feat: mix handlers of proxy server in providers

app/api/provider/[...path]/route.ts

@@ -0,0 +1,93 @@
+import * as ProviderTemplates from "@/app/client/providers";
+import { getServerSideConfig } from "@/app/config/server";
+import { NextRequest, NextResponse } from "next/server";
+import { cloneDeep } from "lodash-es";
+import {
+  disableSystemApiKey,
+  makeUrlsUsable,
+  modelNameRequestHeader,
+} from "@/app/client/common";
+import { collectModelTable } from "@/app/utils/model";
+
+async function handle(
+  req: NextRequest,
+  { params }: { params: { path: string[] } },
+) {
+  const [providerName] = params.path;
+  const { headers } = req;
+  const serverConfig = getServerSideConfig();
+  const modelName = headers.get(modelNameRequestHeader);
+
+  const ProviderTemplate = Object.values(ProviderTemplates).find(
+    (t) => t.prototype.name === providerName,
+  );
+
+  if (!ProviderTemplate) {
+    return NextResponse.json(
+      {
+        error: true,
+        message: "No provider found: " + providerName,
+      },
+      {
+        status: 404,
+      },
+    );
+  }
+
+  // #1815 try to refuse gpt4 request
+  if (modelName && serverConfig.customModels) {
+    try {
+      const modelTable = collectModelTable([], serverConfig.customModels);
+
+      // not undefined and is false
+      if (modelTable[modelName]?.available === false) {
+        return NextResponse.json(
+          {
+            error: true,
+            message: `you are not allowed to use ${modelName} model`,
+          },
+          {
+            status: 403,
+          },
+        );
+      }
+    } catch (e) {
+      console.error("models filter", e);
+    }
+  }
+
+  const config = disableSystemApiKey(
+    makeUrlsUsable(cloneDeep(serverConfig), [
+      "anthropicUrl",
+      "azureUrl",
+      "googleUrl",
+      "baseUrl",
+    ]),
+    ["anthropicApiKey", "azureApiKey", "googleApiKey", "apiKey"],
+    serverConfig.needCode &&
+      ProviderTemplate !== ProviderTemplates.NextChatProvider, // if it must take a access code in the req, do not provide system-keys for Non-nextchat providers
+  );
+
+  const request = Object.assign({}, req, {
+    subpath: params.path.join("/"),
+  });
+
+  return new ProviderTemplate().serverSideRequestHandler(request, config);
+}
+
+export const GET = handle;
+export const POST = handle;
+export const PUT = handle;
+export const PATCH = handle;
+export const DELETE = handle;
+export const OPTIONS = handle;
+
+export const runtime = "edge";
+export const preferredRegion = Array.from(
+  new Set(
+    Object.values(ProviderTemplates).reduce(
+      (arr, t) => [...arr, ...(t.prototype.preferredRegion ?? [])],
+      [] as string[],
+    ),
+  ),
+);