app.py

"""
Hermes HF Space - Multi-Model AI Hub (OpenRouter Edition)
多模型对比助手：使用 OpenRouter 免费模型
"""

import gradio as gr
import os
import time
import requests

# OpenRouter 配置
OPENROUTER_API_KEY = os.environ.get("OPENROUTER_API_KEY", "")
OPENROUTER_BASE_URL = "https://openrouter.ai/api/v1/chat/completions"

# 预设模型列表（OpenRouter 免费模型）
MODELS = {
    "🦙 Llama 3.3 70B (free)": {
        "id": "meta-llama/llama-3.3-70b-instruct:free",
        "name": "🦙 Llama 3.3 70B",
        "context": "66K",
    },
    "🤖 NVIDIA Nemotron 120B (free)": {
        "id": "nvidia/nemotron-3-super-120b-a12b:free",
        "name": "🤖 NVIDIA Nemotron 120B",
        "context": "1M",
    },
    "🧠 Nous Hermes 3 405B (free)": {
        "id": "nousresearch/hermes-3-llama-3.1-405b:free",
        "name": "🧠 Nous Hermes 3 405B",
        "context": "128K",
    },
    "🔧 CoBuddy Code (free)": {
        "id": "baidu/cobuddy:free",
        "name": "🔧 CoBuddy (百度代码模型)",
        "context": "131K",
    },
}

SYSTEM_PROMPTS = {
    "Default": "",
    "Code Assistant": "You are an expert programmer. Write clean, efficient code with brief explanations.",
    "中文助手": "你是一个有帮助的中文AI助手，用简洁清晰的语言回答。",
    "Summarizer": "You are a text summarization expert. Provide concise, accurate summaries.",
    "Creative Writer": "You are a creative writer. Write engaging, imaginative content.",
}


def call_openrouter(model_id: str, prompt: str, max_tokens: int = 384, system: str = "") -> tuple[str, float]:
    """调用 OpenRouter API"""
    if not OPENROUTER_API_KEY:
        return "⚠️ API key not configured. Please set OPENROUTER_API_KEY in Space secrets.", 0.0

    headers = {
        "Authorization": f"Bearer {OPENROUTER_API_KEY}",
        "Content-Type": "application/json",
        "HTTP-Referer": "https://cntalk-hermes.hf.space",
        "X-Title": "Hermes OpenRouter Hub",
    }

    messages = []
    if system:
        messages.append({"role": "system", "content": system})
    messages.append({"role": "user", "content": prompt})

    payload = {
        "model": model_id,
        "messages": messages,
        "max_tokens": max_tokens,
        "temperature": 0.7,
    }

    try:
        start = time.time()
        resp = requests.post(
            OPENROUTER_BASE_URL,
            headers=headers,
            json=payload,
            timeout=90,
        )
        elapsed = time.time() - start

        if resp.status_code == 200:
            result = resp.json()
            content = result["choices"][0]["message"]["content"]
            return content, elapsed
        elif resp.status_code == 429:
            return "⚠️ Rate limit exceeded. Please wait a moment or try a different model.", elapsed
        else:
            error_msg = resp.json().get("error", {}).get("message", resp.text[:150])
            return f"⚠️ Error {resp.status_code}: {error_msg}", elapsed
    except Exception as e:
        return f"⚠️ Request failed: {str(e)[:100]}", 0.0


def format_response(model_name: str, context: str, response: str, elapsed: float) -> str:
    emoji = "✅" if not response.startswith("⚠️") else "⚠️"
    return f"{emoji} **{model_name}** [ctx:{context}] ({elapsed:.1f}s)\n{response}\n"


def compare_models(user_input: str, model_keys: list, system_key: str = "Default"):
    """对比多个模型的回答"""
    if not user_input.strip():
        return "⚠️ Please enter a message."

    system = SYSTEM_PROMPTS.get(system_key, "")
    results = []

    for key in model_keys:
        model = MODELS.get(key)
        if not model:
            continue
        model_id = model["id"]
        model_name = model["name"]
        model_context = model["context"]

        response, elapsed = call_openrouter(model_id, user_input, system=system)
        results.append(format_response(model_name, model_context, response, elapsed))

    if not results:
        return "⚠️ Please select at least one model."

    return "\n---\n".join(results)


def single_chat(model_key: str, user_input: str, system_key: str, history: list):
    """单模型对话（带历史）"""
    if not user_input.strip():
        return history, ""

    model = MODELS.get(model_key, {})
    model_id = model.get("id", "")
    system = SYSTEM_PROMPTS.get(system_key, "")

