import config from '@automattic/calypso-config';
import { translate } from 'i18n-calypso';
import { get, startsWith, pickBy, map } from 'lodash';
import { decodeEntities } from 'calypso/lib/formatting';
import {
	COMMENTS_REQUEST,
	COMMENTS_RECEIVE,
	COMMENTS_UPDATES_RECEIVE,
	COMMENTS_COUNT_RECEIVE,
	COMMENTS_DELETE,
	COMMENTS_EMPTY,
	COMMENTS_EMPTY_SUCCESS,
} from 'calypso/state/action-types';
import { requestCommentsList } from 'calypso/state/comments/actions';
import {
	getPostOldestCommentDate,
	getPostNewestCommentDate,
	getPostCommentsCountAtDate,
	getSiteComment,
} from 'calypso/state/comments/selectors';
import { registerHandlers } from 'calypso/state/data-layer/handler-registry';
import { http } from 'calypso/state/data-layer/wpcom-http/actions';
import { dispatchRequest } from 'calypso/state/data-layer/wpcom-http/utils';
import { errorNotice, infoNotice, successNotice } from 'calypso/state/notices/actions';
import { DEFAULT_NOTICE_DURATION } from 'calypso/state/notices/constants';
import { getSitePost } from 'calypso/state/posts/selectors';

const isDate = ( date ) => date instanceof Date && ! isNaN( date );

export const commentsFromApi = ( comments ) =>
	map( comments, ( comment ) =>
		comment.author
			? {
					...comment,
					author: {
						...comment.author,
						name: decodeEntities( get( comment, [ 'author', 'name' ] ) ),
					},
			  }
			: comment
	);

// @see https://developer.wordpress.com/docs/api/1.1/get/sites/%24site/posts/%24post_ID/replies/
export const fetchPostComments = ( action ) => ( dispatch, getState ) => {
	const { siteId, postId, query, direction, isPoll } = action;
	const state = getState();
	const oldestDate = getPostOldestCommentDate( state, siteId, postId );
	const newestDate = getPostNewestCommentDate( state, siteId, postId );

	// If we're polling for new comments, we query using after= which returns all comments *on or after* the provided date.
	// To offset by the right number, we count the number of comments we already know about on the same second.
	const offset = isPoll ? getPostCommentsCountAtDate( state, siteId, postId, newestDate ) : 0;

	const before =
		direction === 'before' &&
		isDate( oldestDate ) &&
		oldestDate.toISOString &&
		oldestDate.toISOString();

	const after =
		direction === 'after' &&
		isDate( newestDate ) &&
		newestDate.toISOString &&
		newestDate.toISOString();

	dispatch(
		http(
			{
				method: 'GET',
				path: `/sites/${ siteId }/posts/${ postId }/replies`,
				apiVersion: '1.1',
				query: pickBy( {
					...query,
					after,
					before,
					offset,
				} ),
			},
			action
		)
	);
};

export const addComments = ( action, { comments, found } ) => {
	const { siteId, postId, direction, isPoll } = action;

	const type = isPoll ? COMMENTS_UPDATES_RECEIVE : COMMENTS_RECEIVE;
	const receiveAction = {
		type,
		siteId,
		postId,
		comments: commentsFromApi( comments ),
		direction,
	};

	// if the api have returned comments count, dispatch it
	// the api will produce a count only when the request has no
	// query modifiers such as 'before', 'after', 'type' and more.
	// in our case it'll be only on the first request
	if ( found > -1 ) {
		return [
			receiveAction,
			{
				type: COMMENTS_COUNT_RECEIVE,
				siteId,
				postId,
				totalCommentsCount: found,
			},
		];
	}

	return receiveAction;
};

export const announceFailure =
	( { siteId, postId } ) =>
	( dispatch, getState ) => {
		const post = getSitePost( getState(), siteId, postId );
		const postTitle = post && post.title && post.title.trim().slice( 0, 20 ).trim().concat( '…' );
		const error = postTitle
			? translate( 'Could not retrieve comments for “%(postTitle)s”', { args: { postTitle } } )
			: translate( 'Could not retrieve comments for post' );

		const environment = config( 'env_id' );
		if ( environment === 'development' ) {
			dispatch( errorNotice( error, { duration: 5000 } ) );
		}
	};

