<?php
/**
 * Message sending service.
 *
 * @package IntelTele
 */

namespace IntelTele\Services;

use IntelTele\Api\ApiResult;
use IntelTele\Api\ClientFactory;
use IntelTele\Api\HttpClient;
use IntelTele\Repositories\MessageLogRepository;
use IntelTele\Repositories\SettingsRepository;

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

final class MessageSender {
	/**
	 * Settings repository.
	 *
	 * @var SettingsRepository
	 */
	private $settings_repository;

	/**
	 * Log repository.
	 *
	 * @var MessageLogRepository
	 */
	private $log_repository;

	/**
	 * Constructor.
	 */
	public function __construct() {
		$this->settings_repository = new SettingsRepository();
		$this->log_repository      = new MessageLogRepository();
	}

	/**
	 * Send a manual message.
	 *
	 * @param string $message Message text.
	 * @param string $phone Recipient phone.
	 * @param string $scheme Scheme.
	 * @param string $fallback_message SMS fallback message.
	 * @return array{success:bool,messages:string[]}
	 */
	public function send_manual( string $message, string $phone, string $scheme, string $fallback_message = '' ): array {
		return $this->send(
			$message,
			$phone,
			$scheme,
			array(
				'send_type'        => 'manual',
				'fallback_message' => $fallback_message,
			)
		);
	}

	/**
	 * Send an order status message.
	 *
	 * @param string              $message Message text.
	 * @param string              $phone Recipient phone.
	 * @param string              $scheme Scheme.
	 * @param array<string,mixed> $context Context.
	 * @return array{success:bool,messages:string[]}
	 */
	public function send_order_status( string $message, string $phone, string $scheme, array $context ): array {
		$context['send_type'] = 'order_status';

		return $this->send( $message, $phone, $scheme, $context );
	}

	/**
	 * Send message.
	 *
	 * @param string              $message Message text.
	 * @param string              $phone Recipient phone.
	 * @param string              $scheme Scheme.
	 * @param array<string,mixed> $context Context.
	 * @return array{success:bool,messages:string[]}
	 */
	private function send( string $message, string $phone, string $scheme, array $context ): array {
		$settings = $this->settings_repository->get_all();
		$client   = ClientFactory::create( $settings );
		$channel  = 'viber_sms' === $scheme ? 'viber' : $scheme;
		$options  = array();

		if ( 'viber' === $channel ) {
			$options['ttl'] = absint( $settings['viber_ttl'] ?? 600 );
			$result         = $client->send_viber( $message, array( $phone ), $options );
		} else {
			$result = $client->send_sms( $message, array( $phone ), $options );
		}

		$this->store_result( $result, $message, $phone, $scheme, $channel, $options, $context );

		if ( ! $result->is_success() ) {
			PluginLogger::log(
				'error',
				'message_send_failed',
				$result->get_error(),
				array(
					'phone'           => $phone,
					'scheme'          => $scheme,
					'channel'         => $channel,
					'http_status'     => $result->get_status_code(),
					'error_code'      => $this->derive_error_code( $result ),
					'api_response'    => $this->encode_api_response( $result ),
					'send_type'       => isset( $context['send_type'] ) ? (string) $context['send_type'] : 'manual',
				),
				'MessageSender'
			);

			return array(
				'success'  => false,
				'messages' => array(
					__( 'Message was not sent. Please try again.', 'inteltele' ),
					$result->get_error(),
				),
			);
		}

		$item_errors = $this->get_item_errors( $result );

		if ( ! empty( $item_errors ) ) {
			return array(
				'success'  => false,
				'messages' => array_merge(
					array( __( 'Message was not sent. Please try again.', 'inteltele' ) ),
					$item_errors
				),
			);
		}

		return array(
			'success'  => true,
			'messages' => array( __( 'Message sent successfully.', 'inteltele' ) ),
		);
	}

