app.py

import gradio as gr
import time
import base64
from openai import OpenAI
import os
from io import BytesIO
from PIL import Image
import re

# 配置
BASE_URL = "https://api.stepfun.com/v1"
STEP_API_KEY = os.environ.get("STEP_API_KEY", "")

def image_to_base64(image):
    """将图像转换为base64字符串"""
    if image is None:
        return None
    
    if isinstance(image, Image.Image):
        buffered = BytesIO()
        image.save(buffered, format="PNG")
        img_str = base64.b64encode(buffered.getvalue()).decode('utf-8')
        return img_str
    elif isinstance(image, str) and os.path.exists(image):
        with open(image, "rb") as image_file:
            return base64.b64encode(image_file.read()).decode('utf-8')
    
    return None

def process_message(message, history, image, system_prompt, temperature, max_tokens, top_p):
    """处理消息并生成响应，支持可选的图片输入"""
    print(f"[DEBUG] Processing message: {message[:100] if message else 'None'}...")
    print(f"[DEBUG] Has image: {image is not None}")
    
    if not message and not image:
        print("[DEBUG] No message or image provided, skipping")
        yield history
        return
    
    if not STEP_API_KEY:
        print("[DEBUG] No API key configured")
        error_msg = "❌ API key not configured. Please add STEP_API_KEY in Settings."
        display_msg = f"[Image] {message}" if image and message else "[Image]" if image else message
        history.append([display_msg, error_msg])
        yield history
        return
    
    # 处理图片
    image_content = None
    text_content = message or ""
    
    if image:
        # 转换图片为base64
        try:
            image_content = image_to_base64(image)
            print(f"[DEBUG] Image processed successfully")
        except Exception as e:
            print(f"[DEBUG] Failed to process image: {e}")
            history.append([message or "[Image]", f"❌ Failed to process image: {str(e)}"])
            yield history
            return
    
    # 构造显示消息
    if image and message:
        display_message = f"🖼️ [Image] {message}"
    elif image:
        display_message = "🖼️ [Image]"
    else:
        display_message = message
    
    # 添加到历史
    history.append([display_message, ""])
    yield history
    
    # 构建API消息
    messages = []
    
    # 添加系统提示词
    if system_prompt:
        messages.append({"role": "system", "content": system_prompt})
    
    # 添加历史对话
    for h in history[:-1]:
        if h[0]:
            # 用户消息 - 移除图片标签
            user_text = re.sub(r'<img[^>]+>', '', h[0]).strip()
            if user_text:
                messages.append({"role": "user", "content": user_text})
        if h[1] and not h[1].startswith("❌"):
            messages.append({"role": "assistant", "content": h[1]})
    
    # 添加当前消息
    if image_content:
        current_content = [
            {"type": "image_url", "image_url": {"url": f"data:image/jpg;base64,{image_content}", "detail": "high"}}
        ]
        if text_content:
            current_content.append({"type": "text", "text": text_content})
        messages.append({"role": "user", "content": current_content})
    else:
        messages.append({"role": "user", "content": text_content})
    
    print(f"[DEBUG] Sending {len(messages)} messages to API")
    print(f"[DEBUG] Last message: {messages[-1]}")
    
    # 创建客户端并调用API
    try:
        # 清除所有可能的代理环境变量
        import os
        proxy_vars = ['HTTP_PROXY', 'HTTPS_PROXY', 'http_proxy', 'https_proxy', 
                      'ALL_PROXY', 'all_proxy', 'NO_PROXY', 'no_proxy']
        for var in proxy_vars:
            if var in os.environ:
                del os.environ[var]
                print(f"[DEBUG] Removed {var} from environment")
        
        # 尝试创建客户端
        try:
            # 方法1：直接创建
            client = OpenAI(api_key=STEP_API_KEY, base_url=BASE_URL)
            print("[DEBUG] Client created successfully (method 1)")
        except TypeError as e:
            if 'proxies' in str(e):
                print(f"[DEBUG] Method 1 failed with proxy error, trying method 2")
                # 方法2：使用httpx客户端
                import httpx
                http_client = httpx.Client(trust_env=False)
                client = OpenAI(
                    api_key=STEP_API_KEY, 
                    base_url=BASE_URL,
                    http_client=http_client
                )
                print("[DEBUG] Client created successfully (method 2)")
            else:
                raise e
        
        print("[DEBUG] Calling API...")
        response = client.chat.completions.create(
            model="step-3",
            messages=messages,
            temperature=temperature,
            max_tokens=max_tokens,
            top_p=top_p,
            stream=True
        )
        
        print("[DEBUG] API call successful, processing stream...")
        
