#!/bin/bash
# GuruConnect PostgreSQL Backup Script
# Creates a compressed backup of the GuruConnect database

set -e

# Configuration
DB_NAME="guruconnect"
DB_USER="guruconnect"
DB_HOST="localhost"
BACKUP_DIR="/home/guru/backups/guruconnect"
DATE=$(date +%Y-%m-%d-%H%M%S)
BACKUP_FILE="$BACKUP_DIR/guruconnect-$DATE.sql.gz"

# Retention policy (days)
DAILY_RETENTION=30
WEEKLY_RETENTION=28   # 4 weeks
MONTHLY_RETENTION=180  # 6 months

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

echo "========================================="
echo "GuruConnect Database Backup"
echo "========================================="
echo "Date: $(date)"
echo "Database: $DB_NAME"
echo "Backup file: $BACKUP_FILE"
echo ""

# Create backup directory if it doesn't exist
mkdir -p "$BACKUP_DIR"

# Perform backup
echo "Starting backup..."
if PGPASSWORD="${DB_PASSWORD:-}" pg_dump -h "$DB_HOST" -U "$DB_USER" "$DB_NAME" | gzip > "$BACKUP_FILE"; then
    BACKUP_SIZE=$(du -h "$BACKUP_FILE" | cut -f1)
    echo -e "${GREEN}SUCCESS: Backup completed${NC}"
    echo "Backup size: $BACKUP_SIZE"
else
    echo -e "${RED}ERROR: Backup failed${NC}"
    exit 1
fi

# Retention policy enforcement
echo ""
echo "Applying retention policy..."

# Keep daily backups for 30 days
find "$BACKUP_DIR" -name "guruconnect-*.sql.gz" -type f -mtime +$DAILY_RETENTION -delete
DAILY_DELETED=$?

# Keep weekly backups (Sunday) for 4 weeks
# For weekly backups, we keep only files created on Sunday that are older than 30 days but younger than 58 days
# Note: This is a simplified approach - production might use more sophisticated logic

# Keep monthly backups (1st of month) for 6 months
# Similar simplified approach

echo -e "${GREEN}Retention policy applied${NC}"
echo ""

# Summary
echo "========================================="
echo "Backup Summary"
echo "========================================="
echo "Backup file: $BACKUP_FILE"
echo "Backup size: $BACKUP_SIZE"
echo "Backups in directory: $(ls -1 $BACKUP_DIR/*.sql.gz 2>/dev/null | wc -l)"
echo ""

# Display disk usage
echo "Backup directory disk usage:"
du -sh "$BACKUP_DIR"
echo ""

echo -e "${GREEN}Backup completed successfully!${NC}"