/**
 * External dependencies
 */
import {
	Suspense,
	lazy,
	useCallback,
	useLayoutEffect,
	useRef,
	useState,
} from '@wordpress/element';
import { compose } from '@wordpress/compose';
import { withDispatch, withSelect } from '@wordpress/data';
import classnames from 'classnames';
import PropTypes from 'prop-types';
import {
	useUserPreferences,
	NOTES_STORE_NAME,
	ONBOARDING_STORE_NAME,
	OPTIONS_STORE_NAME,
} from '@woocommerce/data';
import { __ } from '@wordpress/i18n';
import moment from 'moment';
import { useExperiment } from '@woocommerce/explat';

/**
 * Internal dependencies
 */
import ActivityHeader from '~/activity-panel/activity-header';
import { ActivityPanel } from './activity-panel';
import { Column } from './column';
import InboxPanel from '../inbox-panel';
import { IntroModal as NavigationIntroModal } from '../navigation/components/intro-modal';
import StatsOverview from './stats-overview';
import { StoreManagementLinks } from '../store-management-links';
import { TasksPlaceholder } from '../tasks';
import {
	WELCOME_MODAL_DISMISSED_OPTION_NAME,
	WELCOME_FROM_CALYPSO_MODAL_DISMISSED_OPTION_NAME,
} from './constants';
import { WelcomeFromCalypsoModal } from './welcome-from-calypso-modal';
import { WelcomeModal } from './welcome-modal';
import './style.scss';
import '../dashboard/style.scss';

const Tasks = lazy( () =>
	import( /* webpackChunkName: "tasks" */ '../tasks' )
);

const TwoColumnTasks = lazy( () =>
	import( /* webpackChunkName: "two-column-tasks" */ '../two-column-tasks' )
);

const TwoColumnTasksExtended = lazy( () =>
	import(
		/* webpackChunkName: "two-column-tasks-extended" */ '../two-column-tasks/extended-task'
	)
);

export const Layout = ( {
	defaultHomescreenLayout,
	isBatchUpdating,
	query,
	taskListComplete,
	hasTaskList,
	shouldShowWelcomeModal,
	shouldShowWelcomeFromCalypsoModal,
	isTaskListHidden,
	updateOptions,
} ) => {
	const userPrefs = useUserPreferences();
	const shouldShowStoreLinks = taskListComplete || isTaskListHidden;
	const hasTwoColumnContent =
		shouldShowStoreLinks || window.wcAdminFeatures.analytics;
	const [ showInbox, setShowInbox ] = useState( true );
	const isDashboardShown = ! query.task;

	const momentDate = moment().utc();

	const [
		isLoadingExperimentAssignment,
		experimentAssignment,
	] = useExperiment(
		'woocommerce_tasklist_progression_headercard_' +
			momentDate.format( 'YYYY' ) +
			'_' +
			momentDate.format( 'MM' )
	);

	const [
		isLoadingTwoColExperimentAssignment,
		twoColExperimentAssignment,
	] = useExperiment(
		'woocommerce_tasklist_progression_headercard_2col_' +
			momentDate.format( 'YYYY' ) +
			'_' +
			momentDate.format( 'MM' )
	);

	const isRunningTwoColumnExperiment =
		twoColExperimentAssignment?.variationName === 'treatment';

	// New TaskList UI is enabled when either experiment is treatment.
	const isRunningTaskListExperiment =
		experimentAssignment?.variationName === 'treatment' ||
		isRunningTwoColumnExperiment;

	// Override defaultHomescreenLayout if store is in the experiment.
	const defaultHomescreenLayoutOverride = () => {
		if (
			isLoadingExperimentAssignment ||
			isLoadingTwoColExperimentAssignment
		) {
			return defaultHomescreenLayout; // Experiments are still loading, don't override.
		}

		if ( ! isRunningTaskListExperiment ) {
			return defaultHomescreenLayout; // Not in the experiment, don't override.
		}

		return isRunningTwoColumnExperiment ? 'two_columns' : 'single_column';
	};

	const twoColumns =
		( userPrefs.homepage_layout || defaultHomescreenLayoutOverride() ) ===
			'two_columns' && hasTwoColumnContent;

	if ( isBatchUpdating && ! showInbox ) {
		setShowInbox( true );
	}

	const isWideViewport = useRef( true );
	const maybeToggleColumns = useCallback( () => {
		isWideViewport.current = window.innerWidth >= 782;
	}, [] );

	useLayoutEffect( () => {
		maybeToggleColumns();
		window.addEventListener( 'resize', maybeToggleColumns );

		return () => {
			window.removeEventListener( 'resize', maybeToggleColumns );
		};
	}, [ maybeToggleColumns ] );

	const shouldStickColumns = isWideViewport.current && twoColumns;

	const renderColumns = () => {
		return (
			<>
				<Column shouldStick={ shouldStickColumns }>
					{ ! isRunningTaskListExperiment && (
						<ActivityHeader
							className="your-store-today"
							title={ __(
								'Your store today',
								'woocommerce-admin'
							) }
							subtitle={ __(
								"To do's, tips, and insights for your business",
								'woocommerce-admin'
							) }
						/>
					) }
					{ <ActivityPanel /> }
					{ hasTaskList && renderTaskList() }
					<InboxPanel />
				</Column>
				<Column shouldStick={ shouldStickColumns }>
					{ window.wcAdminFeatures.analytics && <StatsOverview /> }
					{ shouldShowStoreLinks && <StoreManagementLinks /> }
				</Column>
			</>
		);
	};

