<?php
/**
 * WHMCS API Handler
 *
 * Handles all communication with WHMCS API
 */

// Exit if accessed directly
if (!defined('ABSPATH')) {
    exit;
}

class WHMCS_Pricing_API {

    /**
     * Get settings
     */
    private static function get_settings() {
        $defaults = array(
            'api_url' => '',
            'api_identifier' => '',
            'api_secret' => '',
            'cache_duration' => 3600,
            'default_currency' => 'USD',
            'show_decimals' => true,
            'debug_mode' => false
        );

        $settings = get_option('whmcs_pricing_settings', $defaults);
        return wp_parse_args($settings, $defaults);
    }

    /**
     * Make API request to WHMCS
     */
    private static function make_request($action, $params = array()) {
        $settings = self::get_settings();

        // Validate settings
        if (empty($settings['api_url']) || empty($settings['api_identifier']) || empty($settings['api_secret'])) {
            self::log_error('API credentials not configured');
            return new WP_Error('missing_credentials', __('WHMCS API credentials not configured', 'whmcs-pricing'));
        }

        // Prepare API request
        $api_url = rtrim($settings['api_url'], '/') . '/includes/api.php';

        $post_data = array_merge(array(
            'action' => $action,
            'identifier' => $settings['api_identifier'],
            'secret' => $settings['api_secret'],
            'responsetype' => 'json'
        ), $params);

        // Make request
        $response = wp_remote_post($api_url, array(
            'timeout' => 15,
            'body' => $post_data,
            'sslverify' => true
        ));

        // Check for errors
        if (is_wp_error($response)) {
            self::log_error('API request failed: ' . $response->get_error_message());
            return $response;
        }

        // Parse response
        $body = wp_remote_retrieve_body($response);
        $data = json_decode($body, true);

        if (json_last_error() !== JSON_ERROR_NONE) {
            self::log_error('Invalid JSON response from WHMCS API');
            return new WP_Error('invalid_response', __('Invalid response from WHMCS API', 'whmcs-pricing'));
        }

        // Check API result
        if (isset($data['result']) && $data['result'] === 'error') {
            $error_message = isset($data['message']) ? $data['message'] : __('Unknown API error', 'whmcs-pricing');
            self::log_error('WHMCS API error: ' . $error_message);
            return new WP_Error('api_error', $error_message);
        }

        return $data;
    }

    /**
     * Get product details
     */
    public static function get_product($product_id) {
        $cache_key = 'whmcs_product_' . $product_id;
        $cached_data = get_transient($cache_key);

        if (false !== $cached_data && !self::is_debug_mode()) {
            return $cached_data;
        }

        // Make API request
        $response = self::make_request('GetProducts', array(
            'pid' => $product_id
        ));

        if (is_wp_error($response)) {
            return $response;
        }

        // Extract product data
        if (!isset($response['products']) || !isset($response['products']['product'])) {
            self::log_error('Product not found: ' . $product_id);
            return new WP_Error('product_not_found', __('Product not found', 'whmcs-pricing'));
        }

        $product_data = is_array($response['products']['product']) && isset($response['products']['product'][0])
            ? $response['products']['product'][0]
            : $response['products']['product'];

        // Debug log the product data structure
        if (self::is_debug_mode()) {
            self::log_error('Product data for ID ' . $product_id . ': ' . print_r($product_data, true));
        }

        // Cache the result
        $settings = self::get_settings();
        set_transient($cache_key, $product_data, absint($settings['cache_duration']));

        return $product_data;
    }

    /**
     * Get product price
     */
    public static function get_price($product_id, $args = array()) {
        $defaults = array(
            'billing_cycle' => 'monthly',
            'currency' => null,
            'format' => 'default'
        );

        $args = wp_parse_args($args, $defaults);
        $settings = self::get_settings();

        // Use default currency if not specified
        if (empty($args['currency'])) {
            $args['currency'] = $settings['default_currency'];
        }

        // Get product data
        $product = self::get_product($product_id);

        if (is_wp_error($product)) {
            return $product;
        }

        // Find pricing for the requested currency and billing cycle
        $price = self::extract_price($product, $args['billing_cycle'], $args['currency']);

        if (is_wp_error($price)) {
            return $price;
        }

        // Format the price
        return self::format_price($price, $args['currency'], $args['format']);
    }

