#!/bin/sh
# Run the backup and mail the logs:
# Depending on parameter 1:
# - test-smtp: just send a test email to $MAIL_TO
# - run: create the backup, no checks
# - check: prune, compact and check the backup
# Anything else is an error.
                                                                   
set -o pipefail
                                                                   
# Set up environment
/bin/sh /scripts/msmtprc.sh            
/bin/sh /scripts/env.sh
RUN_COMMAND="borgmatic --stats -v 2 create"
CHECK_COMMAND="borgmatic --stats -v 1 prune compact check"
LOGFILE="/tmp/backup_run_$(date +%s).log"
SUCCESS_PREFIX="=?utf-8?Q? =E2=9C=85 SUCCESS?="
FAILED_PREFIX="=?utf-8?Q? =E2=9D=8C FAILED?="
                                                                   
PARAM="$1"    
                                                                   
# Helper function to prepend a timestamp and the first parameter to every line of STDIN
indent() {                            
    while read -rs line; do
        printf "%s%s%s\n" "$(date -Iminutes)" "${1:- }" "$line"
    done      
}         
                                                                   
# This function prepends timestamps to stderr and stdout of the
# command supplied as parameters to this.
log() {   
    # Adapted from https://stackoverflow.com/a/31151808
    {
        "$@"   2>&1 1>&3 3>&- | indent " ! "
    } 3>&1 1>&2 | indent " | " | tee -a "$LOGFILE"
}                            

report() {
    if [ "$RESULT" = "0" ]; then
        log echo "SUCCESS"
        PREFIX="$SUCCESS_PREFIX"
    else
        log echo "FAILED: $RESULT"
        PREFIX="$FAILED_PREFIX"
    fi
    printf "Subject: $PREFIX: '$PARAM'\n\n$(cat $LOGFILE)\n" |
        sendmail -t "$MAIL_TO"
}

testmail() {
    echo -e "Subject: TESTING!\n\ntest mail, please ignore\n" |
        sendmail -t "$MAIL_TO"
}

failed() {
    log echo "Exited abnormally!"
    report
    rm -f "$LOGFILE"
}

cleanup() {
    borgmatic break-lock
    echo "Done, removing $LOGFILE"
    rm -f "$LOGFILE"
}

# Handle various kinds of exit
trap failed INT QUIT KILL
trap cleanup EXIT

case  "$PARAM" in
    test-smtp)
        echo "Testing mail to $MAIL_TO"
        testmail
        echo "Done."
        ;;
    check)
        log echo STARTED: $CHECK_COMMAND
        log $CHECK_COMMAND
        RESULT=$?
        report
        ;;
    run)
        log echo STARTED: $RUN_COMMAND
        log $RUN_COMMAND
        RESULT=$?
        report
        ;;
    *)
        log echo "UNKNOWN COMMAND: '$PARAM'"
        report
        ;;
esac