<?php
namespace Akram;

defined( 'ABSPATH' ) || exit;

/**
 * Social feeds (RSS/Atom, YouTube, Instagram) and Google reviews, fetched server-side and cached,
 * so visitors never contact third parties and pages stay fast.
 */
final class Feeds {

	const TTL = 3 * HOUR_IN_SECONDS;

	public static function init() {
		add_action( 'akram_refresh_instagram', array( __CLASS__, 'refresh_instagram_token' ) );
		if ( Options::get( 'instagram_token' ) && ! wp_next_scheduled( 'akram_refresh_instagram' ) ) {
			wp_schedule_event( time() + DAY_IN_SECONDS, 'weekly', 'akram_refresh_instagram' );
		}
	}

	/** @return array<int,array{title:string,url:string,date:int,image:string,text:string}>|\WP_Error */
	public static function items( $source, $value, $count ) {
		$count = max( 1, min( 24, (int) $count ) );
		// The Instagram token is part of the key so a new token shows its posts immediately.
		$key   = 'akram_feed_'
			. md5( $source . '|' . $value . '|' . $count . ( 'instagram' === $source ? '|' . Options::get( 'instagram_token', '' ) : '' ) );
		$hit   = get_transient( $key );
		if ( is_array( $hit ) ) {
			return isset( $hit['__err'] ) ? new \WP_Error( 'nx_feed', $hit['__err'] ) : $hit;
		}
		switch ( $source ) {
			case 'instagram':
				$items = self::instagram( $count );
				break;
			case 'youtube':
				$id = preg_replace( '/[^A-Za-z0-9_-]/', '', (string) $value );
				if ( ! $id ) {
					$items = new \WP_Error( 'nx_feed', __( 'Add a YouTube channel ID (it starts with UC).', 'akram' ) );
					break;
				}
				// YouTube's feed sometimes answers 404 or 500 for a moment, so a failed request is tried once more.
				$items = self::rss( 'https://www.youtube.com/feeds/videos.xml?channel_id=' . $id, $count );
				if ( is_wp_error( $items ) ) {
					$items = self::rss( 'https://www.youtube.com/feeds/videos.xml?channel_id=' . $id, $count );
				}
				break;
			default:
				$items = self::rss( esc_url_raw( (string) $value ), $count );
		}
		if ( is_wp_error( $items ) ) {
			// While a source is failing, the last good items (kept for a week) are shown instead.
			$last = get_transient( $key . '_ok' );
			if ( is_array( $last ) && $last ) {
				$items = $last;
			}
			// Failures are remembered for a few minutes so a broken source isn't retried on every page view.
			set_transient( $key, is_wp_error( $items ) ? array( '__err' => $items->get_error_message() ) : $items, 5 * MINUTE_IN_SECONDS );
			return $items;
		}
		set_transient( $key, $items, self::TTL );
		set_transient( $key . '_ok', $items, WEEK_IN_SECONDS );
		return $items;
	}

	private static function rss( $url, $count ) {
		if ( ! $url ) {
			return new \WP_Error( 'nx_feed', __( 'Add a feed URL.', 'akram' ) );
		}
		require_once ABSPATH . WPINC . '/feed.php';
		$feed = fetch_feed( $url );
		if ( is_wp_error( $feed ) ) {
			return $feed;
		}
		$out = array();
		foreach ( $feed->get_items( 0, $count ) as $item ) {
			$image = '';
			$enc   = $item->get_enclosure();
			if ( $enc ) {
				$image = (string) ( $enc->get_thumbnail() ?: ( 0 === strpos( (string) $enc->get_type(), 'image' ) ? $enc->get_link() : '' ) );
			}
			if ( ! $image ) {
				$media = $item->get_item_tags( 'http://search.yahoo.com/mrss/', 'group' );
				if ( ! empty( $media[0]['child']['http://search.yahoo.com/mrss/']['thumbnail'][0]['attribs']['']['url'] ) ) {
					$image = $media[0]['child']['http://search.yahoo.com/mrss/']['thumbnail'][0]['attribs']['']['url'];
				}
			}
			if ( ! $image && preg_match( '/<img[^>]+src=["\']([^"\']+)/i', (string) $item->get_content(), $m ) ) {
				$image = $m[1];
			}
			$out[] = array(
				'title' => wp_strip_all_tags( (string) $item->get_title() ),
				'url'   => esc_url_raw( (string) $item->get_permalink() ),
				'date'  => (int) $item->get_date( 'U' ),
				'image' => esc_url_raw( $image ),
				'text'  => wp_trim_words( wp_strip_all_tags( (string) $item->get_description() ), 28 ),
			);
		}
		return $out;
	}

