import { type ReactElement } from "react";
import * as React from "react";
import {
  ChevronDownIcon,
  ChevronLeftIcon,
  ChevronRightIcon,
} from "lucide-react";
import {
  DayPicker,
  getDefaultClassNames,
  type DayButton,
} from "react-day-picker";
import { cn } from "@/lib/utils";
import { formatDateShort } from "@/lib/format-date";
import { Button, buttonVariants } from "@/components/ui/button";

/**
 * Calendar — shadcn/WealthX
 * Base: npx shadcn\@latest add calendar (latest)
 * Figma: Design-System---shadcn?node-id=72-2720
 *
 * WealthX:
 * - font-sans for consistent Figtree typography
 * - border + shadow-sm on root (square corners — no border radius)
 * - captionLayout defaults to "dropdown" (Figma shows month/year dropdown pills)
 */

export type CalendarProps = React.ComponentProps<typeof DayPicker> & {
  buttonVariant?: React.ComponentProps<typeof Button>["variant"];
};

function CalendarRoot({
  className,
  rootRef,
  ...props
}: {
  className?: string;
  rootRef?: React.Ref<HTMLDivElement>;
} & React.ComponentProps<"div">): ReactElement {
  return (
    <div
      className={cn(className)}
      data-slot="calendar"
      ref={rootRef}
      {...props}
    />
  );
}

function CalendarChevron({
  className,
  orientation,
  ...props
}: {
  className?: string;
  orientation?: string;
} & React.ComponentProps<"svg">): ReactElement {
  if (orientation === "left") {
    return <ChevronLeftIcon className={cn("size-4", className)} {...props} />;
  }

  if (orientation === "right") {
    return <ChevronRightIcon className={cn("size-4", className)} {...props} />;
  }

  return <ChevronDownIcon className={cn("size-4", className)} {...props} />;
}

function CalendarWeekNumber({
  children,
  ...props
}: React.ComponentProps<"td">): ReactElement {
  return (
    <td {...props}>
      <div className="flex size-(--cell-size) items-center justify-center text-center">
        {children}
      </div>
    </td>
  );
}

function Calendar({
  className,
  classNames,
  showOutsideDays = true,
  captionLayout = "dropdown",
  buttonVariant = "ghost",
  formatters,
  components,
  ...props
}: CalendarProps): ReactElement {
  const defaultClassNames = getDefaultClassNames();

