<?php
namespace Formipay\Shipping;
use Formipay\Traits\SingletonTrait;

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

/**
 * Abstract Shipping Class - Core Carrier Extension System
 *
 * This class provides the hook system for carrier API extensions.
 * Carriers like Rajaongkir, Biteship, etc. can extend Formipay shipping
 * by registering themselves via the provided hooks.
 *
 * @phase 4 - Carrier API Extension System
 */
abstract class Shipping {

    use SingletonTrait;

    abstract public function add_shipping_method($shipping_methods);
    abstract public function add_shipping_settings($fields);
    abstract public function add_shipping_to_order_details($details, $form_id, $order_data);

    protected function __construct() {

        // Phase 1-3: Core shipping functionality
        add_filter( 'formipay/global-settings',                  [$this, 'add_setting_shipping_menu'], 15 );
        add_filter( 'formipay/form-config',                      [$this, 'add_form_shipping_config'], 75 );
        add_filter( 'formipay/global-settings/tab:shipping',   [$this, 'add_global_shipping_settings'], 15 );

        // Phase 4: Carrier Extension Hooks
        // Carrier registration - allows carriers to register themselves
        add_filter( 'formipay/shipping/carriers',               '__return_empty_array', 5 );

        // Carrier API keys - inject into global shipping settings
        add_filter( 'formipay/global-settings/tab:shipping',   [$this, 'add_carrier_api_settings'], 20 );

        // Checkout address fields - inject carrier-specific address fields
        add_filter( 'formipay/checkout/shipping-address-fields', [$this, 'get_carrier_address_fields'], 10, 3 );

        // Live rate fetching - allow carriers to provide real-time rates
        add_filter( 'formipay/shipping/live-rates',             '__return_empty_array', 10, 4 );

        // AJAX handler for testing carrier connection
        add_action( 'wp_ajax_formipay_test_carrier_connection', [$this, 'ajax_test_carrier_connection'], 10 );
        add_action( 'wp_ajax_nopriv_formipay_test_carrier_connection', [$this, 'ajax_test_carrier_connection'], 10 );

        // Phase 5: Checkout Integration
        // AJAX endpoint for getting available shipping methods for checkout
        add_action( 'wp_ajax_formipay_get_shipping_methods',    [$this, 'ajax_get_shipping_methods'], 10 );
        add_action( 'wp_ajax_nopriv_formipay_get_shipping_methods', [$this, 'ajax_get_shipping_methods'], 10 );

        // AJAX endpoint for getting supported countries
        add_action( 'wp_ajax_formipay_get_supported_countries', [$this, 'ajax_get_supported_countries'], 10 );
        add_action( 'wp_ajax_nopriv_formipay_get_supported_countries', [$this, 'ajax_get_supported_countries'], 10 );

        // Hook to add shipping cost to cart calculation
        add_filter( 'formipay/checkout/cart/calculation',       [$this, 'add_shipping_to_cart'], 10, 3 );

        // Hook to add shipping data to order submission
        add_filter( 'formipay/order/process-data',               [$this, 'add_shipping_to_order_data'], 10, 2 );

    }

    public function add_setting_shipping_menu($fields){

        $shipping_settings = [];

        $shipping_settings = apply_filters( 'formipay/global-settings/tab:shipping', $shipping_settings );

        if(!empty($shipping_settings)){
            $fields['shipping'] = array(
                'name' => __('Shipping', 'formipay'),
                'fields' => $shipping_settings
            );
        }

        return $fields;

    }

    /**
     * Add global shipping settings fields
     * This implements Phase 3 of the shipping module: Global Shipping Settings
     */
    public function add_global_shipping_settings($fields) {

        // Load countries from JSON file
        $countries_json = FORMIPAY_PATH . 'admin/assets/json/country.json';
        $countries = file_exists($countries_json) ? json_decode(file_get_contents($countries_json), true) : [];

        $country_options = [];
        if (is_array($countries)) {
            foreach ($countries as $country) {
                $code = $country['code'] ?? '';
                $name = $country['name'] ?? '';
                if ($code && $name) {
                    $country_options[$code] = $name;
                }
            }
        }

