feat: 文传易匿名临时文件传输站初始版本

- 后端 .NET 8 + FreeSql + 阿里云 OSS，支持共享/私密/标签三种文件模式 - 前端 Vue3 + Vite + TDesign，上传/取件/管理三页 - 取件码/二维码/海报合成（含保存二维码为图片） - deploy/ 部署文档与一键 FTP 发布脚本 - appsettings.json 含真实凭据，已 gitignore 不入库
2026-08-24 00:03:28 +08:00
commit 1bfc72f9cb
40 changed files with 6849 additions and 0 deletions
@@ -0,0 +1,392 @@
+using System.Text;
+using Aliyun.OSS;
+using Microsoft.AspNetCore.Mvc;
+using WenChuanyi.Api.Dtos;
+using WenChuanyi.Api.Models;
+using WenChuanyi.Api.Services;
+
+namespace WenChuanyi.Api.Controllers;
+
+/// <summary>文件上传 / 查询 / 标签列表 / 预览 / 下载</summary>
+[ApiController]
+[Route("api/files")]
+public class FileController : ControllerBase
+{
+    private readonly IFreeSql _fsql;
+    private readonly CodeGeneratorService _codeGen;
+    private readonly OssStorageService _oss;
+    private readonly string _baseUrl;
+    private readonly ILogger<FileController> _logger;
+
+    public FileController(IFreeSql fsql, CodeGeneratorService codeGen, OssStorageService oss,
+        IConfiguration cfg, ILogger<FileController> logger)
+    {
+        _fsql = fsql;
+        _codeGen = codeGen;
+        _oss = oss;
+        _baseUrl = cfg["App:BaseUrl"] ?? "";
+        _logger = logger;
+    }
+
+    // ---------- 上传 ----------
+
+    /// <summary>multipart 上传：file + expireHours(24/168/0) + password + tag（password 与 tag 可同时设置）</summary>
+    [HttpPost("upload")]
+    [RequestSizeLimit(220_200_960)] // 210MB（Kestrel 同配置）
+    public async Task<IActionResult> Upload([FromForm] int expireHours, [FromForm] string? password,
+        [FromForm] string? tag, IFormFile? file)
+    {
+        if (file == null || file.Length == 0)
+        {
+            return BadRequest(new { message = "请选择要上传的文件" });
+        }
+        if (file.Length > FileRules.MaxFileBytes)
+        {
+            return BadRequest(new { message = "文件超过 200MB 限制，无法上传" });
+        }
+
+        var pwdErr = FileRules.ValidatePassword(password);
+        if (pwdErr != null) return BadRequest(new { message = pwdErr });
+
+        tag = string.IsNullOrWhiteSpace(tag) ? null : tag.Trim();
+        var tagErr = FileRules.ValidateTag(tag);
+        if (tagErr != null) return BadRequest(new { message = tagErr });
+
+        var hasPassword = !string.IsNullOrEmpty(password);
+        var hasTag = !string.IsNullOrEmpty(tag);
+
+        // 有效期：仅 24/168/0 三档；含标签强制永久
+        var effectiveExpire = hasTag ? 0 : (expireHours is 24 or 168 or 0 ? expireHours : 24);
+        var isPermanent = hasTag || effectiveExpire == 0;
+        DateTime? expiresAt = isPermanent ? null : DateTime.Now.AddHours(effectiveExpire);
+
+        var fileType = FileRules.ResolveFileType(hasPassword, hasTag);
+        var originalName = FileRules.SanitizeFileName(file.FileName);
+        var objectKey = _oss.BuildObjectKey(originalName);
+        var ip = HttpContext.Connection.RemoteIpAddress?.ToString();
+        var contentType = string.IsNullOrEmpty(file.ContentType) ? "application/octet-stream" : file.ContentType;
+
+        try
+        {
+            await using var stream = file.OpenReadStream();
+            await _oss.UploadAsync(objectKey, stream, contentType);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "OSS 上传失败：{Name}", file.FileName);
+            return StatusCode(500, new { message = "文件上传失败，请稍后重试" });
+        }
+
+        var item = new FileItem
+        {
+            PickCode = await _codeGen.GeneratePickCodeAsync(FileRules.PickCodeLength(fileType)),
+            AdminCode = await _codeGen.GenerateAdminCodeAsync(),
+            FileType = fileType,
+            Password = hasPassword ? password : null,
