from django.http import JsonResponse
from django.views.decorators.csrf import csrf_exempt
from django.views.decorators.http import require_POST
from .backup_utils import perform_base_backup, restore_to_base_backup
import os
import json
import logging
from datetime import datetime
from apscheduler.schedulers.background import BackgroundScheduler
from django.conf import settings
import math

logger = logging.getLogger(__name__)

# 初始化调度器
scheduler = BackgroundScheduler()

def scheduled_backup():
    """定时备份任务"""
    try:
        backup_path = perform_base_backup()
        logger.info(f"定时备份完成: {backup_path}")
        # 更新托盘分类任务（如果存在）
        try:
            from container.utils import update_container_categories_task,reconcile_material_history
            update_container_categories_task()
            reconcile_material_history()
            logger.info(f"定时更新托盘分类完成")
        except ImportError:
            logger.warning("更新托盘分类模块未找到，跳过更新")
    except Exception as e:
        logger.error(f"定时备份失败: {str(e)}")

# 启动定时备份（每6小时执行一次）
if not scheduler.running:
    scheduler.add_job(
        scheduled_backup,
        'cron',
        hour='*/6',  # 每6小时执行一次
        minute=0,    # 在0分钟时执行
        id='db_backup_job'
    )
    scheduler.start()
    logger.info("定时备份任务已启动")

def get_backup_files(page=1, page_size=5):
    """获取备份文件列表（带分页）"""
    backup_dir = "E:/code/backup/postgres"
    all_backups = []
    
    # 遍历备份目录
    for root, dirs, files in os.walk(backup_dir):
        for file in files:
            if file.endswith(".backup"):
                file_path = os.path.join(root, file)
                file_size = os.path.getsize(file_path)
                timestamp = os.path.getmtime(file_path)
                
                all_backups.append({
                    "name": file,
                    "path": file_path,
                    "size": f"{file_size / (1024 * 1024):.2f} MB",
                    "date": datetime.fromtimestamp(timestamp).strftime("%Y-%m-%d %H:%M:%S")
                })
    
    # 按时间倒序排序
    all_backups.sort(key=lambda x: x["date"], reverse=True)
    
    # 分页处理
    total_items = len(all_backups)
    total_pages = math.ceil(total_items / page_size)
    start_index = (page - 1) * page_size
    end_index = min(start_index + page_size, total_items)
    
    return {
        "backups": all_backups[start_index:end_index],
        "page": page,
        "page_size": page_size,
        "total_items": total_items,
        "total_pages": total_pages
    }

def get_base_backups(page=1, page_size=5):
    """获取基础备份列表（带分页）"""
    base_backup_dir = "E:/code/backup/postgres/base_backup"
    all_backups = []
    
    # 遍历基础备份目录
    for dir_name in os.listdir(base_backup_dir):
        dir_path = os.path.join(base_backup_dir, dir_name)
        if os.path.isdir(dir_path):
            timestamp = os.path.getmtime(dir_path)
            
            all_backups.append({
                "name": dir_name,
                "path": dir_path,
                "date": datetime.fromtimestamp(timestamp).strftime("%Y-%m-%d %H:%M:%S")
            })
    
    # 按时间倒序排序
    all_backups.sort(key=lambda x: x["date"], reverse=True)
    
    # 分页处理
    total_items = len(all_backups)
    total_pages = math.ceil(total_items / page_size)
    start_index = (page - 1) * page_size
    end_index = min(start_index + page_size, total_items)
    
    return {
        "backups": all_backups[start_index:end_index],
        "page": page,
        "page_size": page_size,
        "total_items": total_items,
        "total_pages": total_pages
    }

@csrf_exempt
@require_POST
def trigger_backup(request):
    """手动触发备份的API接口"""
    try:
        backup_path = perform_base_backup()
   

        return JsonResponse({
            'status': 'success',
            'message': '数据库备份完成',
            'path': backup_path
        })
    except Exception as e:
        return JsonResponse({
            'status': 'error',
            'message': str(e)
        }, status=500)

@csrf_exempt
@require_POST
def list_backups(request):
    """获取备份文件列表API（带分页）"""
    try:
        data = json.loads(request.body)
        backup_type = data.get('type', 'file')
        page = data.get('page', 1)
        page_size = data.get('page_size', 5)
        
        if backup_type == 'file':
            result = get_backup_files(page, page_size)
        elif backup_type == 'base':
            result = get_base_backups(page, page_size)
        else:
            return JsonResponse({
                'status': 'error',
                'message': '无效的备份类型'
            }, status=400)
        
        return JsonResponse({
            'status': 'success',
            'data': result
        })
    except Exception as e:
        logger.error(f"获取备份列表失败: {str(e)}")
        return JsonResponse({
            'status': 'error',
            'message': str(e)
        }, status=500)


@csrf_exempt
@require_POST
def restore_to_point(request):
    """执行时间点恢复API"""
    try:
        data = json.loads(request.body)
        base_backup = data.get('base_backup')
       
        
        if not base_backup or not os.path.exists(base_backup):
            return JsonResponse({
                'status': 'error',
                'message': '无效的基础备份路径'
            }, status=400)
        
      
        
        # 暂停定时备份任务
        scheduler.pause_job('db_backup_job')
        logger.info("定时备份任务已暂停")
        
        # 执行时间点恢复
        restore_to_base_backup( base_backup)
        
        # 恢复定时备份任务
        scheduler.resume_job('db_backup_job')
        logger.info("定时备份任务已恢复")
        
        return JsonResponse({
            'status': 'success',
            'message': f'已成功恢复到{base_backup}'
        })
    except Exception as e:
        logger.error(f"时间点恢复失败: {str(e)}")
        # 确保恢复定时备份任务
        if scheduler.get_job('db_backup_job') and scheduler.get_job('db_backup_job').next_run_time is None:
            scheduler.resume_job('db_backup_job')
            logger.info("恢复失败后定时备份任务已恢复")
        return JsonResponse({
            'status': 'error',
            'message': str(e)
        }, status=500)