  return (
    <DayPicker
      captionLayout={captionLayout}
      className={cn(
        "group/calendar bg-background p-3 font-sans border border-border shadow-sm [--cell-size:--spacing(8)] [[data-slot=card-content]_&]:bg-transparent [[data-slot=popover-content]_&]:bg-transparent",
        String.raw`rtl:**:[.rdp-button\_next>svg]:rotate-180`,
        String.raw`rtl:**:[.rdp-button\_previous>svg]:rotate-180`,
        className,
      )}
      classNames={{
        root: cn("w-fit", defaultClassNames.root),
        months: cn(
          "relative flex flex-col gap-4 md:flex-row",
          defaultClassNames.months,
        ),
        month: cn("flex w-full flex-col gap-4", defaultClassNames.month),
        nav: cn(
          "absolute inset-x-0 top-0 flex w-full items-center justify-between gap-1",
          defaultClassNames.nav,
        ),
        button_previous: cn(
          buttonVariants({ variant: buttonVariant }),
          "size-(--cell-size) p-0 select-none aria-disabled:opacity-50",
          defaultClassNames.button_previous,
        ),
        button_next: cn(
          buttonVariants({ variant: buttonVariant }),
          "size-(--cell-size) p-0 select-none aria-disabled:opacity-50",
          defaultClassNames.button_next,
        ),
        month_caption: cn(
          "flex h-(--cell-size) w-full items-center justify-center px-(--cell-size)",
          defaultClassNames.month_caption,
        ),
        dropdowns: cn(
          "flex h-(--cell-size) w-full items-center justify-center gap-1.5 text-label-small",
          defaultClassNames.dropdowns,
        ),
        dropdown_root: cn(
          "relative border border-input shadow-xs has-focus:border-ring has-focus:ring-[3px] has-focus:ring-ring/50",
          defaultClassNames.dropdown_root,
        ),
        dropdown: cn(
          "absolute inset-0 bg-popover opacity-0",
          defaultClassNames.dropdown,
        ),
        caption_label: cn(
          "select-none",
          captionLayout === "label"
            ? "text-label-small"
            : "flex h-8 items-center gap-1 pr-1 pl-2 text-label-small [&>svg]:size-3.5 [&>svg]:text-muted-foreground",
          defaultClassNames.caption_label,
        ),
        table: "w-full border-collapse",
        weekdays: cn("flex", defaultClassNames.weekdays),
        weekday: cn(
          "flex-1 text-caption font-normal text-muted-foreground select-none",
          defaultClassNames.weekday,
        ),
        week: cn("mt-2 flex w-full", defaultClassNames.week),
        week_number_header: cn(
          "w-(--cell-size) select-none",
          defaultClassNames.week_number_header,
        ),
        week_number: cn(
          "text-caption text-muted-foreground select-none",
          defaultClassNames.week_number,
        ),
        day: cn(
          "group/day relative aspect-square h-full w-full p-0 text-center select-none",
          defaultClassNames.day,
        ),
        range_start: cn("bg-accent", defaultClassNames.range_start),
        range_middle: cn("rounded-none", defaultClassNames.range_middle),
        range_end: cn("bg-accent", defaultClassNames.range_end),
        today: cn("bg-accent text-accent-foreground", defaultClassNames.today),
        outside: cn(
          "text-muted-foreground aria-selected:text-muted-foreground",
          defaultClassNames.outside,
        ),
        disabled: cn(
          "text-muted-foreground opacity-50",
          defaultClassNames.disabled,
        ),
        hidden: cn("invisible", defaultClassNames.hidden),
        ...classNames,
      }}
      components={{
        Root: CalendarRoot,
        Chevron: CalendarChevron,
        DayButton: CalendarDayButton,
        WeekNumber: CalendarWeekNumber,
        ...components,
      }}
      formatters={{
        formatMonthDropdown: (date) =>
          date.toLocaleString("default", { month: "short" }),
        ...formatters,
      }}
      showOutsideDays={showOutsideDays}
      {...props}
    />
  );
}

export type CalendarDayButtonProps = React.ComponentProps<typeof DayButton>;

function CalendarDayButton({
  className,
  day,
  modifiers,
  ...props
}: CalendarDayButtonProps): ReactElement {
  const defaultClassNames = getDefaultClassNames();

  const ref = React.useRef<HTMLButtonElement>(null);
  React.useEffect(() => {
    if (modifiers.focused) ref.current?.focus();
  }, [modifiers.focused]);

  const selectedSingle =
    modifiers.selected && !modifiers.range_start && !modifiers.range_end
      ? !modifiers.range_middle
      : null;

  return (
    <Button
      className={cn(
        "flex aspect-square size-auto w-full min-w-(--cell-size) flex-col gap-1 font-normal rounded-none group-data-[focused=true]/day:relative group-data-[focused=true]/day:z-10 group-data-[focused=true]/day:border-ring group-data-[focused=true]/day:ring-[3px] group-data-[focused=true]/day:ring-ring/50 data-[range-end=true]:bg-primary data-[range-end=true]:text-primary-foreground data-[range-middle=true]:rounded-none data-[range-middle=true]:bg-accent data-[range-middle=true]:text-accent-foreground data-[range-start=true]:bg-primary data-[range-start=true]:text-primary-foreground data-[selected-single=true]:bg-primary data-[selected-single=true]:text-primary-foreground dark:hover:text-accent-foreground [&>span]:text-caption [&>span]:opacity-70",
        defaultClassNames.day,
        className,
      )}
      data-day={formatDateShort(day.date.toISOString())}
      data-range-end={modifiers.range_end}
      data-range-middle={modifiers.range_middle}
      data-range-start={modifiers.range_start}
      data-selected-single={selectedSingle}
      ref={ref}
      size="icon"
      variant="ghost"
      {...props}
    />
  );
}

export { Calendar, CalendarDayButton };
