<?php
/**
 * phpList REST API wrapper.
 *
 * The phpList REST API v3 expects a POST request with ALL parameters
 * (including login, password, cmd) in the POST body — NOT the query string.
 * The endpoint URL itself only needs ?page=call&pi=restapi.
 *
 * @package WooList
 */

defined( 'ABSPATH' ) || exit;

class WooList_API {

	/**
	 * Retrieve a saved plugin option.
	 *
	 * @param string $key     Option key without the woolist_ prefix.
	 * @param mixed  $default Default value.
	 * @return mixed
	 */
	public function get_option( string $key, $default = '' ) {
		return get_option( 'woolist_' . $key, $default );
	}

	/**
	 * Return the base API endpoint URL (no credentials, no command).
	 *
	 * @return string|WP_Error
	 */
	private function endpoint_url() {
		$base = rtrim( (string) $this->get_option( 'phplist_url' ), '/' );

		if ( empty( $base ) ) {
			return new WP_Error( 'woolist_no_url', __( 'phpList base URL is not configured.', 'woolist-phplist' ) );
		}

		return $base . '/admin/?page=call&pi=restapi';
	}

	/**
	 * Execute a phpList REST API call.
	 *
	 * Credentials and all command parameters are sent in the POST body so
	 * phpList can authenticate and parse the request correctly.
	 *
	 * @param string $cmd   phpList API command (e.g. subscriberAdd).
	 * @param array  $extra Additional POST body parameters.
	 * @return array|WP_Error Decoded JSON data or WP_Error.
	 */
	public function call( string $cmd, array $extra = [] ) {
		$url = $this->endpoint_url();

		if ( is_wp_error( $url ) ) {
			WooList_Logger::error( 'Cannot build endpoint URL for cmd=' . $cmd . ': ' . $url->get_error_message() );
			return $url;
		}

		// Build the POST body — credentials + command + any extra params.
		$body = array_merge(
			[
				'login'    => (string) $this->get_option( 'phplist_login' ),
				'password' => (string) $this->get_option( 'phplist_password' ),
				'cmd'      => $cmd,
			],
			$extra
		);

		// Log the outgoing request at debug level; redact the password.
		$logged_body = $body;
		$logged_body['password'] = '***';
		WooList_Logger::debug( '→ API request  cmd=' . $cmd . '  endpoint=' . $url . '  body=' . wp_json_encode( $logged_body ) );

		$response = wp_remote_post(
			$url,
			[
				'timeout' => 15,
				'body'    => $body,
			]
		);

		if ( is_wp_error( $response ) ) {
			WooList_Logger::error( 'HTTP request failed  cmd=' . $cmd . '  error=' . $response->get_error_message() );
			return $response;
		}

		$code = wp_remote_retrieve_response_code( $response );
		$body_raw = wp_remote_retrieve_body( $response );

		// Always log the raw response at DEBUG so problems are immediately visible.
		WooList_Logger::debug( '← API response  cmd=' . $cmd . '  http=' . $code . '  body=' . substr( $body_raw, 0, 2048 ) );

		if ( $code < 200 || $code >= 300 ) {
			WooList_Logger::error( 'Non-2xx HTTP response  cmd=' . $cmd . '  http=' . $code . '  body=' . substr( $body_raw, 0, 500 ) );
			return new WP_Error( 'woolist_http_error', 'HTTP error ' . $code );
		}

		$data = json_decode( $body_raw, true );

		if ( json_last_error() !== JSON_ERROR_NONE ) {
			// Not JSON — likely an HTML error page or wrong endpoint.
			WooList_Logger::error( 'Non-JSON response  cmd=' . $cmd . '  body=' . substr( $body_raw, 0, 500 ) );
			return new WP_Error( 'woolist_json_error', 'phpList did not return JSON. Check endpoint URL and credentials.' );
		}

		// phpList signals errors via status=error.
		// v3 nests the message inside data.message: {"status":"error","data":{"code":0,"message":"..."}}
		if ( isset( $data['status'] ) && strtolower( $data['status'] ) === 'error' ) {
			if ( is_array( $data['data'] ?? null ) ) {
				$message = $data['data']['message'] ?? $data['errormessage'] ?? $data['message'] ?? 'Unknown API error';
			} else {
				$message = $data['errormessage'] ?? $data['message'] ?? $data['data'] ?? 'Unknown API error';
			}
			$message = (string) $message;
			WooList_Logger::error( 'API error  cmd=' . $cmd . '  message=' . $message . '  full_response=' . wp_json_encode( $data ) );
			return new WP_Error( 'woolist_api_error', $message );
		}

		WooList_Logger::debug( 'API call succeeded  cmd=' . $cmd . '  response=' . wp_json_encode( $data ) );
		return $data;
	}

