More work on modelProviders

I think everything that's OpenAI-specific is inside modelProviders at this point, so we can get started adding more providers.

src/server/utils/fillTemplate.ts

@@ -1,5 +1,3 @@
-import { type JSONSerializable } from "../types";
-
 export type VariableMap = Record<string, string>;
 
 // Escape quotes to match the way we encode JSON
@@ -15,24 +13,3 @@ export function escapeRegExp(str: string) {
 export function fillTemplate(template: string, variables: VariableMap): string {
   return template.replace(/{{\s*(\w+)\s*}}/g, (_, key: string) => variables[key] || "");
 }
-
-export function fillTemplateJson<T extends JSONSerializable>(
-  template: T,
-  variables: VariableMap,
-): T {
-  if (typeof template === "string") {
-    return fillTemplate(template, variables) as T;
-  } else if (Array.isArray(template)) {
-    return template.map((item) => fillTemplateJson(item, variables)) as T;
-  } else if (typeof template === "object" && template !== null) {
-    return Object.keys(template).reduce(
-      (acc, key) => {
-        acc[key] = fillTemplateJson(template[key] as JSONSerializable, variables);
-        return acc;
-      },
-      {} as { [key: string]: JSONSerializable } & T,
-    );
-  } else {
-    return template;
-  }
-}