+            Tag = hasTag ? tag : null,
+            OriginalName = originalName,
+            ObjectKey = objectKey,
+            Size = file.Length,
+            MimeType = contentType,
+            DownloadCount = 0,
+            UploadIp = ip,
+            IsPermanent = isPermanent,
+            ExpiresAt = expiresAt,
+            CreatedAt = DateTime.Now
+        };
+        await _fsql.Insert(item).ExecuteAffrowsAsync();
+
+        return Ok(new UploadResultDto
+        {
+            Id = item.Id,
+            PickCode = item.PickCode,
+            AdminCode = item.AdminCode,
+            FileType = fileType,
+            OriginalName = item.OriginalName,
+            Size = item.Size,
+            IsPermanent = isPermanent,
+            ExpiresAt = expiresAt,
+            PickUrl = BuildPickUrl(item.PickCode)
+        });
+    }
+
+    // ---------- 查询 ----------
+
+    /// <summary>按取件码查询（私密需带 password；过期返回 410）</summary>
+    [HttpGet("{code}")]
+    public async Task<IActionResult> Query(string code, [FromQuery] string? password)
+    {
+        if (!IsPickCode(code))
+        {
+            return NotFound(new { message = "取件码/标签无效" });
+        }
+        var (item, error, status) = await FindAndValidateAsync(code, password);
+        if (item == null)
+        {
+            return StatusCode(status, new { message = error });
+        }
+        return Ok(ToDto(item));
+    }
+
+    /// <summary>按标签查询文件列表（CreatedAt 倒序，limit 100）</summary>
+    [HttpGet("by-tag/{tag}")]
+    public async Task<IActionResult> ByTag(string tag)
+    {
+        if (string.IsNullOrEmpty(tag) || !tag.All(char.IsLetterOrDigit))
+        {
+            return BadRequest(new { message = "标签无效" });
+        }
+        var list = await _fsql.Select<FileItem>()
+            .Where(f => f.Tag == tag)
+            .OrderByDescending(f => f.CreatedAt)
+            .Limit(100)
+            .ToListAsync();
+        return Ok(list.Select(ToDto));
+    }
+
+    // ---------- 下载 ----------
+
+    /// <summary>流式下载：计数 +1（仅统计），还原原始文件名，支持 Range 断点续传（私密需密码）</summary>
+    [HttpGet("{code}/download")]
+    public async Task<IActionResult> Download(string code, [FromQuery] string? password)
+    {
+        var (item, error, status) = await FindAndValidateAsync(code, password);
+        if (item == null)
+        {
+            return StatusCode(status, new { message = error });
+        }
+        await _fsql.Update<FileItem>()
+            .Set(f => f.DownloadCount + 1)
+            .Where(f => f.Id == item.Id)
+            .ExecuteAffrowsAsync();
+        await ServeStreamAsync(item, inline: false);
+        return new EmptyResult();
+    }
+
+    // ---------- 预览 ----------
+
+    /// <summary>在线预览：PDF/图片（≤30MB）/ 音视频白名单（不限大小）inline 流；不计次数</summary>
+    [HttpGet("{code}/preview")]
+    public async Task<IActionResult> Preview(string code, [FromQuery] string? password)
+    {
+        var (item, error, status) = await FindAndValidateAsync(code, password);
+        if (item == null)
+        {
+            return StatusCode(status, new { message = error });
+        }
+        var ext = Path.GetExtension(item.OriginalName).ToLowerInvariant();
+        var mime = item.MimeType ?? "";
+        if (FileRules.IsText(ext))
+        {
+            return await ServeTextContentAsync(item);
+        }
+        if (FileRules.IsPdfOrImage(mime))
+        {
+            if (item.Size > FileRules.MaxPdfImagePreview)
+            {
+                return BadRequest(new { message = "文件过大，请下载后查看" });
+            }
+            await ServeStreamAsync(item, inline: true);
