<?php
/**
 * Native menu: fetch, cache and normalize the public Bayle menu feed.
 *
 * Source: GET {menu base}/api/{slug}/menu?lang=fi|sv|en on menu.bayle.food,
 * the same public, key-less JSON the Bayle menu page uses. No API keys, no
 * writes: WordPress only reads.
 *
 * @package Bayle_Menu_Widget
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Fresh-copy lifetime in seconds (default 10 minutes).
 *
 * @return int
 */
function bayle_menu_widget_menu_cache_ttl(): int {
	/**
	 * Filters how long a fetched menu is reused before Bayle is asked again.
	 *
	 * @param int $ttl Seconds. Default 600.
	 */
	return max( 60, (int) apply_filters( 'bayle_menu_widget_menu_cache_ttl', 10 * MINUTE_IN_SECONDS ) );
}

/**
 * Whether a slug has the shape Bayle accepts (lowercase, digits, hyphens).
 *
 * @param string $slug Slug.
 * @return bool
 */
function bayle_menu_widget_is_valid_slug( string $slug ): bool {
	return (bool) preg_match( '/^[a-z0-9](?:[a-z0-9-]{0,78}[a-z0-9])?$/', $slug );
}

/**
 * Cache key for a slug + language (+ base URL and cache generation).
 *
 * @param string $kind  fresh|good|fail.
 * @param string $slug  Slug.
 * @param string $lang  fi|sv|en.
 * @param string $base  Menu base URL.
 * @return string
 */
function bayle_menu_widget_menu_cache_key( string $kind, string $slug, string $lang, string $base ): string {
	$gen = (int) get_option( 'bayle_menu_widget_menu_cache_gen', 0 );
	return 'bayle_menu_widget_' . $kind . '_' . md5( $base . '|' . $slug . '|' . $lang . '|' . $gen );
}

/**
 * Forget cached menus (new slug or base URL, or "Refresh menu now").
 */
function bayle_menu_widget_menu_flush_cache(): void {
	update_option( 'bayle_menu_widget_menu_cache_gen', (int) get_option( 'bayle_menu_widget_menu_cache_gen', 0 ) + 1, false );
}

/**
 * Get the menu for a restaurant.
 *
 * Fresh copy for 10 minutes; when Bayle cannot be reached the last good copy
 * (kept 7 days) is shown and flagged as stale, so the page never breaks.
 * Failures are remembered for a minute so a Bayle outage does not slow every
 * page view down.
 *
 * @param string $slug Restaurant slug.
 * @param string $lang fi|sv|en.
 * @return array{status:string,data:?array,stale:bool} status ok|unavailable|error.
 */
function bayle_menu_widget_get_menu( string $slug, string $lang ): array {
	$slug = strtolower( trim( $slug ) );
	$lang = in_array( $lang, bayle_menu_widget_allowed_langs(), true ) ? $lang : 'en';
	if ( ! bayle_menu_widget_is_valid_slug( $slug ) ) {
		return array(
			'status' => 'unavailable',
			'data'   => null,
			'stale'  => false,
		);
	}

	$base      = bayle_menu_widget_resolve_base_url();
	$fresh_key = bayle_menu_widget_menu_cache_key( 'fresh', $slug, $lang, $base );
	$good_key  = bayle_menu_widget_menu_cache_key( 'good', $slug, $lang, $base );
	$fail_key  = bayle_menu_widget_menu_cache_key( 'fail', $slug, $lang, $base );

	$fresh = get_transient( $fresh_key );
	if ( is_array( $fresh ) && isset( $fresh['status'] ) ) {
		return bayle_menu_widget_menu_result( $fresh['status'], $fresh['data'] ?? null, false );
	}

	$failed = get_transient( $fail_key );
	if ( false === $failed ) {
		$fetched = bayle_menu_widget_fetch_menu( $base, $slug, $lang );
		if ( 'ok' === $fetched['status'] || 'unavailable' === $fetched['status'] ) {
			set_transient( $fresh_key, $fetched, bayle_menu_widget_menu_cache_ttl() );
			if ( 'ok' === $fetched['status'] ) {
				set_transient( $good_key, $fetched['data'], 7 * DAY_IN_SECONDS );
			} else {
				delete_transient( $good_key );
			}
			return bayle_menu_widget_menu_result( $fetched['status'], $fetched['data'], false );
		}
		set_transient( $fail_key, 1, MINUTE_IN_SECONDS );
	}

