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 +1,57 @@
+using WenChuanyi.Api.Models;
+
+namespace WenChuanyi.Api.Services;
+
+/// <summary>取件码/管理码生成与查重（冲突自动重生成）</summary>
+public class CodeGeneratorService
+{
+    // 排除易混淆 0/O/1/I/l
+    private const string AdminChars = "ABCDEFGHJKMNPQRSTUVWXYZabcdefghjkmnpqrstuvwxyz23456789";
+
+    private readonly IFreeSql _fsql;
+
+    public CodeGeneratorService(IFreeSql fsql) => _fsql = fsql;
+
+    /// <summary>生成 length 位纯数字取件码（全局唯一）</summary>
+    public async Task<string> GeneratePickCodeAsync(int length)
+    {
+        for (var i = 0; i < 30; i++)
+        {
+            var code = GenerateDigits(length);
+            var exists = await _fsql.Select<FileItem>().Where(f => f.PickCode == code).AnyAsync();
+            if (!exists)
+            {
+                return code;
+            }
+        }
+        throw new InvalidOperationException("取件码生成冲突次数过多，请重试");
+    }
+
+    /// <summary>生成 8 位字母数字管理码（全局唯一）</summary>
+    public async Task<string> GenerateAdminCodeAsync()
+    {
+        for (var i = 0; i < 30; i++)
+        {
+            var code = new string(Enumerable.Range(0, 8)
+                .Select(_ => AdminChars[Random.Shared.Next(AdminChars.Length)]).ToArray());
+            var exists = await _fsql.Select<FileItem>().Where(f => f.AdminCode == code).AnyAsync();
+            if (!exists)
+            {
+                return code;
+            }
+        }
+        throw new InvalidOperationException("管理码生成冲突次数过多，请重试");
+    }
+
+    private static string GenerateDigits(int length)
+    {
+        var first = Random.Shared.Next(1, 10); // 首位非 0
+        var sb = new System.Text.StringBuilder();
+        sb.Append(first);
+        for (var i = 1; i < length; i++)
+        {
+            sb.Append(Random.Shared.Next(0, 10));
+        }
+        return sb.ToString();
+    }
+}
@@ -0,0 +1,67 @@
+using WenChuanyi.Api.Models;
+
+namespace WenChuanyi.Api.Services;
+
+/// <summary>过期文件定时清理：每 N 分钟扫描 IsPermanent=false 且已过期的记录，先删记录再删 OSS 对象</summary>
+public class ExpiredFileCleanerService : BackgroundService
+{
+    private readonly IServiceScopeFactory _scopeFactory;
+    private readonly ILogger<ExpiredFileCleanerService> _logger;
+    private readonly TimeSpan _interval;
+
+    public ExpiredFileCleanerService(
+        IServiceScopeFactory scopeFactory,
+        IConfiguration cfg,
+        ILogger<ExpiredFileCleanerService> logger)
+    {
+        _scopeFactory = scopeFactory;
+        _logger = logger;
+        var minutes = cfg.GetValue<int>("Cleaner:IntervalMinutes", 30);
+        _interval = TimeSpan.FromMinutes(Math.Max(1, minutes));
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        _logger.LogInformation("过期文件清理任务启动，间隔 {Minutes} 分钟", _interval.TotalMinutes);
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try
+            {
+                await CleanExpiredAsync(stoppingToken);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogWarning(ex, "过期文件清理任务异常");
+            }
+            await Task.Delay(_interval, stoppingToken);
+        }
+    }
+
+    private async Task CleanExpiredAsync(CancellationToken ct)
+    {
+        await using var scope = _scopeFactory.CreateAsyncScope();
+        var fsql = scope.ServiceProvider.GetRequiredService<IFreeSql>();
+        var oss = scope.ServiceProvider.GetRequiredService<OssStorageService>();
+
+        var expired = await fsql.Select<FileItem>()
+            .Where(f => !f.IsPermanent && f.ExpiresAt != null && f.ExpiresAt < DateTime.Now)
+            .ToListAsync(ct);
+
+        if (expired.Count == 0)
+        {
+            return;
+        }
+
+        _logger.LogInformation("发现 {Count} 个过期文件，开始清理", expired.Count);
+        foreach (var item in expired)