+            return new EmptyResult();
+        }
+        if (FileRules.IsVideoWhitelist(ext) || FileRules.IsAudioWhitelist(ext))
+        {
+            await ServeStreamAsync(item, inline: true);
+            return new EmptyResult();
+        }
+        return BadRequest(new { message = "该格式不支持在线预览，请下载查看" });
+    }
+
+    /// <summary>文本类内容（≤2MB），供在线阅读渲染（私密需密码）</summary>
+    [HttpGet("{code}/content")]
+    public async Task<IActionResult> GetContent(string code, [FromQuery] string? password)
+    {
+        var (item, error, status) = await FindAndValidateAsync(code, password);
+        if (item == null)
+        {
+            return StatusCode(status, new { message = error });
+        }
+        if (!FileRules.IsText(Path.GetExtension(item.OriginalName).ToLowerInvariant()))
+        {
+            return BadRequest(new { message = "该类型不支持文本预览" });
+        }
+        return await ServeTextContentAsync(item);
+    }
+
+    // ---------- 私有辅助 ----------
+
+    private static bool IsPickCode(string code)
+        => code.Length is 6 or 8 && code.All(char.IsDigit);
+
+    /// <summary>校验取件码 + 过期（懒检查）+ 私密密码；错误时返回 (null, message, status)</summary>
+    private async Task<(FileItem? Item, string? Error, int Status)> FindAndValidateAsync(string code, string? password)
+    {
+        if (!IsPickCode(code))
+        {
+            return (null, "取件码/标签无效", StatusCodes.Status404NotFound);
+        }
+        var item = await _fsql.Select<FileItem>().Where(f => f.PickCode == code).FirstAsync();
+        if (item == null)
+        {
+            return (null, "取件码/标签无效", StatusCodes.Status404NotFound);
+        }
+        if (!item.IsPermanent && item.ExpiresAt != null && item.ExpiresAt < DateTime.Now)
+        {
+            return (null, "文件已过期", StatusCodes.Status410Gone);
+        }
+        if (item.FileType == "private")
+        {
+            if (string.IsNullOrEmpty(password) || password != item.Password)
+            {
+                return (null, "密码错误", StatusCodes.Status401Unauthorized);
+            }
+        }
+        return (item, null, StatusCodes.Status200OK);
+    }
+
+    private FileInfoDto ToDto(FileItem f) => new()
+    {
+        Id = f.Id,
+        PickCode = f.PickCode,
+        FileType = f.FileType,
+        HasPassword = f.FileType == "private",
+        OriginalName = f.OriginalName,
+        Size = f.Size,
+        MimeType = f.MimeType,
+        DownloadCount = f.DownloadCount,
+        IsPermanent = f.IsPermanent,
+        ExpiresAt = f.ExpiresAt,
+        CreatedAt = f.CreatedAt,
+        ExpireText = FileRules.ExpireText(f)
+    };
+
+    private string BuildPickUrl(string pickCode)
+        => $"{_baseUrl}/#/pickup?code={pickCode}";
+
+    /// <summary>OSS 流式输出到响应（inline/attachment + Range 206 透传）</summary>
+    private async Task ServeStreamAsync(FileItem item, bool inline)
+    {
+        var rangeHeader = Request.Headers.Range.ToString();
+        long? start = null, end = null;
+        if (!string.IsNullOrEmpty(rangeHeader) && TryParseRange(rangeHeader, item.Size, out var rs, out var re))
+        {
+            start = rs;
+            end = re;
+        }
+        OssObject obj;
+        try
+        {
+            obj = _oss.GetObject(item.ObjectKey, start, end);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "OSS 读取失败：{Key}", item.ObjectKey);
+            Response.StatusCode = StatusCodes.Status500InternalServerError;
+            await Response.WriteAsync("文件读取失败，请稍后重试");
+            return;
+        }
+
+        Response.StatusCode = StatusCodes.Status200OK;
+        Response.ContentType = item.MimeType ?? "application/octet-stream";