	/**
	 * Retrieve a subscriber by email address.
	 *
	 * @param string $email Subscriber email.
	 * @return array|WP_Error
	 */
	public function subscriber_get_by_email( string $email ) {
		// No manual encoding — wp_remote_post encodes POST body values correctly.
		return $this->call( 'subscriberGetByEmail', [ 'email' => $email ] );
	}

	/**
	 * Add a new confirmed subscriber.
	 *
	 * @param string $email Subscriber email.
	 * @return array|WP_Error
	 */
	public function subscriber_add( string $email ) {
		return $this->call(
			'subscriberAdd',
			[
				'email'     => $email,
				'confirmed' => 1,
				'htmlemail' => 1,
			]
		);
	}

	/**
	 * Add a subscriber (by ID) to a phpList list.
	 *
	 * phpList REST API v3 accepts both "listid"/"subscriberid" (older) and
	 * "list_id"/"subscriber_id" (some builds). We send all four so whichever
	 * naming convention this installation uses will be satisfied.
	 *
	 * @param int $list_id       phpList list ID.
	 * @param int $subscriber_id phpList subscriber ID.
	 * @return array|WP_Error
	 */
	public function list_subscriber_add( int $list_id, int $subscriber_id ) {
		WooList_Logger::debug(
			'listSubscriberAdd params  listid=' . $list_id . '  subscriberid=' . $subscriber_id
		);
		return $this->call(
			'listSubscriberAdd',
			[
				'listid'       => $list_id,
				'subscriberid' => $subscriber_id,
				'list_id'      => $list_id,      // alternate param name used by some v3 builds
				'subscriber_id' => $subscriber_id, // alternate param name
			]
		);
	}

	/**
	 * Subscribe an email address to a phpList list.
	 *
	 * Looks up the subscriber first; creates one if not found; then adds
	 * them to the target list. Returns a result array so callers can check
	 * success without inspecting WP_Error internals.
	 *
	 * @param string $email   Subscriber email address.
	 * @param int    $list_id phpList list ID.
	 * @return array{success: bool, subscriber_id: int|null}
	 */
	public function subscribe_email_to_list( string $email, int $list_id ): array {
		WooList_Logger::debug( 'subscribe_email_to_list  email=' . $email . '  list_id=' . $list_id );

		// Step 1: look up existing subscriber.
		$subscriber_id = null;
		$existing      = $this->subscriber_get_by_email( $email );

		// phpList wraps subscriber data inside a "data" key: {"status":"success","data":{"id":…}}
		$existing_id = $existing['data']['id'] ?? $existing['id'] ?? null;
		if ( ! is_wp_error( $existing ) && ! empty( $existing_id ) ) {
			$subscriber_id = (int) $existing_id;
			WooList_Logger::debug( 'Found existing subscriber  id=' . $subscriber_id . '  email=' . $email );
		} else {
			// Step 2: create a new subscriber.
			WooList_Logger::debug( 'Subscriber not found, creating new  email=' . $email );
			$added = $this->subscriber_add( $email );

			if ( is_wp_error( $added ) ) {
				WooList_Logger::error( 'Could not create subscriber  email=' . $email . '  error=' . $added->get_error_message() );
				return [ 'success' => false, 'subscriber_id' => null ];
			}

			// phpList wraps the new subscriber inside a "data" key.
			$subscriber_id = isset( $added['data']['id'] ) ? (int) $added['data']['id']
				: ( isset( $added['id'] ) ? (int) $added['id'] : null );

			if ( $subscriber_id ) {
				WooList_Logger::info( 'Created new subscriber  id=' . $subscriber_id . '  email=' . $email );
			} else {
				WooList_Logger::error( 'API returned no subscriber ID after add  email=' . $email . '  response=' . wp_json_encode( $added ) );
				return [ 'success' => false, 'subscriber_id' => null ];
			}
		}

		// Step 3: add subscriber to the list.
		WooList_Logger::debug( 'Adding subscriber ' . $subscriber_id . ' to list ' . $list_id );
		$result = $this->list_subscriber_add( $list_id, $subscriber_id );

		if ( is_wp_error( $result ) ) {
			WooList_Logger::error( 'Could not add subscriber to list  subscriber_id=' . $subscriber_id . '  list_id=' . $list_id . '  error=' . $result->get_error_message() );
			return [ 'success' => false, 'subscriber_id' => $subscriber_id ];
		}

		WooList_Logger::info( 'Subscribed  email=' . $email . '  subscriber_id=' . $subscriber_id . '  list_id=' . $list_id );
		return [ 'success' => true, 'subscriber_id' => $subscriber_id ];
	}

	/**
	 * Retrieve all lists (used for connection testing).
	 *
	 * @return array|WP_Error
	 */
	public function lists_get() {
		return $this->call( 'listsGet' );
	}
}