        // Store Origin Section
        $fields['shipping_origin_group'] = array(
            'type' => 'group_title',
            'label' => __( 'Store Origin', 'formipay' ),
            'description' => __( 'Your business location for shipping calculations', 'formipay' ),
            'group' => 'started'
        );

        $fields['shipping_origin_country'] = array(
            'type' => 'select',
            'label' => __( 'Origin Country', 'formipay' ),
            'options' => $country_options,
            'searchable' => true,
            'description' => __( 'Select the country where your products ship from', 'formipay' ),
        );

        $fields['shipping_weight_unit'] = array(
            'type' => 'select',
            'label' => __( 'Weight Unit', 'formipay' ),
            'options' => array(
                'kg' => __( 'Kilograms (kg)', 'formipay' ),
                'g' => __( 'Grams (g)', 'formipay' ),
                'lb' => __( 'Pounds (lb)', 'formipay' ),
                'oz' => __( 'Ounces (oz)', 'formipay' ),
            ),
            'value' => 'kg',
        );

        $fields['shipping_dimension_unit'] = array(
            'type' => 'select',
            'label' => __( 'Dimension Unit', 'formipay' ),
            'options' => array(
                'cm' => __( 'Centimeters (cm)', 'formipay' ),
                'in' => __( 'Inches (in)', 'formipay' ),
                'm' => __( 'Meters (m)', 'formipay' ),
            ),
            'value' => 'cm',
            'group' => 'ended'
        );

        // Shipping Calculation Method
        $fields['shipping_calculation_group'] = array(
            'type' => 'group_title',
            'label' => __( 'Shipping Calculation', 'formipay' ),
            'description' => __( 'How shipping costs are calculated for orders', 'formipay' ),
            'group' => 'started'
        );

        $fields['shipping_calculation_method'] = array(
            'type' => 'select',
            'label' => __( 'Calculation Method', 'formipay' ),
            'options' => array(
                'per_order' => __( 'Per Order (single shipping fee for entire order)', 'formipay' ),
                'per_item' => __( 'Per Item (shipping fee multiplied by quantity)', 'formipay' ),
            ),
            'value' => 'per_order',
            'group' => 'ended'
        );

        // Supported Destinations Section
        $fields['shipping_destinations_group'] = array(
            'type' => 'group_title',
            'label' => __( 'Supported Destinations', 'formipay' ),
            'description' => __( 'Configure which countries you ship to and their shipping rates', 'formipay' ),
            'group' => 'started'
        );

        // Get enabled currencies for flat rate table
        $formipay_settings = get_option('formipay_settings', []);
        $enabled_currencies = [];

        if (!empty($formipay_settings['multicurrencies']) && is_array($formipay_settings['multicurrencies'])) {
            foreach ($formipay_settings['multicurrencies'] as $currency) {
                if (isset($currency['currency'])) {
                    $parts = explode(':::', $currency['currency']);
                    $enabled_currencies[] = [
                        'code' => $parts[0] ?? '',
                        'title' => $parts[1] ?? '',
                        'symbol' => $parts[2] ?? $parts[0] ?? '',
                    ];
                }
            }
        }

        // Fallback to default currency if multicurrency is not enabled
        if (empty($enabled_currencies)) {
            $default_currency = $formipay_settings['default_currency'] ?? 'IDR:::Indonesian rupiah:::Rp';
            $parts = explode(':::', $default_currency);
            $enabled_currencies[] = [
                'code' => $parts[0] ?? 'IDR',
                'title' => $parts[1] ?? 'Indonesian rupiah',
                'symbol' => $parts[2] ?? 'Rp',
            ];
        }

        // Build currency amount fields for the repeater
        $currency_fields = [];
        foreach ($enabled_currencies as $curr) {
            $code = $curr['code'];
            $symbol = $curr['symbol'];
            $currency_fields['flat_rate_' . $code] = array(
                'type' => 'number',
                'label' => sprintf(__( 'Flat Rate (%s)', 'formipay' ), $code),
                'step' => 0.01,
                'min' => 0,
                'placeholder' => '0.00',
            );
        }

        // Build free shipping threshold field (use primary currency)
        $primary_currency = $enabled_currencies[0] ?? [];
        $primary_symbol = $primary_currency['symbol'] ?? '';

