#!/usr/bin/env python3
"""
文件上传下载功能模块演示脚本

展示文件处理的核心功能。
"""

import os
import tempfile
from core.file_handler import (
    FileUploader,
    FileDownloader,
    FileTypeValidator,
    FileSizeValidator,
    FilenameSanitizer,
    FileStorageManager,
)


def demo_file_upload():
    """演示文件上传"""
    print("\n" + "="*60)
    print("演示1: 文件上传")
    print("="*60)
    
    uploader = FileUploader(upload_dir="/tmp/demo_uploads")
    
    # 创建测试文件
    with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
        f.write("测试文件内容")
        test_file_path = f.name
    
    # 上传文件
    with open(test_file_path, 'rb') as f:
        result = uploader.upload(f, filename="test.txt")
    
    print(f"✅ 上传结果: {result.success}")
    print(f"✅ 文件ID: {result.file_id}")
    print(f"✅ 文件名: {result.filename}")
    print(f"✅ 文件大小: {result.size} bytes")
    
    # 清理
    os.unlink(test_file_path)
    
    return result.file_id, uploader._storage


def demo_file_download(file_id, storage):
    """演示文件下载"""
    print("\n" + "="*60)
    print("演示2: 文件下载")
    print("="*60)
    
    downloader = FileDownloader(storage_manager=storage)
    result = downloader.download(file_id)
    
    print(f"✅ 下载结果: {result.success}")
    if result.content:
        print(f"✅ 文件内容: {result.content.decode('utf-8')}")


def demo_file_type_validation():
    """演示文件类型验证"""
    print("\n" + "="*60)
    print("演示3: 文件类型验证")
    print("="*60)
    
    validator = FileTypeValidator(allowed_extensions=['.txt', '.pdf', '.jpg'])
    
    test_files = [
        ("document.txt", True),
        ("image.jpg", True),
        ("script.exe", False),
        ("virus.bat", False),
    ]
    
    for filename, expected in test_files:
        is_valid = validator.validate(filename)
        status = "✅" if is_valid == expected else "❌"
        print(f"{status} {filename}: {'允许' if is_valid else '拒绝'}")


def demo_file_size_validation():
    """演示文件大小验证"""
    print("\n" + "="*60)
    print("演示4: 文件大小验证")
    print("="*60)
    
    validator = FileSizeValidator(max_size=1024)  # 1KB
    
    test_sizes = [
        (512, True, "512 bytes"),
        (1024, True, "1KB"),
        (2048, False, "2KB"),
    ]
    
    for size, expected, desc in test_sizes:
        is_valid = validator.validate(size)
        status = "✅" if is_valid == expected else "❌"
        print(f"{status} {desc}: {'允许' if is_valid else '拒绝'}")


def demo_filename_sanitization():
    """演示文件名净化"""
    print("\n" + "="*60)
    print("演示5: 文件名净化")
    print("="*60)
    
    sanitizer = FilenameSanitizer()
    
    test_names = [
        "../../../etc/passwd",
        "file;rm -rf /|.txt",
        "normal_file.txt",
        "<script>alert('xss')</script>.txt",
    ]
    
    for name in test_names:
        safe_name = sanitizer.sanitize(name)
        print(f"✅ 原始: {name[:40]:<40}")
        print(f"   净化: {safe_name}")


def demo_file_storage():
    """演示文件存储管理"""
    print("\n" + "="*60)
    print("演示6: 文件存储管理")
    print("="*60)
    
    manager = FileStorageManager(storage_dir="/tmp/demo_storage")
    
    # 保存文件
    file_id = manager.save(
        "存储测试内容".encode('utf-8'),
        filename="stored.txt",
        metadata={"author": "demo", "tags": ["test"]}
    )
    print(f"✅ 保存文件，ID: {file_id}")
    
    # 获取文件
    content = manager.get(file_id)
    print(f"✅ 获取文件内容: {content.decode('utf-8')}")
    
    # 获取元数据
    metadata = manager.get_metadata(file_id)
    print(f"✅ 元数据: {metadata}")
    
    # 删除文件
    deleted = manager.delete(file_id)
    print(f"✅ 删除文件: {deleted}")


def demo_batch_upload():
    """演示批量上传"""
    print("\n" + "="*60)
    print("演示7: 批量上传")
    print("="*60)
    
    uploader = FileUploader(upload_dir="/tmp/demo_batch")
    
    # 创建多个测试文件
    files = []
    for i in range(3):
        with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
            f.write(f"文件{i}内容")
            files.append(f.name)
    
    # 批量上传
    results = uploader.upload_batch(files)
    
    print(f"✅ 批量上传: {len(results)}个文件")
    for i, result in enumerate(results):
        print(f"   文件{i}: {result.success} (ID: {result.file_id})")
    
    # 清理
    for f in files:
        if os.path.exists(f):
            os.unlink(f)


def main():
    """主函数"""
    print("\n" + "="*60)
    print("文件上传下载功能模块演示")
    print("="*60)
    
    file_id, storage = demo_file_upload()
    demo_file_download(file_id, storage)
    demo_file_type_validation()
    demo_file_size_validation()
    demo_filename_sanitization()
    demo_file_storage()
    demo_batch_upload()
    
    print("\n" + "="*60)
    print("✅ 所有演示完成!")
    print("="*60)


if __name__ == "__main__":
    main()