#!/usr/bin/env bash
BASEDIR=/git

C_bg_green=$(echo -e "\e[42m")
C_bg_magenta=$(echo -e "\e[45m")
C_bg_default=$(echo -e "\e[49m")
C_bg_lblue=$(echo -e "\e[104m")

_getent() {
        local db=$1
        local key=$2
        getent $db $key | cut -d ':' -f 1
}

_list_repo_dirs() {
        find "$1" -maxdepth 6 -type d -not -path '*.git/*' -name '*.git' 2>/dev/null
}

do_list() {
	if [ -n "$1" ]; then
		local root_path=$(readlink -f "$1")
	else
		local root_path=$BASEDIR
	fi
        echo -n "Working.. listing repositories under $root_path"
        for repo_path in $(_list_repo_dirs $root_path | sort); do
                echo -ne "\r" # to remove working
		eval $(stat --format 'local repo_path_uid=%u repo_path_gid=%g repo_path_mode=%a' "$repo_path")
                if [ "$repo_path_uid" != "$UID" ]; then
                        # so there must be a matching gid
                        local pass=false
                        for user_gid in $(id -G); do
                        	if [ "$repo_path_gid" == "$user_gid" ]; then
                        		pass=true
                        	fi
                        done
                        if ! $pass; then
                        	continue # skip that repo since uid and gids don't match
                        fi

                fi

                local shortdesc=$(cut -c 1-40 < "$repo_path/description")
		local permissions="owner=$(_getent passwd $repo_path_uid)"
		local color="$C_bg_green"
                if [ $(( 0$repo_path_mode & 070 )) -gt 0 ]; then # shared
			permissions="$permissions group=$(_getent group $repo_path_gid)"
			color="$C_bg_lblue"
		fi
                if [ $(( 0$repo_path_mode & 07 )) -gt 0 ]; then # public
			permissions="$permissions PUBLIC"
			color="$C_bg_magenta"
		fi
		printf "%s%-60s (%s) (%s)\n" "$color" "$repo_path$C_bg_default" "$permissions" "$shortdesc"
        done
}

_create_repo() {
	local label=$1
	local shared=$2
	local group=$3
	local is_public=$4

        read -p 'New repository name.git: '
        local repo_name=$REPLY

	if ! `expr "$repo_name" : '.*\.git' >/dev/null`; then
		echo "Repository name must end with .git"
		return 1
	fi

        local repo_dir=$BASEDIR/$USER/${repo_name}

        test \! -e "$repo_dir" || { echo "Repo $repo_dir already exist"; exit 1; }

        read -p 'Set Description:         '
        local repo_desc=$REPLY

        read -p "Create $label in $repo_dir Ok? (y/N)"
        test "$REPLY" == "y" || exit 1

        mkdir -p "$repo_dir"
        git init -q --bare --shared=$shared "$repo_dir"
	chgrp -R "$group" "$repo_dir"
        echo "$repo_desc" > "$repo_dir/description"

	if $is_public; then
		touch "$repo_dir/PUBLIC"
		echo "created $repo_dir/PUBLIC to expose via cgit"
	fi

        echo "done creating $label in $repo_dir"
	echo "use 'git repo show $repo_dir' for details"
	return 0
}

do_create_public() {
	_create_repo "public repository" "0664" "share" true
	return $?
}

do_create_shared() {
	_create_repo "group-writeable repository" "0660" "share" false
	return $?
}

do_create_private() {
	_create_repo "private repository" "0600" "$USER" false
	return $?
}

do_show() {
        for repo_path in $*; do
		if ! [ -f "$repo_path/HEAD" ]; then
			repo_path="$BASEDIR/$repo_path"
		fi
                if ! [ -f "$repo_path/HEAD" ]; then
                        echo "Not a git repository: $repo_path"
                        continue
                fi

                local repo_file_mode=$(stat --format %a "$repo_path")
                local repo_file_uid=$(stat --format %u "$repo_path")
                local repo_file_user=$(_getent passwd $repo_file_uid)
                local repo_file_gid=$(stat --format %g "$repo_path")
                local repo_file_group=$(_getent group $repo_file_gid)
                local repo_git_shared=$(GIT_DIR="$repo_path" git config --get core.sharedrepository)

