#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
PLC指令模拟测试工具
仅显示请求详情，不实际发送，用于调试和验证
"""

import json
import hashlib
import time


def load_config(config_file='config.json'):
    """加载配置文件"""
    with open(config_file, 'r', encoding='utf-8') as f:
        return json.load(f)


def generate_md5_signature(record_data, secret, timestamp):
    """生成MD5签名"""
    cal_str = f"{record_data}{secret}{timestamp}"
    cal_md5 = hashlib.md5(cal_str.encode('utf-8')).hexdigest()
    return cal_md5.upper()


def prepare_plc_request(device_name, item, old_value, new_value, command_type):
    """
    准备PLC请求参数
    
    参数:
        device_name: 设备名称
        item: 参数项名称
        old_value: 当前值
        new_value: 目标值
        command_type: 命令类型
        
    返回:
        请求信息字典
    """
    config = load_config()
    
    PLC_URL = config['api']['base_url'] + config['api']['plc_endpoint']
    PROJECT_ID = config['scada']['project_id']
    SCADA_SECRET = config['scada']['secret']
    
    timestamp = int(time.time())
    
    record_dict = {
        "project_id": PROJECT_ID,
        "item": item,
        "old_value": old_value,
        "new_value": new_value,
        "command_type": command_type
    }
    record_data = json.dumps(record_dict, separators=(',', ':'))
    
    signature = generate_md5_signature(record_data, SCADA_SECRET, timestamp)
    full_url = f"{PLC_URL}?sign={signature}&timestamp={timestamp}"
    payload = [record_dict]
    
    return {
        'url': full_url,
        'payload': payload,
        'signature_data': record_data,
        'signature': signature,
        'timestamp': timestamp,
        'secret': SCADA_SECRET
    }

if __name__ == "__main__":
    print("=== PLC指令测试 - 模拟运行 ===")
    print()
    
    # 测试参数
    device_name = "UF2"
    item = "C.M.UF2_DB@time_production"
    old_value = "3800"
    new_value = "3801"
    command_type = 1
    
    # 准备请求
    request_info = prepare_plc_request(device_name, item, old_value, new_value, command_type)
    
    print(f"📋 测试场景:")
    print(f"   设备: {device_name}")
    print(f"   参数项: {item}")
    print(f"   当前值: {old_value}")
    print(f"   目标值: {new_value}")
    print(f"   命令类型: {command_type}")
    print()
    
    print(f"🔧 请求详情:")
    print(f"   完整URL: {request_info['url']}")
    print()
    
    print(f"📝 请求头:")
    print(f"   Content-Type: application/json")
    print()
    
    print(f"📦 请求体:")
    print(json.dumps(request_info['payload'], indent=4, ensure_ascii=False))
    print()
    
    print(f"🔐 签名计算:")
    print(f"   SCADA密钥: {request_info['secret']}")
    print(f"   时间戳: {request_info['timestamp']}")
    print(f"   签名原数据: {request_info['signature_data']}")
    print(f"   计算字符串: {request_info['signature_data']}{request_info['secret']}{request_info['timestamp']}")
    print(f"   MD5签名: {request_info['signature']}")
    print()
    
    print(f"✨ curl命令:")
    curl_cmd = f"""curl -X POST '{request_info['url']}' \\
  -H 'Content-Type: application/json' \\
  -d '{json.dumps(request_info['payload'], separators=(',', ':'), ensure_ascii=False)}'"""
    print(curl_cmd)
    print()
    
    print("🚀 这就是将要发送给PLC系统的完整请求！")
    print("   如果看起来正确，您可以运行 test_plc_update.py 来实际发送。")