import type { ChatModel } from "./modelRegistry.js";

export type TemplateContext = {
  draw: number;
  model: ChatModel;
  startedAt: Date;
};

export const renderPrompt = (template: string, context: TemplateContext) => {
  const values: Record<string, string> = {
    draw: String(context.draw),
    model: context.model.label,
    provider: context.model.providerName,
    now: context.startedAt.toLocaleString("zh-CN", { hour12: false }),
    timestamp: context.startedAt.toISOString()
  };

  return template.replace(/\{\{\s*([a-zA-Z0-9_-]+)\s*\}\}/g, (match, key: string) => {
    return values[key] ?? match;
  });
};