#!/bin/bash

# Database Backup Script for Bakery IA
# This script backs up all PostgreSQL databases in the Kubernetes cluster
# Designed to run on the VPS via cron

set -e

# Configuration
BACKUP_ROOT="/backups"
NAMESPACE="bakery-ia"
RETENTION_DAYS=7
DATE=$(date +%Y-%m-%d_%H-%M-%S)
BACKUP_DIR="${BACKUP_ROOT}/${DATE}"

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

# Logging
log() {
    echo "[$(date +'%Y-%m-%d %H:%M:%S')] $1"
}

log_error() {
    echo -e "${RED}[$(date +'%Y-%m-%d %H:%M:%S')] ERROR: $1${NC}"
}

log_success() {
    echo -e "${GREEN}[$(date +'%Y-%m-%d %H:%M:%S')] SUCCESS: $1${NC}"
}

log_warning() {
    echo -e "${YELLOW}[$(date +'%Y-%m-%d %H:%M:%S')] WARNING: $1${NC}"
}

# Create backup directory
mkdir -p "$BACKUP_DIR"

log "Starting database backup to $BACKUP_DIR"

# Get all database pods
DB_PODS=$(kubectl get pods -n "$NAMESPACE" -l app.kubernetes.io/component=database -o jsonpath='{.items[*].metadata.name}')

if [ -z "$DB_PODS" ]; then
    log_error "No database pods found in namespace $NAMESPACE"
    exit 1
fi

log "Found database pods: $DB_PODS"

# Backup counter
SUCCESS_COUNT=0
FAILED_COUNT=0
FAILED_DBS=()

# Backup each database
for pod in $DB_PODS; do
    log "Backing up database: $pod"

    # Get database name from pod labels
    DB_NAME=$(kubectl get pod "$pod" -n "$NAMESPACE" -o jsonpath='{.metadata.labels.app\.kubernetes\.io/name}')

    if [ -z "$DB_NAME" ]; then
        DB_NAME=$pod
    fi

    BACKUP_FILE="${BACKUP_DIR}/${DB_NAME}.sql"

    # Perform backup
    if kubectl exec -n "$NAMESPACE" "$pod" -- pg_dumpall -U postgres > "$BACKUP_FILE" 2>/dev/null; then
        FILE_SIZE=$(du -h "$BACKUP_FILE" | cut -f1)
        log_success "Backed up $DB_NAME ($FILE_SIZE)"
        ((SUCCESS_COUNT++))
    else
        log_error "Failed to backup $DB_NAME"
        FAILED_DBS+=("$DB_NAME")
        ((FAILED_COUNT++))
        rm -f "$BACKUP_FILE"  # Remove partial backup
    fi
done

# Also backup Redis if present
REDIS_POD=$(kubectl get pods -n "$NAMESPACE" -l app.kubernetes.io/name=redis -o jsonpath='{.items[0].metadata.name}' 2>/dev/null || echo "")

if [ -n "$REDIS_POD" ]; then
    log "Backing up Redis: $REDIS_POD"
    REDIS_BACKUP="${BACKUP_DIR}/redis.rdb"

    if kubectl exec -n "$NAMESPACE" "$REDIS_POD" -- redis-cli --rdb /tmp/dump.rdb SAVE > /dev/null 2>&1 && \
       kubectl cp "$NAMESPACE/$REDIS_POD:/tmp/dump.rdb" "$REDIS_BACKUP" > /dev/null 2>&1; then
        FILE_SIZE=$(du -h "$REDIS_BACKUP" | cut -f1)
        log_success "Backed up Redis ($FILE_SIZE)"
        ((SUCCESS_COUNT++))
    else
        log_warning "Failed to backup Redis (non-critical)"
    fi
fi

# Create backup metadata
cat > "${BACKUP_DIR}/backup-info.txt" <<EOF
Backup Date: $(date)
Namespace: $NAMESPACE
Success Count: $SUCCESS_COUNT
Failed Count: $FAILED_COUNT
Failed Databases: ${FAILED_DBS[@]:-none}
Kubernetes Cluster: $(kubectl config current-context)
EOF

# Compress backup
log "Compressing backup..."
COMPRESSED_FILE="${BACKUP_ROOT}/backup-${DATE}.tar.gz"

if tar -czf "$COMPRESSED_FILE" -C "$BACKUP_ROOT" "$(basename "$BACKUP_DIR")"; then
    COMPRESSED_SIZE=$(du -h "$COMPRESSED_FILE" | cut -f1)
    log_success "Backup compressed: $COMPRESSED_FILE ($COMPRESSED_SIZE)"

    # Remove uncompressed backup
    rm -rf "$BACKUP_DIR"
else
    log_error "Failed to compress backup"
    exit 1
fi

# Cleanup old backups
log "Cleaning up backups older than $RETENTION_DAYS days..."
DELETED_COUNT=$(find "$BACKUP_ROOT" -name "backup-*.tar.gz" -mtime "+$RETENTION_DAYS" -delete -print | wc -l)

if [ "$DELETED_COUNT" -gt 0 ]; then
    log "Deleted $DELETED_COUNT old backup(s)"
fi

# Calculate total backup size
TOTAL_SIZE=$(du -sh "$BACKUP_ROOT" | cut -f1)

# Summary
echo ""
log "========================================="
log "Backup Summary"
log "========================================="
log "Successful backups: $SUCCESS_COUNT"
log "Failed backups: $FAILED_COUNT"
log "Backup location: $COMPRESSED_FILE"
log "Backup size: $COMPRESSED_SIZE"
log "Total backup storage: $TOTAL_SIZE"
log "========================================="

if [ $FAILED_COUNT -gt 0 ]; then
    log_error "Some backups failed: ${FAILED_DBS[*]}"
    exit 1
fi

log_success "Backup completed successfully!"

# Optional: Send notification
# Uncomment and configure if you want email/slack notifications
# send_notification "Bakery IA Backup Completed" "Successfully backed up $SUCCESS_COUNT databases. Size: $COMPRESSED_SIZE"

exit 0