import React from 'react';

import { css } from '@patternfly/react-styles';
import styles from '@patternfly/react-styles/css/components/Wizard/wizard';
import wizardHeightToken from '@patternfly/react-tokens/dist/esm/c_wizard_Height';

import {
  isWizardParentStep,
  WizardStepType,
  isCustomWizardNav,
  WizardFooterType,
  WizardNavType,
  WizardStepChangeScope
} from './types';
import { buildSteps, isStepEnabled } from './utils';
import { useWizardContext, WizardContextProvider } from './WizardContext';
import { WizardToggle } from './WizardToggle';
import { WizardNavInternal } from './WizardNavInternal';

/**
 * Wrapper for all steps and hosts state, including navigation helpers, within context.
 * The WizardContext provided by default gives any child of wizard access to those resources.
 */

export interface WizardProps extends React.HTMLProps<HTMLDivElement> {
  /** Step components */
  children: React.ReactNode;
  /** Wizard header */
  header?: React.ReactNode;
  /** Wizard footer */
  footer?: WizardFooterType;
  /** Wizard navigation */
  nav?: WizardNavType;
  /** Aria-label for the Nav */
  navAriaLabel?: string;
  /** The initial index the wizard is to start on (1 or higher). Defaults to 1. */
  startIndex?: number;
  /** Additional classes spread to the wizard */
  className?: string;
  /** Custom width of the wizard */
  width?: number | string;
  /** Custom height of the wizard */
  height?: number | string;
  /** Disables steps that haven't been visited. Defaults to false. */
  isVisitRequired?: boolean;
  /** Progressively shows steps, where all steps following the active step are hidden. Defaults to false. */
  isProgressive?: boolean;
  /** Callback function when navigating between steps */
  onStepChange?: (
    event: React.MouseEvent<HTMLButtonElement>,
    currentStep: WizardStepType,
    prevStep: WizardStepType,
    scope: WizardStepChangeScope
  ) => void | Promise<void>;
  /** Callback function to save at the end of the wizard, if not specified uses onClose */
  onSave?: (event: React.MouseEvent<HTMLButtonElement>) => void | Promise<void>;
  /** Callback function to close the wizard */
  onClose?: (event: React.MouseEvent<HTMLButtonElement>) => void;
  /** Flag indicating whether the wizard content should be focused after the onNext or onBack callbacks
   * are called.
   */
  shouldFocusContent?: boolean;
}

export const Wizard = ({
  children,
  footer,
  height,
  width,
  className,
  header,
  nav,
  navAriaLabel,
  startIndex = 1,
  isVisitRequired = false,
  isProgressive = false,
  onStepChange,
  onSave,
  onClose,
  shouldFocusContent = true,
  ...wrapperProps
}: WizardProps) => {
  const [activeStepIndex, setActiveStepIndex] = React.useState(startIndex);
  const initialSteps = buildSteps(children);
  const firstStepRef = React.useRef(initialSteps[startIndex - 1]);
  const wrapperRef = React.useRef(null);

  // When the startIndex maps to a parent step, focus on the first sub-step
  React.useEffect(() => {
    if (isWizardParentStep(firstStepRef.current)) {
      setActiveStepIndex(startIndex + 1);
    }
  }, [startIndex]);

  // When the number of steps changes and pushes activeStepIndex out of bounds, reset back to startIndex
  React.useEffect(() => {
    if (activeStepIndex > initialSteps.length) {
      setActiveStepIndex(startIndex);
    }
  }, [initialSteps, activeStepIndex, startIndex]);

  const focusMainContentElement = () =>
    setTimeout(() => {
      wrapperRef?.current?.focus && wrapperRef.current.focus();
    }, 0);

  const goToNextStep = (event: React.MouseEvent<HTMLButtonElement>, steps: WizardStepType[] = initialSteps) => {
    const newStep = steps.find((step) => step.index > activeStepIndex && isStepEnabled(steps, step));

    if (activeStepIndex >= steps.length || !newStep?.index) {
      return onSave ? onSave(event) : onClose?.(event);
    }

    setActiveStepIndex(newStep?.index);
    onStepChange?.(event, newStep, steps[activeStepIndex - 1], WizardStepChangeScope.Next);
    shouldFocusContent && focusMainContentElement();
  };

  const goToPrevStep = (event