#!/bin/bash

# YourDreamNameHere Backup Script
# This script creates automated backups of the PostgreSQL database

set -euo pipefail

# Configuration
DB_HOST="${DB_HOST:-ydn-db}"
DB_PORT="${DB_PORT:-5432}"
DB_USER="${DB_USER:-ydn_user}"
DB_NAME="${DB_NAME:-ydn_db}"
DOLIBARR_DB="dolibarr_db"
BACKUP_DIR="/backups"
TIMESTAMP=$(date +"%Y%m%d_%H%M%S")
RETENTION_DAYS=30

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

echo "Starting database backup at $(date)"

# Function to create backup
create_backup() {
    local database=$1
    local filename="${database}_backup_${TIMESTAMP}.sql"
    local filepath="$BACKUP_DIR/$filename"
    
    echo "Creating backup for database: $database"
    
    # Create compressed backup
    pg_dump -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" \
            --no-password --verbose --clean --if-exists \
            --format=custom --compress=9 \
            --file="$filepath" "$database"
    
    if [ $? -eq 0 ]; then
        echo "Backup created successfully: $filepath"
        
        # Create checksum for integrity verification
        sha256sum "$filepath" > "${filepath}.sha256"
        
        # Compress further with gzip if needed
        # gzip "$filepath"
        
        echo "Backup size: $(du -h "$filepath" | cut -f1)"
    else
        echo "Failed to create backup for database: $database"
        return 1
    fi
}

# Function to clean old backups
cleanup_old_backups() {
    echo "Cleaning up backups older than $RETENTION_DAYS days"
    
    # Remove old SQL backups
    find "$BACKUP_DIR" -name "*_backup_*.sql" -type f -mtime +$RETENTION_DAYS -delete
    find "$BACKUP_DIR" -name "*_backup_*.sql.sha256" -type f -mtime +$RETENTION_DAYS -delete
    
    echo "Cleanup completed"
}

# Function to verify backup integrity
verify_backup() {
    local filepath=$1
    local checksum_file="${filepath}.sha256"
    
    if [ -f "$checksum_file" ]; then
        if sha256sum -c "$checksum_file" >/dev/null 2>&1; then
            echo "Backup integrity verified: $filepath"
            return 0
        else
            echo "Backup integrity check failed: $filepath"
            return 1
        fi
    else
        echo "Checksum file not found for: $filepath"
        return 1
    fi
}

# Main execution
echo "========================================"
echo "Database Backup Started: $(date)"
echo "========================================"

# Set password for PostgreSQL if environment variable is set
if [ -n "${DB_PASSWORD:-}" ]; then
    export PGPASSWORD="$DB_PASSWORD"
fi

# Create backups
BACKUP_SUCCESS=true

echo "Backing up main application database..."
if create_backup "$DB_NAME"; then
    # Verify main backup
    main_backup="$BACKUP_DIR/${DB_NAME}_backup_${TIMESTAMP}.sql"
    if ! verify_backup "$main_backup"; then
        BACKUP_SUCCESS=false
    fi
else
    BACKUP_SUCCESS=false
fi

echo "Backing up Dolibarr database..."
if create_backup "$DOLIBARR_DB"; then
    # Verify Dolibarr backup
    dolibarr_backup="$BACKUP_DIR/${DOLIBARR_DB}_backup_${TIMESTAMP}.sql"
    if ! verify_backup "$dolibarr_backup"; then
        BACKUP_SUCCESS=false
    fi
else
    BACKUP_SUCCESS=false
fi

# Clean old backups
cleanup_old_backups

# Summary
echo "========================================"
echo "Database Backup Completed: $(date)"

if [ "$BACKUP_SUCCESS" = true ]; then
    echo "✅ All backups completed successfully"
    
    # List current backups
    echo "Current backups:"
    ls -lh "$BACKUP_DIR"/*_backup_*.sql 2>/dev/null || echo "No backup files found"
else
    echo "❌ Some backups failed"
    exit 1
fi

echo "========================================"

# Send notification if webhook URL is configured
if [ -n "${BACKUP_WEBHOOK_URL:-}" ]; then
    status=$([ "$BACKUP_SUCCESS" = true ] && echo "success" || echo "failed")
    curl -X POST "$BACKUP_WEBHOOK_URL" \
         -H "Content-Type: application/json" \
         -d "{\"text\":\"Database backup $status at $(date)\",\"status\":\"$status\"}" \
         2>/dev/null || true
fi

exit 0