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

// Extracted components to avoid defining during render
function CalendarRoot({
  className,
  rootRef,
  ...props
}: Readonly<{
  className?: string;
  rootRef?: React.Ref<HTMLDivElement>;
  children?: React.ReactNode;
}>): React.JSX.Element {
  return <div data-slot="calendar" ref={rootRef} className={cn(className)} {...props} />;
}

function CalendarChevron({
  className,
  orientation,
  ...props
}: Readonly<{
  className?: string;
  orientation?: "left" | "right" | "up" | "down";
}>): React.JSX.Element {
  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
}: Readonly<{ children?: React.ReactNode }>): React.JSX.Element {
  return (
    <td {...props}>
      <div className="flex h-[--cell-size] w-[--cell-size] items-center justify-center text-center">
        {children}
      </div>
    </td>
  );
}

function Calendar({
  className,
  classNames,
  showOutsideDays = true,
  captionLayout = "label",
  buttonVariant = "ghost",
  formatters,
  components,
  locale,
  startMonth,
  endMonth,
  ...props
}: Readonly<
  React.ComponentProps<typeof DayPicker> & {
    buttonVariant?: React.ComponentProps<typeof Button>["variant"];
    locale?: Locale | string;
  }
>): React.JSX.Element {
  const defaultClassNames = getDefaultClassNames();

  // Resolve locale to Locale object if string is provided
  const resolvedLocale = React.useMemo(() => {
    if (!locale) return undefined;
    if (typeof locale === "string") {
      return getDateFnsLocale(locale);
    }
    return locale;
  }, [locale]);

  const resolvedStartMonth = React.useMemo(() => {
    if (startMonth) return startMonth;
    if (captionLayout === "dropdown") {
      return new Date(new Date().getFullYear() - 100, 0);
    }
    return undefined;
  }, [startMonth, captionLayout]);

  const resolvedEndMonth = React.useMemo(() => {
    if (endMonth) return endMonth;
    if (captionLayout === "dropdown") {
      return new Date(new Date().getFullYear() + 100, 11);
    }
    return undefined;
  }, [endMonth, captionLayout]);

