#!/usr/bin/env python3
"""
Day 083 - 实战案例：多服务器滚动部署系统
支持蓝绿部署、滚动更新、健康检查、自动回滚
"""

import os
import time
import json
import random
from datetime import datetime
from dataclasses import dataclass, field
from typing import List, Dict, Optional
from enum import Enum

# ============ 配置 ============
class DeployStrategy(Enum):
    ROLLING = "rolling"         # 滚动更新
    BLUE_GREEN = "blue_green"   # 蓝绿部署
    CANARY = "canary"           # 金丝雀

@dataclass
class Server:
    """服务器配置"""
    host: str
    name: str
    role: str = "web"           # web / worker / db
    status: str = "active"
    weight: int = 1             # 流量权重

@dataclass
class DeployConfig:
    """部署配置"""
    app_name: str = "myapp"
    version: str = "1.0.0"
    strategy: DeployStrategy = DeployStrategy.ROLLING
    service_port: int = 8080
    health_check_url: str = "/health"
    health_check_interval: int = 5
    health_check_retries: int = 3
    deploy_timeout: int = 300
    rollback_on_failure: bool = True

# ============ 滚动更新执行器 ============
class RollingDeployer:
    """滚动更新部署器"""

    def __init__(self, config: DeployConfig, servers: List[Server]):
        self.config = config
        self.servers = servers
        self.deployed_servers: List[str] = []
        self.failed_servers: List[str] = []

    def deploy(self) -> bool:
        """执行滚动部署"""
        print(f"\n{'='*60}")
        print(f"🚀 滚动部署开始 — {self.config.app_name} v{self.config.version}")
        print(f"{'='*60}")
        print(f"策略: {self.config.strategy.value}")
        print(f"服务器数: {len(self.servers)}")
        print()

        for i, server in enumerate(self.servers, 1):
            print(f"\n📦 部署进度: {i}/{len(self.servers)}")
            print(f"  目标: {server.name} ({server.host})")

            success = self._deploy_to_server(server)

            if success:
                self.deployed_servers.append(server.host)
                print(f"  ✅ {server.name} 部署成功")

                # 健康检查
                if not self._health_check(server):
                    print(f"  ❌ {server.name} 健康检查失败")
                    if self.config.rollback_on_failure:
                        self._rollback_server(server)
                    return False
            else:
                self.failed_servers.append(server.host)
                print(f"  ❌ {server.name} 部署失败")

                if self.config.rollback_on_failure:
                    print("\n🔄 开始回滚已部署的服务器...")
                    self._rollback_deployed()
                    return False

            # 等待间隔（滚动更新的节奏）
            if i < len(self.servers):
                print(f"  ⏳ 等待 {self.config.health_check_interval}s...")
                time.sleep(1)  # 实际使用时改为 self.config.health_check_interval

        print(f"\n{'='*60}")
        print(f"✅ 滚动部署完成！")
        print(f"  成功: {len(self.deployed_servers)} 台")
        print(f"  失败: {len(self.failed_servers)} 台")
        print(f"{'='*60}")
        return True

    def _deploy_to_server(self, server: Server) -> bool:
        """部署到单台服务器"""
        try:
            # 实际使用 Paramiko/Fabric
            # conn = Connection(f'root@{server.host}')
            # conn.put(package, '/tmp/app.tar.gz')
            # conn.run(f'cd /opt/app && tar xzf /tmp/app.tar.gz')
            # conn.run(f'systemctl restart {self.config.app_name}')
            time.sleep(0.5)  # 模拟部署时间
            return True
        except Exception as e:
            print(f"    错误: {e}")
            return False

    def _health_check(self, server: Server) -> bool:
        """健康检查"""
        print(f"  🏥 健康检查 {server.name}...")
        for attempt in range(self.config.health_check_retries):
            try:
                # 实际: requests.get(f"http://{server.host}:{self.config.service_port}{self.config.health_check_url}")
                time.sleep(0.2)  # 模拟检查时间
                print(f"    尝试 {attempt+1}/{self.config.health_check_retries}: ✅")
                return True
            except:
                print(f"    尝试 {attempt+1}/{self.config.health_check_retries}: ❌")
                time.sleep(1)
        return False

    def _rollback_server(self, server: Server):
        """回滚单台服务器"""
        print(f"  🔄 回滚 {server.name}...")
        # 实际: 恢复备份版本
        time.sleep(0.3)
        print(f"  ✅ {server.name} 已回滚")

    def _rollback_deployed(self):
        """回滚所有已部署的服务器"""
        for host in reversed(self.deployed_servers):
            server = next((s for s in self.servers if s.host == host), None)
            if server:
                self._rollback_server(server)
        print("  ✅ 回滚完成")

