<?php
/**
 * HTTP client wrapping POST {endpoint} on the Adara Translate API.
 *
 * @package AdaraTranslate
 */

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

final class Adara_Translate_Client {

	/**
	 * Translate a single string. Returns either an associative array with at
	 * least `translatedText`, or a WP_Error.
	 *
	 * @param string      $text        Source text (may contain HTML; sent with format=html).
	 * @param string      $target_lang ISO target language code.
	 * @param string|null $source_lang Optional ISO source language code.
	 * @param string|null $engine      Optional engine override.
	 * @return array|WP_Error
	 */
	public static function translate( string $text, string $target_lang, ?string $source_lang = null, ?string $engine = null ) {
		$api_key = Adara_Translate_Settings::get_api_key();
		if ( '' === $api_key ) {
			return new WP_Error(
				'adara_no_api_key',
				__( 'Adara Translate API key is not configured.', 'adara-translate' ),
				[ 'status' => 400 ]
			);
		}

		if ( '' === trim( $text ) ) {
			return [ 'translatedText' => '' ];
		}

		$body = [
			'text'       => $text,
			'targetLang' => $target_lang,
			'engine'     => $engine ?? Adara_Translate_Settings::get_engine(),
			'format'     => 'html',
		];
		if ( null !== $source_lang && '' !== $source_lang ) {
			$body['sourceLang'] = $source_lang;
		}

		$response = wp_remote_post(
			Adara_Translate_Settings::get_endpoint(),
			[
				'timeout' => 60,
				'headers' => [
					'Content-Type' => 'application/json',
					'X-API-Key'    => $api_key,
				],
				'body'    => wp_json_encode( $body ),
			]
		);

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

		$status  = (int) wp_remote_retrieve_response_code( $response );
		$payload = json_decode( wp_remote_retrieve_body( $response ), true );

		if ( $status < 200 || $status >= 300 ) {
			$message = is_array( $payload ) && isset( $payload['error'] )
				? (string) $payload['error']
				: sprintf(
					/* translators: %d: HTTP status code */
					__( 'Adara API returned HTTP %d.', 'adara-translate' ),
					$status
				);
			return new WP_Error(
				'adara_api_error',
				$message,
				[ 'status' => $status, 'payload' => $payload ]
			);
		}

		if ( ! is_array( $payload ) || ! isset( $payload['translatedText'] ) ) {
			return new WP_Error(
				'adara_bad_response',
				__( 'Unexpected response from Adara API.', 'adara-translate' ),
				[ 'status' => 502 ]
			);
		}

		return $payload;
	}
}