feat(saas): implement marketplace and tenant onboarding

Tiku.Api/Controllers/PlatformBillingCallbackController.cs

@@ -0,0 +1,45 @@
+using System.Text;
+using System.Text.Json;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Tiku.Application.PlatformBilling;
+
+namespace Tiku.Api.Controllers;
+
+[ApiController]
+[Route("api/platform-billing/callbacks")]
+public sealed class PlatformBillingCallbackController(
+    IPlatformBillingNotificationService notificationService) : ControllerBase
+{
+    [AllowAnonymous]
+    [HttpPost("{provider}")]
+    public async Task<IActionResult> Notify(string provider, CancellationToken cancellationToken)
+    {
+        Request.EnableBuffering();
+        using var reader = new StreamReader(Request.Body, Encoding.UTF8, leaveOpen: true);
+        var rawBody = await reader.ReadToEndAsync(cancellationToken);
+        Request.Body.Position = 0;
+        JsonElement body;
+        try
+        {
+            body = string.IsNullOrWhiteSpace(rawBody)
+                ? JsonDocument.Parse("{}").RootElement.Clone()
+                : JsonDocument.Parse(rawBody).RootElement.Clone();
+        }
+        catch (JsonException)
+        {
+            body = JsonDocument.Parse("{}").RootElement.Clone();
+        }
+        var normalizedProvider = provider.Trim().ToLowerInvariant().Replace('-', '_');
+        await notificationService.ProcessAsync(new PlatformBillingNotification(
+            normalizedProvider,
+            Request.Headers.ToDictionary(value => value.Key, value => value.Value.ToString(), StringComparer.OrdinalIgnoreCase),
+            rawBody,
+            body), cancellationToken);
+        if (normalizedProvider is "alipay" or "ali_pay")
+        {
+            return Content("success", "text/plain", Encoding.UTF8);
+        }
+        return Ok(new { code = "SUCCESS", message = "成功" });
+    }
+}