#!/bin/bash

# Physical backup script using mariabackup with S3 upload
# Runs every 12 hours and keeps last 7 local backups

BACKUP_DIR="/backups"
DB_HOST="${DB_HOST:-db}"
DB_USER="${DB_USER:-root}"
DB_PASSWORD="${MYSQL_ROOT_PASSWORD}"
KEEP_BACKUPS="${KEEP_BACKUPS:-7}"
S3_BUCKET="${S3_BUCKET:-selectel:backup_db}"
S3_PATH="${S3_PATH:-dot}"
ENVIRONMENT="${ENVIRONMENT:-prod}"

while true; do
    echo "[$(date)] Starting physical backup process with mariabackup..."

    TIMESTAMP=$(date +%Y%m%d_%H%M%S)
    DAY_NAME=$(date +%a)
    BACKUP_NAME="full_backup.${DAY_NAME}"
    BACKUP_PATH="${BACKUP_DIR}/${BACKUP_NAME}"
    BACKUP_ARCHIVE="${BACKUP_PATH}.tar.gz"

    # Remove previous backup with same day name if exists
    if [ -d "${BACKUP_PATH}" ]; then
        echo "[$(date)] Removing old backup: ${BACKUP_PATH}"
        rm -rf "${BACKUP_PATH}"
    fi
    [ -f "${BACKUP_ARCHIVE}" ] && rm -f "${BACKUP_ARCHIVE}"

    echo "[$(date)] Creating full physical backup..."

    # Create full backup using mariabackup
    mariabackup --backup \
        --target-dir="${BACKUP_PATH}" \
        --host="${DB_HOST}" \
        --user="${DB_USER}" \
        --password="${DB_PASSWORD}" \
        --no-lock \
        --parallel=4

    if [ $? -eq 0 ]; then
        echo "[$(date)] Backup created successfully, preparing..."

        # Prepare the backup (apply log)
        mariabackup --prepare \
            --target-dir="${BACKUP_PATH}"

        if [ $? -eq 0 ]; then
            echo "[$(date)] Backup prepared successfully, compressing..."

            # Compress the backup
            tar -czf "${BACKUP_ARCHIVE}" -C "${BACKUP_DIR}" "${BACKUP_NAME}"

            if [ $? -eq 0 ]; then
                # Remove uncompressed backup to save space
                rm -rf "${BACKUP_PATH}"

                # Get file size for logging
                BACKUP_SIZE=$(du -h "${BACKUP_ARCHIVE}" | cut -f1)
                echo "[$(date)] Backup compressed: ${BACKUP_ARCHIVE} (${BACKUP_SIZE})"

                # Upload to S3 if rclone is configured
                if [ -f /root/.config/rclone/rclone.conf ]; then
                    echo "[$(date)] Uploading backup to S3..."
                    rclone copy "${BACKUP_ARCHIVE}" "${S3_BUCKET}/${S3_PATH}/${ENVIRONMENT}/" --progress

                    if [ $? -eq 0 ]; then
                        echo "[$(date)] Successfully uploaded backup to S3"
                    else
                        echo "[$(date)] WARNING: Failed to upload backup to S3"
                    fi
                else
                    echo "[$(date)] Rclone not configured, keeping backup locally only"
                fi
            else
                echo "[$(date)] ERROR: Failed to compress backup!"
                rm -rf "${BACKUP_PATH}"
            fi
        else
            echo "[$(date)] ERROR: Failed to prepare backup!"
            rm -rf "${BACKUP_PATH}"
        fi
    else
        echo "[$(date)] ERROR: Failed to create backup!"
        [ -d "${BACKUP_PATH}" ] && rm -rf "${BACKUP_PATH}"
    fi

    # Clean old local backups (keep last N backups)
    echo "[$(date)] Cleaning old local backups..."
    ls -t ${BACKUP_DIR}/full_backup.*.tar.gz 2>/dev/null | tail -n +$((KEEP_BACKUPS + 1)) | xargs -r rm -f

    # List current backups
    echo "[$(date)] Current local backups:"
    ls -lah ${BACKUP_DIR}/*.tar.gz 2>/dev/null || echo "No backups found"

    echo "[$(date)] Next backup will run in 12 hours..."
    echo "========================================="

    # Sleep for 12 hours (43200 seconds)
    sleep 43200
done