#!/usr/bin/env bash
set -euo pipefail

REPO="/backup/borgrepo"

export BORG_PASSPHRASE
BORG_PASSPHRASE="$(cat /app/host_vars/repokey)"

export BORG_RSH="ssh -o BatchMode=yes"

HOSTS_FILE="$(dirname "$0")/host_vars/hosts"
TIMESTAMP="$(date +%Y-%m-%dT%H%M%S)"

HOSTS=()
while read -r host; do
    [[ -z "$host" || "$host" =~ ^# ]] && continue
    HOSTS+=("$host")
done < "$HOSTS_FILE"

echo "Backing up hosts:"
printf ' - %s\n' "${HOSTS[@]}"

FAILED_HOSTS=()

for HOST in "${HOSTS[@]}"; do
    ARCHIVE="${HOST}-backup-${TIMESTAMP}"
    echo "--- Backing up $HOST ---"

    # IMPORTANT: repo is LOCAL, source is REMOTE via SSH
    if ! borg create \
        "$REPO::$ARCHIVE" \
        "$HOST:/BACKUP" \
        --stats \
        --compression lz4; then

        echo "WARNING: Failed to back up $HOST"
        FAILED_HOSTS+=("$HOST")
    fi
done

echo "Applying retention policy..."

for HOST in "${HOSTS[@]}"; do
    borg prune \
        "$REPO" \
        --keep-daily=7 \
        --keep-weekly=8 \
        --glob-archives "${HOST}-backup-*" \
        --stats
done

if [[ ${#FAILED_HOSTS[@]} -gt 0 ]]; then
    echo "DONE WITH ERRORS:"
    printf ' - %s\n' "${FAILED_HOSTS[@]}"
    exit 1
fi

echo "Done: all hosts backed up at $TIMESTAMP"