	/**
	 * Store API send result.
	 *
	 * @param ApiResult           $result API result.
	 * @param string              $message Message.
	 * @param string              $phone Phone.
	 * @param string              $scheme Scheme.
	 * @param string              $channel Channel.
	 * @param array<string,mixed> $options Options.
	 * @param array<string,mixed> $context Context.
	 */
	private function store_result( ApiResult $result, string $message, string $phone, string $scheme, string $channel, array $options, array $context ): void {
		$base = array(
			'send_type'       => isset( $context['send_type'] ) ? (string) $context['send_type'] : 'manual',
			'order_id'        => isset( $context['order_id'] ) ? absint( $context['order_id'] ) : null,
			'recipient_name'  => isset( $context['recipient_name'] ) ? (string) $context['recipient_name'] : '',
			'recipient_role'  => isset( $context['recipient_role'] ) ? (string) $context['recipient_role'] : '',
			'fallback_message' => isset( $context['fallback_message'] ) ? (string) $context['fallback_message'] : '',
			'duplicate_key'   => isset( $context['duplicate_key'] ) ? (string) $context['duplicate_key'] : '',
		);

		if ( ! $result->is_success() ) {
			$this->log_repository->insert(
				array_merge(
					$base,
					array(
					'recipient_phone' => $phone,
					'channel'         => $channel,
					'scheme'          => $scheme,
					'message'         => $message,
					'api_status_code' => $result->get_status_code(),
					'error_code'      => $this->derive_error_code( $result ),
					'api_response'    => $this->encode_api_response( $result ),
					'status'          => 'failed',
					'error_reason'    => $result->get_error(),
					'viber_ttl'       => isset( $options['ttl'] ) ? absint( $options['ttl'] ) : null,
					'viber_sent_at'   => 'viber' === $channel ? current_time( 'mysql' ) : null,
					)
				)
			);
			return;
		}

		$data  = $result->get_data();
		$items = isset( $data['items'] ) && is_array( $data['items'] ) ? $data['items'] : array();

		if ( empty( $items ) ) {
			$this->log_repository->insert(
				array_merge(
					$base,
					array(
					'recipient_phone' => $phone,
					'channel'         => $channel,
					'scheme'          => $scheme,
					'message'         => $message,
					'api_status_code' => $result->get_status_code(),
					'api_response'    => $this->encode_api_response( $result ),
					'status'          => 'sent',
					'viber_ttl'       => isset( $options['ttl'] ) ? absint( $options['ttl'] ) : null,
					'viber_sent_at'   => 'viber' === $channel ? current_time( 'mysql' ) : null,
					)
				)
			);
			return;
		}

		foreach ( $items as $item ) {
			$item_phone = isset( $item['number'] ) ? (string) $item['number'] : $phone;
			$api_status = isset( $item['status'] ) ? (string) $item['status'] : '';
			$is_sent    = 'OK' === strtoupper( $api_status );
			$error_code = $is_sent ? '' : $this->derive_item_error_code( $item, $api_status, $result );

			$this->log_repository->insert(
				array_merge(
					$base,
					array(
					'recipient_phone'   => $item_phone,
					'channel'           => $channel,
					'scheme'            => $scheme,
					'message'           => $message,
					'api_message_id'    => isset( $item['message_id'] ) ? (string) $item['message_id'] : '',
					'api_status'        => $api_status,
					'api_status_code'   => $result->get_status_code(),
					'error_code'        => $error_code,
					'api_response'      => $this->encode_api_response( $result ),
					'status'            => $is_sent ? 'sent' : 'failed',
					'error_reason'      => $is_sent ? null : $api_status,
					'viber_ttl'         => isset( $options['ttl'] ) ? absint( $options['ttl'] ) : null,
					'viber_sent_at'     => 'viber' === $channel ? current_time( 'mysql' ) : null,
					'status_updated_at' => current_time( 'mysql' ),
					)
				)
			);

