'use client';

import * as React from 'react';
import { cva, type VariantProps } from '@/lib/cva';
import { ChevronRightIcon, MoreHorizontalIcon } from '@/icons';
import * as Slot from 'radix-ui/slot';

import { cn } from '@/lib/utils';
import { colorPalettes } from '@/lib/cva-presets';

/*
 * CBAR builds each crumb out of its Button component, which is why the sizes
 * below are button heights rather than line heights. The list publishes the
 * size as `data-size` and the crumbs read it back with `group-data-*`, so a
 * caller sets it once.
 */
const breadcrumbListVariants = cva(
  'group/breadcrumb-list flex flex-wrap items-center gap-1 break-words text-foreground',
  {
    variants: {
      size: {
        xs: 'text-xs',
        md: 'text-sm',
      },
      /** Only the separator takes palette colour; CBAR draws it turquoise. */
      colorPalette: colorPalettes,
    },
    defaultVariants: {
      size: 'md',
      colorPalette: 'secondary',
    },
  }
);

export type BreadcrumbProps = React.ComponentProps<'nav'>;
export interface BreadcrumbListProps
  extends React.ComponentProps<'ol'>,
    VariantProps<typeof breadcrumbListVariants> {}
export interface BreadcrumbLinkProps extends React.ComponentProps<'a'> {
  /** Render the child element instead of an `<a>` — e.g. a router `<Link>`. */
  asChild?: boolean;
}

/**
 * Trail showing where the current page sits in the hierarchy.
 *
 * The last crumb is the current page: render it as `BreadcrumbPage`, not a
 * link, so it is announced with `aria-current="page"`.
 */
function Breadcrumb(props: BreadcrumbProps) {
  return <nav aria-label="breadcrumb" data-slot="breadcrumb" {...props} />;
}

function BreadcrumbList({ className, size = 'md', colorPalette, ...props }: BreadcrumbListProps) {
  return (
    <ol
      data-slot="breadcrumb-list"
      data-size={size}
      className={cn(breadcrumbListVariants({ size, colorPalette }), className)}
      {...props}
    />
  );
}

function BreadcrumbItem({ className, ...props }: React.ComponentProps<'li'>) {
  return (
    <li
      data-slot="breadcrumb-item"
      className={cn(
        'inline-flex items-center rounded-xs',
        'group-data-[size=xs]/breadcrumb-list:h-8 group-data-[size=xs]/breadcrumb-list:gap-1 group-data-[size=xs]/breadcrumb-list:px-2.5 group-data-[size=xs]/breadcrumb-list:[&_svg]:size-4',
        'group-data-[size=md]/breadcrumb-list:h-10 group-data-[size=md]/breadcrumb-list:gap-2 group-data-[size=md]/breadcrumb-list:px-4 group-data-[size=md]/breadcrumb-list:[&_svg]:size-6',
        className
      )}
      {...props}
    />
  );
}

function BreadcrumbLink({ asChild, className, ...props }: BreadcrumbLinkProps) {
  const Comp = asChild ? Slot.Root : 'a';

  return (
    <Comp
      data-slot="breadcrumb-link"
      className={cn(
        'transition-colors duration-(--ui-duration-fast) hover:text-(--ctl-fg)',
        className
      )}
      {...props}
    />
  );
}

/**
 * The current page. Not a link — it is where the user already is.
 *
 * CBAR does not dim the ancestors the way most breadcrumbs do; every crumb is
 * body ink and only the weight changes, so this is the one that stands out.
 */
function BreadcrumbPage({ className, ...props }: React.ComponentProps<'span'>) {
  return (
    <span
      data-slot="breadcrumb-page"
      role="link"
      aria-disabled="true"
      aria-current="page"
      className={cn('font-medium text-foreground', className)}
      {...props}
    />
  );
}

/**
 * Separator between crumbs. It does **not** scale with `size` — CBAR draws it
 * at 16px in both, so the chevrons stay level as the crumbs grow.
 */
function BreadcrumbSeparator({ children, className, ...props }: React.ComponentProps<'li'>) {
  return (
    <li
      data-slot="breadcrumb-separator"
      role="presentation"
      aria-hidden="true"
      className={cn('text-(--ctl-solid) [&>svg]:size-4', className)}
      {...props}
    >
      {children ?? <ChevronRightIcon />}
    </li>
  );
}

/** Stands in for collapsed middle crumbs on narrow screens. */
function BreadcrumbEllipsis({ className, ...props }: React.ComponentProps<'span'>) {
  return (
    <span
      data-slot="breadcrumb-ellipsis"
      role="presentation"
      aria-hidden="true"
      className={cn('flex size-9 items-center justify-center', className)}
      {...props}
    >
      <MoreHorizontalIcon className="size-4" />
      <span className="sr-only">More</span>
    </span>
  );
}

export {
  Breadcrumb,
  BreadcrumbList,
  BreadcrumbItem,
  BreadcrumbLink,
  BreadcrumbPage,
  BreadcrumbSeparator,
  BreadcrumbEllipsis,
  breadcrumbListVariants,
};