import os
import json
import uuid
from flask import Flask, render_template, request, jsonify, send_from_directory

app = Flask(__name__)
app.config['MAX_CONTENT_LENGTH'] = 16 * 1024 * 1024  # 16MB limit for safety

# 配置
DATA_DIR = os.path.join(os.path.dirname(__file__), 'data')
DATA_FILE = os.path.join(DATA_DIR, 'postmortems.json')

# 确保数据目录存在
os.makedirs(DATA_DIR, exist_ok=True)

def load_data():
    if not os.path.exists(DATA_FILE):
        # 初始化默认数据
        default_data = [
            {
                "id": "demo-001",
                "title": "生产环境数据库连接池耗尽导致服务不可用",
                "date": "2023-10-24",
                "severity": "P0",
                "owner": "张三",
                "created_at": "2023-10-24T10:00:00Z",
                "summary": "在双十一预热活动期间，主数据库连接数突然飙升至 100%，导致订单服务无法连接数据库，所有下单请求失败。持续时间约 15 分钟。",
                "impact": "造成约 5000 单交易失败，预估 GMV 损失 100 万。用户投诉激增。",
                "timeline": [
                    {"time": "20:00", "description": "流量开始激增，达到平时峰值的 3 倍", "type": "detection"},
                    {"time": "20:05", "description": "监控系统报警，DB CPU 飙升至 90%", "type": "detection"},
                    {"time": "20:08", "description": "DBA 介入排查，发现活动连接数打满", "type": "investigation"},
                    {"time": "20:12", "description": "紧急扩容 Read Replica，并临时调大 Max Connections", "type": "fix"},
                    {"time": "20:15", "description": "服务逐步恢复正常", "type": "verification"}
                ],
                "root_cause": {
                    "whys": [
                        "数据库连接数打满，拒绝新连接",
                        "后端服务实例扩容后，每个实例的连接池配置未做相应调整",
                        "微服务配置中心下发的连接池参数是静态的，未随实例数动态计算",
                        "在进行压力测试时，只测试了单实例性能，未测试全链路大规模并发下的 DB 瓶颈",
                        "缺乏对数据库总连接数的全局管控机制"
                    ],
                    "conclusion": "缺乏全局的数据库连接治理机制，且压测覆盖不全。"
                },
                "action_items": [
                    {"task": "实施数据库连接代理 (Proxy) 层", "owner": "李四", "deadline": "2023-11-01", "status": "in_progress"},
                    {"task": "优化全链路压测模型，包含 DB 极限场景", "owner": "王五", "deadline": "2023-11-15", "status": "pending"}
                ]
            },
            {
                "id": "demo-002",
                "title": "支付回调接口验签逻辑缺陷",
                "date": "2023-09-15",
                "severity": "P2",
                "owner": "赵六",
                "created_at": "2023-09-15T14:00:00Z",
                "summary": "收到用户反馈支付成功但订单状态未更新。排查发现部分特殊字符导致签名验证失败。",
                "impact": "约 20 笔订单卡单，需人工补单。",
                "timeline": [
                    {"time": "14:00", "description": "客服收到用户反馈", "type": "detection"},
                    {"time": "14:30", "description": "定位到日志中存在大量验签失败错误", "type": "investigation"},
                    {"time": "15:00", "description": "修复验签逻辑中的字符编码处理问题", "type": "fix"}
                ],
                "root_cause": {
                    "whys": [
                        "签名验证失败",
                        "第三方支付回调参数中包含特殊 Emoji 字符",
                        "验签逻辑未正确处理 UTF-8 编码",
                        "开发测试阶段未覆盖特殊字符场景",
                        ""
                    ],
                    "conclusion": "编码规范执行不到位，测试用例缺失。"
                },
                "action_items": [
                    {"task": "修复代码并补充单元测试", "owner": "赵六", "deadline": "2023-09-16", "status": "done"}
                ]
            }
        ]
        save_data(default_data)
        return default_data
    try:
        with open(DATA_FILE, 'r', encoding='utf-8') as f:
            return json.load(f)
    except Exception:
        return []

def save_data(data):
    with open(DATA_FILE, 'w', encoding='utf-8') as f:
        json.dump(data, f, ensure_ascii=False, indent=2)

@app.route('/')
def index():
    return render_template('index.html')

@app.route('/api/postmortems', methods=['GET'])
def get_postmortems():
    data = load_data()
    # 按最后修改时间或创建时间排序（这里简单按列表顺序倒序）
    return jsonify(data[::-1])

@app.route('/api/postmortems', methods=['POST'])
def create_postmortem():
    data = load_data()
    new_item = request.json
    
    # 基础验证与默认值
    if not new_item.get('id'):
        new_item['id'] = str(uuid.uuid4())
    
    new_item['created_at'] = new_item.get('created_at', '')
    new_item['updated_at'] = new_item.get('updated_at', '')
    
    data.append(new_item)
    save_data(data)
    return jsonify(new_item), 201

@app.route('/api/postmortems/<item_id>', methods=['PUT'])
def update_postmortem(item_id):
    data = load_data()
    updated_item = request.json
    
    for i, item in enumerate(data):
        if item['id'] == item_id:
            data[i] = updated_item
            save_data(data)
            return jsonify(updated_item)
            
    return jsonify({'error': 'Not found'}), 404

@app.route('/api/postmortems/<item_id>', methods=['DELETE'])
def delete_postmortem(item_id):
    data = load_data()
    data = [item for item in data if item['id'] != item_id]
    save_data(data)
    return jsonify({'success': True})

@app.route('/api/export/<item_id>', methods=['GET'])
def export_markdown(item_id):
    data = load_data()
    item = next((i for i in data if i['id'] == item_id), None)
    if not item:
        return "Not Found", 404
        
    # 生成 Markdown 内容
    md = f"# 事故复盘: {item.get('title', '无标题')}\n\n"
    md += f"**日期**: {item.get('date', '')} | **级别**: {item.get('severity', '')} | **负责人**: {item.get('owner', '')}\n\n"
    
    md += "## 1. 事故摘要 (Summary)\n"
    md += f"{item.get('summary', '无')}\n\n"
    
    md += "## 2. 影响范围 (Impact)\n"
    md += f"{item.get('impact', '无')}\n\n"
    
    md += "## 3. 时间线 (Timeline)\n"
    for t in item.get('timeline', []):
        md += f"- **{t.get('time', '')}**: {t.get('description', '')} ({t.get('type', '')})\n"
    md += "\n"
    
    md += "## 4. 根因分析 (5 Whys)\n"
    whys = item.get('root_cause', {}).get('whys', [])
    for idx, why in enumerate(whys):
        if why:
            md += f"{idx+1}. Why? {why}\n"
    md += f"\n**结论**: {item.get('root_cause', {}).get('conclusion', '')}\n\n"
    
    md += "## 5. 改进措施 (Action Items)\n"
    md += "| 任务 | 负责人 | 截止日期 | 状态 |\n"
    md += "| --- | --- | --- | --- |\n"
    for action in item.get('action_items', []):
        md += f"| {action.get('task', '')} | {action.get('owner', '')} | {action.get('deadline', '')} | {action.get('status', '')} |\n"
        
    return jsonify({'markdown': md})

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=7860, debug=True)