<?php
defined( 'ABSPATH' ) || exit;

/**
 * The Readerr service, spoken to from PHP only.
 *
 * Every method returns ['status' => int, 'body' => ?array, 'error' => ?string];
 * status 0 is a transport failure. A 409 or 429 is an answer, not an error —
 * callers branch on the status, never on is_wp_error alone.
 */
final class Readerr_Client {
	private const TIMEOUT_S = 15;

	private string $base_url;
	private string $api_key;

	// No constructor promotion: the plugin runs on PHP 7.4 (readerr.php header).
	public function __construct( string $base_url, string $api_key ) {
		$this->base_url = $base_url;
		$this->api_key  = $api_key;
	}

	public static function from_settings(): ?self {
		$url = (string) Readerr_Settings::get( 'service_url' );
		$key = Readerr_Settings::api_key();
		return ( '' === $key || ! self::is_valid_url( $url ) ) ? null : new self( $url, $key );
	}

	/**
	 * service_url is production-fixed https:// (Readerr_Settings::INFRA) and
	 * only a wp-config.php constant can move it, dev included (docs/todo.md,
	 * "Adresy infrastruktury nieedytowalne na produkcji") — so the constant is
	 * the only way a malformed value reaches here. A broken override must not
	 * become "send the key nowhere safe"; it becomes "no client", same as no
	 * key at all.
	 */
	private static function is_valid_url( string $url ): bool {
		$parts = wp_parse_url( $url );
		return is_array( $parts ) && ! empty( $parts['host'] ) && in_array( $parts['scheme'] ?? '', array( 'http', 'https' ), true );
	}

	public function ingest( array $payload ): array {
		return $this->request( 'POST', '/v1/ingest', $payload );
	}

	public function article( string $external_id ): array {
		return $this->request( 'GET', '/v1/articles/' . rawurlencode( $external_id ) );
	}

	public function delete_article( string $external_id ): array {
		return $this->request( 'DELETE', '/v1/articles/' . rawurlencode( $external_id ) );
	}

	public function quota(): array {
		return $this->request( 'GET', '/v1/quota' );
	}

	/** The editor waits on this one, so its caller picks a shorter timeout. */
	public function voices( int $timeout = self::TIMEOUT_S ): array {
		return $this->request( 'GET', '/v1/voices', null, $timeout );
	}

	private function request( string $method, string $path, ?array $json = null, int $timeout = self::TIMEOUT_S ): array {
		$args = array(
			'method'     => $method,
			'timeout'    => $timeout,
			// Which plugin a site runs, for support: the service keeps it.
			'user-agent' => 'Readerr-WordPress/' . READERR_VERSION . ' WordPress/' . get_bloginfo( 'version' ) . ' PHP/' . PHP_VERSION,
			'headers'    => array(
				'Authorization' => 'Bearer ' . $this->api_key,
				'Accept'        => 'application/json',
			),
		);
		if ( null !== $json ) {
			$args['headers']['Content-Type'] = 'application/json';
			$args['body']                    = wp_json_encode( $json );
		}
		$response = wp_remote_request( rtrim( $this->base_url, '/' ) . $path, $args );
		if ( is_wp_error( $response ) ) {
			return array( 'status' => 0, 'body' => null, 'error' => $response->get_error_message() );
		}
		$status = (int) wp_remote_retrieve_response_code( $response );
		if ( 401 === $status ) {
			// Customer-panel spec §6.1: any call the plugin makes, not just
			// the quota poll, learns fast that the key is dead — Readerr_Access
			// listens for this and lapses the account.
			do_action( 'readerr_unauthorized' );
		}
		$body = json_decode( (string) wp_remote_retrieve_body( $response ), true );
		return array(
			'status' => $status,
			'body'   => is_array( $body ) ? $body : null,
			'error'  => null,
		);
	}
}