        $fields['shipping_destinations'] = array(
            'type' => 'repeater',
            'label' => __( 'Destinations', 'formipay' ),
            'description' => __( 'Add countries you ship to and configure their shipping options', 'formipay' ),
            'fields' => array_merge(
                [
                    'country' => array(
                        'type' => 'select',
                        'label' => __('Country', 'formipay'),
                        'options' => $country_options,
                        'required' => true,
                        'searchable' => true,
                        'is_group_title' => true
                    ),
                    'rate_source' => array(
                        'type' => 'select',
                        'label' => __('Rate Source', 'formipay'),
                        'options' => array(
                            'flat_rate' => __( 'Flat Rate', 'formipay' ),
                            // 'api' => __( 'Carrier API', 'formipay' ), // Phase 4
                        ),
                        'value' => 'flat_rate',
                    ),
                ],
                $currency_fields,
                [
                    'free_shipping_threshold' => array(
                        'type' => 'number',
                        'label' => sprintf(__( 'Free Shipping Threshold (%s)', 'formipay' ), $primary_symbol),
                        'description' => __( 'Order amount above which shipping is free. Leave empty to disable.', 'formipay' ),
                        'step' => 0.01,
                        'min' => 0,
                        'placeholder' => 'Empty = disabled',
                    ),
                ]
            )
        );

        // Note: Carrier API settings will be added in Phase 4
        $fields['carrier_api_note'] = array(
            'type' => 'notification_message',
            'description' => __( '
                <h3>Carrier API Integration</h3>
                <p>Live carrier rates (Rajaongkir, Biteship, etc.) will be available in Phase 4 of the shipping module.</p>
                <p>Currently, only Flat Rate and Free Shipping methods are available at the product level.</p>
            ', 'formipay' ),
        );

        return $fields;

    }

    /**
     * Add shipping configuration to form settings
     * This replaces product-level shipping with form-level shipping
     */
    public function add_form_shipping_config($fields) {

        $shipping_methods = apply_filters( 'formipay/form-settings/tab:shipping/method', [
            'no_shipping' => [
                'method' => __( 'No Shipping Required', 'formipay' )
            ],
            'flat_rate' => [
                'method' => __( 'Flat Rate', 'formipay' )
            ],
            'free_shipping' => [
                'method' => __( 'Free Shipping', 'formipay' )
            ]
        ] );

        $shipping_options = [];
        foreach($shipping_methods as $id => $shipping){
            $label = $shipping['method'];
            if(isset($shipping['courier'])){
                $label .= ' - '.$shipping['courier'];
                if(isset($shipping['service'])){
                    $label .= ' - '.$shipping['service'];
                }
            }
            $shipping_options[$id] = $label;
        }

        // Main shipping configuration group
        $shipping_config_group = [
            'shipping_enable_group' => [
                'type'          => 'group_title',
                'label'         => __( 'Shipping Configuration', 'formipay' ),
                'description'   => __( 'Configure shipping options for this form. Shipping will be calculated based on form settings, not per-product.', 'formipay' ),
                'group'         => 'started'
            ],
            'shipping_enabled' => [
                'type'          => 'radio',
                'label'         => __( 'Shipping Method', 'formipay' ),
                'options'       => $shipping_options,
                'value'         => 'no_shipping',
                'description'   => __( 'Select how shipping should be handled for orders from this form', 'formipay' ),
            ]
        ];

        $shipping_config_group = apply_filters( 'formipay/form-settings/tab:shipping/group:config', $shipping_config_group );
        $last_config_key = array_key_last($shipping_config_group);
        $shipping_config_group[$last_config_key]['group'] = 'ended';

        // Apply carrier-specific settings (Flat Rate, etc.)
        $carrier_settings = apply_filters( 'formipay/form-settings/tab:shipping', [] );

        $all_shipping_fields = array_merge($shipping_config_group, $carrier_settings);

        $fields['formipay_form_settings']['shipping'] = [
            'name'      => __( 'Shipping', 'formipay' ),
            'fields'    => $all_shipping_fields
        ];

        return $fields;

    }

    /**
     * =============================================
     * PHASE 4: CARRIER EXTENSION HOOKS
     * =============================================
     */

    /**
     * Add carrier API settings to global shipping settings
     * Carriers can hook into `formipay/global-settings/tab:shipping/carriers` to add their API key fields
     *
     * @param array $fields Existing shipping settings fields
     * @return array Updated fields with carrier API settings
     */
    public function add_carrier_api_settings($fields) {

