import { z } from "zod";

// Structured data schemas
const howtoStepSchema = z.object({
  name: z.string(),
  text: z.string(),
  image: z.string().optional(),
  url: z.string().optional(),
});

const howtoSchema = z.object({
  totalTime: z.string().optional(), // ISO 8601 duration format (e.g., "PT2H")
  steps: z.array(howtoStepSchema),
});

const faqItemSchema = z.object({
  question: z.string(),
  answer: z.string(),
});

// Per-page SEO/social overrides. Each falls back to its top-level twin
// (seo.title ?? title, seo.description ?? description); the rest are opt-in.
const seoSchema = z
  .object({
    title: z.string(),
    description: z.string(),
    ogImage: z.string(),
    noindex: z.boolean(),
    canonical: z.string(),
  })
  .partial();

export const metadataSchema = z.object({
  title: z.string(),
  // Visible page heading; falls back to `title`. Lets the on-page h1 differ
  // from the canonical `title` used for SEO, breadcrumbs, search, and nav.
  hero: z.string().optional(),
  publishedAt: z.coerce.date(),
  // Last meaningful content edit. Feeds og:article:modified_time and JSON-LD
  // dateModified; falls back to `publishedAt` when absent.
  updatedAt: z.coerce.date().optional(),
  description: z.string(),
  category: z.string(),
  author: z.string(),
  image: z.string().optional(),
  seo: seoSchema.optional(),
  // Structured data fields
  howto: howtoSchema.optional(),
  faq: z.array(faqItemSchema).optional(),
});

export type Metadata = z.infer<typeof metadataSchema>;
export type SeoData = z.infer<typeof seoSchema>;
export type HowToStep = z.infer<typeof howtoStepSchema>;
export type HowToData = z.infer<typeof howtoSchema>;
export type FAQItem = z.infer<typeof faqItemSchema>;