#!/usr/bin/env bash
# svn-mirror --- Keep local mirror of remote svn server
# Created: 2010-03-03
# Public domain

# $Id: svn-mirror,v 1.2 2016/08/01 14:38:28 friedman Exp $

# Commentary:
# Code:

get_dst_url()
{
    set : ${1%/}; shift  # remove any trailing /
    case $1 in
        /* ) echo file://$1               ;;
        '' ) echo file://`pwd`            ;;
        *  ) echo file://`cd "$1" && pwd` ;;
    esac
}

get_src_url()
{
    svnlook propget --revprop -r0 "$1" svn:sync-from-url
}

set_src_url()
{
    local dst_url=`get_dst_url "$1"`
    local old_src_url=`get_src_url "$1"`

    case $2 in
        $old_src_url )
            echo Source URL unchanged from $old_src_url
            return 0 ;;
    esac

    if svn propset --revprop -r0 svn:sync-from-url "$2" "$dst_url"; then
        echo "Old URL: $old_src_url"
        echo "New URL: $2"
    fi
}

svn_setup()
{
    local dst_dir=$1
    local src_url=$2

    svnadmin create "$dst_dir"
    echo '#!/bin/sh' > "$dst_dir/hooks/pre-revprop-change"
    chmod a+x "$dst_dir/hooks/pre-revprop-change"

    local dst_url=`get_dst_url "$dst_dir"`
    svnsync init "$dst_url" "$src_url"
}

svn_sync()
{
    local dst_url=`get_dst_url "$1"`
    svnsync sync "$dst_url"
}

usage()
{
    progname=${0##*/}

    {
        case $# in
            0 ) : ;;
            * ) echo "$progname: $*"; echo ;;
        esac

        echo "Usage: $progname [path to local repository] {remote svn url}"
        echo
        echo If the local repository is already present, the url is not required
        echo and the local repository will just be brought up to date.
    } 1>&2

    exit 1
}

main()
{
    case $# in
        1|2 ) :     ;;
        *   ) usage ;;
    esac

    local dst_dir=$1
    local src_url=$2

    if [ ! -d "$dst_dir/db" ]; then
        case $src_url in
            '' ) usage "Need to specify URL to mirror." ;;
        esac

        svn_setup "$dst_dir" "$src_url"
    elif [ -n "$src_url" ]; then
        set_src_url "$dst_dir" "$src_url"
    fi

    svn_sync "$dst_dir"
}

main "$@"

# eof