        // Get all registered carriers
        $carriers = apply_filters('formipay/shipping/carriers', []);

        if (empty($carriers)) {
            // No carriers registered, add info message
            $fields['carrier_api_info'] = array(
                'type' => 'notification_message',
                'description' => __( '
                    <h3>Carrier API Integration</h3>
                    <p>To enable live shipping rates, install a carrier extension plugin.</p>
                    <p>Extensions register themselves via the <code>formipay/shipping/carriers</code> filter.</p>
                ', 'formipay' ),
            );
            return $fields;
        }

        // Add carrier API settings section
        $fields['carrier_api_group'] = array(
            'type' => 'group_title',
            'label' => __( 'Carrier API Keys', 'formipay' ),
            'description' => __( 'Configure API credentials for live shipping rate calculation', 'formipay' ),
            'group' => 'started'
        );

        // Allow carriers to inject their API key fields
        $carrier_fields = apply_filters('formipay/global-settings/tab:shipping/carriers', []);

        foreach ($carrier_fields as $key => $field) {
            $fields[$key] = $field;
        }

        // Add test connection buttons for each carrier
        foreach ($carriers as $carrier_id => $carrier) {
            if (isset($carrier['test_connection']) && $carrier['test_connection']) {
                $fields['test_connection_' . $carrier_id] = array(
                    'type' => 'html',
                    'label' => __( 'Test Connection', 'formipay' ),
                    'html' => sprintf(
                        '<button type="button" class="button formipay-test-connection" data-carrier="%s">%s</button>
                         <span class="formipay-connection-result" style="margin-left: 10px;"></span>',
                        esc_attr($carrier_id),
                        esc_html__('Test Connection', 'formipay')
                    ),
                    'group' => ($carrier_id === array_key_last($carriers)) ? 'ended' : null,
                );
            }
        }

        return $fields;

    }

    /**
     * Get carrier-specific address fields for checkout
     * Carriers can hook into `formipay/checkout/address-fields/{carrier_id}` to provide their fields
     *
     * @param array $fields Current address fields
     * @param string $carrier_id Carrier identifier (e.g., 'rajaongkir', 'biteship')
     * @param string $country_code Destination country code
     * @return array Address fields for this carrier
     */
    public function get_carrier_address_fields($fields, $carrier_id, $country_code) {

        // Get carrier-specific address fields
        $carrier_fields = apply_filters('formipay/checkout/address-fields/' . $carrier_id, [], $country_code);

        return array_merge($fields, $carrier_fields);

    }

    /**
     * AJAX handler for testing carrier connection
     * Carriers can hook into `formipay/test_carrier_connection/{carrier_id}` to handle the test
     */
    public function ajax_test_carrier_connection() {

        check_ajax_referer('formipay-admin', 'nonce', true);

        if (!current_user_can('manage_options')) {
            wp_send_json_error(['message' => __('Unauthorized', 'formipay')]);
        }

        $carrier_id = isset($_POST['carrier']) ? sanitize_text_field(wp_unslash($_POST['carrier'])) : '';

        if (empty($carrier_id)) {
            wp_send_json_error(['message' => __('Missing carrier ID', 'formipay')]);
        }

        // Allow carriers to handle their own connection test
        $result = apply_filters('formipay/test_carrier_connection/' . $carrier_id, [
            'success' => false,
            'message' => __('Carrier does not implement connection test', 'formipay'),
        ], $_POST);

        if ($result['success']) {
            wp_send_json_success($result);
        } else {
            wp_send_json_error($result);
        }

    }

    /**
     * Helper method: Get registered carriers
     * Returns all carriers that have registered via the filter
     *
     * @return array Registered carriers
     */
    public static function get_registered_carriers() {

        return apply_filters('formipay/shipping/carriers', []);

    }

    /**
     * Helper method: Get carrier by ID
     *
     * @param string $carrier_id Carrier identifier
     * @return array|null Carrier data or null if not found
     */
    public static function get_carrier($carrier_id) {

        $carriers = self::get_registered_carriers();
        return $carriers[$carrier_id] ?? null;