        # 流式输出
        full_response = ""
        chunk_count = 0
        in_reasoning = False
        reasoning_content = ""
        final_content = ""
        
        for chunk in response:
            chunk_count += 1
            if chunk.choices and len(chunk.choices) > 0:
                delta = chunk.choices[0].delta
                if hasattr(delta, 'content') and delta.content:
                    content = delta.content
                    full_response += content
                    
                    # 检测 <reasoning> 标签
                    if '<reasoning>' in content:
                        in_reasoning = True
                        # 分割内容
                        parts = content.split('<reasoning>')
                        final_content += parts[0]
                        if len(parts) > 1:
                            reasoning_content += parts[1]
                    elif '</reasoning>' in content:
                        # 结束推理部分
                        parts = content.split('</reasoning>')
                        if parts[0]:
                            reasoning_content += parts[0]
                        in_reasoning = False
                        if len(parts) > 1:
                            final_content += parts[1]
                    elif in_reasoning:
                        # 在推理标签内
                        reasoning_content += content
                    else:
                        # 在推理标签外
                        final_content += content
                    
                    # 实时更新显示
                    if reasoning_content and final_content:
                        # 有推理和最终答案
                        display_text = f"💭 **Chain of Thought:**\n\n{reasoning_content}\n\n---\n\n📝 **Answer:**\n\n{final_content}"
                    elif reasoning_content:
                        # 只有推理过程
                        display_text = f"💭 **Chain of Thought:**\n\n{reasoning_content}\n\n---\n\n📝 **Answer:**\n\n*Generating...*"
                    else:
                        # 只有答案或普通回复
                        display_text = full_response
                    
                    history[-1][1] = display_text
                    
                    if chunk_count % 5 == 0:
                        print(f"[DEBUG] Received {chunk_count} chunks, {len(full_response)} chars")
                    yield history
        
        print(f"[DEBUG] Stream complete. Total chunks: {chunk_count}, Total chars: {len(full_response)}")
        
        # 最终格式化
        if reasoning_content:
            # 如果有推理内容，使用格式化显示
            final_display = f"💭 **Chain of Thought:**\n\n{reasoning_content}\n\n---\n\n📝 **Answer:**\n\n{final_content.strip()}"
            history[-1][1] = final_display
            yield history
        
        if not full_response:
            print("[DEBUG] No response content received")
            history[-1][1] = "⚠️ No response received from API"
            yield history
            
    except Exception as e:
        print(f"[DEBUG] API error: {e}")
        import traceback
        traceback.print_exc()
        history[-1][1] = f"❌ Error: {str(e)}"
        yield history

# 创建Gradio界面
with gr.Blocks(title="Step-3 Chat", theme=gr.themes.Soft()) as demo:
    gr.Markdown("""
    # 🤖 Step-3 Chat
    
    Welcome to Step-3, an advanced multimodal AI assistant by StepFun.
    """)
    
    with gr.Row():
        with gr.Column(scale=3):
            # 聊天界面
            chatbot = gr.Chatbot(
                height=600,
                show_label=False,
                elem_id="chatbot",
                bubble_full_width=False,
                avatar_images=None,
                render_markdown=True
            )
            
            # 输入区域
            with gr.Row():
                with gr.Column(scale=8):
                    msg = gr.Textbox(
                        label="Message",
                        placeholder="Type your message here...",
                        lines=2,
                        max_lines=10,
                        show_label=False,
                        elem_id="message-textbox"
                    )
                with gr.Column(scale=2):
                    image_input = gr.Image(
                        label="Upload Image (Optional)",
                        type="filepath",
                        height=100,
                        interactive=True,
                        show_label=True
                    )
                with gr.Column(scale=1, min_width=100):
                    submit_btn = gr.Button("Send", variant="primary")
            