	private static function instagram( $count ) {
		$token = (string) Options::get( 'instagram_token', '' );
		if ( ! $token ) {
			return new \WP_Error( 'nx_feed', __( 'Add an Instagram access token in Akram → Settings → Integrations.', 'akram' ) );
		}
		$res = wp_remote_get( add_query_arg( array(
			'fields'       => 'id,caption,media_type,media_url,thumbnail_url,permalink,timestamp',
			'limit'        => $count,
			'access_token' => $token,
		), 'https://graph.instagram.com/me/media' ), array( 'timeout' => 10 ) );
		if ( is_wp_error( $res ) ) {
			return $res;
		}
		$body = json_decode( wp_remote_retrieve_body( $res ), true );
		if ( empty( $body['data'] ) ) {
			return new \WP_Error( 'nx_feed', ! empty( $body['error']['message'] ) ? (string) $body['error']['message'] : __( 'Instagram returned no posts.', 'akram' ) );
		}
		$out = array();
		foreach ( $body['data'] as $p ) {
			$out[] = array(
				'title' => '',
				'url'   => esc_url_raw( (string) ( $p['permalink'] ?? '' ) ),
				'date'  => strtotime( (string) ( $p['timestamp'] ?? '' ) ) ?: 0,
				'image' => esc_url_raw( (string) ( 'VIDEO' === ( $p['media_type'] ?? '' ) ? ( $p['thumbnail_url'] ?? '' ) : ( $p['media_url'] ?? '' ) ) ),
				'text'  => wp_trim_words( (string) ( $p['caption'] ?? '' ), 20 ),
			);
		}
		return $out;
	}

	/** Long-lived Instagram tokens last 60 days; refresh weekly. */
	public static function refresh_instagram_token() {
		$token = (string) Options::get( 'instagram_token', '' );
		if ( ! $token ) {
			return;
		}
		$res  = wp_remote_get( add_query_arg( array(
			'grant_type'   => 'ig_refresh_token',
			'access_token' => $token,
		), 'https://graph.instagram.com/refresh_access_token' ), array( 'timeout' => 10 ) );
		$body = is_wp_error( $res ) ? array() : json_decode( wp_remote_retrieve_body( $res ), true );
		if ( ! empty( $body['access_token'] ) ) {
			Options::update( array( 'instagram_token' => (string) $body['access_token'] ) );
		}
	}

	/** Google Places (New) reviews: { rating, total, url, reviews: [{ author, photo, rating, text, time }] } */
	public static function google_reviews( $place_id ) {
		$place_id = preg_replace( '/[^A-Za-z0-9_-]/', '', (string) $place_id );
		$api_key  = (string) Options::get( 'google_places_key', '' );
		if ( ! $place_id || ! $api_key ) {
			return new \WP_Error( 'nx_reviews', __( 'Add a Google Places API key (Settings → Integrations) and a Place ID.', 'akram' ) );
		}
		$key = 'akram_greviews_' . md5( $place_id . determine_locale() . $api_key );
		$hit = get_transient( $key );
		if ( is_array( $hit ) ) {
			return isset( $hit['__err'] ) ? new \WP_Error( 'nx_reviews', $hit['__err'] ) : $hit;
		}
		$res = wp_remote_get(
			'https://places.googleapis.com/v1/places/' . rawurlencode( $place_id ) . '?languageCode=' . rawurlencode( substr( determine_locale(), 0, 2 ) ),
			array(
				'timeout' => 10,
				'headers' => array(
					'X-Goog-Api-Key'   => $api_key,
					'X-Goog-FieldMask' => 'displayName,rating,userRatingCount,googleMapsUri,reviews',
				),
			)
		);
		if ( is_wp_error( $res ) ) {
			set_transient( $key, array( '__err' => $res->get_error_message() ), 5 * MINUTE_IN_SECONDS );
			return $res;
		}
		$b = json_decode( wp_remote_retrieve_body( $res ), true );
		if ( ! is_array( $b ) || isset( $b['error'] ) ) {
			$msg = (string) ( $b['error']['message'] ?? __( 'Google returned an error.', 'akram' ) );
			set_transient( $key, array( '__err' => $msg ), 5 * MINUTE_IN_SECONDS );
			return new \WP_Error( 'nx_reviews', $msg );
		}
		$out = array(
			'name'    => (string) ( $b['displayName']['text'] ?? '' ),
			'rating'  => (float) ( $b['rating'] ?? 0 ),
			'total'   => (int) ( $b['userRatingCount'] ?? 0 ),
			'url'     => esc_url_raw( (string) ( $b['googleMapsUri'] ?? '' ) ),
			'reviews' => array(),
		);
		foreach ( (array) ( $b['reviews'] ?? array() ) as $r ) {
			$out['reviews'][] = array(
				'author' => (string) ( $r['authorAttribution']['displayName'] ?? '' ),
				'photo'  => esc_url_raw( (string) ( $r['authorAttribution']['photoUri'] ?? '' ) ),
				'rating' => (int) ( $r['rating'] ?? 0 ),
				'text'   => (string) ( $r['text']['text'] ?? ( $r['originalText']['text'] ?? '' ) ),
				'time'   => (string) ( $r['relativePublishTimeDescription'] ?? '' ),
			);
		}
		set_transient( $key, $out, 12 * HOUR_IN_SECONDS );
		return $out;
	}
}