from flask import Flask, render_template, request, Response, stream_with_context, jsonify, send_file
import subprocess
import os
import requests
import signal

app = Flask(__name__)

# 全局变量存储当前进程
current_process = None

# 默认配置
DEFAULT_CONFIG = {
    "OLD_GITLAB_URL": os.environ.get("OLD_GITLAB_URL", "http://172.25.254.5:10088"),
    "OLD_TOKEN": os.environ.get("OLD_TOKEN", "YJKiyTUEsfCpQ9yMSrwn"),
    "NEW_GITLAB_URL": os.environ.get("NEW_GITLAB_URL", "http://172.23.24.8:32272"),
    "NEW_TOKEN": os.environ.get("NEW_TOKEN", "glpat-jT8miNczJBRh9xRQbNoc"),
    "DEFAULT_PASSWORD": os.environ.get("DEFAULT_PASSWORD", "Password123!@#"),
}

@app.route('/', methods=['GET'])
def index():
    return render_template('index.html', config=DEFAULT_CONFIG)

@app.route('/check_connection', methods=['POST'])
def check_connection():
    """
    检查与 GitLab 的连接状态。
    接收 form-data: url, token
    """
    url = request.form.get('url')
    token = request.form.get('token')
    
    if not url or not token:
        return jsonify({"status": "error", "message": "URL 或 Token 为空"})
    
    try:
        # 尝试请求 version 接口 (需要认证)
        # 兼容旧版本可能没有 version 权限，尝试 user 接口
        target_url = f"{url.rstrip('/')}/api/v4/user"
        resp = requests.get(target_url, headers={"Private-Token": token}, timeout=5)
        
        if resp.status_code == 200:
            user_data = resp.json()
            return jsonify({
                "status": "success", 
                "message": f"连接成功! 当前用户: {user_data.get('username')} ({user_data.get('name')})"
            })
        elif resp.status_code == 401:
            return jsonify({"status": "error", "message": "认证失败: Token 无效"})
        else:
            return jsonify({"status": "error", "message": f"连接失败 (HTTP {resp.status_code})"})
            
    except Exception as e:
        return jsonify({"status": "error", "message": f"请求异常: {str(e)}"})

@app.route('/download_log', methods=['GET'])
def download_log():
    """下载服务器端的迁移日志文件"""
    log_file = os.path.join(os.getcwd(), 'migration.log')
    if os.path.exists(log_file):
        return send_file(log_file, as_attachment=True, download_name='migration.log')
    else:
        return "Log file not found", 404

@app.route('/stop', methods=['POST'])
def stop_migration():
    """停止当前正在运行的迁移任务"""
    global current_process
    if current_process and current_process.poll() is None:
        try:
            # 发送 SIGTERM 信号
            current_process.terminate()
            # 也可以尝试 kill: current_process.kill()
            return jsonify({"status": "success", "message": "任务已发送停止信号"})
        except Exception as e:
            return jsonify({"status": "error", "message": f"停止失败: {str(e)}"})
    else:
        return jsonify({"status": "error", "message": "当前没有正在运行的任务"})

@app.route('/run', methods=['POST'])
def run_migration():
    """启动迁移任务 (SSE 流式输出)"""
    global current_process
    mode = request.form.get('mode', 'all')
    
    # 如果已有任务在运行，拒绝新任务
    if current_process and current_process.poll() is None:
        return jsonify({"status": "error", "message": "已有任务正在运行，请先停止"}), 400
    
    # 仅复制必要的环境变量，避免污染
    env = os.environ.copy()
    env.update({
        'OLD_GITLAB_URL': request.form.get('old_url', ''),
        'OLD_TOKEN': request.form.get('old_token', ''),
        'NEW_GITLAB_URL': request.form.get('new_url', ''),
        'NEW_TOKEN': request.form.get('new_token', ''),
        'DEFAULT_PASSWORD': request.form.get('default_password', ''),
        'PYTHONUNBUFFERED': '1', # 强制 Python 输出不缓冲
        'MAX_JOBS': '5'          # 并发数配置
    })

    def generate():
        global current_process
        cmd = ["./gitlab_migration.sh", mode]
        yield f"data: 🚀 开始执行迁移任务: {mode} ...\n\n"
        
        # 使用上下文管理器确保资源释放
        try:
            process = subprocess.Popen(
                cmd,
                stdout=subprocess.PIPE,
                stderr=subprocess.STDOUT,
                env=env,
                text=True,
                bufsize=1  # 行缓冲
            )
            current_process = process
            
            # 手动管理资源，不使用 with，以便全局变量引用
            try:
                for line in process.stdout:
                    if line:
                        yield f"data: {line}\n\n"
                
                return_code = process.wait()
                if return_code == 0:
                    yield f"data: ✅ 迁移任务完成!\n\n"
                elif return_code == -15: # SIGTERM
                    yield f"data: 🛑 迁移任务已手动停止。\n\n"
                else:
                    yield f"data: ❌ 迁移任务失败 (Exit Code: {return_code})\n\n"
            finally:
                if process.stdout:
                    process.stdout.close()
                if process.poll() is None:
                    process.terminate()
                    
        except Exception as e:
            yield f"data: ❌ 系统错误: {str(e)}\n\n"
        finally:
            current_process = None
        
        yield "event: close\ndata: closed\n\n"

    return Response(stream_with_context(generate()), mimetype='text/event-stream')

if __name__ == '__main__':
    # 生产环境建议关闭 debug
    app.run(host='0.0.0.0', port=5000, debug=False)