    }

    /**
     * Helper method: Check if carrier supports a country
     *
     * @param string $carrier_id Carrier identifier
     * @param string $country_code Country code to check
     * @return bool True if carrier supports the country
     */
    public static function carrier_supports_country($carrier_id, $country_code) {

        $carrier = self::get_carrier($carrier_id);
        if (!$carrier) {
            return false;
        }

        $supported_countries = $carrier['countries'] ?? [];
        return in_array($country_code, $supported_countries, true);

    }

    /**
     * Helper method: Fetch live rates from carrier
     *
     * @param string $carrier_id Carrier identifier
     * @param array $params Rate request parameters (origin, destination, weight, dimensions)
     * @return array Available rates with costs
     */
    public static function fetch_live_rates($carrier_id, $params) {

        $default_params = [
            'origin_country' => '',
            'origin_city' => '',
            'origin_postcode' => '',
            'destination_country' => '',
            'destination_city' => '',
            'destination_postcode' => '',
            'weight' => 0,
            'weight_unit' => 'kg',
            'length' => 0,
            'width' => 0,
            'height' => 0,
            'dimension_unit' => 'cm',
        ];

        $params = wp_parse_args($params, $default_params);

        return apply_filters('formipay/shipping/live-rates', [], $carrier_id, $params);

    }

    /**
     * =============================================
     * PHASE 5: CHECKOUT INTEGRATION
     * =============================================
     */

    /**
     * AJAX: Get available shipping methods for a form
     * Now reads from form-level shipping settings instead of global settings
     */
    public function ajax_get_shipping_methods() {

        check_ajax_referer('formipay-public', 'nonce', true);

        $form_id = isset($_POST['form_id']) ? intval($_POST['form_id']) : 0;
        $country_code = isset($_POST['country']) ? sanitize_text_field(wp_unslash($_POST['country'])) : '';
        $currency = isset($_POST['currency']) ? sanitize_text_field(wp_unslash($_POST['currency'])) : '';

        if (!$form_id) {
            wp_send_json_error(['message' => __('Invalid request', 'formipay')]);
        }

        // Get form shipping settings
        $form_settings = get_post_meta($form_id, 'formipay_form_settings', true);
        $shipping_enabled = $form_settings['shipping_enabled'] ?? 'no_shipping';

        $available_methods = [];

        if ($shipping_enabled === 'flat_rate') {
            // Get flat rate from form settings
            $currency_code = $currency ?: 'IDR';
            $rate_key = 'flat_rate_amount_' . $currency_code;
            $flat_rate = floatval($form_settings[$rate_key] ?? 0);
            $flat_rate_type = $form_settings['flat_rate_type'] ?? 'fixed';

            // For percentage, we'll calculate on frontend based on cart total
            // For now, store the type so frontend knows how to handle it
            $available_methods[] = [
                'id' => 'flat_rate',
                'name' => __('Standard Shipping', 'formipay'),
                'description' => $flat_rate_type === 'percentage'
                    ? sprintf(__('%s%% of order total', 'formipay'), $flat_rate)
                    : __('Delivery in 3-5 business days', 'formipay'),
                'cost' => $flat_rate,
                'currency' => $currency_code,
                'type' => $flat_rate_type,
            ];

        } elseif ($shipping_enabled === 'free_shipping') {
            // Free shipping from form settings
            $free_label = $form_settings['free_shipping_label'] ?? __('Free Shipping', 'formipay');
            $available_methods[] = [
                'id' => 'free_shipping',
                'name' => $free_label,
                'description' => __('No shipping cost', 'formipay'),
                'cost' => 0,
                'currency' => $currency_code ?? '',
            ];
        }

        // If country-specific shipping is needed in future, add check here
        // For now, form-level shipping applies to all countries

        if (empty($available_methods)) {
            wp_send_json_error([
                'message' => __('Shipping is not available for this form', 'formipay'),
                'methods' => []
            ]);
        }

        wp_send_json_success([
            'methods' => $available_methods,
            'default_method' => $available_methods[0]['id'],
        ]);

    }

    /**
     * Add shipping cost to cart calculation
     * Hooked into formipay/checkout/cart/calculation
     */
    public function add_shipping_to_cart($cart, $form_id, $selected_currency) {

