Add production-ready media library

lib/media-validation.ts

@@ -0,0 +1,42 @@
+import { MediaKind } from "@prisma/client";
+import { z } from "zod";
+
+const mediaModeSchema = z.enum(["library", "external", "upload"]);
+
+const optionalTrimmedText = z.string().trim().optional().transform((value) => value ?? "");
+
+export const mediaFieldInputSchema = z
+  .object({
+    mode: mediaModeSchema,
+    assetId: optionalTrimmedText,
+    url: optionalTrimmedText,
+    label: optionalTrimmedText,
+    kind: z.nativeEnum(MediaKind),
+  })
+  .superRefine((value, context) => {
+    if (value.mode === "library" && !value.assetId) {
+      context.addIssue({
+        code: z.ZodIssueCode.custom,
+        path: ["assetId"],
+        message: "Library selection requires a media asset.",
+      });
+    }
+
+    if (value.mode === "external" && !value.url) {
+      context.addIssue({
+        code: z.ZodIssueCode.custom,
+        path: ["url"],
+        message: "External media requires a URL.",
+      });
+    }
+
+    if (value.url && !/^https?:\/\//.test(value.url) && !value.url.startsWith("/")) {
+      context.addIssue({
+        code: z.ZodIssueCode.custom,
+        path: ["url"],
+        message: "Media URL must be an absolute URL or start with /.",
+      });
+    }
+  });
+
+export type MediaFieldInput = z.infer<typeof mediaFieldInputSchema>;