/**
 * Field builders shared by every note type.
 *
 * Each field carries `title` and `description` metadata. The JSON Schema
 * export keeps them, so the MCP server, the admin page and any later editor
 * can render a form or explain a field without a second definition. Image
 * and link fields also carry a `format` (`vault-image`, `vault-link`,
 * `vault-links`) so a form knows to offer a picker.
 */
import { z } from "zod";
import { normalizeWikilinkInput, wikilinkTarget } from "./names.ts";

type Meta = { title: string; description?: string };

/** A calendar date written `YYYY-MM-DD`, as Obsidian writes dates. */
export const isoDate = (meta: Meta) =>
  z
    .preprocess(
      (v) => (v instanceof Date ? v.toISOString().slice(0, 10) : v),
      z.string().regex(/^\d{4}-\d{2}-\d{2}$/, "Use a date like 2026-10-11"),
    )
    .meta(meta);

/** A month written `YYYY-MM`, for resume dates. */
export const isoMonth = (meta: Meta) =>
  z.string().regex(/^\d{4}-\d{2}$/, "Use a month like 2019-03").meta(meta);

/** A link to another note, written `[[Note name]]`. */
export const wikilink = (meta: Meta) =>
  z
    .preprocess(
      normalizeWikilinkInput,
      z.string().refine((v) => wikilinkTarget(v) !== null, "Write a link as [[Note name]]"),
    )
    .meta({ format: "vault-link", ...meta });

/** A list of links to other notes. */
export const wikilinks = (meta: Meta) =>
  z
    .preprocess(
      (v) => (Array.isArray(v) ? v.map(normalizeWikilinkInput) : v),
      z.array(z.string().refine((v) => wikilinkTarget(v) !== null, "Write each link as [[Note name]]")),
    )
    .meta({ format: "vault-links", ...meta });

/** An image: a vault attachment as `[[file.jpg]]`, or a full https URL. */
export const image = (meta: Meta) =>
  z
    .preprocess(
      normalizeWikilinkInput,
      z
        .string()
        .refine(
          (v) => wikilinkTarget(v) !== null || /^https:\/\//.test(v),
          "Use a vault image as [[file.jpg]] or a full https URL",
        ),
    )
    .meta({ format: "vault-image", ...meta });

/** One short line of text. */
export const line = (meta: Meta) => z.string().trim().min(1).meta(meta);

/** A list of short tags or names. */
export const strings = (meta: Meta) => z.array(z.string().trim().min(1)).meta(meta);

/**
 * Fields every note shares. `type` is added per note type.
 *
 * `publish` defaults to false: a note goes live only when it says so.
 */
export const baseFields = {
  title: line({ title: "Title" }),
  slug: z
    .string()
    .regex(/^[a-z0-9]+(?:-[a-z0-9]+)*$/, "Lowercase words joined by hyphens")
    .meta({ title: "Slug", description: "The last part of the page address. Made from the title when left out." })
    .optional(),
  publish: z
    .boolean()
    .default(false)
    .meta({ title: "Publish", description: "Only notes set to true appear on the site." }),
  favorite: z.boolean().meta({ title: "Favorite", description: "Starred on the site." }).optional(),
  tags: strings({ title: "Tags" }).optional(),
  links: wikilinks({
    title: "Links",
    description: "Other notes this one is about. The site shows the link on both notes.",
  }).optional(),
  cover: image({ title: "Cover image" }).optional(),
  created: isoDate({ title: "Created" }).optional(),
  updated: isoDate({ title: "Updated" }).optional(),
  updatedBy: z
    .enum(["greg", "agent", "admin", "sync"])
    .meta({ title: "Last edited by", description: "Set by the content service; you never need to write it." })
    .optional(),
  agentEdits: z
    .boolean()
    .meta({ title: "Agents may edit", description: "Let agents change this note without your review." })
    .optional(),
};