    /**
     * Extract price from product data
     */
    private static function extract_price($product, $billing_cycle, $currency) {
        // Normalize billing cycle
        $cycle_map = array(
            'monthly' => 'monthly',
            'quarterly' => 'quarterly',
            'semiannually' => 'semiannually',
            'annually' => 'annually',
            'biennially' => 'biennially',
            'triennially' => 'triennially',
            'month' => 'monthly',
            'quarter' => 'quarterly',
            'year' => 'annually',
            'annual' => 'annually'
        );

        $billing_cycle = strtolower($billing_cycle);
        $billing_cycle = isset($cycle_map[$billing_cycle]) ? $cycle_map[$billing_cycle] : $billing_cycle;

        // Debug pricing structure
        if (self::is_debug_mode()) {
            self::log_error("Looking for price: currency={$currency}, cycle={$billing_cycle}");
            if (isset($product['pricing'])) {
                self::log_error('Available pricing: ' . print_r($product['pricing'], true));
            }
        }

        // Look for pricing in product data
        if (isset($product['pricing'][$currency][$billing_cycle])) {
            $price = floatval($product['pricing'][$currency][$billing_cycle]);

            // WHMCS uses -1.00 to indicate billing cycle not available
            if ($price < 0) {
                if (self::is_debug_mode()) {
                    self::log_error("Price is -1 (not available) for cycle: {$billing_cycle}");
                }
                return new WP_Error('price_not_available', __('This billing cycle is not available for this product', 'whmcs-pricing'));
            }

            if (self::is_debug_mode()) {
                self::log_error("Found price: {$price}");
            }
            return $price;
        }

        // Try to find any available pricing and log it
        if (self::is_debug_mode() && isset($product['pricing'])) {
            self::log_error("Available currencies: " . implode(', ', array_keys($product['pricing'])));
            if (isset($product['pricing'][$currency])) {
                self::log_error("Available cycles for {$currency}: " . implode(', ', array_keys($product['pricing'][$currency])));
            }
        }

        self::log_error("Price not found for product {$product['pid']}, cycle: {$billing_cycle}, currency: {$currency}");
        return new WP_Error('price_not_found', __('Price not available for selected options', 'whmcs-pricing'));
    }

    /**
     * Format price
     */
    private static function format_price($price, $currency, $format) {
        $settings = self::get_settings();

        // Apply decimal formatting
        if ($format === 'no_decimals' || !$settings['show_decimals']) {
            $price = round($price);
            $formatted_price = number_format($price, 0);
        } else {
            $formatted_price = number_format($price, 2);
        }

        // Get currency symbol
        $currency_symbol = self::get_currency_symbol($currency);

        return array(
            'raw' => $price,
            'formatted' => $formatted_price,
            'currency' => $currency,
            'symbol' => $currency_symbol
        );
    }

    /**
     * Get currency symbol
     */
    private static function get_currency_symbol($currency) {
        $symbols = array(
            'USD' => '$',
            'EUR' => '€',
            'GBP' => '£',
            'AUD' => 'A$',
            'CAD' => 'C$',
            'JPY' => '¥',
            'CNY' => '¥',
            'INR' => '₹',
            'BRL' => 'R$',
            'RUB' => '₽',
            'CHF' => 'Fr',
            'SEK' => 'kr',
            'NOK' => 'kr',
            'DKK' => 'kr',
            'PLN' => 'zł',
            'THB' => '฿',
            'MYR' => 'RM',
            'SGD' => 'S$',
            'NZD' => 'NZ$',
            'MXN' => 'Mex$',
            'ZAR' => 'R'
        );

        return isset($symbols[$currency]) ? $symbols[$currency] : $currency;
    }

    /**
     * Clear cache for specific product
     */
    public static function clear_cache($product_id) {
        delete_transient('whmcs_product_' . $product_id);
    }

    /**
     * Clear all cached products
     */
    public static function clear_all_cache() {
        global $wpdb;

        $wpdb->query(
            "DELETE FROM {$wpdb->options}
            WHERE option_name LIKE '_transient_whmcs_product_%'
            OR option_name LIKE '_transient_timeout_whmcs_product_%'"
        );
    }

    /**
     * Check if debug mode is enabled
     */
    private static function is_debug_mode() {
        $settings = self::get_settings();
        return !empty($settings['debug_mode']);
    }

    /**
     * Log error message
     */
    private static function log_error($message) {
        if (self::is_debug_mode() && function_exists('error_log')) {
            error_log('[WHMCS Pricing] ' . $message);
        }
    }
}