<?php
/**
 * MITECO / MINETUR ServiciosRestCarburantes API client.
 *
 * @package FontdelboscCombustible
 */

declare( strict_types=1 );

defined( 'ABSPATH' ) || exit;

/**
 * Fetches and normalizes province station data and the product catalog.
 */
final class Fontdelbosc_Combustible_Api {

	/**
	 * Hardcoded province ID: Barcelona (08).
	 */
	public const PROVINCE_ID = '08';

	/**
	 * Primary API base URL.
	 */
	private const BASE_PRIMARY = 'https://energia.serviciosmin.gob.es/ServiciosRestCarburantes/PreciosCarburantes/';

	/**
	 * Fallback API base URL.
	 */
	private const BASE_FALLBACK = 'https://sedeaplicaciones.minetur.gob.es/ServiciosRESTCarburantes/PreciosCarburantes/';

	/**
	 * Per-request timeout in seconds. Worst case (primary + fallback) stays bounded.
	 */
	private const TIMEOUT = 8;

	/**
	 * Fetches all stations of the province, normalized with distance.
	 *
	 * @return array{fecha:string,stations:array<int,array<string,mixed>>,fetched_at:int,duration:float}|null Null on total failure.
	 */
	public static function fetch_province(): ?array {
		$started = microtime( true );
		$body    = self::get( 'EstacionesTerrestres/FiltroProvincia/' . self::PROVINCE_ID );

		if ( null === $body ) {
			return null;
		}

		$decoded = json_decode( $body, true );

		if ( ! is_array( $decoded ) ) {
			return null;
		}

		$fecha    = Fontdelbosc_Combustible_Payload::str( Fontdelbosc_Combustible_Payload::get( $decoded, 'Fecha' ) ) ?? '';
		$raw_list = Fontdelbosc_Combustible_Payload::arr( Fontdelbosc_Combustible_Payload::get( $decoded, 'ListaEESSPrecio' ) );
		$stations = array();

		foreach ( $raw_list as $raw ) {
			$station = self::normalize_station( $raw );

			if ( null !== $station ) {
				$stations[] = $station;
			}
		}

		return array(
			'fecha'      => $fecha,
			'stations'   => $stations,
			'fetched_at' => time(),
			'duration'   => microtime( true ) - $started,
		);
	}

	/**
	 * Fetches the petroleum product catalog.
	 *
	 * @return array<int,array{id:int,name:string,abbr:string}>|null Null on total failure.
	 */
	public static function fetch_products(): ?array {
		$body = self::get( 'Listados/ProductosPetroliferos/' );

		if ( null === $body ) {
			return null;
		}

		$decoded = json_decode( $body, true );

		if ( ! is_array( $decoded ) ) {
			return null;
		}

		$products = array();

		foreach ( $decoded as $entry ) {
			$id = Fontdelbosc_Combustible_Payload::int( Fontdelbosc_Combustible_Payload::get( $entry, 'IDProducto' ) );

			if ( null === $id ) {
				continue;
			}

			$products[] = array(
				'id'   => $id,
				'name' => Fontdelbosc_Combustible_Payload::str( Fontdelbosc_Combustible_Payload::get( $entry, 'NombreProducto' ) ) ?? (string) $id,
				'abbr' => Fontdelbosc_Combustible_Payload::str( Fontdelbosc_Combustible_Payload::get( $entry, 'NombreProductoAbreviatura' ) ) ?? '',
			);
		}

		return $products;
	}

	/**
	 * GETs a path against the primary base URL, falling back to the legacy host.
	 *
	 * @param string $path API path relative to the base URL.
	 * @return string|null Response body, or null when both hosts fail.
	 */
	private static function get( string $path ): ?string {
		foreach ( array( self::BASE_PRIMARY, self::BASE_FALLBACK ) as $base ) {
			$response = wp_remote_get(
				$base . $path,
				array(
					'timeout' => self::TIMEOUT,
					'headers' => array( 'Accept' => 'application/json' ),
				)
			);

			if ( is_wp_error( $response ) ) {
				continue;
			}

			if ( 200 !== wp_remote_retrieve_response_code( $response ) ) {
				continue;
			}

			$body = wp_remote_retrieve_body( $response );

			if ( '' !== $body ) {
				return $body;
			}
		}

		return null;
	}

	/**
	 * Normalizes one raw station entry; null when coordinates are unusable.
	 *
	 * @param mixed $raw Raw station.
	 * @return array<string,mixed>|null
	 */
	private static function normalize_station( mixed $raw ): ?array {
		if ( ! is_array( $raw ) ) {
			return null;
		}

		$lat = self::coord( Fontdelbosc_Combustible_Payload::get( $raw, 'Latitud' ) );
		$lon = self::coord( Fontdelbosc_Combustible_Payload::get( $raw, 'Longitud (WGS84)' ) );

		if ( null === $lat || null === $lon ) {
			return null;
		}

		$prices = array();

		foreach ( $raw as $key => $value ) {
			if ( ! is_string( $key ) || ! str_starts_with( $key, 'Precio ' ) ) {
				continue;
			}

			$text  = Fontdelbosc_Combustible_Payload::str( $value );
			$price = null === $text ? null : Fontdelbosc_Combustible_Payload::float( str_replace( ',', '.', $text ) );

			if ( null !== $price && $price > 0.0 ) {
				$prices[ substr( $key, 7 ) ] = $price;
			}
		}

		return array(
			'id'           => Fontdelbosc_Combustible_Payload::int( Fontdelbosc_Combustible_Payload::get( $raw, 'IDEESS' ) ) ?? 0,
			'brand'        => Fontdelbosc_Combustible_Payload::str( Fontdelbosc_Combustible_Payload::get( $raw, 'Rótulo' ) ) ?? '',
			'address'      => Fontdelbosc_Combustible_Payload::str( Fontdelbosc_Combustible_Payload::get( $raw, 'Dirección' ) ) ?? '',
			'locality'     => Fontdelbosc_Combustible_Payload::str( Fontdelbosc_Combustible_Payload::get( $raw, 'Localidad' ) ) ?? '',
			'municipality' => Fontdelbosc_Combustible_Payload::str( Fontdelbosc_Combustible_Payload::get( $raw, 'Municipio' ) ) ?? '',
			'cp'           => Fontdelbosc_Combustible_Payload::str( Fontdelbosc_Combustible_Payload::get( $raw, 'C.P.' ) ) ?? '',
			'schedule'     => Fontdelbosc_Combustible_Payload::str( Fontdelbosc_Combustible_Payload::get( $raw, 'Horario' ) ) ?? '',
			'tipo_venta'   => Fontdelbosc_Combustible_Payload::str( Fontdelbosc_Combustible_Payload::get( $raw, 'Tipo Venta' ) ) ?? '',
			'lat'          => $lat,
			'lon'          => $lon,
			'distance'     => Fontdelbosc_Combustible_Geo::haversine( $lat, $lon ),
			'prices'       => $prices,
		);
	}

	/**
	 * Parses a comma-decimal coordinate string.
	 *
	 * @param mixed $value Raw coordinate value.
	 */
	private static function coord( mixed $value ): ?float {
		$text  = Fontdelbosc_Combustible_Payload::str( $value );
		$float = null === $text ? null : Fontdelbosc_Combustible_Payload::float( str_replace( ',', '.', $text ) );

		if ( null === $float || abs( $float ) > 180.0 ) {
			return null;
		}

		return $float;
	}
}