+        Response.Headers["Accept-Ranges"] = "bytes";
+        Response.Headers["Content-Disposition"] = inline
+            ? "inline"
+            : $"attachment; filename*=UTF-8''{Uri.EscapeDataString(item.OriginalName)}";
+
+        if (start.HasValue)
+        {
+            Response.StatusCode = StatusCodes.Status206PartialContent;
+            var actualEnd = end < 0 || end == null ? item.Size - 1 : end.Value;
+            Response.Headers["Content-Range"] = $"bytes {start}-{actualEnd}/{item.Size}";
+        }
+        Response.Headers["Content-Length"] = obj.ContentLength.ToString();
+        await obj.Content.CopyToAsync(Response.Body);
+    }
+
+    /// <summary>文本内容读取（≤2MB，UTF-8 优先，GBK 兜底）</summary>
+    private async Task<IActionResult> ServeTextContentAsync(FileItem item)
+    {
+        if (item.Size > FileRules.MaxTextPreview)
+        {
+            return BadRequest(new { message = "文件过大，请下载后查看" });
+        }
+        OssObject obj;
+        try
+        {
+            obj = _oss.GetObject(item.ObjectKey);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "OSS 读取失败：{Key}", item.ObjectKey);
+            return StatusCode(500, new { message = "文件读取失败，请稍后重试" });
+        }
+        using var ms = new MemoryStream();
+        await obj.Content.CopyToAsync(ms);
+        var bytes = ms.ToArray();
+        var text = DecodeText(bytes);
+        return Content(text, "text/plain; charset=utf-8");
+    }
+
+    private static string DecodeText(byte[] bytes)
+    {
+        if (bytes.Length >= 3 && bytes[0] == 0xEF && bytes[1] == 0xBB && bytes[2] == 0xBF)
+        {
+            return Encoding.UTF8.GetString(bytes, 3, bytes.Length - 3);
+        }
+        if (bytes.Length >= 2 && bytes[0] == 0xFF && bytes[1] == 0xFE)
+        {
+            return Encoding.Unicode.GetString(bytes, 2, bytes.Length - 2);
+        }
+        return IsValidUtf8(bytes) ? Encoding.UTF8.GetString(bytes) : Encoding.GetEncoding("GBK").GetString(bytes);
+    }
+
+    private static bool IsValidUtf8(byte[] bytes)
+    {
+        try
+        {
+            var decoder = new UTF8Encoding(false, true).GetDecoder();
+            var charCount = decoder.GetCharCount(bytes, 0, bytes.Length, flush: true);
+            return charCount >= 0;
+        }
+        catch (DecoderFallbackException)
+        {
+            return false;
+        }
+    }
+
+    private static bool TryParseRange(string rangeHeader, long total, out long start, out long end)
+    {
+        start = 0;
+        end = -1; // -1 表示到文件末尾
+        if (string.IsNullOrEmpty(rangeHeader) || !rangeHeader.StartsWith("bytes=", StringComparison.OrdinalIgnoreCase))
+        {
+            return false;
+        }
+        var spec = rangeHeader["bytes=".Length..];
+        var idx = spec.IndexOf('-');
+        if (idx < 0) return false;
+        var startPart = spec[..idx];
+        var endPart = spec[(idx + 1)..];
+        if (startPart.Length > 0 && long.TryParse(startPart, out start))
+        {
+            if (start >= total) return false;
+            if (endPart.Length > 0 && long.TryParse(endPart, out var e))
+            {
+                end = Math.Min(e, total - 1);
+                if (start > end) return false;
+            }
+            // "bytes=start-"：end 保持 -1（到末尾）
+        }
+        else if (endPart.Length > 0 && long.TryParse(endPart, out var suffix))
+        {
+            // "bytes=-N"：末尾 N 字节
+            start = Math.Max(0, total - suffix);
+            end = -1;
+        }
+        else
+        {
+            return false;
+        }
+        return true;
+    }
+}