			PluginLogger::log(
				$is_sent ? 'info' : 'error',
				$is_sent ? 'message_sent' : 'message_send_failed',
				$is_sent ? __( 'Message accepted by API.', 'inteltele' ) : __( 'Message item failed in API response.', 'inteltele' ),
				array(
					'phone'          => $item_phone,
					'scheme'         => $scheme,
					'channel'        => $channel,
					'api_message_id' => isset( $item['message_id'] ) ? (string) $item['message_id'] : '',
					'api_status'     => $api_status,
					'http_status'    => $result->get_status_code(),
					'error_code'     => $error_code,
					'send_type'      => isset( $context['send_type'] ) ? (string) $context['send_type'] : 'manual',
				),
				'MessageSender'
			);
		}
	}

	/**
	 * Encode API response for diagnostics.
	 *
	 * @param ApiResult $result API result.
	 */
	private function encode_api_response( ApiResult $result ): string {
		$raw = $result->get_raw();

		if ( is_wp_error( $raw ) ) {
			$raw = array(
				'errors' => $raw->errors,
				'data'   => $raw->error_data,
			);
		}

		return (string) wp_json_encode(
			array(
				'http_status' => $result->get_status_code(),
				'data'        => $result->get_data(),
				'error'       => $result->get_error(),
				'raw'         => $raw,
			),
			JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES
		);
	}

	/**
	 * Get item-level API errors from a successful HTTP response.
	 *
	 * @param ApiResult $result API result.
	 * @return string[]
	 */
	private function get_item_errors( ApiResult $result ): array {
		$data  = $result->get_data();
		$items = isset( $data['items'] ) && is_array( $data['items'] ) ? $data['items'] : array();
		$errors = array();

		foreach ( $items as $item ) {
			if ( ! is_array( $item ) ) {
				continue;
			}

			$status = isset( $item['status'] ) ? (string) $item['status'] : '';

			if ( 'OK' === strtoupper( $status ) ) {
				continue;
			}

			$errors[] = '' === $status ? __( 'API did not return an item status.', 'inteltele' ) : HttpClient::translate_api_status( $status );
		}

		return array_values( array_unique( $errors ) );
	}

	/**
	 * Derive a stable error code for failed API requests.
	 *
	 * @param ApiResult $result API result.
	 */
	private function derive_error_code( ApiResult $result ): string {
		$raw = $result->get_raw();

		if ( is_wp_error( $raw ) ) {
			$codes = $raw->get_error_codes();
			return isset( $codes[0] ) ? $this->normalize_error_code( (string) $codes[0] ) : 'wp_error';
		}

		if ( $result->get_status_code() > 0 && ! $result->is_success() ) {
			return 'http_' . $result->get_status_code();
		}

		return $this->normalize_error_code( $result->get_error() );
	}

	/**
	 * Derive item-level error code.
	 *
	 * @param array<string,mixed> $item API response item.
	 * @param string              $api_status API status.
	 * @param ApiResult           $result API result.
	 */
	private function derive_item_error_code( array $item, string $api_status, ApiResult $result ): string {
		foreach ( array( 'error_code', 'code', 'status' ) as $key ) {
			if ( isset( $item[ $key ] ) && '' !== (string) $item[ $key ] ) {
				return $this->normalize_error_code( (string) $item[ $key ] );
			}
		}

		if ( '' !== $api_status ) {
			return $this->normalize_error_code( $api_status );
		}

		return $this->derive_error_code( $result );
	}

	/**
	 * Normalize arbitrary API/WP error text to a searchable code.
	 *
	 * @param string $value Error text.
	 */
	private function normalize_error_code( string $value ): string {
		$value = preg_replace( '/^error:\s*/i', '', $value );
		$value = strtolower( trim( (string) $value ) );
		$value = preg_replace( '/[^a-z0-9_:-]+/', '_', $value );
		$value = trim( (string) $value, '_' );

		return '' === $value ? 'unknown_error' : substr( $value, 0, 191 );
	}
}