            # 底部按钮
            with gr.Row():
                clear_btn = gr.Button("🗑️ Clear", scale=1)
                undo_btn = gr.Button("↩️ Undo", scale=1)
                retry_btn = gr.Button("🔄 Retry", scale=1)
        
        with gr.Column(scale=1):
            # 设置面板
            with gr.Accordion("⚙️ Settings", open=True):
                system_prompt = gr.Textbox(
                    label="System Prompt",
                    placeholder="You are a helpful assistant...",
                    lines=3,
                    value="You are Step-3, a helpful AI assistant created by StepFun."
                )
                
                temperature = gr.Slider(
                    minimum=0,
                    maximum=2,
                    value=0.7,
                    step=0.1,
                    label="Temperature"
                )
                
                max_tokens = gr.Slider(
                    minimum=1,
                    maximum=4096,
                    value=2048,
                    step=1,
                    label="Max Tokens"
                )
                
                top_p = gr.Slider(
                    minimum=0,
                    maximum=1,
                    value=0.95,
                    step=0.01,
                    label="Top P"
                )
            
            # 示例
            with gr.Accordion("📝 Examples", open=False):
                gr.Examples(
                    examples=[
                        ["What is machine learning?"],
                        ["Write a Python function to calculate fibonacci numbers"],
                        ["Explain quantum computing in simple terms"],
                        ["What are the benefits of renewable energy?"],
                        ["How does blockchain technology work?"]
                    ],
                    inputs=msg,
                    label=""
                )
    
    # 事件处理函数
    def user_submit(message, history, image):
        """用户提交消息时的处理"""
        print(f"[DEBUG] user_submit called with message: {message[:50] if message else 'None'}...")
        print(f"[DEBUG] user_submit called with image: {image is not None}")
        if message or image:
            # 清空输入，保存消息和图片用于后续处理
            return gr.update(value=""), history, gr.update(value=None), message, image
        return gr.update(value=message), history, gr.update(value=image), message, image
    
    def bot_response(history, saved_message, saved_image, system_prompt, temperature, max_tokens, top_p):
        """生成机器人响应"""
        print(f"[DEBUG] bot_response called with saved_message: {saved_message[:50] if saved_message else 'None'}...")
        print(f"[DEBUG] bot_response called with saved_image: {saved_image is not None}")
        if saved_message or saved_image:
            # 使用生成器处理消息
            for updated_history in process_message(saved_message, history, saved_image, system_prompt, temperature, max_tokens, top_p):
                yield updated_history
        else:
            yield history
    
    def undo_last(history):
        if history:
            return history[:-1]
        return history
    
    def retry_last(history):
        if history and history[-1][0]:
            last_message = history[-1][0]
            new_history = history[:-1]
            return new_history, last_message
        return history, ""
    
    # 创建隐藏的组件来存储消息和图片
    saved_msg = gr.State("")
    saved_img = gr.State(None)
    
    # 提交消息 - Enter键
    msg.submit(
        user_submit,
        [msg, chatbot, image_input],
        [msg, chatbot, image_input, saved_msg, saved_img],
        queue=False
    ).then(
        bot_response,
        [chatbot, saved_msg, saved_img, system_prompt, temperature, max_tokens, top_p],
        chatbot
    )
    
    # 提交消息 - Send按钮
    submit_btn.click(
        user_submit,
        [msg, chatbot, image_input],
        [msg, chatbot, image_input, saved_msg, saved_img],
        queue=False
    ).then(
        bot_response,
        [chatbot, saved_msg, saved_img, system_prompt, temperature, max_tokens, top_p],
        chatbot
    )
    
    # 清空对话
    clear_btn.click(
        lambda: ([], "", None),
        None,
        [chatbot, msg, image_input]
    )
    
    # 撤销最后一条
    undo_btn.click(
        undo_last,
        chatbot,
        chatbot
    )
    
    # 重试最后一条
    retry_btn.click(
        retry_last,
        chatbot,
        [chatbot, saved_msg]
    ).then(
        bot_response,
        [chatbot, saved_msg, saved_img, system_prompt, temperature, max_tokens, top_p],
        chatbot
    )
    
    # 页脚
    gr.Markdown("""
    ---
    <div style="text-align: center; color: #666;">
        <p>Powered by <a href="https://www.stepfun.com/" target="_blank" style="color: #0969da;">StepFun</a> | 
        Model: Step-3 | 
        <a href="https://github.com/stepfun-ai" target="_blank" style="color: #0969da;">GitHub</a></p>
    </div>
    """)

# 启动应用
if __name__ == "__main__":
    print(f"[DEBUG] Starting app with API key: {'Set' if STEP_API_KEY else 'Not set'}")
    print(f"[DEBUG] Base URL: {BASE_URL}")
    
    demo.queue(max_size=20)
    demo.launch(
        server_name="0.0.0.0",
        server_port=7860,
        share=False,
        debug=False,
        show_error=True
    )