/**
 * External dependencies
 */
import { has } from 'lodash';
import { decodeHtmlEntities, isUrl } from '@nelio-content/utils';
import type { AnyAction, ImageId, Url } from '@nelio-content/types';

/**
 * Internal dependencies
 */
import { INIT_STATE } from '../config';
import type { State as FullState } from '../types';
import type { PostAction as Action } from '../actions/post';

type State = FullState[ 'post' ];

export function post( state = INIT_STATE.post, action: AnyAction ): State {
	return actualReducer( state, action as Action ) ?? state;
}

function actualReducer( state: State, action: Action ): State {
	switch ( action.type ) {
		case 'SET_POST_ID':
			return state.id ? state : { ...state, id: state.id };

		case 'SET_POST': {
			const { imageSrc, ...p } = action.post;
			return {
				...INIT_STATE.post,
				...p,
				imageSrc: imageSrc || false,
				...extractImages( p?.content ),
				automationSources: {
					...INIT_STATE.post.automationSources,
					...p?.automationSources,
				},
			};
		}

		case 'SET_QUERY_ARGS':
			return {
				...state,
				permalinkQueryArgs: action.args,
			};

		case 'SET_CUSTOM_FIELD':
			return {
				...state,
				customFields: has( state.customFields, action.key )
					? {
							...state.customFields,
							[ action.key ]: {
								...state.customFields[ action.key ],
								value: action.value,
							},
					  }
					: state.customFields,
			};

		case 'REMOVE_CUSTOM_FIELD':
			return {
				...state,
				customFields: has( state.customFields, action.key )
					? {
							...state.customFields,
							[ action.key ]: {
								...state.customFields[ action.key ],
								value: '',
							},
					  }
					: state.customFields,
			};

		case 'SET_TITLE':
			return {
				...state,
				title: action.title,
			};

		case 'SET_EXCERPT':
			return {
				...state,
				excerpt: action.excerpt,
			};

		case 'SET_CONTENT':
			return {
				...state,
				content: action.content,
				...extractImages( action.content ),
			};

		case 'SET_DATE':
			return {
				...state,
				date: action.date ?? false,
			};

		case 'SET_AUTHOR':
			return {
				...state,
				author: action.authorId,
				authorName: action.authorName,
			};

		case 'SET_PERMALINK':
			return {
				...state,
				permalink: action.permalink,
			};

		case 'SET_FEATURED_IMAGE':
			return {
				...state,
				imageId: action.imageId,
				imageSrc: action.imageSrc,
				thumbnailSrc: action.thumbnailSrc,
				imageAltText: action.imageAltText ?? '',
			};

		case 'REMOVE_FEATURED_IMAGE':
			return {
				...state,
				imageId: 0,
				imageSrc: false,
				thumbnailSrc: false,
			};

		case 'SET_FOLLOWERS':
			return {
				...state,
				followers: action.followers,
			};

		case 'SET_STATUS':
			return {
				...state,
				status: action.status,
			};

		case 'SET_TERMS':
			return {
				...state,
				taxonomies: {
					...state.taxonomies,
					[ action.taxonomy ]: action.terms,
				},
			};

		case 'ENABLE_AUTO_SHARE':
			return {
				...state,
				isAutoShareEnabled: action.isAutoShareEnabled,
			};

		case 'SET_AUTO_SHARE_END_MODE':
			return {
				...state,
				autoShareEndMode: action.autoShareEndMode,
			};

		case 'SET_AUTOMATION_SOURCES':
			return {
				...state,
				automationSources: {
					...state.automationSources,
					...action.sources,
				},
			};

		case 'SET_NETWORK_IMAGE':
			return {
				...state,
				networkImages: {
					...state.networkImages,
					[ action.network ]: action.imageUrl,
				},
				networkImageIds: {
					...state.networkImageIds,
					[ action.network ]: action.imageId,
				},
				networkImageAltTexts: {
					...state.networkImageAltTexts,
					[ action.network ]: action.imageAltText,
				},
			};

		case 'SET_SERIES':
			return {
				...state,
				series: action.series,
			};

		case 'MARK_AS_LOADING_POST_ITEMS':
			return state;
	}
}

// =======
// HELPERS
// =======

function extractImages( content = '' ): {
	images: Url[];
	imageIds: ImageId[];
	imageAltTexts: string[];
} {
	const imgTags = content.match( /<img[^>]*>/gi ) || [];

	const images: Url[] = [];
	const imageIds: ImageId[] = [];
	const imageAltTexts: string[] = [];

	imgTags.forEach( ( tag ) => {
		// Extract URL from src or data-src
		const srcMatch = tag.match( /(?:src|data-src)=["']([^"']+)["']/i );
		const imageUrl =
			srcMatch && isUrl( srcMatch[ 1 ] ) ? srcMatch[ 1 ] : null;

		if ( imageUrl && ! images.includes( imageUrl ) ) {
			images.push( imageUrl );

			// Extract image ID from wp-image-XXXXX class.
			const idMatch = tag.match( /wp-image-(\d+)/ );
			imageIds.push(
				idMatch
					? ( parseInt( idMatch[ 1 ] ?? '0', 10 ) as ImageId )
					: ( 0 as ImageId )
			);

			// Extract alt text.
			const altMatch = tag.match( /alt=["']([^"']*)["']/i );
			imageAltTexts.push(
				altMatch ? decodeHtmlEntities( altMatch[ 1 ] ?? '' ) : ''
			);
		}
	} );

	return {
		images,
		imageIds,
		imageAltTexts,
	};
}