import gradio as gr
import os
import json
import time
from filelock import FileLock
from datetime import datetime

# 定义评价标准
CRITERIA = ["画质清晰度", "物理真实感", "流畅度", "色彩表现", "整体观感"]

# 数据保存路径
RESULTS_FILE = "results.json"
LOCK_FILE = "results.json.lock"

def save_result(left_video, right_video, selections):
    """保存用户的评价结果到文件，使用 FileLock 确保并发安全"""
    result = {
        "timestamp": datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
        "left_video": left_video,
        "right_video": right_video,
        "selections": selections
    }
    
    # 确保文件存在
    if not os.path.exists(RESULTS_FILE):
        with open(RESULTS_FILE, 'w') as f:
            json.dump([], f)
    
    # 使用 FileLock 保证并发安全
    lock = FileLock(LOCK_FILE, timeout=60)  # 设置 60 秒超时
    try:
        with lock:
            # 读取现有数据
            with open(RESULTS_FILE, 'r') as f:
                data = json.load(f)
            
            # 添加新结果
            data.append(result)
            
            # 写入更新后的数据
            with open(RESULTS_FILE, 'w') as f:
                json.dump(data, f, indent=2)
            
            return True
    except Exception as e:
        # 如果发生异常，尝试使用备用方法保存
        try:
            backup_file = f"backup_{int(time.time())}.json"
            with open(backup_file, 'w') as bf:
                json.dump([result], bf, indent=2)
            return True
        except:
            return False

def submit_evaluation(left_video, right_video, *selections):
    """处理用户提交的评价"""
    selections_dict = {}
    for i, criterion in enumerate(CRITERIA):
        selections_dict[criterion] = "左侧" if selections[i] == "左侧视频更好" else "右侧"
    
    success = save_result(left_video, right_video, selections_dict)
    
    if success:
        return "感谢您的评价！您的反馈已成功保存。"
    else:
        return "保存失败，请稍后再试。"

def create_ui():
    """创建Gradio界面"""
    with gr.Blocks(css="""
        .container {max-width: 1200px; margin: 0 auto;}
        .header {text-align: center; margin-bottom: 20px;}
        .videos {display: flex; gap: 20px;}
        .video-container {flex: 1; text-align: center;}
        .criteria {margin-top: 30px;}
        .criterion {margin-bottom: 15px; padding: 10px; background: #f7f7f7; border-radius: 8px;}
        .submit-btn {margin-top: 30px;}
        footer {margin-top: 50px; text-align: center; font-size: 0.8em; color: #666;}
    """) as demo:
        gr.Markdown("# 视频比较评价系统", elem_classes=["header"])
        gr.Markdown("### 请观看下方两个视频，并根据各项标准选择您认为更好的一个", elem_classes=["header"])
        
        with gr.Row(elem_classes=["videos"]):
            with gr.Column(elem_classes=["video-container"]):
                gr.Markdown("### 视频 A")
                left_video = gr.Video(label="左侧视频", value="./videos/test/test1.mp4")
            
            with gr.Column(elem_classes=["video-container"]):
                gr.Markdown("### 视频 B")
                right_video = gr.Video(label="右侧视频", value="./videos/test/test2.mp4")
        
        selections = []
        with gr.Group(elem_classes=["criteria"]):
            gr.Markdown("## 评价标准")
            for criterion in CRITERIA:
                with gr.Row(elem_classes=["criterion"]):
                    gr.Markdown(f"### {criterion}")
                    selection = gr.Radio(
                        ["左侧视频更好", "右侧视频更好"], 
                        label="您的选择",
                        info="请选择您认为在此标准下表现更好的视频"
                    )
                    selections.append(selection)
        
        submit_btn = gr.Button("提交评价", variant="primary", elem_classes=["submit-btn"])
        result = gr.Markdown()
        
        submit_btn.click(
            fn=submit_evaluation,
            inputs=[left_video, right_video] + selections,
            outputs=result
        )
        
        gr.Markdown(
            "---\n"
            "© 2023 视频比较评价系统 | 感谢您的参与",
            elem_classes=["footer"]
        )
    
    return demo

if __name__ == "__main__":
    demo = create_ui()
    demo.launch()