#!/bin/bash

# Advanced Database Backup Script for CKB Docker
# ===============================================

# Configuration
CONTAINER_NAME="ckb-mysql-dev"
DB_NAME="ckb_db"
DB_USER="root"
DB_PASSWORD="root"
BACKUP_DIR="./backups"
DATE=$(date +%Y%m%d_%H%M%S)
RETENTION_DAYS=30  # Keep backups for 30 days

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Functions
print_header() {
    echo -e "${BLUE}================================================${NC}"
    echo -e "${BLUE}    CKB Database Advanced Backup Tool${NC}"
    echo -e "${BLUE}================================================${NC}"
}

print_success() {
    echo -e "${GREEN}✅ $1${NC}"
}

print_error() {
    echo -e "${RED}❌ $1${NC}"
}

print_warning() {
    echo -e "${YELLOW}⚠️ $1${NC}"
}

print_info() {
    echo -e "${BLUE}ℹ️ $1${NC}"
}

check_container() {
    if ! docker ps | grep -q $CONTAINER_NAME; then
        print_error "Container $CONTAINER_NAME is not running!"
        exit 1
    fi
    print_success "Container $CONTAINER_NAME is running"
}

create_backup_dir() {
    mkdir -p $BACKUP_DIR
    print_info "Backup directory: $BACKUP_DIR"
}

cleanup_old_backups() {
    print_info "Cleaning up backups older than $RETENTION_DAYS days..."
    
    # Find and delete old backup files
    old_files=$(find $BACKUP_DIR -name "ckb_backup_*.sql*" -mtime +$RETENTION_DAYS 2>/dev/null)
    
    if [[ -z "$old_files" ]]; then
        print_info "No old backup files found"
    else
        echo "$old_files" | while read file; do
            rm -f "$file"
            print_warning "Deleted old backup: $(basename "$file")"
        done
    fi
}

backup_full() {
    local backup_file="$BACKUP_DIR/ckb_backup_${DATE}.sql"
    print_info "Creating full backup..."
    
    if docker exec $CONTAINER_NAME mysqldump -u $DB_USER -p$DB_PASSWORD \
        --single-transaction \
        --routines \
        --triggers \
        --add-drop-table \
        $DB_NAME > "$backup_file"; then
        
        print_success "Full backup created: $backup_file"
        return 0
    else
        print_error "Full backup failed!"
        return 1
    fi
}

backup_structure_only() {
    local backup_file="$BACKUP_DIR/ckb_structure_${DATE}.sql"
    print_info "Creating structure-only backup..."
    
    if docker exec $CONTAINER_NAME mysqldump -u $DB_USER -p$DB_PASSWORD \
        --no-data \
        --routines \
        --triggers \
        $DB_NAME > "$backup_file"; then
        
        print_success "Structure backup created: $backup_file"
        return 0
    else
        print_error "Structure backup failed!"
        return 1
    fi
}

backup_data_only() {
    local backup_file="$BACKUP_DIR/ckb_data_${DATE}.sql"
    print_info "Creating data-only backup..."
    
    if docker exec $CONTAINER_NAME mysqldump -u $DB_USER -p$DB_PASSWORD \
        --no-create-info \
        --single-transaction \
        $DB_NAME > "$backup_file"; then
        
        print_success "Data backup created: $backup_file"
        return 0
    else
        print_error "Data backup failed!"
        return 1
    fi
}

compress_backup() {
    local file="$1"
    if [[ -f "$file" ]]; then
        print_info "Compressing backup..."
        if gzip "$file"; then
            print_success "Backup compressed: $file.gz"
            
            # Show compression ratio
            original_size=$(stat -c%s "$file" 2>/dev/null || echo "0")
            compressed_size=$(stat -c%s "$file.gz" 2>/dev/null || echo "0")
            if [[ $original_size -gt 0 ]]; then
                ratio=$(echo "scale=1; (1 - $compressed_size/$original_size) * 100" | bc -l 2>/dev/null || echo "0")
                print_info "Compression ratio: ${ratio}%"
            fi
        else
            print_error "Compression failed!"
        fi
    fi
}

show_backup_stats() {
    print_info "Backup Statistics:"
    echo "----------------------------------------"
    
    # Count backup files
    total_backups=$(ls -1 $BACKUP_DIR/ckb_backup_*.sql* 2>/dev/null | wc -l)
    total_size=$(du -sh $BACKUP_DIR 2>/dev/null | cut -f1)
    
    echo "Total backups: $total_backups"
    echo "Total size: $total_size"
    echo "Newest backup: $(ls -1t $BACKUP_DIR/ckb_backup_*.sql* 2>/dev/null | head -1 | xargs basename 2>/dev/null || echo "None")"
    echo "Oldest backup: $(ls -1tr $BACKUP_DIR/ckb_backup_*.sql* 2>/dev/null | head -1 | xargs basename 2>/dev/null || echo "None")"
}

# Main Script
print_header

echo "Backup Options:"
echo "1. Full backup (structure + data)"
echo "2. Structure only backup"
echo "3. Data only backup"
echo "4. All backup types"
echo "5. Show backup statistics"
echo "6. Cleanup old backups"
echo "7. Exit"
echo

read -p "Choose option (1-7): " -n 1 -r option
echo

case $option in
    1)
        check_container
        create_backup_dir
        if backup_full; then
            backup_file="$BACKUP_DIR/ckb_backup_${DATE}.sql"
            
            read -p "Compress backup? (y/n): " -n 1 -r
            echo
            if [[ $REPLY =~ ^[Yy]$ ]]; then
                compress_backup "$backup_file"
            fi
            
            cleanup_old_backups
            show_backup_stats
        fi
        ;;
    2)
        check_container
        create_backup_dir
        if backup_structure_only; then
            backup_file="$BACKUP_DIR/ckb_structure_${DATE}.sql"
            
            read -p "Compress backup? (y/n): " -n 1 -r
            echo
            if [[ $REPLY =~ ^[Yy]$ ]]; then
                compress_backup "$backup_file"
            fi
        fi
        ;;
    3)
        check_container
        create_backup_dir
        if backup_data_only; then
            backup_file="$BACKUP_DIR/ckb_data_${DATE}.sql"
            
            read -p "Compress backup? (y/n): " -n 1 -r
            echo
            if [[ $REPLY =~ ^[Yy]$ ]]; then
                compress_backup "$backup_file"
            fi
        fi
        ;;
    4)
        check_container
        create_backup_dir
        
        print_info "Creating all backup types..."
        
        backup_full && compress_backup "$BACKUP_DIR/ckb_backup_${DATE}.sql"
        backup_structure_only && compress_backup "$BACKUP_DIR/ckb_structure_${DATE}.sql"
        backup_data_only && compress_backup "$BACKUP_DIR/ckb_data_${DATE}.sql"
        
        cleanup_old_backups
        show_backup_stats
        ;;
    5)
        create_backup_dir
        show_backup_stats
        ;;
    6)
        create_backup_dir
        cleanup_old_backups
        show_backup_stats
        ;;
    7)
        print_info "Goodbye!"
        exit 0
        ;;
    *)
        print_error "Invalid option!"
        exit 1
        ;;
esac

print_success "Backup process completed!"