  return (
    <DayPicker
      showOutsideDays={showOutsideDays}
      className={cn(
        "bg-background group/calendar p-3 [--cell-size:2rem] [[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
      )}
      captionLayout={captionLayout}
      locale={resolvedLocale}
      startMonth={resolvedStartMonth}
      endMonth={resolvedEndMonth}
      formatters={{
        formatMonthDropdown: (date) => {
          if (resolvedLocale) {
            return format(date, "MMM", { locale: resolvedLocale });
          }
          return date.toLocaleString("default", { month: "short" });
        },
        ...formatters,
      }}
      classNames={{
        root: cn("w-fit", defaultClassNames.root),
        months: cn("flex gap-4 flex-col md:flex-row relative", defaultClassNames.months),
        month: cn("flex flex-col w-full gap-4", defaultClassNames.month),
        nav: cn(
          "flex items-center gap-1 w-full absolute top-0 inset-x-0 justify-between",
          defaultClassNames.nav
        ),
        button_previous: cn(
          buttonVariants({ variant: buttonVariant }),
          "h-[--cell-size] w-[--cell-size] aria-disabled:opacity-50 p-0 select-none",
          defaultClassNames.button_previous
        ),
        button_next: cn(
          buttonVariants({ variant: buttonVariant }),
          "h-[--cell-size] w-[--cell-size] aria-disabled:opacity-50 p-0 select-none",
          defaultClassNames.button_next
        ),
        month_caption: cn(
          "flex items-center justify-center h-[--cell-size] w-full px-[--cell-size]",
          defaultClassNames.month_caption
        ),
        dropdowns: cn(
          "w-full flex items-center text-sm font-medium justify-center h-[--cell-size] gap-1.5",
          defaultClassNames.dropdowns
        ),
        dropdown_root: cn(
          "relative has-focus:border-ring border border-input-border shadow-xs has-focus:ring-ring/50 has-focus:ring-[3px] rounded-md",
          defaultClassNames.dropdown_root
        ),
        dropdown: cn("absolute bg-popover inset-0 opacity-0", defaultClassNames.dropdown),
        caption_label: cn(
          "select-none font-medium",
          captionLayout === "label"
            ? "text-sm"
            : "rounded-md pl-2 pr-1 flex items-center gap-1 text-sm h-8 [&>svg]:text-muted-foreground [&>svg]:size-3.5",
          defaultClassNames.caption_label
        ),
        table: "w-full border-collapse",
        weekdays: cn("flex", defaultClassNames.weekdays),
        weekday: cn(
          "text-muted-foreground rounded-md flex-1 font-normal text-[0.8rem] select-none text-[var(--fb-input-color)] opacity-70",
          defaultClassNames.weekday
        ),
        week: cn("flex w-full mt-2", defaultClassNames.week),
        week_number_header: cn("select-none w-[--cell-size]", defaultClassNames.week_number_header),
        week_number: cn("text-[0.8rem] select-none text-muted-foreground", defaultClassNames.week_number),
        day: cn(
          "relative w-full h-full p-0 text-center [&:last-child[data-selected=true]_button]:rounded-r-md group/day aspect-square select-none",
          props.showWeekNumber
            ? "[&:nth-child(2)[data-selected=true]_button]:rounded-l-md"
            : "[&:first-child[data-selected=true]_button]:rounded-l-md",
          defaultClassNames.day
        ),
        range_start: cn("rounded-l-md bg-accent", defaultClassNames.range_start),
        range_middle: cn("rounded-none", defaultClassNames.range_middle),
        range_end: cn("rounded-r-md bg-accent", defaultClassNames.range_end),
        today: cn(
          "bg-accent text-brand-foreground rounded-md data-[selected=true]:rounded-none bg-brand opacity-50",
          defaultClassNames.today
        ),
        outside: cn(
          "text-[var(--fb-input-color)] opacity-70 aria-selected:text-[var(--fb-input-color)] opacity-70",
          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,
      }}
      {...props}
    />
  );
}

function CalendarDayButton({
  className,
  day,
  modifiers,
  ...props
}: React.ComponentProps<typeof DayButton>): React.JSX.Element {
  const defaultClassNames = getDefaultClassNames();

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

  return (
    <Button
      ref={ref}
      variant="ghost"
      size="icon"
      data-day={day.date.toLocaleDateString()}
      data-selected-single={
        modifiers.selected && !modifiers.range_start && !modifiers.range_end ? !modifiers.range_middle : null
      }
      data-range-start={modifiers.range_start}
      data-range-end={modifiers.range_end}
      data-range-middle={modifiers.range_middle}
      className={cn(
        "data-[selected-single=true]:bg-brand data-[selected-single=true]:text-primary-foreground 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-[range-end=true]:bg-primary data-[range-end=true]:text-primary-foreground hover:text-primary-foreground data-[selected-single=true]:hover:bg-brand data-[selected-single=true]:hover:text-primary-foreground data-[range-start=true]:hover:bg-primary data-[range-start=true]:hover:text-primary-foreground data-[range-end=true]:hover:bg-primary data-[range-end=true]:hover:text-primary-foreground group-data-[focused=true]/day:border-ring group-data-[focused=true]/day:ring-ring/50 flex aspect-square h-auto w-full min-w-[--cell-size] flex-col gap-1 leading-none font-normal group-data-[focused=true]/day:relative group-data-[focused=true]/day:z-10 group-data-[focused=true]/day:ring-[3px] hover:bg-[color-mix(in_srgb,var(--fb-survey-brand-color)_70%,transparent)] data-[range-end=true]:rounded-md data-[range-end=true]:rounded-r-md data-[range-middle=true]:rounded-none data-[range-start=true]:rounded-md data-[range-start=true]:rounded-l-md [&>span]:text-xs [&>span]:opacity-70",
        defaultClassNames.day,
        className
      )}
      {...props}
    />
  );
}

export { Calendar, CalendarDayButton };
