/**
 * Typography roles. `leading` is an absolute line height in pt: Txt turns it into `lineHeight: "Npt"`
 * on the same node as fontSize. Roles used by render-prop text (page numbers) have no leading, because
 * react-pdf multiplies a render-prop lineHeight again on every relayout.
 *
 * TYPE_ROLES holds Classic's values. Every other template declares its own role table (see
 * defineRoles) from the faces below and passes those tokens wherever a role is accepted.
 */
export type FaceKey =
  | "IBM Plex Sans"
  | "IBM Plex Mono"
  | "Montserrat"
  | "Open Sans"
  | "Poppins"
  | "Inter"
  | "DM Sans"
  | "Jost"
  // Licensed faces of the Canva designs; SUBSTITUTES maps each to the bundled look-alike.
  | "Now"
  | "Gotham"
  | "Open Sauce One";

export interface TypeToken {
  face: FaceKey;
  weight: 300 | 400 | 500 | 600 | 700 | 800;
  italic?: boolean;
  size: number;
  /** pt, absolute. Optional only for tokens used by RenderTxt. */
  leading?: number;
  /** em; applied as letterSpacing = tracking * size. */
  tracking?: number;
  caps?: boolean;
  /** Intent only: textkit exposes no OpenType feature switch, so this does not change rendering yet. */
  tnum?: boolean;
  /** Smallest size IdText/FitText may shrink to. */
  minSize?: number;
}

const SANS: FaceKey = "IBM Plex Sans";

export const TYPE_ROLES = {
  display: { face: SANS, weight: 600, size: 26, leading: 30 },
  title: { face: SANS, weight: 600, size: 18, leading: 22, tracking: 1.5 / 18, caps: true },
  h1: { face: SANS, weight: 600, size: 18, leading: 22 },
  h2: { face: SANS, weight: 600, size: 13, leading: 17 },
  body: { face: SANS, weight: 400, size: 9.5, leading: 13.8 },
  bodyStrong: { face: SANS, weight: 600, size: 9.5, leading: 13.8 },
  small: { face: SANS, weight: 400, size: 8.5, leading: 12 },
  fine: { face: SANS, weight: 400, size: 7.5, leading: 10.5 },
  tableHead: { face: SANS, weight: 400, size: 7.5, leading: 10, tracking: 0.8 / 7.5, caps: true },
  tableBody: { face: SANS, weight: 400, size: 9.5, leading: 13.8 },
  money: { face: SANS, weight: 400, size: 9.5, leading: 13.8, tnum: true },
  moneyStrong: { face: SANS, weight: 600, size: 9.5, leading: 13.8, tnum: true },
  footer: { face: SANS, weight: 400, size: 7.5 },
  label: { face: SANS, weight: 400, size: 7.5, leading: 10, tracking: 1 / 7.5, caps: true },
} as const satisfies Record<string, TypeToken>;

export type RoleName = keyof typeof TYPE_ROLES;

/** A template's own role table: names to tokens. `satisfies`-friendly, so each template keeps its literal keys. */
export type RoleTable<K extends string = string> = Record<K, TypeToken>;

/** Checks a role table against TypeToken and keeps its literal keys: `export const ROLES = defineRoles({ ... })`. */
export function defineRoles<const T extends Record<string, TypeToken>>(table: T): T {
  return table;
}

/**
 * Licensed template faces (Now, Gotham, Open Sauce One, ...) map to the OFL look-alike that is
 * actually bundled. A user-imported font replaces the licensed name through `faceOverrides`.
 * Gotham runs about 4% narrower than Montserrat, so tokens that use it carry sizes already scaled by
 * GOTHAM_SIZE (see templates/northline); a real Gotham import would need them back at 1.
 */
export const SUBSTITUTES: Readonly<Record<string, string>> = {
  Now: "Jost",
  Gotham: "Montserrat",
  "Open Sauce One": "Poppins",
};

/** The family name to register/look up for a face: user override first, then substitute, then itself. */
export function resolveFace(face: string, overrides?: Readonly<Record<string, string>>): string {
  return overrides?.[face] ?? SUBSTITUTES[face] ?? face;
}

export function roleToken(role: RoleName | TypeToken): TypeToken {
  return typeof role === "string" ? TYPE_ROLES[role] : role;
}

/** Smallest shrink size for a token: its minSize, else 0.9x the size but never below 7 pt (or the size itself). */
export function minSizeOf(token: TypeToken): number {
  return token.minSize ?? Math.min(token.size, Math.max(7, token.size * 0.9));
}