#!/bin/bash
#
# kbgit-backups-rsync
# John Simpson <jms1@jms1.net> 2025-01-17
#
# Use rsync to back up all Keybase git repos the current user has access to.
# Note that the backed-up directories will all be BARE repos. They won't be
# usable as "working directories", but you can `git clone` from them in order
# to access the content stored in the various branches.
#
###############################################################################
#
# MIT License
#
# Copyright 2025 John Simpson
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the “Software”),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.
#
###############################################################################

###############################################################################
#
# usage

function usage {
    MSG="${*:-}"
    cat <<EOF
$0 [OPTIONS] TARGET

Use 'rsync' to create or update backups of the bare git repos for each
Keybase git repo you have access to.

Specify the directory where the backups should be created.

-x      Show the commands being executed.

-h      Show this help message.

EOF

    if [[ -n "$MSG" ]]
    then
        echo "$MSG"
        exit 1
    fi

    exit 0
}

###############################################################################
#
# Coloured lines

function blueline {
    if [[ -t 1 ]]
    then
        printf "\e[0;1;37;44m\e[0K\n%s\e[0K\n\e[0K\e[0m\n" "$*"
    else
        echo "===== $* ====="
    fi
}

function yellowline {
    if [[ -t 1 ]]
    then
        printf "\e[0;30;43m%s\e[K\e[0m\n" "$*"
    else
        echo "===== $* ====="
    fi
}

###############################################################################
#
# Maybe print a command before executing it

SET_X="${SET_X:-false}"

function set_x {
    if [[ "${SET_X:-false}" == "true" ]]
    then
        local IFS=$' '
        yellowline "$PS4$*" 1>&2
    fi
    "$@"
}

########################################
# Show the same output that set_x would show,
# but don't actually run the command

function show_x {
    if [[ "${SET_X:-false}" == "true" ]]
    then
        local IFS=$' '
        yellowline "$PS4$*" 1>&2
    fi
}

###############################################################################
###############################################################################
###############################################################################

while getopts ':hx' OPT
do
    case $OPT in
        h)  usage
            ;;
        x)  SET_X=true
            ;;
        *)  usage "ERROR: unknown option '-$OPTARG'"
            ;;
    esac
done

shift $((OPTIND-1))

########################################
# Get the backup directory from the command line.
# - make sure it *doesn't* end with "/", this will be added below as needed

BACKUP_DIR="${1:-}"

if [[ -z "$BACKUP_DIR" ]]
then
    usage
fi

BACKUP_DIR="${BACKUP_DIR%/}"

###############################################################################
#
# Find KBFS

if [[ -d /keybase/private ]]
then
    KBFS="/keybase"
elif [[ -d "/Volumes/Keybase ($( whoami ))" ]]
then
    KBFS="/Volumes/Keybase ($( whoami ))"
else
    echo "ERROR: can't find KBFS, cannot continue"
    exit 1
fi

############################################################
# Do the deeds

for REPO_DIR in $KBFS/*/*/.kbfs_git/*
do
    TLF="${REPO_DIR%/.kbfs_git/*}"          # "/keybase/team/TTT"
    SLF="${TLF#$KBFS/}"                     # "team/TTT"
    REPO_NAME="${REPO_DIR#*/.kbfs_git/}"    # repo name

    blueline "keybase://$SLF/$REPO_NAME"

    if [[ ! -d "$BACKUP_DIR/$SLF/$REPO_NAME" ]]
    then
        set_x mkdir -p "$BACKUP_DIR/$SLF/$REPO_NAME"
    fi

    set_x rsync -crv "$REPO_DIR/" "$BACKUP_DIR/$SLF/$REPO_NAME/"
done