	$good = get_transient( $good_key );
	if ( is_array( $good ) ) {
		return bayle_menu_widget_menu_result( 'ok', $good, true );
	}
	return bayle_menu_widget_menu_result( 'error', null, false );
}

/**
 * Build a result and run the data filter.
 *
 * @param string     $status ok|unavailable|error.
 * @param array|null $data   Normalized menu.
 * @param bool       $stale  Served from the last good copy.
 * @return array{status:string,data:?array,stale:bool}
 */
function bayle_menu_widget_menu_result( string $status, $data, bool $stale ): array {
	$data = is_array( $data ) ? $data : null;
	if ( null !== $data ) {
		/**
		 * Filters the normalized menu before it is rendered.
		 *
		 * Values are already sanitized; anything a filter adds is escaped
		 * again on output.
		 *
		 * @param array $data Normalized menu.
		 */
		$data = apply_filters( 'bayle_menu_widget_menu_data', $data );
		$data = is_array( $data ) ? $data : null;
	}
	return array(
		'status' => null === $data && 'ok' === $status ? 'error' : $status,
		'data'   => $data,
		'stale'  => $stale,
	);
}

/**
 * One GET to Bayle.
 *
 * @param string $base Menu base URL (https://*.bayle.food).
 * @param string $slug Slug.
 * @param string $lang Language.
 * @return array{status:string,data:?array}
 */
function bayle_menu_widget_fetch_menu( string $base, string $slug, string $lang ): array {
	$url      = rtrim( $base, '/' ) . '/api/' . rawurlencode( $slug ) . '/menu?lang=' . rawurlencode( $lang );
	$response = wp_safe_remote_get(
		$url,
		array(
			'timeout'     => 5,
			'redirection' => 0,
			'headers'     => array( 'Accept' => 'application/json' ),
			'user-agent'  => 'BayleMenuWidgetWP/' . BAYLE_MENU_WIDGET_VERSION . '; ' . home_url( '/' ),
		)
	);
	if ( is_wp_error( $response ) ) {
		return array(
			'status' => 'error',
			'data'   => null,
		);
	}
	$code = (int) wp_remote_retrieve_response_code( $response );
	if ( 404 === $code ) {
		// Unknown slug or the menu module is off in Bayle.
		return array(
			'status' => 'unavailable',
			'data'   => null,
		);
	}
	if ( 200 !== $code ) {
		return array(
			'status' => 'error',
			'data'   => null,
		);
	}
	$body = json_decode( (string) wp_remote_retrieve_body( $response ), true );
	if ( ! is_array( $body ) || ! isset( $body['data'] ) || ! is_array( $body['data'] ) ) {
		return array(
			'status' => 'error',
			'data'   => null,
		);
	}
	if ( empty( $body['data']['enabled'] ) ) {
		return array(
			'status' => 'unavailable',
			'data'   => null,
		);
	}
	return array(
		'status' => 'ok',
		'data'   => bayle_menu_widget_normalize_menu( $body['data'], $slug ),
	);
}

/**
 * Plain text from a feed value.
 *
 * @param mixed $value Value.
 * @param int   $max   Max length.
 * @return string
 */
function bayle_menu_widget_feed_text( $value, int $max = 500 ): string {
	if ( ! is_scalar( $value ) ) {
		return '';
	}
	$text = trim( sanitize_text_field( (string) $value ) );
	return function_exists( 'mb_substr' ) ? mb_substr( $text, 0, $max ) : substr( $text, 0, $max );
}

/**
 * Multi-line text (descriptions).
 *
 * @param mixed $value Value.
 * @return string
 */
function bayle_menu_widget_feed_textarea( $value ): string {
	if ( ! is_scalar( $value ) ) {
		return '';
	}
	$text = trim( sanitize_textarea_field( (string) $value ) );
	return function_exists( 'mb_substr' ) ? mb_substr( $text, 0, 1000 ) : substr( $text, 0, 1000 );
}

