<?php
/**
 * Pushover API client.
 *
 * @package PingPush
 */

defined( 'ABSPATH' ) || exit;

/**
 * Thin wrapper around the Pushover REST API.
 */
class PingPush_API {

	const MESSAGES_URL = 'https://api.pushover.net/1/messages.json';
	const VALIDATE_URL = 'https://api.pushover.net/1/users/validate.json';

	// Limits from https://pushover.net/api#limits.
	const MAX_MESSAGE   = 1024;
	const MAX_TITLE     = 250;
	const MAX_URL       = 512;
	const MAX_URL_TITLE = 100;

	/**
	 * Built-in sounds. Empty key = the user's default sound.
	 *
	 * @return array<string,string>
	 */
	public static function sounds() {
		return array(
			''             => __( 'Device default', 'pingpush' ),
			'pushover'     => 'Pushover',
			'bike'         => 'Bike',
			'bugle'        => 'Bugle',
			'cashregister' => 'Cash Register',
			'classical'    => 'Classical',
			'cosmic'       => 'Cosmic',
			'falling'      => 'Falling',
			'gamelan'      => 'Gamelan',
			'incoming'     => 'Incoming',
			'intermission' => 'Intermission',
			'magic'        => 'Magic',
			'mechanical'   => 'Mechanical',
			'pianobar'     => 'Piano Bar',
			'siren'        => 'Siren',
			'spacealarm'   => 'Space Alarm',
			'tugboat'      => 'Tug Boat',
			'alien'        => 'Alien Alarm (long)',
			'climb'        => 'Climb (long)',
			'persistent'   => 'Persistent (long)',
			'echo'         => 'Pushover Echo (long)',
			'updown'       => 'Up Down (long)',
			'vibrate'      => __( 'Vibrate only', 'pingpush' ),
			'none'         => __( 'Silent', 'pingpush' ),
		);
	}

	/**
	 * The priorities PingPush supports. Settings, templates and send() all use this list.
	 *
	 * @return array<int,string>
	 */
	public static function priorities() {
		return array(
			-2 => __( 'Lowest (no alert)', 'pingpush' ),
			-1 => __( 'Low (no sound)', 'pingpush' ),
			0  => __( 'Normal', 'pingpush' ),
			1  => __( 'High (bypasses quiet hours)', 'pingpush' ),
		);
	}

	/**
	 * Normalize a priority to one of the supported values (-2, -1, 0, 1); anything else becomes 0 (normal).
	 *
	 * @param mixed $priority Priority.
	 * @return int
	 */
	public static function sanitize_priority( $priority ) {
		$priority = is_numeric( $priority ) ? (int) $priority : 0;
		return array_key_exists( $priority, self::priorities() ) ? $priority : 0;
	}

	/**
	 * A Pushover token or user/group key: 30 chars, [A-Za-z0-9].
	 *
	 * @param string $key Key.
	 * @return bool
	 */
	public static function looks_like_key( $key ) {
		return (bool) preg_match( '/^[A-Za-z0-9]{30}$/', (string) $key );
	}

	/**
	 * Send a message.
	 *
	 * @param string $token    Application API token.
	 * @param string $user     User or group key.
	 * @param array  $message  title, message, url, url_title, priority (-2..1), sound, timestamp. Other keys are ignored.
	 * @param int    $timeout  Request timeout in seconds.
	 * @return array{ok:bool,retry:bool,code:int,error:string,remaining:?int}
	 */
	public static function send( $token, $user, array $message, $timeout = 15 ) {
		$body = array(
			'token'   => $token,
			'user'    => $user,
			'message' => (string) ( $message['message'] ?? '' ),
		);

		foreach ( array( 'title', 'url', 'url_title' ) as $field ) {
			if ( isset( $message[ $field ] ) && '' !== $message[ $field ] ) {
				$body[ $field ] = (string) $message[ $field ];
			}
		}
		if ( isset( $message['sound'] ) && '' !== $message['sound'] && array_key_exists( (string) $message['sound'], self::sounds() ) ) {
			$body['sound'] = (string) $message['sound'];
		}
		if ( isset( $message['priority'] ) ) {
			$body['priority'] = self::sanitize_priority( $message['priority'] );
		}
		if ( ! empty( $message['timestamp'] ) ) {
			$body['timestamp'] = (int) $message['timestamp'];
		}
		if ( '' === trim( $body['message'] ) ) {
			$body['message'] = '-';
		}

		$response = wp_remote_post(
			self::MESSAGES_URL,
			array(
				'timeout'    => $timeout,
				'body'       => $body,
				'user-agent' => 'PingPush/' . PINGPUSH_VERSION . '; ' . home_url( '/' ),
			)
		);

		return self::parse( $response );
	}

	/**
	 * Validate a user/group key against an app token.
	 *
	 * @param string $token Token.
	 * @param string $user  User key.
	 * @return array{ok:bool,retry:bool,code:int,error:string,remaining:?int,devices:array}
	 */
	public static function validate( $token, $user ) {
		$response = wp_remote_post(
			self::VALIDATE_URL,
			array(
				'timeout'    => 15,
				'body'       => array(
					'token' => $token,
					'user'  => $user,
				),
				'user-agent' => 'PingPush/' . PINGPUSH_VERSION . '; ' . home_url( '/' ),
			)
		);

		$result            = self::parse( $response );
		$result['devices'] = array();
		if ( $result['ok'] && ! is_wp_error( $response ) ) {
			$data = json_decode( wp_remote_retrieve_body( $response ), true );
			if ( isset( $data['devices'] ) && is_array( $data['devices'] ) ) {
				$result['devices'] = array_map( 'strval', $data['devices'] );
			}
		}
		return $result;
	}

	/**
	 * Normalize an HTTP response.
	 *
	 * Per Pushover: 200 + status 1 = ok; 4xx = bad input, never retry; 5xx / no response = retry later.
	 *
	 * @param array|WP_Error $response Response.
	 * @return array{ok:bool,retry:bool,code:int,error:string,remaining:?int}
	 */
	private static function parse( $response ) {
		if ( is_wp_error( $response ) ) {
			return array(
				'ok'        => false,
				'retry'     => true,
				'code'      => 0,
				'error'     => $response->get_error_message(),
				'remaining' => null,
			);
		}

		$code      = (int) wp_remote_retrieve_response_code( $response );
		$data      = json_decode( wp_remote_retrieve_body( $response ), true );
		$remaining = wp_remote_retrieve_header( $response, 'x-limit-app-remaining' );
		$remaining = ( '' === $remaining || is_array( $remaining ) ) ? null : (int) $remaining;

		if ( 200 === $code && is_array( $data ) && isset( $data['status'] ) && 1 === (int) $data['status'] ) {
			return array(
				'ok'        => true,
				'retry'     => false,
				'code'      => $code,
				'error'     => '',
				'remaining' => $remaining,
			);
		}

		$error = '';
		if ( is_array( $data ) && ! empty( $data['errors'] ) && is_array( $data['errors'] ) ) {
			$error = implode( '; ', array_map( 'strval', $data['errors'] ) );
		}
		if ( 429 === $code ) {
			$error = __( 'Monthly Pushover message limit reached.', 'pingpush' ) . ( $error ? ' ' . $error : '' );
		}
		if ( '' === $error ) {
			/* translators: %d: HTTP status code. */
			$error = sprintf( __( 'Unexpected response from Pushover (HTTP %d).', 'pingpush' ), $code );
		}

		return array(
			'ok'        => false,
			'retry'     => ( $code < 400 || $code >= 500 ),
			'code'      => $code,
			'error'     => $error,
			'remaining' => $remaining,
		);
	}
}