<?php
if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly.
}

/**
 * Low-level OpenAI Responses API client.
 */
class AIEditor_OpenAI_Client {

	/**
	 * Create a response using the OpenAI Responses API.
	 *
	 * @param array  $payload Request payload.
	 * @param string $api_key OpenAI API key.
	 * @param int    $timeout OpenAI HTTP timeout in seconds.
	 * @return array|WP_Error
	 */
	public function create_response( $payload, $api_key, $timeout = 120 ) {
		$response = wp_remote_post(
			'https://api.openai.com/v1/responses',
			array(
				'headers' => array(
					'Content-Type'  => 'application/json',
					'Authorization' => 'Bearer ' . $api_key,
				),
				'body'    => wp_json_encode( $payload ),
				'timeout' => absint( $timeout ),
			)
		);

		return $this->normalize_response( $response );
	}

	/**
	 * Retrieve a response by id from the OpenAI Responses API.
	 *
	 * @param string $response_id OpenAI response id.
	 * @param string $api_key OpenAI API key.
	 * @param int    $timeout OpenAI HTTP timeout in seconds.
	 * @return array|WP_Error
	 */
	public function retrieve_response( $response_id, $api_key, $timeout = 120 ) {
		$response = wp_remote_get(
			'https://api.openai.com/v1/responses/' . rawurlencode( $response_id ),
			array(
				'headers' => array(
					'Authorization' => 'Bearer ' . $api_key,
				),
				'timeout' => absint( $timeout ),
			)
		);

		return $this->normalize_response( $response );
	}

	/**
	 * Cancel a background response via the OpenAI Responses API.
	 *
	 * @param string $response_id OpenAI response id.
	 * @param string $api_key OpenAI API key.
	 * @return array|WP_Error
	 */
	public function cancel_response( $response_id, $api_key ) {
		$response = wp_remote_post(
			'https://api.openai.com/v1/responses/' . rawurlencode( $response_id ) . '/cancel',
			array(
				'headers' => array(
					'Content-Type'  => 'application/json',
					'Authorization' => 'Bearer ' . $api_key,
				),
				'timeout' => 120,
			)
		);

		return $this->normalize_response( $response );
	}

	/**
	 * Build a user-facing error response for OpenAI API errors.
	 *
	 * @param array $response_data OpenAI response data.
	 * @param int   $http_status HTTP status code.
	 * @return WP_REST_Response
	 */
	public function build_error_response( $response_data, $http_status ) {
		if ( isset( $response_data['error']['code'] ) && 'model_not_found' === $response_data['error']['code'] ) {
			$error_message = __( 'You do not have access to this GPT model. Please choose a different model from Settings -> AI Editor.', 'ai-editor' );
		} else {
			$error_message = isset( $response_data['error']['message'] ) ? $response_data['error']['message'] : __( 'Unknown error.', 'ai-editor' );
		}

		return new WP_REST_Response(
			array(
				'error'   => true,
				'message' => $error_message,
				'status'  => $http_status,
			),
			$http_status
		);
	}

	/**
	 * Normalize a WordPress HTTP response.
	 *
	 * @param array|WP_Error $response WordPress HTTP response.
	 * @return array|WP_Error
	 */
	private function normalize_response( $response ) {
		if ( is_wp_error( $response ) ) {
			return new WP_Error( 'request_failed', $response->get_error_message(), array( 'status' => 500 ) );
		}

		$body          = wp_remote_retrieve_body( $response );
		$response_data = json_decode( $body, true );

		if ( JSON_ERROR_NONE !== json_last_error() ) {
			return new WP_Error( 'json_error', __( 'JSON parsing error: ', 'ai-editor' ) . json_last_error_msg(), array( 'status' => 500 ) );
		}

		return array(
			'data' => $response_data,
			'meta' => array(
				'status' => wp_remote_retrieve_response_code( $response ),
			),
		);
	}
}