/**
 * Integer cents or null.
 *
 * @param mixed $value Value.
 * @return int|null
 */
function bayle_menu_widget_feed_cents( $value ) {
	if ( null === $value || '' === $value || ! is_numeric( $value ) ) {
		return null;
	}
	$cents = (int) round( (float) $value );
	return ( $cents >= 0 && $cents < 100000000 ) ? $cents : null;
}

/**
 * Absolute https URL or ''.
 *
 * @param mixed $value Value.
 * @return string
 */
function bayle_menu_widget_feed_https_url( $value ): string {
	if ( ! is_string( $value ) || '' === trim( $value ) ) {
		return '';
	}
	$url   = esc_url_raw( trim( $value ), array( 'https' ) );
	$parts = wp_parse_url( $url );
	if ( ! is_array( $parts ) || 'https' !== strtolower( (string) ( $parts['scheme'] ?? '' ) ) || empty( $parts['host'] ) || isset( $parts['user'] ) || isset( $parts['pass'] ) ) {
		return '';
	}
	return $url;
}

/**
 * Opaque order reference (letters, digits, - _ . :) or ''.
 *
 * @param mixed $value Value.
 * @return string
 */
function bayle_menu_widget_feed_ref( $value ): string {
	if ( ! is_string( $value ) ) {
		return '';
	}
	$value = trim( $value );
	return preg_match( '/^[A-Za-z0-9._:-]{1,128}$/', $value ) ? $value : '';
}

/**
 * Normalize one dish.
 *
 * @param mixed $raw Item.
 * @return array|null
 */
function bayle_menu_widget_normalize_item( $raw ) {
	if ( ! is_array( $raw ) ) {
		return null;
	}
	$name = bayle_menu_widget_feed_text( $raw['name'] ?? '', 200 );
	if ( '' === $name ) {
		return null;
	}
	$price   = bayle_menu_widget_feed_cents( $raw['priceCents'] ?? null );
	$compare = bayle_menu_widget_feed_cents( $raw['compareAtCents'] ?? null );
	$item    = array(
		'name'        => $name,
		'description' => bayle_menu_widget_feed_textarea( $raw['description'] ?? '' ),
		'price'       => $price,
		'compareAt'   => ( null !== $compare && null !== $price && $compare > $price ) ? $compare : null,
		'sizes'       => array(),
		'addons'      => array(),
		'diets'       => array(),
		'image'       => bayle_menu_widget_feed_https_url( $raw['imageUrl'] ?? '' ),
		'category'    => bayle_menu_widget_feed_text( $raw['category'] ?? '', 40 ),
		// Ordering (only when Bayle sends it): an opaque reference the Bayle
		// checkout resolves, and whether the dish can be ordered right now.
		'orderRef'    => bayle_menu_widget_feed_ref( $raw['orderRef'] ?? '' ),
		'soldOut'     => ! empty( $raw['soldOut'] ) || ( isset( $raw['orderable'] ) && false === $raw['orderable'] ),
	);
	foreach ( array_slice( is_array( $raw['sizes'] ?? null ) ? $raw['sizes'] : array(), 0, 12 ) as $size ) {
		if ( ! is_array( $size ) ) {
			continue;
		}
		$label = bayle_menu_widget_feed_text( $size['label'] ?? '', 80 );
		if ( '' !== $label ) {
			$item['sizes'][] = array(
				'label'    => $label,
				'price'    => bayle_menu_widget_feed_cents( $size['priceCents'] ?? null ),
				'orderRef' => bayle_menu_widget_feed_ref( $size['orderRef'] ?? '' ),
			);
		}
	}
	$item['addons'] = bayle_menu_widget_normalize_addons( $raw['addons'] ?? null );
	foreach ( array_slice( is_array( $raw['dietaries'] ?? null ) ? $raw['dietaries'] : array(), 0, 20 ) as $diet ) {
		if ( ! is_array( $diet ) ) {
			continue;
		}
		$code = bayle_menu_widget_feed_text( $diet['code'] ?? '', 12 );
		if ( '' !== $code ) {
			$label           = bayle_menu_widget_feed_text( $diet['label'] ?? '', 80 );
			$item['diets'][] = array(
				'code'  => $code,
				'label' => '' !== $label ? $label : $code,
			);
		}
	}
	return $item;
}

