using Microsoft.AspNetCore.Mvc;

namespace CodePlay.WebAPI.Controllers;

[ApiController]
[Route("api/[controller]")]
public class FileController : ControllerBase
{
    private readonly ILogger<FileController> _logger;
    private readonly string _uploadPath;

    public FileController(ILogger<FileController> logger, IWebHostEnvironment env)
    {
        _logger = logger;
        _uploadPath = Path.Combine(env.ContentRootPath, "uploads");
        if (!Directory.Exists(_uploadPath))
            Directory.CreateDirectory(_uploadPath);
    }

    [HttpPost("upload")]
    public async Task<ActionResult<FileUploadResult>> UploadFile(IFormFile file)
    {
        if (file == null || file.Length == 0)
            return BadRequest("请选择要上传的文件");

        var ext = Path.GetExtension(file.FileName).ToLower();
        if (!new[] { ".cs", ".java", ".cpp", ".hpp", ".cc", ".py", ".txt" }.Contains(ext))
            return BadRequest($"不支持的文件类型：{ext}");

        var fileName = $"{Guid.NewGuid():N}{ext}";
        var filePath = Path.Combine(_uploadPath, fileName);

        using (var stream = new FileStream(filePath, FileMode.Create))
        {
            await file.CopyToAsync(stream);
        }

        var content = await System.IO.File.ReadAllTextAsync(filePath);
        
        _logger.LogInformation("文件上传成功：{FileName} ({Size} bytes)", file.FileName, file.Length);

        return Ok(new FileUploadResult
        {
            FileName = file.FileName,
            StoredName = fileName,
            FilePath = filePath,
            FileSize = file.Length,
            Content = content,
            Language = DetectLanguage(ext)
        });
    }

    [HttpPost("upload-content")]
    public ActionResult<FileUploadResult> UploadContent([FromBody] UploadContentRequest request)
    {
        if (string.IsNullOrWhiteSpace(request.Content))
            return BadRequest("内容不能为空");

        var ext = GetExtensionFromLanguage(request.Language);
        var fileName = $"{Guid.NewGuid():N}{ext}";
        var filePath = Path.Combine(_uploadPath, fileName);

        System.IO.File.WriteAllText(filePath, request.Content);

        return Ok(new FileUploadResult
        {
            FileName = request.FileName ?? $"code{ext}",
            StoredName = fileName,
            FilePath = filePath,
            FileSize = request.Content.Length,
            Content = request.Content,
            Language = request.Language
        });
    }

    [HttpGet("{fileName}/content")]
    public async Task<ActionResult<string>> GetFileContent(string fileName)
    {
        var filePath = Path.Combine(_uploadPath, fileName);
        if (!System.IO.File.Exists(filePath))
            return NotFound();

        var content = await System.IO.File.ReadAllTextAsync(filePath);
        return Ok(content);
    }

    private string DetectLanguage(string ext) => ext switch
    {
        ".cs" => "CSharp",
        ".java" => "Java",
        ".cpp" or ".hpp" or ".cc" => "CPlusPlus",
        ".py" => "Python",
        _ => "Unknown"
    };

    private string GetExtensionFromLanguage(string language) => language.ToLower() switch
    {
        "csharp" => ".cs",
        "java" => ".java",
        "cplusplus" or "c++" => ".cpp",
        "python" => ".py",
        _ => ".txt"
    };
}

public class FileUploadResult
{
    public string FileName { get; set; } = "";
    public string StoredName { get; set; } = "";
    public string FilePath { get; set; } = "";
    public long FileSize { get; set; }
    public string Content { get; set; } = "";
    public string Language { get; set; } = "";
}

public class UploadContentRequest
{
    public string? FileName { get; set; }
    public string Content { get; set; } = "";
    public string Language { get; set; } = "CSharp";
}