+        {
+            // 先删数据库记录
+            var deleted = await fsql.Delete<FileItem>().Where(f => f.Id == item.Id).ExecuteAffrowsAsync(ct) > 0;
+            // 再删 OSS 对象（失败仅记日志，不阻塞任务）
+            if (deleted)
+            {
+                oss.TryDeleteObject(item.ObjectKey);
+            }
+        }
+    }
+}
@@ -0,0 +1,108 @@
+using System.Text.RegularExpressions;
+using WenChuanyi.Api.Models;
+
+namespace WenChuanyi.Api.Services;
+
+/// <summary>业务规则共享静态工具：密码/标签校验、模式判定、预览分类</summary>
+public static class FileRules
+{
+    public const long MaxFileBytes = 200L * 1024 * 1024;   // 200MB
+    public const long MaxTextPreview = 2L * 1024 * 1024;   // 文本预览 2MB
+    public const long MaxPdfImagePreview = 30L * 1024 * 1024; // PDF/图片预览 30MB
+
+    /// <summary>清洗文件名：去除 Windows 非法字符/控制字符、首尾空格与点、保留名与超长限制，防止存储路径注入</summary>
+    public static string SanitizeFileName(string? name)
+    {
+        if (string.IsNullOrWhiteSpace(name)) return "未命名";
+        var dot = name.LastIndexOf('.');
+        var ext = dot >= 0 ? name[(dot + 1)..] : "";
+        var baseName = dot >= 0 ? name[..dot] : name;
+
+        var cleanBase = new string(baseName
+            .Where(c => c >= 32 && c != 127 && c != '<' && c != '>' && c != ':' && c != '"'
+                && c != '/' && c != '\\' && c != '|' && c != '?' && c != '*')
+            .ToArray()).Trim().TrimEnd('.', ' ');
+
+        var result = string.IsNullOrEmpty(cleanBase) ? "未命名" : cleanBase;
+
+        // Windows 保留设备名：CON PRN AUX NUL COM1-9 LPT1-9（含扩展名也禁止）
+        var upperBase = result.Split('.')[0].ToUpperInvariant();
+        if (upperBase is "CON" or "PRN" or "AUX" or "NUL"
+            || Regex.IsMatch(upperBase, @"^COM[1-9]$") || Regex.IsMatch(upperBase, @"^LPT[1-9]$"))
+        {
+            result = "_" + result;
+        }
+
+        // 长度限制（保留扩展名，主体最长 180 字符）
+        if (result.Length > 180) result = result[..180];
+
+        // 扩展名仅保留字母/数字/点，最长 10 字符
+        var extRaw = new string(ext.Where(c => char.IsLetterOrDigit(c) || c == '.').ToArray()).TrimStart('.');
+        var cleanExt = extRaw.Length > 0 ? "." + (extRaw.Length > 10 ? extRaw[..10] : extRaw) : "";
+
+        return result + cleanExt;
+    }
+
+    /// <summary>校验密码（4-12 位），null 表示通过</summary>
+    public static string? ValidatePassword(string? pwd)
+    {
+        if (string.IsNullOrEmpty(pwd)) return null;
+        if (pwd.Length < 4 || pwd.Length > 12)
+        {
+            return "密码长度须为 4-12 位";
+        }
+        return null;
+    }
+
+    /// <summary>校验标签：仅英文+数字；纯数字须 &gt;8 位；含英文须 &gt;4 位；null 表示通过</summary>
+    public static string? ValidateTag(string? tag)
+    {
+        if (string.IsNullOrEmpty(tag)) return null;
+        if (!Regex.IsMatch(tag, "^[A-Za-z0-9]+$"))
+        {
+            return "标签仅允许英文与数字，不能包含符号或空格";
+        }
+        if (Regex.IsMatch(tag, "^[0-9]+$"))
+        {
+            if (tag.Length <= 8)
+            {
+                return "纯数字标签须超过 8 位（建议使用 11 位手机号码）";
+            }
+        }
+        else if (tag.Length <= 4)
+        {
+            return "含英文字母的标签须超过 4 位";
+        }
+        return null;
+    }
+
+    /// <summary>模式判定：有密码→private；仅标签→tagged；否则 standard</summary>
+    public static string ResolveFileType(bool hasPassword, bool hasTag)
+        => hasPassword ? "private" : hasTag ? "tagged" : "standard";
+
+    /// <summary>取件码位数：私密 6 位，其余 8 位</summary>
+    public static int PickCodeLength(string fileType) => fileType == "private" ? 6 : 8;
+
+    /// <summary>剩余有效期文本</summary>
+    public static string ExpireText(FileItem f)
+    {
+        if (f.IsPermanent || f.ExpiresAt == null) return "永久";
+        var remain = f.ExpiresAt.Value - DateTime.Now;
+        if (remain <= TimeSpan.Zero) return "已过期";
