chore: 提交当前变更

src/Modules/TakeoutSaaS.Module.Tenancy/TenantResolutionMiddleware.cs

@@ -0,0 +1,191 @@
+using System.Linq;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using TakeoutSaaS.Shared.Abstractions.Constants;
+using TakeoutSaaS.Shared.Abstractions.Results;
+using TakeoutSaaS.Shared.Abstractions.Tenancy;
+
+namespace TakeoutSaaS.Module.Tenancy;
+
+/// <summary>
+/// 多租户解析中间件：支持 Header、域名与 Token Claim 的优先级解析。
+/// </summary>
+public sealed class TenantResolutionMiddleware
+{
+    private readonly RequestDelegate _next;
+    private readonly ILogger<TenantResolutionMiddleware> _logger;
+    private readonly ITenantContextAccessor _tenantContextAccessor;
+    private readonly IOptionsMonitor<TenantResolutionOptions> _optionsMonitor;
+
+    /// <summary>
+    /// 初始化中间件。
+    /// </summary>
+    public TenantResolutionMiddleware(
+        RequestDelegate next,
+        ILogger<TenantResolutionMiddleware> logger,
+        ITenantContextAccessor tenantContextAccessor,
+        IOptionsMonitor<TenantResolutionOptions> optionsMonitor)
+    {
+        _next = next;
+        _logger = logger;
+        _tenantContextAccessor = tenantContextAccessor;
+        _optionsMonitor = optionsMonitor;
+    }
+
+    /// <summary>
+    /// 解析租户并将上下文注入请求。
+    /// </summary>
+    public async Task InvokeAsync(HttpContext context)
+    {
+        var options = _optionsMonitor.CurrentValue ?? new TenantResolutionOptions();
+        if (ShouldSkip(context.Request.Path, options))
+        {
+            await _next(context);
+            return;
+        }
+
+        var tenantContext = ResolveTenant(context, options);
+        _tenantContextAccessor.Current = tenantContext;
+        context.Items[TenantConstants.HttpContextItemKey] = tenantContext;
+
+        if (!tenantContext.IsResolved)
+        {
+            _logger.LogDebug("未能解析租户：{Path}", context.Request.Path);
+
+            if (options.ThrowIfUnresolved)
+            {
+                var response = ApiResponse.Error(ErrorCodes.BadRequest, "缺少租户标识");
+                context.Response.StatusCode = StatusCodes.Status400BadRequest;
+                await context.Response.WriteAsJsonAsync(response, cancellationToken: context.RequestAborted);
+                _tenantContextAccessor.Current = null;
+                context.Items.Remove(TenantConstants.HttpContextItemKey);
+                return;
+            }
+        }
+
+        try
+        {
+            await _next(context);
+        }
+        finally
+        {
+            _tenantContextAccessor.Current = null;
+            context.Items.Remove(TenantConstants.HttpContextItemKey);
+        }
+    }
+
+    private static bool ShouldSkip(PathString path, TenantResolutionOptions options)
+    {
+        if (!path.HasValue)
+        {
+            return false;
+        }
+
+        var value = path.Value ?? string.Empty;
+        if (options.IgnoredPaths.Contains(value))
+        {
+            return true;
+        }
+
+        return options.IgnoredPaths.Any(ignore =>
+        {
+            if (string.IsNullOrWhiteSpace(ignore))
+            {
+                return false;
+            }
+
+            var ignorePath = new PathString(ignore);
+            return path.StartsWithSegments(ignorePath);
+        });
+    }
+
+    private TenantContext ResolveTenant(HttpContext context, TenantResolutionOptions options)
+    {
+        var request = context.Request;
+
+        // 1. Header 中的租户 ID
+        if (!string.IsNullOrWhiteSpace(options.TenantIdHeaderName) &&
+            request.Headers.TryGetValue(options.TenantIdHeaderName, out var tenantHeader) &&
+            Guid.TryParse(tenantHeader.FirstOrDefault(), out var headerTenantId))
+        {
+            return new TenantContext(headerTenantId, null, $"header:{options.TenantIdHeaderName}");
+        }
+
+        // 2. Header 中的租户编码
+        if (!string.IsNullOrWhiteSpace(options.TenantCodeHeaderName) &&
+            request.Headers.TryGetValue(options.TenantCodeHeaderName, out var codeHeader))
+        {
+            var code = codeHeader.FirstOrDefault();
+            if (TryResolveByCode(code, options, out var tenantFromCode))
+            {
+                return new TenantContext(tenantFromCode, code, $"header:{options.TenantCodeHeaderName}");
+            }
+        }
+
+        // 3. Host 映射/子域名解析
+        var host = request.Host.Host;
+        if (!string.IsNullOrWhiteSpace(host))
+        {
+            if (options.DomainTenantMap.TryGetValue(host, out var tenantFromHost))
+            {
+                return new TenantContext(tenantFromHost, null, $"host:{host}");
+            }
+
+            var codeFromHost = ResolveCodeFromHost(host, options.RootDomain);
+            if (TryResolveByCode(codeFromHost, options, out var tenantFromSubdomain))
+            {
+                return new TenantContext(tenantFromSubdomain, codeFromHost, $"host:{host}");
+            }
+        }
+
+        // 4. Token Claim
+        var claim = context.User?.FindFirst("tenant_id");
+        if (claim != null && Guid.TryParse(claim.Value, out var claimTenant))
+        {
+            return new TenantContext(claimTenant, null, "claim:tenant_id");
+        }
+
+        return TenantContext.Empty;
+    }
+
+    private static bool TryResolveByCode(string? code, TenantResolutionOptions options, out Guid tenantId)
+    {
+        tenantId = Guid.Empty;
+        if (string.IsNullOrWhiteSpace(code))
+        {
+            return false;
+        }
+
+        return options.CodeTenantMap.TryGetValue(code, out tenantId);
+    }
+
+    private static string? ResolveCodeFromHost(string host, string? rootDomain)
+    {
+        if (string.IsNullOrWhiteSpace(rootDomain))
+        {
+            return null;
+        }
+
+        var normalizedRoot = rootDomain.TrimStart('.');
+        if (!host.EndsWith(normalizedRoot, StringComparison.OrdinalIgnoreCase))
+        {
+            return null;
+        }
+
+        var suffixLength = normalizedRoot.Length;
+        if (host.Length <= suffixLength)
+        {
+            return null;
+        }
+
+        var withoutRoot = host[..(host.Length - suffixLength)];
+        if (withoutRoot.EndsWith('.'))
+        {
+            withoutRoot = withoutRoot[..^1];
+        }
+
+        var segments = withoutRoot.Split('.', StringSplitOptions.RemoveEmptyEntries);
+        return segments.Length == 0 ? null : segments[0];
+    }
+}