[workers] Add the cast-albums worker (#1151)

infra/workers/cast-albums/package.json

@@ -0,0 +1,9 @@
+{
+    "name": "cast-albums",
+    "private": true,
+    "devDependencies": {
+        "@cloudflare/workers-types": "^4.20240314.0",
+        "typescript": "^5",
+        "wrangler": "^3"
+    }
+}

infra/workers/cast-albums/src/index.ts

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+/** Proxy file and thumbnail requests from the cast web app */
+
+export default {
+    async fetch(request: Request) {
+        switch (request.method) {
+            case "GET":
+                return handleGET(request);
+            case "OPTIONS":
+                return handleOPTIONS(request);
+            default:
+                throw new Error(
+                    `HTTP 405 Method Not Allowed: ${request.method}`
+                );
+        }
+    },
+} satisfies ExportedHandler;
+
+const handleGET = async (request: Request) => {
+    const url = new URL(request.url);
+    const urlParams = new URLSearchParams(url.search);
+    const token =
+        request.headers.get("X-Cast-Access-Token") ??
+        urlParams.get("castToken");
+
+    const fileID = urlParams.get("fileID");
+    const pathname = url.pathname;
+
+    let response = await fetch(
+        `https://api.ente.io/cast/files${pathname}${fileID}?castToken=${token}`
+    );
+
+    response = new Response(response.body, response);
+    response.headers.set("Access-Control-Allow-Origin", "*");
+    return response;
+};
+
+const handleOPTIONS = (request: Request) => {
+    let corsHeaders: Record<string, string> = {
+        "Access-Control-Allow-Origin": "*",
+        "Access-Control-Allow-Methods": "GET,OPTIONS",
+        "Access-Control-Max-Age": "86400",
+    };
+
+    const acrh = request.headers.get("Access-Control-Request-Headers");
+    if (acrh) {
+        corsHeaders["Access-Control-Allow-Headers"] = acrh;
+    }
+
+    return new Response("", { headers: corsHeaders });
+};

infra/workers/cast-albums/tsconfig.json

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+{ "extends": "../tsconfig.base.json", "include": ["src/**/*.ts"] }

infra/workers/cast-albums/wrangler.toml

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+name = "cast-albums"
+main = "src/index.ts"
+compatibility_date = "2024-03-14"
+
+[[routes]]
+pattern = "cast-albums.ente.io"
+zone_name = "ente.io"
+custom_domain = true