        // Check if shipping is enabled for this form
        $form_settings = get_post_meta($form_id, 'formipay_form_settings', true);
        $shipping_enabled = $form_settings['shipping_enabled'] ?? 'no_shipping';

        if ($shipping_enabled === 'no_shipping') {
            return $cart;
        }

        // Get selected shipping method from POST data or session
        $shipping_method = isset($_POST['shipping_method']) ? sanitize_text_field(wp_unslash($_POST['shipping_method'])) : '';
        $shipping_country = isset($_POST['shipping_country']) ? sanitize_text_field(wp_unslash($_POST['shipping_country'])) : '';

        if (empty($shipping_method) || empty($shipping_country)) {
            return $cart;
        }

        // Parse shipping method ID to get cost
        // Format: flat_rate, free_shipping, or {carrier}_{service}
        if ($shipping_method === 'free_shipping') {
            // Free shipping
            $cart['shipping'] = [
                'name' => __('Free Shipping', 'formipay'),
                'cost' => 0,
            ];
        } elseif ($shipping_method === 'flat_rate') {
            // Flat rate - get cost from form settings
            $currency_code = $selected_currency ?: 'IDR';
            $rate_key = 'flat_rate_amount_' . $currency_code;
            $flat_rate = floatval($form_settings[$rate_key] ?? 0);

            // Check if percentage
            $flat_rate_type = $form_settings['flat_rate_type'] ?? 'fixed';
            if ($flat_rate_type === 'percentage') {
                $subtotal = floatval($cart['subtotal'] ?? 0);
                $flat_rate = ($subtotal * $flat_rate) / 100;
            }

            $cart['shipping'] = [
                'name' => __('Standard Shipping', 'formipay'),
                'cost' => $flat_rate,
            ];

            // Recalculate totals
            $cart['subtotal'] = floatval($cart['subtotal'] ?? 0);
            $cart['tax'] = floatval($cart['tax'] ?? 0);
            $cart['discount'] = floatval($cart['discount'] ?? 0);

            $cart['grand'] = $cart['subtotal'] + $cart['tax'] + $cart['shipping']['cost'] - $cart['discount'];
        }

        return $cart;

    }

    /**
     * Add shipping data to order submission
     * Hooked into formipay/order/process-data
     */
    public function add_shipping_to_order_data($form_data, $form_id) {

        // Check if shipping is enabled for this form
        $form_settings = get_post_meta($form_id, 'formipay_form_settings', true);
        $shipping_enabled = $form_settings['shipping_enabled'] ?? 'no_shipping';

        if ($shipping_enabled === 'no_shipping') {
            return $form_data;
        }

        // Add shipping info to form data
        if (isset($_POST['shipping_method'])) {
            $form_data['shipping_method'] = sanitize_text_field(wp_unslash($_POST['shipping_method']));
        }

        if (isset($_POST['shipping_country'])) {
            $form_data['shipping_country'] = sanitize_text_field(wp_unslash($_POST['shipping_country']));
        }

        return $form_data;

    }

    /**
     * AJAX: Get supported shipping countries
     * With form-level shipping, returns all available countries
     */
    public function ajax_get_supported_countries() {

        // Verify nonce
        if (!isset($_POST['nonce']) || !wp_verify_nonce(sanitize_text_field(wp_unslash($_POST['nonce'])), 'formipay_public_nonce')) {
            wp_send_json_error(['message' => __('Invalid security token', 'formipay')]);
        }

        $form_id = isset($_POST['form_id']) ? intval($_POST['form_id']) : 0;

        if (!$form_id) {
            wp_send_json_error(['message' => __('Invalid form ID', 'formipay')]);
        }

        // Load countries from JSON file
        $countries_json = FORMIPAY_PATH . 'admin/assets/json/country.json';
        $all_countries = file_exists($countries_json) ? json_decode(file_get_contents($countries_json), true) : [];

        // Build country list
        $countries = [];
        if (is_array($all_countries)) {
            foreach ($all_countries as $country) {
                $code = $country['code'] ?? '';
                $name = $country['name'] ?? '';
                if ($code && $name) {
                    $countries[$code] = $name;
                }
            }
        }

        if (empty($countries)) {
            wp_send_json_error([
                'message' => __('No countries available', 'formipay'),
                'countries' => []
            ]);
        }

        wp_send_json_success([
            'countries' => $countries,
        ]);

    }

}