import { clsx, type ClassValue } from "clsx";
import { extendTailwindMerge } from "tailwind-merge";

const SPACING_TOKENS = ["text-pair", "field", "stack", "section"];

/**
 * tailwind-merge only dedupes classes it can classify. Without these, a caller's
 * `gap-4` and the component's `gap-text-pair` both survive cn() and stylesheet
 * order silently decides the winner, so the override looks applied but is a no-op.
 */
const spacingClassGroups = Object.fromEntries(
  [
    "gap",
    "gap-x",
    "gap-y",
    "space-x",
    "space-y",
    "m",
    "mx",
    "my",
    "ms",
    "me",
    "mt",
    "mr",
    "mb",
    "ml",
    "p",
    "px",
    "py",
    "ps",
    "pe",
    "pt",
    "pr",
    "pb",
    "pl",
    "inset",
    "inset-x",
    "inset-y",
    "top",
    "right",
    "bottom",
    "left",
    "start",
    "end",
    "w",
    "min-w",
    "max-w",
    "h",
    "min-h",
    "max-h",
    "size",
    "basis",
    "indent",
    "translate-x",
    "translate-y",
  ].map((group) => [group, [{ [group]: [...SPACING_TOKENS] }]]),
);

/**
 * Custom twMerge that recognises WealthX typography tokens as font-size
 * utilities so they don't conflict with text-color utilities
 * (e.g. text-button vs text-primary-foreground).
 */
const twMerge = extendTailwindMerge({
  extend: {
    classGroups: {
      ...spacingClassGroups,
      "font-size": [
        {
          text: [
            "display-large",
            "display-medium",
            "display-small",
            "h1",
            "h2",
            "h3",
            "h4",
            "h5",
            "h6",
            "body-large",
            "body-medium",
            "body-small",
            "label-large",
            "label-medium",
            "label-small",
            "button",
            "button-xs",
            "caption",
            "overline",
            "code",
          ],
        },
      ],
    },
  },
});

export function cn(...inputs: ClassValue[]): string {
  return twMerge(clsx(inputs));
}

export function getInitials(name: string): string {
  if (!name.trim()) return "?";
  return name
    .split(" ")
    .filter(Boolean)
    .map((word) => word[0])
    .join("")
    .toUpperCase()
    .slice(0, 2);
}