import type { ColorPalette, ControlSize, ControlVariant, FieldSize } from '@/lib';

/**
 * The axis values every entry and every page draws from.
 *
 * These used to be restated in ten places — seven registry files and both
 * `/buttons` tabs — because the kit did not export its own vocabulary. It does
 * now (`colorPalettes`, `controlVariants`, `controlHeights`, `fieldHeights` in
 * `src/lib/cva-presets.ts`, re-exported from `@/lib`), so the lists live here
 * once and the types below make a drift a compile error rather than a grid with
 * a missing column.
 *
 * They are written out rather than derived with `Object.keys()` for two
 * reasons: order is meaningful (it is the order of the columns on screen, and
 * CBAR's canvas order is not alphabetical), and `Object.keys` widens to
 * `string[]`, which would take the literal types out of every `axes` block.
 * `satisfies` gives back what `Object.keys` would have cost.
 */

/**
 * `true` if `Listed` covers every member of `All`, otherwise a tuple naming what
 * is missing — which is the text that ends up in the compiler error.
 *
 * Exported because `pages/buttons-figma.tsx` keeps its own ordering — CBAR's
 * canvas order, which is deliberately not the kit's — and needs the same
 * coverage check over a list this file cannot own.
 */
export type Complete<Listed extends string, All extends string> = Exclude<
  All,
  Listed
> extends never
  ? true
  : ['a value is missing from this list:', Exclude<All, Listed>];

/**
 * What turns {@link Complete} into an actual compile error.
 *
 * `Complete<…>` on its own is inert: a type alias resolving to a tuple is a
 * perfectly legal type, so `type _X = Complete<A, B>` type-checks whether the
 * answer is `true` or `['a value is missing from this list:', 'xl']`. Measured
 * with the kit's own `tsc` — the guards below were silent for exactly that
 * reason. Passing the answer through a parameter constrained to `true` is what
 * makes the failing case unassignable, and the tuple is then quoted in the
 * error.
 */
export type Assert<T extends true> = T;

/**
 * The seven palettes, minus the deprecated `third` alias of `tertiary`.
 *
 * `third` is excluded deliberately: it resolves to the same eight `--ctl-*`
 * roles, so showing it would draw an identical column twice.
 */
export const PALETTES = [
  'primary',
  'secondary',
  'tertiary',
  'black',
  'red',
  'green',
  'yellow',
] as const satisfies readonly ColorPalette[];

export type Palette = (typeof PALETTES)[number];

/* Exclude the alias here too, or adding a palette would not be caught. */
export type _PalettesCovered = Assert<Complete<Palette | 'third', ColorPalette>>;

/**
 * The five fill treatments that compose with a palette.
 *
 * Button carries three more (`link`, `destructive`, `secondary-solid`) that pin
 * their own colour from the semantic roles in theme.css and therefore ignore
 * `colorPalette`. Those are Button's own business and stay in its entry.
 */
export const VARIANTS = [
  'solid',
  'subtle',
  'surface',
  'outline',
  'ghost',
] as const satisfies readonly ControlVariant[];

export type Variant = (typeof VARIANTS)[number];

export type _VariantsCovered = Assert<Complete<Variant, ControlVariant>>;

/** Button's height ladder — 32 / 36 / 40 / 48 / 56px. */
export const CONTROL_SIZES = ['xs', 'sm', 'md', 'lg', 'xl'] as const satisfies readonly ControlSize[];

export type ControlSizeValue = (typeof CONTROL_SIZES)[number];

export type _ControlSizesCovered = Assert<Complete<ControlSizeValue, ControlSize>>;

/**
 * The form-field ladder — 32 / 36 / 44 / 56px.
 *
 * Deliberately shorter than {@link CONTROL_SIZES} and deliberately not the same
 * heights: CBAR draws fields taller than buttons from `md` up. See the note on
 * `fieldHeights` in `src/lib/cva-presets.ts`.
 */
export const FIELD_SIZES = ['xs', 'sm', 'md', 'lg'] as const satisfies readonly FieldSize[];

export type FieldSizeValue = (typeof FIELD_SIZES)[number];

export type _FieldSizesCovered = Assert<Complete<FieldSizeValue, FieldSize>>;