import type {
  ButtonHTMLAttributes,
  HTMLAttributes,
  KeyboardEvent,
  LabelHTMLAttributes,
  ReactNode,
  Ref,
} from 'react';
import { forwardRef } from 'react';

export type PlatformIconButtonVariant =
  | 'platformIcon'
  | 'surfaceFloating'
  | 'darkMini';
export type PlatformIconButtonSize = 'sm' | 'md' | 'lg';

type PlatformIconButtonBaseProps = {
  label: string;
  icon: ReactNode;
  children?: ReactNode;
  variant?: PlatformIconButtonVariant;
};

type PlatformIconButtonButtonProps = Omit<
  ButtonHTMLAttributes<HTMLButtonElement>,
  'aria-label' | 'children'
> &
  PlatformIconButtonBaseProps & {
    asChild?: false;
  };

type PlatformIconButtonLabelProps = Omit<
  LabelHTMLAttributes<HTMLLabelElement>,
  'aria-label' | 'children'
> &
  PlatformIconButtonBaseProps & {
    asChild: 'label';
  };

type PlatformIconButtonSpanButtonProps = Omit<
  HTMLAttributes<HTMLSpanElement>,
  'aria-label' | 'children' | 'role'
> &
  PlatformIconButtonBaseProps & {
    asChild: 'spanButton';
    disabled?: boolean;
  };

export type PlatformIconButtonProps =
  | PlatformIconButtonButtonProps
  | PlatformIconButtonLabelProps
  | PlatformIconButtonSpanButtonProps;

/**
 * 平台通用图标动作按钮。
 * 统一承接纯图标动作、图标上传 label 和带短标签的浮动图标动作。
 */
export const PlatformIconButton = forwardRef<
  HTMLButtonElement | HTMLLabelElement | HTMLSpanElement,
  PlatformIconButtonProps
>(function PlatformIconButton(
  {
    label,
    icon,
    children,
    variant = 'platformIcon',
    title,
    className,
    asChild,
    ...actionProps
  },
  ref,
) {
  const variantClassName = {
    platformIcon: 'platform-icon-button',
    surfaceFloating:
      'inline-flex items-center justify-center rounded-full border border-white/80 bg-white/94 text-[var(--platform-text-strong)] shadow-sm backdrop-blur transition hover:text-[var(--platform-accent)] disabled:cursor-not-allowed disabled:opacity-55',
    darkMini:
      'inline-flex items-center justify-center rounded-full border border-white/16 bg-black/55 text-white transition-colors hover:bg-black/70 disabled:cursor-not-allowed disabled:opacity-55',
  }[variant];

  const actionClassName = [variantClassName, className]
    .filter(Boolean)
    .join(' ');

  if (asChild === 'label') {
    return (
      <label
        {...(actionProps as LabelHTMLAttributes<HTMLLabelElement>)}
        ref={ref as Ref<HTMLLabelElement>}
        title={title}
        className={actionClassName}
      >
        <span className="sr-only">{label}</span>
        {icon}
        {children}
      </label>
    );
  }

  if (asChild === 'spanButton') {
    const { disabled, onClick, onKeyDown, tabIndex, ...spanProps } =
      actionProps as HTMLAttributes<HTMLSpanElement> & {
        disabled?: boolean;
      };
    const handleKeyDown = (event: KeyboardEvent<HTMLSpanElement>) => {
      onKeyDown?.(event);
      if (event.defaultPrevented || disabled) {
        return;
      }
      if (event.key === 'Enter' || event.key === ' ') {
        event.preventDefault();
        event.currentTarget.click();
      }
    };

    return (
      <span
        {...spanProps}
        ref={ref as Ref<HTMLSpanElement>}
        aria-disabled={disabled}
        aria-label={label}
        className={actionClassName}
        onClick={disabled ? undefined : onClick}
        onKeyDown={handleKeyDown}
        role="button"
        tabIndex={disabled ? -1 : (tabIndex ?? 0)}
        title={title}
      >
        {icon}
        {children}
      </span>
    );
  }

  const { type = 'button', ...buttonProps } =
    actionProps as ButtonHTMLAttributes<HTMLButtonElement>;

  return (
    <button
      {...buttonProps}
      ref={ref as Ref<HTMLButtonElement>}
      type={type}
      aria-label={label}
      title={title}
      className={actionClassName}
    >
      {icon}
      {children}
    </button>
  );
});