    # 构建带历史的 prompt
    prompt = ""
    for h_user, h_bot in history:
        prompt += f"User: {h_user}\nAssistant: {h_bot}\n"
    prompt += f"User: {user_input}"

    response, elapsed = call_openrouter(model_id, prompt, system=system)

    history.append((user_input, f"{response}\n\n⏱️ {elapsed:.1f}s"))
    return history, ""


# Gradio UI
with gr.Blocks(title="Hermes OpenRouter Hub", theme=gr.themes.Soft()) as demo:
    gr.Markdown("""
    # 🐠 Hermes OpenRouter Hub
    ### 多模型 AI 助手 — 同时对比多个开源模型的回答

    基于 OpenRouter API，支持 Llama 3.3 / Nemotron / Hermes 3 等免费模型

    ⚠️ 免费模型有速率限制，如遇报错稍后重试即可
    """)

    with gr.Tabs():
        with gr.TabItem("🔍 模型对比"):
            with gr.Row():
                with gr.Column(scale=2):
                    user_input = gr.Textbox(
                        label="✏️ 输入问题",
                        placeholder="例如: 解释一下什么是transformer架构",
                        lines=4,
                    )
                    with gr.Row():
                        system_dropdown = gr.Dropdown(
                            choices=list(SYSTEM_PROMPTS.keys()),
                            value="Default",
                            label="系统提示",
                        )
                        compare_btn = gr.Button("🚀 对比模型", variant="primary")

                    gr.Markdown("**选择要对比的模型：**")
                    model_checkboxes = gr.CheckboxGroup(
                        choices=[(v["name"], k) for k, v in MODELS.items()],
                        value=["🤖 NVIDIA Nemotron 120B (free)", "🔧 CoBuddy Code (free)"],
                        interactive=True,
                    )
                with gr.Column(scale=3):
                    output = gr.Markdown("""
                    *选择模型后点击「对比模型」开始分析*

                    每个模型独立回答，可对比：
                    - 回答质量与风格
                    - 响应速度
                    - Context 长度差异

                    💡 免费模型有并发限制，高频使用建议错峰
                    """)

            compare_btn.click(
                fn=compare_models,
                inputs=[user_input, model_checkboxes, system_dropdown],
                outputs=output,
            )

        with gr.TabItem("💬 单模型对话"):
            with gr.Row():
                with gr.Column(scale=1):
                    model_select = gr.Dropdown(
                        choices=[(v["name"], k) for k, v in MODELS.items()],
                        value="🤖 NVIDIA Nemotron 120B (free)",
                        label="选择模型",
                    )
                    system_s = gr.Dropdown(
                        choices=list(SYSTEM_PROMPTS.keys()),
                        value="Default",
                        label="系统提示",
                    )
                with gr.Column(scale=3):
                    chat_history = gr.Chatbot(label="对话历史", height=400)
                    with gr.Row():
                        msg_input = gr.Textbox(
                            placeholder="输入消息...",
                            scale=4,
                            lines=2,
                        )
                        send_btn = gr.Button("发送", variant="primary", scale=1)

            def on_send(msg, history):
                return single_chat(model_select.value, msg, system_s.value, history)

            send_btn.click(
                fn=on_send, inputs=[msg_input, chat_history], outputs=[chat_history, msg_input]
            )
            msg_input.submit(
                fn=on_send, inputs=[msg_input, chat_history], outputs=[chat_history, msg_input]
            )

        with gr.TabItem("ℹ️ 关于"):
            gr.Markdown("""
            ## 🐠 Hermes OpenRouter Hub

            **功能：**
            - 🔍 多模型对比：一次提问，同时获得多个模型的回答
            - 💬 单模型对话：深入对话某一特定模型
            - 🌐 中英文支持

            **支持的免费模型：**
            | 模型 | 参数量 | Context | 特点 |
            |------|--------|---------|------|
            | Llama 3.3 70B | 70B | 66K | 高质量多语言 |
            | NVIDIA Nemotron 120B | 120B MoE | 1M | 超长上下文 |
            | Nous Hermes 3 405B | 405B | 128K | 超大模型 |
            | CoBuddy | 1.44B | 131K | 代码专用，百度 |

            **限制：** 免费 tier 有速率限制，高频使用请考虑升级或自备 key。

            Powered by [OpenRouter](https://openrouter.ai)
            """)

# 启动
demo.launch()