/**
 * Normalize a dish's extras (add-on groups). Bayle sends them only for dishes
 * that can be ordered: a group label, how many options the guest must / may
 * pick (min, max) and the options with their opaque ref and the price each
 * adds to the dish. Bayle prices the order again at checkout.
 *
 * @param mixed $raw Feed "addons".
 * @return array<int,array{label:string,min:int,max:int,options:array<int,array{label:string,price:int,ref:string}>}>
 */
function bayle_menu_widget_normalize_addons( $raw ): array {
	$groups = array();
	foreach ( array_slice( is_array( $raw ) ? $raw : array(), 0, 10 ) as $group ) {
		if ( ! is_array( $group ) ) {
			continue;
		}
		$options = array();
		foreach ( array_slice( is_array( $group['options'] ?? null ) ? $group['options'] : array(), 0, 30 ) as $option ) {
			if ( ! is_array( $option ) ) {
				continue;
			}
			$label = bayle_menu_widget_feed_text( $option['label'] ?? '', 80 );
			$ref   = bayle_menu_widget_feed_ref( $option['ref'] ?? '' );
			if ( '' !== $label && '' !== $ref ) {
				$price     = bayle_menu_widget_feed_cents( $option['priceCents'] ?? 0 );
				$options[] = array(
					'label' => $label,
					'price' => null === $price ? 0 : $price,
					'ref'   => $ref,
				);
			}
		}
		if ( ! $options ) {
			continue;
		}
		$count = count( $options );
		$min   = max( 0, (int) ( $group['min'] ?? 0 ) );
		if ( ! empty( $group['required'] ) ) {
			$min = max( 1, $min );
		}
		$max = isset( $group['max'] ) && is_numeric( $group['max'] ) ? (int) $group['max'] : $count;
		$max = max( 1, min( $count, $max ) );
		if ( $min > $max ) {
			continue; // Bayle would refuse any choice; leave the group out.
		}
		$groups[] = array(
			'label'   => bayle_menu_widget_feed_text( $group['label'] ?? '', 80 ),
			'min'     => $min,
			'max'     => $max,
			'options' => $options,
		);
	}
	return $groups;
}

/**
 * HH:MM or ''.
 *
 * @param mixed $value Value.
 * @return string
 */
function bayle_menu_widget_feed_clock( $value ): string {
	return ( is_string( $value ) && preg_match( '/^([01]\d|2[0-3]):[0-5]\d$/', trim( $value ) ) ) ? trim( $value ) : '';
}

/**
 * Normalize the feed into the shape the renderer uses.
 *
 * @param array  $raw  Feed "data".
 * @param string $slug Requested slug.
 * @return array
 */
function bayle_menu_widget_normalize_menu( array $raw, string $slug ): array {
	$menu     = is_array( $raw['menu'] ?? null ) ? $raw['menu'] : array();
	$currency = strtoupper( bayle_menu_widget_feed_text( $raw['currency'] ?? 'EUR', 3 ) );
	$timezone = bayle_menu_widget_feed_text( $raw['timezone'] ?? '', 64 );
	$hours    = is_array( $raw['hours'] ?? null ) ? $raw['hours'] : null;
	// Online-ordering hours (can differ from opening hours); null when Bayle does not send them.
	$o_hours  = is_array( $raw['orderHours'] ?? null ) ? $raw['orderHours'] : null;
	$links    = is_array( $raw['links'] ?? null ) ? $raw['links'] : array();