+        if (remain.TotalDays >= 1) return $"{(int)remain.TotalDays} 天";
+        if (remain.TotalHours >= 1) return $"{(int)remain.TotalHours} 小时";
+        return $"{(int)Math.Max(1, remain.TotalMinutes)} 分钟";
+    }
+
+    public static bool IsText(string ext)
+        => ext is ".txt" or ".md" or ".xml" or ".json" or ".csv" or ".log" or ".ini" or ".conf"
+            or ".srt" or ".html" or ".htm" or ".css" or ".js" or ".ts" or ".cs" or ".java" or ".sql"
+            or ".yml" or ".yaml" or ".sh" or ".bat" or ".ps1" or ".py" or ".go" or ".c" or ".h" or ".php";
+
+    public static bool IsPdfOrImage(string mime)
+        => mime is "application/pdf"
+            or "image/png" or "image/jpeg" or "image/gif" or "image/webp" or "image/bmp" or "image/svg+xml";
+
+    public static bool IsVideoWhitelist(string ext) => ext is ".mp4" or ".webm";
+    public static bool IsAudioWhitelist(string ext) => ext is ".mp3" or ".wav" or ".m4a" or ".aac" or ".ogg";
+}
@@ -0,0 +1,68 @@
+using Aliyun.OSS;
+
+namespace WenChuanyi.Api.Services;
+
+/// <summary>OSS 存储服务：对象键构造、流式上传/下载/删除（后端中转，前端不接触凭据）</summary>
+public class OssStorageService
+{
+    private readonly OssClient _client;
+    private readonly string _bucket;
+    private readonly string _baseKey;
+    private readonly ILogger<OssStorageService> _logger;
+
+    public OssStorageService(IConfiguration cfg, ILogger<OssStorageService> logger)
+    {
+        var endpoint = cfg["Oss:Endpoint"] ?? throw new InvalidOperationException("缺少配置 Oss:Endpoint");
+        var ak = cfg["Oss:AccessKeyId"] ?? throw new InvalidOperationException("缺少配置 Oss:AccessKeyId");
+        var sk = cfg["Oss:AccessKeySecret"] ?? throw new InvalidOperationException("缺少配置 Oss:AccessKeySecret");
+        _bucket = cfg["Oss:Bucket"] ?? throw new InvalidOperationException("缺少配置 Oss:Bucket");
+        _baseKey = cfg["Oss:BaseKey"] ?? "文传易2026";
+        _client = new OssClient(endpoint, ak, sk);
+        _logger = logger;
+    }
+
+    /// <summary>构造对象键：文传易2026/{yyyyMM}/{Guid}{ext}（按上传月份建子目录）</summary>
+    public string BuildObjectKey(string originalName)
+    {
+        var month = DateTime.Now.ToString("yyyyMM");
+        var ext = Path.GetExtension(originalName).ToLowerInvariant();
+        return $"{_baseKey}/{month}/{Guid.NewGuid():N}{ext}";
+    }
+
+    /// <summary>流式上传（不落本地、不整体读内存）。ContentType 会去除参数部分（如 ";charset=utf-8"），
+    /// 因为 OSS SDK 对带参数的 Content-Type 签名会与服务端校验不一致，导致 403 签名不匹配。</summary>
+    public async Task UploadAsync(string objectKey, Stream stream, string contentType)
+    {
+        var safeContentType = (contentType ?? "application/octet-stream").Split(';')[0].Trim();
+        if (string.IsNullOrEmpty(safeContentType)) safeContentType = "application/octet-stream";
+        var req = new PutObjectRequest(_bucket, objectKey, stream);
+        req.Metadata = new ObjectMetadata { ContentType = safeContentType };
+        await Task.Run(() => _client.PutObject(req)).ConfigureAwait(false);
+    }
+
+    /// <summary>获取对象（支持 Range；end 为 -1 表示到文件末尾）</summary>
+    public OssObject GetObject(string objectKey, long? start = null, long? end = null)
+    {
+        var req = new GetObjectRequest(_bucket, objectKey);
+        if (start.HasValue || end.HasValue)
+        {
+            req.SetRange(start ?? 0, end ?? -1);
+        }
+        return _client.GetObject(req);
+    }
+
+    /// <summary>删除对象（失败不抛出，由调用方记录日志）</summary>
+    public bool TryDeleteObject(string objectKey)
+    {
+        try
+        {
+            _client.DeleteObject(_bucket, objectKey);
+            return true;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "OSS 对象删除失败：{ObjectKey}", objectKey);
+            return false;
+        }
+    }
+}