<?php
/**
 * Outbound API client for the AiM Blog Engine service.
 *
 * All requests use the WordPress HTTP API (Guideline-compliant — no raw cURL),
 * are signed with the site key returned at connect time, and treat every
 * response strictly as DATA (never executed — Guideline 8).
 *
 * @package AiM_Blog_Engine
 */

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

/**
 * Thin wrapper around wp_remote_* for the three plugin endpoints.
 */
class Aim_Be_Api {

	/**
	 * Exchange a member's Connect Code for a long-lived site key.
	 *
	 * @param string $code The Connect Code pasted from the AiM platform.
	 * @return true|WP_Error True on success (key stored), WP_Error otherwise.
	 */
	public function connect( $code ) {
		$response = wp_remote_post(
			AIM_BE_API_BASE . '/connect',
			array(
				'timeout' => 20,
				'headers' => array( 'Content-Type' => 'application/json' ),
				'body'    => wp_json_encode(
					array(
						'code'           => $code,
						'site_url'       => home_url(),
						'plugin_version' => AIM_BE_VERSION,
						// Lets AiM ask this site to sync the moment a post is
						// ready, instead of waiting for WP-Cron to be triggered
						// by a visitor.
						'wake_token'     => aim_be_wake_token(),
					)
				),
			)
		);

		$data = $this->parse( $response );
		if ( is_wp_error( $data ) ) {
			return $data;
		}
		if ( empty( $data['site_key'] ) ) {
			return new WP_Error( 'aim_be_no_key', __( 'The Connect Code was not accepted. Generate a new one in your AiM account and try again.', 'aim-blog-engine' ) );
		}

		update_option( AIM_BE_OPT_SITE_KEY, sanitize_text_field( $data['site_key'] ) );
		if ( ! empty( $data['site_id'] ) ) {
			update_option( AIM_BE_OPT_SITE_ID, sanitize_text_field( $data['site_id'] ) );
		}
		update_option( AIM_BE_OPT_STATUS, 'connected' );
		return true;
	}

	/**
	 * Fetch blog posts queued for this site.
	 *
	 * @return array|WP_Error List of post payloads, or WP_Error.
	 */
	public function get_pending() {
		$site_key = get_option( AIM_BE_OPT_SITE_KEY, '' );
		if ( empty( $site_key ) ) {
			return new WP_Error( 'aim_be_not_connected', __( 'Not connected.', 'aim-blog-engine' ) );
		}
		$response = wp_remote_get(
			AIM_BE_API_BASE . '/pending',
			array(
				'timeout' => 20,
				'headers' => $this->auth_headers( $site_key ),
			)
		);
		$data = $this->parse( $response );
		if ( is_wp_error( $data ) ) {
			return $data;
		}
		return isset( $data['posts'] ) && is_array( $data['posts'] ) ? $data['posts'] : array();
	}

	/**
	 * Report the local result of publishing a post back to AiM.
	 *
	 * @param array $result { blog_id, post_id, post_url, status }.
	 * @return void
	 */
	public function ack( $result ) {
		$site_key = get_option( AIM_BE_OPT_SITE_KEY, '' );
		if ( empty( $site_key ) || empty( $result['blog_id'] ) ) {
			return;
		}
		wp_remote_post(
			AIM_BE_API_BASE . '/ack',
			array(
				'timeout' => 15,
				'headers' => $this->auth_headers( $site_key ),
				'body'    => wp_json_encode( $result ),
			)
		);
	}

	/**
	 * Report liveness + versions to AiM so the dashboard shows connection health
	 * and the installed plugin/WordPress versions. Best-effort.
	 *
	 * @return void
	 */
	public function heartbeat() {
		$site_key = get_option( AIM_BE_OPT_SITE_KEY, '' );
		if ( empty( $site_key ) ) {
			return;
		}
		wp_remote_post(
			AIM_BE_API_BASE . '/heartbeat',
			array(
				'timeout' => 15,
				'headers' => $this->auth_headers( $site_key ),
				'body'    => wp_json_encode(
					array(
						'plugin_version' => AIM_BE_VERSION,
						'wp_version'     => get_bloginfo( 'version' ),
						// Sent every time, so a site that connected before the
						// wake route existed starts using it after updating,
						// with nothing for the member to do.
						'wake_token'     => aim_be_wake_token(),
					)
				),
			)
		);
	}

	/**
	 * Authorization headers for signed requests.
	 *
	 * @param string $site_key The stored site key.
	 * @return array
	 */
	private function auth_headers( $site_key ) {
		return array(
			'Content-Type'    => 'application/json',
			'Authorization'   => 'Bearer ' . $site_key,
			'X-AiM-Site-Url'  => home_url(),
			'X-AiM-Plugin-Ver' => AIM_BE_VERSION,
		);
	}

	/**
	 * Decode a WordPress HTTP response into an array, or a WP_Error.
	 *
	 * @param array|WP_Error $response Raw wp_remote_* return.
	 * @return array|WP_Error
	 */
	private function parse( $response ) {
		if ( is_wp_error( $response ) ) {
			return $response;
		}
		$code = wp_remote_retrieve_response_code( $response );
		$body = json_decode( wp_remote_retrieve_body( $response ), true );
		if ( $code < 200 || $code >= 300 ) {
			$message = is_array( $body ) && ! empty( $body['error'] )
				? $body['error']
				: sprintf( /* translators: %d: HTTP status code. */ __( 'AiM request failed (HTTP %d).', 'aim-blog-engine' ), (int) $code );
			return new WP_Error( 'aim_be_http', $message );
		}
		return is_array( $body ) ? $body : array();
	}
}