		echo "  Directory: $repo_path"
                echo "  ✔ Permissions mode ${repo_file_mode} (uid=${repo_file_uid}/${repo_file_user} gid=${repo_file_gid}/${repo_file_group})"
		echo "    git core.sharedrepository=$repo_git_shared"
                echo " ⚡ Clone read/write SSH: git clone 'ssh://localnet.cc${repo_path}'"
                if [ $(( 0$repo_file_mode & 07 )) -gt 0 ]; then
			echo "    Clone read/-  HTTP:   git clone 'http://localnet.cc/cgit/cgit.cgi/${repo_path#$BASEDIR/}'"
		fi
		echo "    Update remote:        git remote set-url origin 'ssh://localnet.cc${repo_path}"
                echo "  ☛ To update description execute: $EDITOR $repo_path/description"
		echo ""
        done
}

do_mirror() {
        local root_path=$(readlink -f "$1")
        for repo_path in $(_list_repo_dirs $root_path); do
		local is_mirror=$(GIT_DIR="$repo_path" git config --get remote.origin.mirror)
		if [ "$is_mirror" != "true" ]; then
			continue # skip non-mirror repo
		fi
		echo "Mirror $repo_path from $(GIT_DIR="$repo_path" git config --get remote.origin.url)"
		GIT_DIR="$repo_path" git fetch --force --prune origin
        done
}

do_make_public() {
        local repo_path=$1
        test -f "$repo_path/HEAD" || { echo "$repo_path is not a git repository"; exit 1; }
        set -x
        git init -q --bare --shared=0664 "$repo_path"
        find "$repo_path" -type d -exec chown $USER:share \{\} \;
        find "$repo_path" -type d -exec chmod 0775 \{\} \;
        find "$repo_path" -type f -exec chmod 0664 \{\} \;
        touch "$repo_path/PUBLIC"
        set +x
}

do_make_shared() {
        local repo_path=$1
        test -f "$repo_path/HEAD" || { echo "$repo_path is not a git repository"; exit 1; }
        set -x
        git init -q --bare --shared=0660 "$repo_path"
        find "$repo_path" -type d -exec chown $USER:share \{\} \;
        find "$repo_path" -type d -exec chmod 0770 \{\} \;
        find "$repo_path" -type f -exec chmod 0660 \{\} \;
	chgrp -R share "$repo_path"
        rm -f "$repo_path/PUBLIC"
        set +x
}

do_make_private() {
        local repo_path=$1
        test -f "$repo_path/HEAD" || { echo "$repo_path is not a git repository"; exit 1; }
        set -x
        git init -q --bare --shared=0600 "$repo_path"
        find "$repo_path" -type d -exec chown $USER:$USER \{\} \;
        find "$repo_path" -type d -exec chmod 0700 \{\} \;
        find "$repo_path" -type f -exec chmod 0600 \{\} \;
	chgrp -R $USER "$repo_path"
        rm -f "$repo_path/PUBLIC"
        set +x
}

case "$1" in
        list) do_list "$2" ;;
        create-public) do_create_public ;;
        create-shared) do_create_shared ;;
        create-private) do_create_private ;;
        make-public) do_make_public "$2" ;;
        make-shared) do_make_shared "$2" ;;
        make-private) do_make_private "$2" ;;
        show)
                shift
                do_show $*
                ;;
        mirror) do_mirror "$2" ;;
        *)
                cat <<HERE
Unknown subcommand: '$1'

Subcommands of git repo:
  list [<dir>]        List infos (optional: only below <dir>)
  show <dir...>       Show Commands for repo <dir>
  mirror <dir>        Mirror git repositories under <dir> by looking
                      for 'Mirror for https://..' in description"
  create-public       Create new repository that is
                        - Read/Write by Owner
                        - Read/Write by 'share' group.
                        - Read-Only through www via cgit
  create-shared       Create new repository that is
                        - Read/Write by Owner
                        - Read/Write by 'share' group.
  create-private      Create new repository that is
                        - Read/Write by Owner only
  make-public <dir>   Change permissions to public
  make-shared <dir>   Change permissions to shared
  make-private <dir>  Change permissions to private


  ☛ Base directory of repositories: $BASEDIR
  ☛ Color codes: ${C_bg_magenta}public${C_bg_default}, ${C_bg_lblue}shared${C_bg_default}, ${C_bg_green}private${C_bg_default}
  ☛ For limited ssh-access with current user configure ~/.ssh/authorized_keys with:
      command=\"git shell -c \\\"\$SSH_ORIGINAL_COMMAND\\\"\",no-port-forwarding,no-agent-forwarding,no-X11-forwarding,no-pty ssh-rsa AAAAB3.....
HERE
                ;;
esac