events {
    worker_connections 1024;
}

http {
    # 上游服务器配置
    upstream multi_agent_backend {
        server multi-agent-system:8000;
        keepalive 32;
    }

    # 日志格式
    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" "$http_x_forwarded_for"';

    access_log /var/log/nginx/access.log main;
    error_log /var/log/nginx/error.log warn;

    # 连接超时设置
    proxy_connect_timeout 60s;
    proxy_send_timeout 60s;
    proxy_read_timeout 60s;

    # SSE 特殊配置：禁用缓冲
    # 这对于 Server-Sent Events 至关重要
    map $http_accept $sse_connection {
        default "keep-alive";
        "text/event-stream" "keep-alive";
    }

    server {
        listen 80;
        server_name localhost;

        # 客户端请求体大小限制
        client_max_body_size 10M;

        # API 代理配置
        location /api/ {
            proxy_pass http://multi_agent_backend;
            
            # 必要的代理头
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            
            # HTTP/1.1 支持（SSE 必需）
            proxy_http_version 1.1;
            proxy_set_header Connection "";
            
            # 禁用缓冲（SSE 关键配置）
            proxy_buffering off;
            proxy_cache off;
            proxy_request_buffering off;
            
            # Chunked 传输编码
            chunked_transfer_encoding on;
        }

        # SSE 流端点特殊配置
        location /api/stream/ {
            proxy_pass http://multi_agent_backend;
            
            # 代理头
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            
            # HTTP/1.1 和 Connection
            proxy_http_version 1.1;
            proxy_set_header Connection "";
            
            # SSE 关键：完全禁用缓冲
            proxy_buffering off;
            proxy_cache off;
            proxy_request_buffering off;
            
            # Nginx 特殊指令：禁用 FastCGI 缓冲
            fastcgi_buffering off;
            
            # 保持长连接
            proxy_connect_timeout 60s;
            proxy_send_timeout 300s;
            proxy_read_timeout 300s;
            
            # SSE 心跳
            proxy_ignore_client_abort off;
        }

        # 测试 UI 页面
        location /test-ui {
            proxy_pass http://multi_agent_backend;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
        }

        # 健康检查端点
        location /health {
            proxy_pass http://multi_agent_backend;
            access_log off;
        }

        # API 文档
        location /docs {
            proxy_pass http://multi_agent_backend;
            proxy_set_header Host $host;
        }

        location /openapi.json {
            proxy_pass http://multi_agent_backend;
            proxy_set_header Host $host;
        }
    }

    # HTTPS 配置（可选，取消注释启用）
    # server {
    #     listen 443 ssl http2;
    #     server_name your-domain.com;
    #     
    #     ssl_certificate /etc/nginx/ssl/fullchain.pem;
    #     ssl_certificate_key /etc/nginx/ssl/privkey.pem;
    #     ssl_protocols TLSv1.2 TLSv1.3;
    #     ssl_ciphers HIGH:!aNULL:!MD5;
    #     
    #     # 同样的代理配置...
    # }
}