#!/bin/bash
#
# kbgit-backup
# John Simpson <jms1@jms1.net> 2023-06-25
#
# Make/update backups of all Keybase git repos you have access to
#
# 2024-01-26 jms1 - report errors but don't fully stop because of them
#
# 2025-01-18 jms1 - run 'git fetch --tags' in addition to 'git fetch --all'
#
###############################################################################
#
# MIT License
#
# Copyright 2023-2025 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.
#
###############################################################################


TARGET=""

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

function redline {
    if [[ -t 1 ]]
    then
        printf "\e[0;1;37;41m%s\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
}

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

function greenline {
    if [[ -t 1 ]]
    then
        printf "\e[0;1;37;42m%s\e[0K\e[0m\n" "$*"
    else
        echo "----- $* -----"
    fi
}

SET_X="${SET_X:-false}"

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

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

function usage {
    MSG="${*:-}"

    cat <<EOF
$0 [OPTIONS] TARGET

Use 'git' commands to back up all Keybase git repos that you have access to.

Specify the directory where the backups should be created.

If the script is run multiple times with the same target directory, it will
*assume* that the existing directory is a backup of the same repo, and use
'git fetch' (but not 'git pull') to update the backup.

A target directory MUST be specified.

-x      Show commands before executing them.

-h      Show this help message.

EOF

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

    exit 0
}

###############################################################################
###############################################################################
###############################################################################
#
# Handle command line

while getopts ':hx' OPT
do
    case $OPT in
        h)  usage
            ;;
        x)  SET_X=true
            ;;
        *)  usage "ERROR: unknown option '-${OPTARG}'"
            ;;
    esac
done
shift $((OPTIND-1))

if [[ -n "$1" ]]
then
    TARGET="${1%/}"
else
    usage
fi

###############################################################################
#
# Let's do this

echo "Backing up Keybase git repos to '$TARGET'"

########################################
# Make sure $TARGET exists

if [[ ! -d "$TARGET" ]]
then
    set_x mkdir -p "$TARGET"
fi

########################################
# Do the deed

URLS=( $( keybase git list | awk '/keybase:/{print $2}' ) )
ERR_LIST=()

for URL in "${URLS[@]}"
do
    TDIR="$TARGET/${URL#keybase://}"

    echo ''
    blueline "$URL -> $TDIR"
    echo ''

    ########################################
    # If the repo's target directory already exists
    # - update the repo

    if [[ -d "$TDIR" ]]
    then
        if ! ( set_x cd "$TDIR" && set_x git fetch --all && set_x git fetch --tags )
        then
            redline "ERROR, backup image was not updated"
            ERR_LIST+=( "git fetch failed: $URL" )
        fi

    ########################################
    # If the repo's target directory doesn't already exist
    # - clone the repo

    else
        if ! set_x git clone --mirror "$URL" "$TDIR"
        then
            redline "ERROR, backup image was not cloned"
            ERR_LIST+=( "git clone failed: $URL" )
        fi
    fi
done

########################################
# Recap errors

if [[ "${#ERR_LIST[@]}" > 0 ]]
then
    echo ''
    redline "List of repos with errors"
    echo ''

    for E in "${ERR_LIST[@]}"
    do
        echo "$E"
    done
fi