# ============ 蓝绿部署执行器 ============
class BlueGreenDeployer:
    """蓝绿部署执行器"""

    def __init__(self, config: DeployConfig, servers: List[Server]):
        self.config = config
        self.servers = servers
        self.blue_servers = servers[:len(servers)//2]
        self.green_servers = servers[len(servers)//2:]

    def deploy(self) -> bool:
        """执行蓝绿部署"""
        print(f"\n{'='*60}")
        print(f"🔵🟢 蓝绿部署开始 — v{self.config.version}")
        print(f"{'='*60}")

        # 1. 确定当前活跃组
        active_group = "blue"
        standby_group = "green"
        standby_servers = self.green_servers

        print(f"  当前活跃组: {active_group}")
        print(f"  部署目标组: {standby_group}")

        # 2. 部署到备用组
        print(f"\n📦 部署到 {standby_group} 组...")
        for server in standby_servers:
            print(f"  部署: {server.name} ({server.host})")
            time.sleep(0.3)

        # 3. 健康检查
        print(f"\n🏥 检查 {standby_group} 组健康状态...")
        all_healthy = True
        for server in standby_servers:
            print(f"  检查: {server.name}")
            time.sleep(0.2)

        if not all_healthy:
            print(f"  ❌ {standby_group} 组健康检查失败，放弃部署")
            return False

        # 4. 切换流量
        print(f"\n🔄 切换流量: {active_group} → {standby_group}")
        print(f"  更新负载均衡配置...")
        time.sleep(0.5)
        print(f"  流量已切换到 {standby_group} 组")

        # 5. 验证
        print(f"\n✅ 蓝绿部署完成！")
        print(f"  旧活跃组: {active_group} (备用)")
        print(f"  新活跃组: {standby_group} (服务中)")

        return True

# ============ 监控仪表盘 ============
class DeployMonitor:
    """部署监控"""

    def __init__(self):
        self.metrics_history: List[Dict] = []

    def record(self, server: str, metrics: Dict):
        """记录指标"""
        entry = {
            'timestamp': datetime.now().isoformat(),
            'server': server,
            **metrics
        }
        self.metrics_history.append(entry)

    def get_summary(self) -> Dict:
        """获取汇总"""
        if not self.metrics_history:
            return {}

        latest = self.metrics_history[-1]
        return {
            'total_records': len(self.metrics_history),
            'servers': list(set(m['server'] for m in self.metrics_history)),
            'latest_metrics': latest
        }

    def print_dashboard(self):
        """打印监控仪表盘"""
        print("\n" + "="*60)
        print("📊 部署监控仪表盘")
        print("="*60)

        summary = self.get_summary()
        if not summary:
            print("  暂无监控数据")
            return

        print(f"  总记录数: {summary['total_records']}")
        print(f"  监控服务器: {', '.join(summary['servers'])}")

        latest = summary.get('latest_metrics', {})
        if latest:
            print(f"\n  最新指标 ({latest.get('server', 'N/A')}):")
            for key, value in latest.items():
                if key not in ('timestamp', 'server'):
                    print(f"    {key}: {value}")

# ============ 主程序 ============
if __name__ == '__main__':
    # 配置
    config = DeployConfig(
        app_name="webapp",
        version="2.0.0",
        strategy=DeployStrategy.ROLLING,
        service_port=8080,
        health_check_retries=3,
    )

    # 服务器列表
    servers = [
        Server(host="192.168.1.101", name="Web-01", role="web"),
        Server(host="192.168.1.102", name="Web-02", role="web"),
        Server(host="192.168.1.103", name="Web-03", role="web"),
    ]

    # 选择部署策略
    if config.strategy == DeployStrategy.ROLLING:
        deployer = RollingDeployer(config, servers)
        success = deployer.deploy()
    elif config.strategy == DeployStrategy.BLUE_GREEN:
        deployer = BlueGreenDeployer(config, servers)
        success = deployer.deploy()
    else:
        print(f"⚠️  策略 {config.strategy.value} 暂未实现")
        success = False

    # 监控
    monitor = DeployMonitor()
    for server in servers:
        monitor.record(server.host, {
            'cpu': random.uniform(20, 80),
            'memory': random.uniform(40, 90),
            'status': 'healthy' if success else 'degraded'
        })

    monitor.print_dashboard()

    # 输出结果
    print(f"\n{'='*60}")
    if success:
        print(f"🎉 部署成功！{config.app_name} v{config.version} 已上线")
    else:
        print(f"❌ 部署失败，已回滚")
    print(f"{'='*60}")