#!/bin/bash
# =============================================================================
# Borg Backup Script - MariaDB Restart Guaranteed
# =============================================================================

set -euo pipefail

# ========================= CONFIGURATION =========================

NAME="borg-2025"
REPO="/home/srv/files/backups/$NAME"
TARGET="/home/srv/files/content"

LOGDIR="/var/log/borg"
LOGFILE="${LOGDIR}/backup-$(date +%Y-%m-%d-%H%M%S).log"

# Optional but strongly recommended
HEALTHCHECK_URL="https://hc-ping.com/your-uuid-here"

RCLONE_REMOTE="scaleway"

# =================================================================

mkdir -p "$LOGDIR"
exec > >(tee -a "$LOGFILE")
exec 2>&1

echo "=== Backup started at $(date '+%Y-%m-%d %H:%M:%S') ==="
echo "Repository: $REPO"
echo "Target: $TARGET"
echo "Log: $LOGFILE"
echo "-----------------------------------------------------------"

# ----------------------- Lockfile -----------------------
LOCKFILE="/var/lock/borg-backup.lock"
MARIADB_STOPPED=false

cleanup() {
    local exit_code=${1:-$?}

    if [ "$MARIADB_STOPPED" = true ]; then
        echo "=== Cleanup: Starting MariaDB container ==="
        docker start mariadb || echo "WARNING: Failed to start mariadb container"
        sleep 3
        echo "MariaDB restart completed."
    fi

    rm -f "$LOCKFILE"

    if [ "$exit_code" -eq 0 ]; then
        echo "=== Backup completed SUCCESSFULLY at $(date '+%Y-%m-%d %H:%M:%S') ==="
        send_healthcheck
    else
        echo "=== Backup FAILED at $(date '+%Y-%m-%d %H:%M:%S') (exit code $exit_code) ==="
        send_healthcheck "fail"
    fi
    echo "Full log: $LOGFILE"
}

if [ -e "$LOCKFILE" ]; then
    echo "ERROR: Another backup is already running (lockfile exists)"
    echo "Remove it manually if stale: $LOCKFILE"
    exit 1
fi

touch "$LOCKFILE"
trap 'cleanup $?' EXIT

# ----------------------- Borg & Functions -----------------------
export BORG_REPO="$REPO"
export BORG_UNKNOWN_UNENCRYPTED_REPO_ACCESS_IS_OK=yes

send_healthcheck() {
    local status="${1:-}"
    if [[ -n "${HEALTHCHECK_URL:-}" ]] && [[ "$HEALTHCHECK_URL" != *"your-uuid-here"* ]]; then
        case "$status" in
            start) curl -s -m 10 --retry 3 "${HEALTHCHECK_URL}/start" >/dev/null || true ;;
            fail)  curl -s -m 10 --retry 3 "${HEALTHCHECK_URL}/fail" -d "Backup failed - check $LOGFILE" >/dev/null || true ;;
            *)     curl -s -m 10 --retry 3 "$HEALTHCHECK_URL" >/dev/null || true ;;
        esac
    fi
}

run_cmd() {
    echo "[RUN] $*"
    "$@"
}

# =================================================================

send_healthcheck "start"

# 1. MariaDB dump (while running)
echo "=== Step 1: MariaDB dump ==="
DUMP_SCRIPT="${TARGET}/mariadb/dump_db.sh"
if [[ -x "$DUMP_SCRIPT" ]]; then
    run_cmd "$DUMP_SCRIPT"
else
    echo "WARNING: Dump script not found or not executable: $DUMP_SCRIPT"
fi

# 2. Stop MariaDB for consistent backup
echo "=== Step 2: Stopping MariaDB container ==="
run_cmd docker stop mariadb
MARIADB_STOPPED=true

# 3. Create Borg archive
echo "=== Step 3: Creating Borg archive ==="
run_cmd borg create \
    --stats \
    --progress \
    --list \
    --filter=AME \
    --compression zstd,8 \
    --exclude-caches \
    --exclude-if-present .nobackup \
    "::${now:%Y-%m-%dT%H-%M-%S}" \
    "$TARGET"

# 4. Restart MariaDB (this line is now also in the cleanup trap)
echo "=== Step 4: Starting MariaDB container ==="
run_cmd docker start mariadb
MARIADB_STOPPED=false

# 5. Offsite sync
echo "=== Step 5: Syncing to Scaleway S3 ==="
run_cmd rclone sync -v \
    --fast-list \
    --transfers=8 \
    --checkers=16 \
    "$REPO" "${RCLONE_REMOTE}:/par-backup-1/$NAME"

# 6. Prune & Compact
echo "=== Step 6: Pruning and compacting ==="
run_cmd borg prune \
    --list \
    --keep-daily=7 \
    --keep-weekly=4 \
    --keep-monthly=6 \
    --keep-within=7d \
    "$REPO"

run_cmd borg compact --progress "$REPO"

# The cleanup trap will run automatically and mark success