import type { CreateFlowStep } from "../types";
import { CREATE_FLOW_SCREEN_REGISTRY } from "../utils/createFlowScreenRegistry";

/**
 * Shared page gutters for create-flow chrome and step shells.
 * Six viewport bands collapse to three values: 20px below `md`, 48px from `md`,
 * 64px from `lg` (320–639 / 640–1023 / 1024+).
 */
export const CREATE_FLOW_PAGE_GUTTER_CLASS = "px-5 md:px-12 lg:px-16";

/**
 * Wizard viewport frame. `dvh` tracks mobile browser chrome so the action bar
 * stays on-screen; `max-h-dvh` keeps the flex column from overflowing it.
 */
export const CREATE_FLOW_VIEWPORT_FRAME_CLASS =
  "relative flex h-dvh max-h-dvh min-h-0 flex-col overflow-hidden";

/** Design-system scrollbar for create-flow scroll regions (not `scrollbar-hide`). */
export const CREATE_FLOW_SCROLL_REGION_CLASS = "scrollbar-design";

/**
 * Fade above the fixed action bar so content that continues below the fold is
 * visible as a continuation cue (Figma Scrim / footer overlay).
 */
export const CREATE_FLOW_FOOTER_SCRIM_CLASS =
  "pointer-events-none absolute inset-x-0 top-0 z-[1] h-8 -translate-y-full bg-gradient-to-t from-[var(--color-surface-default-primary,#000)] to-transparent";

/**
 * Single column: full width below `lg` so tablet widths use available space;
 * 640px from `--breakpoint-lg` up (two-column layouts start at `lg`).
 */
export const CREATE_FLOW_MD_UP_COLUMN_MAX_CLASS =
  "w-full min-w-0 lg:max-w-[640px]";

/** Grid cell: same cap as column max, centered when the track is wider than 640px. */
export const CREATE_FLOW_MD_UP_GRID_CELL_CLASS =
  "w-full min-w-0 lg:mx-auto lg:max-w-[640px]";

/** Two 640px columns + `--measures-spacing-1200` (48px) gutter. */
export const CREATE_FLOW_TWO_COLUMN_MAX_WIDTH_CLASS =
  "w-full min-w-0 lg:max-w-[1328px]";

/** Review / card-stack frames (Figma Flow — Review max 1440). */
export const CREATE_FLOW_WIDE_MAX_CLASS = "w-full min-w-0 lg:max-w-[1440px]";

/**
 * Lockup+card and card-stack `<main>`: keep `items-start` so a tall card can
 * scroll from the top. Pair with {@link CREATE_FLOW_MD_CENTERED_SHELL_CLASS}.
 */
export const CREATE_FLOW_MD_CENTERED_MAIN_CLASS =
  "items-start justify-center overflow-y-auto";

/**
 * Center the step in the nav–footer band from `md` when it fits (`my-auto`),
 * and drop the mobile top inset so that centering is not biased downward.
 */
export const CREATE_FLOW_MD_CENTERED_SHELL_CLASS = "md:my-auto md:pt-0";

/**
 * Card-stack steps only (Figma compact card stack): wider than header lockup so the card grid /
 * pyramid fits (max 860px). Header lockup stays {@link CREATE_FLOW_MD_UP_COLUMN_MAX_CLASS}.
 * Card–card gap uses `gap-2` in `CardStack` (same on mobile and md+).
 */
export const CREATE_FLOW_CARD_STACK_AREA_MAX_CLASS =
  "w-full min-w-0 md:max-w-[min(100%,860px)]";

/**
 * Inner max-width for step content and the action bar, so the primary button
 * lines up with the nearest content column above 1440.
 */
export function getCreateFlowContentMaxClass(options: {
  step: CreateFlowStep | null | undefined;
  isTemplateReview?: boolean;
  isTemplatesPicker?: boolean;
}): string {
  if (options.isTemplateReview || options.isTemplatesPicker) {
    return CREATE_FLOW_TWO_COLUMN_MAX_WIDTH_CLASS;
  }
  if (!options.step) {
    return CREATE_FLOW_MD_UP_COLUMN_MAX_CLASS;
  }
  switch (CREATE_FLOW_SCREEN_REGISTRY[options.step].layoutKind) {
    case "select":
    case "right-rail":
    case "completed":
    case "review":
      return CREATE_FLOW_TWO_COLUMN_MAX_WIDTH_CLASS;
    case "card":
      return CREATE_FLOW_WIDE_MAX_CLASS;
    default:
      return CREATE_FLOW_MD_UP_COLUMN_MAX_CLASS;
  }
}