import os
import json
import requests
import base64
import time
from pathlib import Path

# 設定檔案路徑
CONFIG_FILE = "/etc/cloudflare_nas/config.json"
CREDENTIALS_FILE = "/etc/cloudflare_nas/credentials.json"
CLOUDFLARED_CONFIG = "/etc/cloudflare/config.yml"
CLOUDFLARED_BIN = "/usr/local/bin/cloudflared"

class CloudflareNAS:
    def __init__(self):
        self.load_config()
        self.headers = {
            "Authorization": f"Bearer {self.config['api_token']}",
            "Content-Type": "application/json"
        }

    def load_config(self):
        """載入設定檔"""
        with open(CONFIG_FILE, "r") as f:
            self.config = json.load(f)

    def get_public_ip(self):
        """獲取當前公網 IP"""
        try:
            return requests.get('https://api.ipify.org').text
        except Exception as e:
            print(f"獲取 IP 失敗: {e}")
            return None

    def update_dns_record(self, ip):
        """更新或創建 DNS A 紀錄"""
        url = f"https://api.cloudflare.com/client/v4/zones/{self.config['zone_id']}/dns_records"
        params = {
            "type": "A",
            "name": self.config["dns_record"]
        }

        # 檢查現有紀錄
        response = requests.get(url, headers=self.headers, params=params)
        records = response.json()["result"]

        data = {
            "type": "A",
            "name": self.config["dns_record"],
            "content": ip,
            "ttl": 1,
            "proxied": False
        }

        if records:
            # 更新現有紀錄
            record_id = records[0]["id"]
            response = requests.put(f"{url}/{record_id}", headers=self.headers, json=data)
        else:
            # 創建新紀錄
            response = requests.post(url, headers=self.headers, json=data)

        return response.json()

    def create_tunnel(self):
        """透過 API 創建 Cloudflare Tunnel"""
        url = f"https://api.cloudflare.com/client/v4/accounts/{self.config['account_id']}/tunnels"
        
        # 生成隨機 Tunnel Secret
        tunnel_secret = base64.b64encode(os.urandom(32)).decode('utf-8')
        
        data = {
            "name": self.config["tunnel_name"],
            "tunnel_secret": tunnel_secret
        }
        
        response = requests.post(url, headers=self.headers, json=data)
        result = response.json()
        
        if response.status_code == 200:
            self.tunnel_id = result["result"]["id"]
            self.tunnel_secret = tunnel_secret
            return True
        else:
            print(f"創建 Tunnel 失敗: {result}")
            return False

    def configure_tunnel_route(self):
        """配置 Tunnel 路由到域名"""
        url = f"https://api.cloudflare.com/client/v4/accounts/{self.config['account_id']}/tunnels/{self.tunnel_id}/routes"
        data = {
            "type": "dns",
            "hostname": self.config["dns_record"],
            "service": self.config["nas_service_url"]
        }
        response = requests.post(url, headers=self.headers, json=data)
        return response.json()

    def save_tunnel_credentials(self):
        """保存 Tunnel 憑證文件"""
        credentials = {
            "AccountTag": self.config["account_id"],
            "TunnelID": self.tunnel_id,
            "TunnelSecret": self.tunnel_secret
        }
        with open(CREDENTIALS_FILE, "w") as f:
            json.dump(credentials, f)
        os.chmod(CREDENTIALS_FILE, 0o600)

    def generate_cloudflared_config(self):
        """生成 cloudflared 配置文件"""
        config = {
            "tunnel": self.tunnel_id,
            "credentials-file": CREDENTIALS_FILE,
            "ingress": [
                {"hostname": self.config["dns_record"], "service": self.config["nas_service_url"]},
                {"service": "http_status:404"}
            ]
        }
        with open(CLOUDFLARED_CONFIG, "w") as f:
            json.dump(config, f, indent=2)

    def install_cloudflared(self):
        """下載並安裝 cloudflared"""
        if not Path(CLOUDFLARED_BIN).exists():
            os.system("wget https://github.com/cloudflare/cloudflared/releases/latest/download/cloudflared-linux-amd64 -O /tmp/cloudflared")
            os.system("chmod +x /tmp/cloudflared")
            os.system("sudo mv /tmp/cloudflared /usr/local/bin/cloudflared")

    def setup_service(self):
        """設置 systemd 服務"""
        service_content = f"""
        [Unit]
        Description=Cloudflare Tunnel
        After=network.target

        [Service]
        ExecStart={CLOUDFLARED_BIN} tunnel run --config {CLOUDFLARED_CONFIG}
        Restart=always

        [Install]
        WantedBy=multi-user.target
        """
        with open("/etc/systemd/system/cloudflared.service", "w") as f:
            f.write(service_content)
        
        os.system("sudo systemctl daemon-reload")
        os.system("sudo systemctl enable cloudflared")
        os.system("sudo systemctl start cloudflared")

    def run(self):
        """主執行流程"""
        # 步驟 1: 更新 DDNS
        current_ip = self.get_public_ip()
        if current_ip:
            print(f"當前公網 IP: {current_ip}")
            dns_result = self.update_dns_record(current_ip)
            print(f"DNS 更新結果: {dns_result['success']}")

        # 步驟 2: 創建 Tunnel
        if self.create_tunnel():
            print(f"Tunnel 創建成功: {self.tunnel_id}")
            self.configure_tunnel_route()
            self.save_tunnel_credentials()
            self.generate_cloudflared_config()

            # 步驟 3: 安裝並啟動服務
            self.install_cloudflared()
            self.setup_service()
            print("Cloudflare Tunnel 服務已啟動")

if __name__ == "__main__":
    # 初次運行前需手動創建設定檔案
    config_path = Path(CONFIG_FILE)
    if not config_path.exists():
        config = {
            "api_token": "YOUR_API_TOKEN",
            "zone_id": "YOUR_ZONE_ID",
            "account_id": "YOUR_ACCOUNT_ID",
            "dns_record": "nas.yourdomain.com",
            "tunnel_name": "feynax_nas_tunnel",
            "nas_service_url": "http://localhost:8080"  # 修改為 NAS 實際服務地址
        }
        config_path.parent.mkdir(parents=True, exist_ok=True)
        with open(CONFIG_FILE, "w") as f:
            json.dump(config, f, indent=2)
        print(f"請先編輯設定檔: {CONFIG_FILE}")
    else:
        nas = CloudflareNAS()
        nas.run()