	$out = array(
		'slug'       => $slug,
		'name'       => bayle_menu_widget_feed_text( $raw['name'] ?? '', 200 ),
		'address'    => bayle_menu_widget_feed_text( $raw['address'] ?? '', 300 ),
		'currency'   => preg_match( '/^[A-Z]{3}$/', $currency ) ? $currency : 'EUR',
		'timezone'   => in_array( $timezone, timezone_identifiers_list(), true ) ? $timezone : 'Europe/Helsinki',
		'hourCycle'  => 'h12' === ( $raw['hourCycle'] ?? '' ) ? 'h12' : 'h23',
		'updatedAt'  => bayle_menu_widget_feed_text( $raw['updatedAt'] ?? '', 40 ),
		'openNow'    => null === $hours ? null : ! empty( $hours['openNow'] ),
		'nextChange' => null === $hours ? '' : bayle_menu_widget_feed_text( $hours['nextChangeAt'] ?? '', 40 ),
		'orderOpen'  => null === $o_hours ? null : ! empty( $o_hours['openNow'] ),
		'orderNext'  => null === $o_hours ? '' : bayle_menu_widget_feed_text( $o_hours['nextChangeAt'] ?? '', 40 ),
		// Bayle sends links.order only when online ordering is on for the
		// restaurant: it is the source of truth for ordering.
		'orderUrl'   => bayle_menu_widget_feed_https_url( $links['order'] ?? '' ),
		// Hosted cart hand-off (the restaurant's own storefront). Newer feeds send
		// links.checkout (null when there is none, e.g. links.order is the Bayle
		// marketplace page); older feeds only had links.order = the storefront.
		'checkoutBase' => bayle_menu_widget_feed_https_url( array_key_exists( 'checkout', $links ) ? ( $links['checkout'] ?? '' ) : ( $links['order'] ?? '' ) ),
		'categories' => array(),
		'items'      => array(),
		'lunch'      => null,
		'notes'      => array(),
	);

	$alacarte = is_array( $menu['alacarte'] ?? null ) ? $menu['alacarte'] : array();
	foreach ( is_array( $alacarte['categories'] ?? null ) ? $alacarte['categories'] : array() as $cat ) {
		if ( ! is_array( $cat ) ) {
			continue;
		}
		$key = bayle_menu_widget_feed_text( $cat['key'] ?? '', 40 );
		if ( '' !== $key ) {
			$out['categories'][] = array(
				'key'         => $key,
				'name'        => bayle_menu_widget_feed_text( $cat['name'] ?? '', 200 ),
				'description' => bayle_menu_widget_feed_textarea( $cat['description'] ?? '' ),
			);
		}
	}
	foreach ( array_slice( is_array( $alacarte['items'] ?? null ) ? $alacarte['items'] : array(), 0, 500 ) as $raw_item ) {
		$item = bayle_menu_widget_normalize_item( $raw_item );
		if ( null !== $item ) {
			$out['items'][] = $item;
		}
	}

	$lunch = is_array( $menu['lunch'] ?? null ) ? $menu['lunch'] : null;
	if ( null !== $lunch && is_array( $lunch['days'] ?? null ) ) {
		$days = array();
		for ( $d = 1; $d <= 7; $d++ ) {
			$list = $lunch['days'][ (string) $d ] ?? null;
			if ( ! is_array( $list ) ) {
				continue;
			}
			foreach ( array_slice( $list, 0, 60 ) as $raw_item ) {
				$item = bayle_menu_widget_normalize_item( $raw_item );
				if ( null !== $item ) {
					$days[ $d ][] = $item;
				}
			}
		}
		if ( $days ) {
			$range        = static function ( $r ) {
				$start = is_array( $r ) ? bayle_menu_widget_feed_clock( $r['start'] ?? '' ) : '';
				$end   = is_array( $r ) ? bayle_menu_widget_feed_clock( $r['end'] ?? '' ) : '';
				return ( '' !== $start && '' !== $end ) ? $start . '–' . $end : '';
			};
			$lunch_hours  = is_array( $lunch['hours'] ?? null ) ? $lunch['hours'] : array();
			$today        = (int) ( $lunch['today'] ?? 0 );
			$out['lunch'] = array(
				'today'   => ( $today >= 1 && $today <= 7 ) ? $today : 0,
				'weekday' => $range( $lunch_hours['weekday'] ?? null ),
				'weekend' => $range( $lunch_hours['weekend'] ?? null ),
				'days'    => $days,
			);
		}
	}

	foreach ( array_slice( is_array( $menu['notes'] ?? null ) ? $menu['notes'] : array(), 0, 20 ) as $note ) {
		if ( ! is_array( $note ) ) {
			continue;
		}
		$text = bayle_menu_widget_feed_textarea( $note['text'] ?? '' );
		if ( '' !== $text ) {
			$scope          = (string) ( $note['scope'] ?? 'all' );
			$out['notes'][] = array(
				'text'  => $text,
				'scope' => in_array( $scope, array( 'lunch', 'a_la_carte' ), true ) ? $scope : 'all',
			);
		}
	}

	return $out;
}