<?php
/**
 * SMS Manager
 *
 * Manages SMS provider selection and message sending
 */
class TWP_SMS_Manager {

    private static $provider = null;

    /**
     * Get the active SMS provider instance
     *
     * @return TWP_SMS_Provider|null
     */
    public static function get_provider() {
        if (self::$provider !== null) {
            return self::$provider;
        }

        // Load interface and providers
        require_once dirname(__FILE__) . '/interface-twp-sms-provider.php';
        require_once dirname(__FILE__) . '/class-twp-sms-provider-twilio.php';
        require_once dirname(__FILE__) . '/class-twp-sms-provider-sns.php';

        // Get selected provider from settings
        $selected_provider = get_option('twp_sms_provider', 'twilio');

        switch ($selected_provider) {
            case 'aws_sns':
                self::$provider = new TWP_SMS_Provider_SNS();
                break;

            case 'twilio':
            default:
                self::$provider = new TWP_SMS_Provider_Twilio();
                break;
        }

        return self::$provider;
    }

    /**
     * Send an SMS message using the configured provider
     *
     * @param string $to_number Recipient phone number (E.164 format)
     * @param string $message Message body
     * @param string $from_number Sender phone number (E.164 format)
     * @return array Response array with 'success' and 'data' or 'error'
     */
    public static function send_sms($to_number, $message, $from_number = null) {
        $provider = self::get_provider();

        if (!$provider) {
            return [
                'success' => false,
                'error' => 'No SMS provider configured'
            ];
        }

        // Validate provider configuration before sending
        $validation = $provider->validate_configuration();
        if (!$validation['success']) {
            error_log('TWP SMS Error: Provider validation failed - ' . $validation['error']);
            return $validation;
        }

        // Send SMS
        $result = $provider->send_sms($to_number, $message, $from_number);

        // Log the result
        if ($result['success']) {
            error_log(sprintf(
                'TWP SMS: Message sent via %s to %s',
                $provider->get_provider_name(),
                $to_number
            ));
        } else {
            error_log(sprintf(
                'TWP SMS Error: Failed to send via %s to %s - %s',
                $provider->get_provider_name(),
                $to_number,
                $result['error'] ?? 'Unknown error'
            ));
        }

        return $result;
    }

    /**
     * Get list of available SMS providers
     *
     * @return array Array of provider IDs and names
     */
    public static function get_available_providers() {
        return [
            'twilio' => 'Twilio',
            'aws_sns' => 'Amazon SNS'
        ];
    }

    /**
     * Validate current provider configuration
     *
     * @return array Response array with 'success' and 'message' or 'error'
     */
    public static function validate_current_provider() {
        $provider = self::get_provider();

        if (!$provider) {
            return [
                'success' => false,
                'error' => 'No SMS provider configured'
            ];
        }

        return $provider->validate_configuration();
    }

    /**
     * Get current provider name
     *
     * @return string Provider name
     */
    public static function get_current_provider_name() {
        $provider = self::get_provider();

        if (!$provider) {
            return 'None';
        }

        return $provider->get_provider_name();
    }

    /**
     * Test SMS send
     *
     * @param string $to_number Test recipient number
     * @return array Response array
     */
    public static function send_test_sms($to_number) {
        $message = sprintf(
            'This is a test message from Twilio WordPress Plugin using %s provider at %s',
            self::get_current_provider_name(),
            current_time('Y-m-d H:i:s')
        );

        return self::send_sms($to_number, $message);
    }
}