// @see https://developer.wordpress.com/docs/api/1.1/post/sites/%24site/comments/%24comment_ID/delete/
export const deleteComment = ( action ) => ( dispatch, getState ) => {
	const { siteId, commentId } = action;

	if ( startsWith( commentId, 'placeholder' ) ) {
		return;
	}

	const comment = getSiteComment( getState(), siteId, commentId );

	dispatch(
		http(
			{
				method: 'POST',
				apiVersion: '1.1',
				path: `/sites/${ siteId }/comments/${ commentId }/delete`,
			},
			{
				...action,
				comment,
			}
		)
	);
};

export const handleDeleteSuccess = ( { options, refreshCommentListQuery } ) => {
	const showSuccessNotice = get( options, 'showSuccessNotice', false );

	return [
		showSuccessNotice &&
			successNotice( translate( 'Comment deleted permanently.' ), {
				duration: 5000,
				id: 'comment-notice',
				isPersistent: true,
			} ),
		!! refreshCommentListQuery && requestCommentsList( refreshCommentListQuery ),
	].filter( Boolean );
};

export const announceDeleteFailure = ( action ) => {
	const { siteId, postId, comment } = action;

	const error = errorNotice( translate( 'Could not delete the comment.' ), {
		duration: 5000,
		isPersistent: true,
	} );

	if ( ! comment ) {
		return error;
	}

	return [
		error,
		{
			type: COMMENTS_RECEIVE,
			siteId,
			postId,
			comments: [ comment ],
			skipSort: !! get( comment, 'parent.ID' ),
			meta: {
				comment: {
					context: 'add', //adds a hint for the counts reducer.
				},
			},
		},
	];
};

const emptyNoticeOptions = {
	duration: DEFAULT_NOTICE_DURATION,
	id: 'comment-notice',
	isPersistent: true,
};

export const emptyComments = ( action ) => ( dispatch ) => {
	const { siteId, status } = action;

	dispatch(
		infoNotice(
			status === 'spam'
				? translate( 'Spam emptying in progress.' )
				: translate( 'Trash emptying in progress.' ),
			emptyNoticeOptions
		)
	);

	dispatch(
		http(
			{
				apiVersion: '1',
				body: {
					empty_status: status,
				},
				method: 'POST',
				path: `/sites/${ siteId }/comments/delete`,
			},
			action
		)
	);
};

export const handleEmptySuccess = (
	{ status, siteId, options, refreshCommentListQuery },
	apiResponse
) => {
	const showSuccessNotice = options?.showSuccessNotice;

	return [
		showSuccessNotice &&
			successNotice(
				status === 'spam' ? translate( 'Spam emptied.' ) : translate( 'Trash emptied.' ),
				emptyNoticeOptions
			),
		!! refreshCommentListQuery && requestCommentsList( refreshCommentListQuery ),
		{
			type: COMMENTS_EMPTY_SUCCESS,
			siteId,
			status,
			commentIds: apiResponse.results.map( ( x ) => +x ), // convert to number
		},
	];
};

export const announceEmptyFailure = ( action ) => {
	const { status } = action;

	const error = errorNotice(
		status === 'spam'
			? translate( 'Could not empty spam.' )
			: translate( 'Could not empty trash.' ),
		emptyNoticeOptions
	);

	return error;
};

registerHandlers( 'state/data-layer/wpcom/comments/index.js', {
	[ COMMENTS_REQUEST ]: [
		dispatchRequest( {
			fetch: fetchPostComments,
			onSuccess: addComments,
			onError: announceFailure,
		} ),
	],

	[ COMMENTS_DELETE ]: [
		dispatchRequest( {
			fetch: deleteComment,
			onSuccess: handleDeleteSuccess,
			onError: announceDeleteFailure,
		} ),
	],

	[ COMMENTS_EMPTY ]: [
		dispatchRequest( {
			fetch: emptyComments,
			onSuccess: handleEmptySuccess,
			onError: announceEmptyFailure,
		} ),
	],
} );