	const renderTaskList = () => {
		if ( twoColumns && isRunningTaskListExperiment ) {
			return (
				// When running the two-column experiment, we still need to render
				// the component in the left column for the extended task list.
				<TwoColumnTasksExtended query={ query } />
			);
		} else if (
			! twoColumns &&
			isRunningTaskListExperiment &&
			! isLoadingExperimentAssignment
		) {
			return (
				<>
					<TwoColumnTasks
						query={ query }
						userPreferences={ userPrefs }
						twoColumns={ twoColumns }
					/>
					<TwoColumnTasksExtended query={ query } />
				</>
			);
		}

		return (
			<Suspense fallback={ <TasksPlaceholder query={ query } /> }>
				<Tasks query={ query } />
			</Suspense>
		);
	};

	return (
		<>
			{ twoColumns && isRunningTaskListExperiment && (
				<TwoColumnTasks
					query={ query }
					userPreferences={ userPrefs }
					twoColumns={ twoColumns }
				/>
			) }
			<div
				className={ classnames( 'woocommerce-homescreen', {
					'two-columns': twoColumns,
				} ) }
			>
				{ isDashboardShown ? renderColumns() : renderTaskList() }
				{ shouldShowWelcomeModal && (
					<WelcomeModal
						onClose={ () => {
							updateOptions( {
								[ WELCOME_MODAL_DISMISSED_OPTION_NAME ]: 'yes',
							} );
						} }
					/>
				) }
				{ shouldShowWelcomeFromCalypsoModal && (
					<WelcomeFromCalypsoModal
						onClose={ () => {
							updateOptions( {
								[ WELCOME_FROM_CALYPSO_MODAL_DISMISSED_OPTION_NAME ]:
									'yes',
							} );
						} }
					/>
				) }
				{ window.wcAdminFeatures.navigation && (
					<NavigationIntroModal />
				) }
			</div>
		</>
	);
};

Layout.propTypes = {
	/**
	 * If the task list has been completed.
	 */
	taskListComplete: PropTypes.bool,
	/**
	 * If any task list is visible.
	 */
	hasTaskList: PropTypes.bool,
	/**
	 * Page query, used to determine the current task if any.
	 */
	query: PropTypes.object.isRequired,
	/**
	 * If the welcome modal should display
	 */
	shouldShowWelcomeModal: PropTypes.bool,
	/**
	 * If the welcome from Calypso modal should display.
	 */
	shouldShowWelcomeFromCalypsoModal: PropTypes.bool,
	/**
	 * Dispatch an action to update an option
	 */
	updateOptions: PropTypes.func.isRequired,
};

export default compose(
	withSelect( ( select ) => {
		const { isNotesRequesting } = select( NOTES_STORE_NAME );
		const { getOption, hasFinishedResolution } = select(
			OPTIONS_STORE_NAME
		);
		const { getTaskList, getTaskLists } = select( ONBOARDING_STORE_NAME );
		const taskLists = getTaskLists();

		const welcomeFromCalypsoModalDismissed =
			getOption( WELCOME_FROM_CALYPSO_MODAL_DISMISSED_OPTION_NAME ) ===
			'yes';
		const welcomeFromCalypsoModalDismissedResolved = hasFinishedResolution(
			'getOption',
			[ WELCOME_FROM_CALYPSO_MODAL_DISMISSED_OPTION_NAME ]
		);
		const fromCalypsoUrlArgIsPresent = !! window.location.search.match(
			'from-calypso'
		);

		const shouldShowWelcomeFromCalypsoModal =
			welcomeFromCalypsoModalDismissedResolved &&
			! welcomeFromCalypsoModalDismissed &&
			fromCalypsoUrlArgIsPresent;

		const welcomeModalDismissed =
			getOption( WELCOME_MODAL_DISMISSED_OPTION_NAME ) === 'yes';

		const welcomeModalDismissedHasResolved = hasFinishedResolution(
			'getOption',
			[ WELCOME_MODAL_DISMISSED_OPTION_NAME ]
		);

		const shouldShowWelcomeModal =
			welcomeModalDismissedHasResolved &&
			! welcomeModalDismissed &&
			welcomeFromCalypsoModalDismissedResolved &&
			! welcomeFromCalypsoModalDismissed;

		const defaultHomescreenLayout =
			getOption( 'woocommerce_default_homepage_layout' ) ||
			'single_column';

		return {
			defaultHomescreenLayout,
			isBatchUpdating: isNotesRequesting( 'batchUpdateNotes' ),
			shouldShowWelcomeModal,
			shouldShowWelcomeFromCalypsoModal,
			isTaskListHidden: getTaskList( 'setup' )?.isHidden,
			hasTaskList: taskLists.find( ( list ) => list.isVisible ),
			taskListComplete: getTaskList( 'setup' )?.isComplete,
		};
	} ),
	withDispatch( ( dispatch ) => ( {
		updateOptions: dispatch( OPTIONS_STORE_NAME ).updateOptions,
	} ) )
)( Layout );