        case "$head_sha1" in
        'ref: refs/'*)
                # Uh-oh, the remote told us (http transport done against
                # new style repository with a symref HEAD).
                # Ideally we should skip the guesswork but for now
                # opt for minimum change.
                head_sha1=`expr "z$head_sha1" : 'zref: refs/heads/\(.*\)'`
                head_sha1=`cat "$GIT_DIR/$remote_top/$head_sha1"`
                ;;
        esac

        # The name under $remote_top the remote HEAD seems to point at.
        head_points_at=$(
                (
                        test -f "$GIT_DIR/$remote_top/master" && echo "master"
                        cd "$GIT_DIR/$remote_top" &&
                        find . -type f -print | sed -e 's/^\.\///'
                ) | (
                done=f
                while read name
                do
                        test t = $done && continue
                        branch_tip=`cat "$GIT_DIR/$remote_top/$name"`
                        if test "$head_sha1" = "$branch_tip"
                        then
                                echo "$name"
                                done=t
                        fi
                done
                )
        )

        # Write out remote.$origin config, and update our "$head_points_at".
        case "$head_points_at" in
        ?*)
                # Local default branch
                git-symbolic-ref HEAD "refs/heads/$head_points_at" &&

                # Tracking branch for the primary branch at the remote.
                origin_track="$remote_top/$head_points_at" &&
                git-update-ref HEAD "$head_sha1" &&

                # Upstream URL
                git-repo-config remote."$origin".url "$repo" &&

                # Set up the mappings to track the remote branches.
                git-repo-config remote."$origin".fetch \
                        "+refs/heads/*:$remote_top/*" '^$' &&
                rm -f "refs/remotes/$origin/HEAD"
                git-symbolic-ref "refs/remotes/$origin/HEAD" \
                        "refs/remotes/$origin/$head_points_at" &&

                git-repo-config branch."$head_points_at".remote "$origin" &&
                git-repo-config branch."$head_points_at".merge "refs/heads/$head_points_at"
        esac

        case "$no_checkout" in
        '')
                test "z$quiet" = z && v=-v || v=
                git-read-tree -m -u $v HEAD HEAD
        esac
fi
rm -f "$GIT_DIR/CLONE_HEAD" "$GIT_DIR/REMOTE_HEAD"

trap - 0