<?php
defined( 'ABSPATH' ) || exit;

class Extnify_Offer_Plugin {

    private static $instance = null;

    public static function instance(): self {
        if ( null === self::$instance ) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    private function __construct() {
        $this->includes();
        $this->init_hooks();
    }

    private function includes(): void {
        // Model + fee engine: needed on both frontend and admin.
        require_once EXTNIFY_OFFER_PLUGIN_PATH . 'admin/model.php';
        Extnify_Offer_Model::maybe_upgrade(); // sync DB schema (handles updates, not just activation)
        require_once EXTNIFY_OFFER_PLUGIN_PATH . 'front/class-offer.php';

        if ( is_admin() ) {
            require_once EXTNIFY_OFFER_PLUGIN_PATH . 'system/extnify-core/ui/autoloader.php';
            require_once EXTNIFY_OFFER_PLUGIN_PATH . 'system/framework/traits/woo-helpers.php';
            require_once EXTNIFY_OFFER_PLUGIN_PATH . 'admin/controller.php';
            new Extnify_Offer_Back( new Extnify_Offer_Model() );
        }
    }

    private function init_hooks(): void {
        // Translations load automatically on WP 4.6+ (slug = text domain = "extnify-offer"),
        // so no load_plugin_textdomain() call is needed.
        //
        // Offers are added to the cart/checkout totals via woocommerce_cart_calculate_fees.
        // The engine reads the shared methods table and calls WC()->cart->add_fee().
        add_action( 'woocommerce_cart_calculate_fees', array( $this, 'calculate_fees' ) );

        // ── Selectable offers: a row inside the cart/checkout totals table, styled like
        // the Shipment row. Position is store-configurable (After Subtotal / Before Tax /
        // Before Total). These rows live inside the fragments WooCommerce refreshes, so
        // the list re-evaluates on a shipping change with no JS. The applied discount stays
        // a real (taxable, recorded) fee; its separate line is hidden in front.js.
        $pos        = (string) ( ( (array) get_option( 'extnify_offer', array() ) )['offer_position'] ?? 'before_tax' );
        $cart_hooks = array(
            'after_subtotal' => 'woocommerce_cart_totals_before_shipping',
            'before_tax'     => 'woocommerce_cart_totals_after_shipping',
            'before_total'   => 'woocommerce_cart_totals_before_order_total',
        );
        $chk_hooks  = array(
            'after_subtotal' => 'woocommerce_review_order_before_shipping',
            'before_tax'     => 'woocommerce_review_order_after_shipping',
            'before_total'   => 'woocommerce_review_order_before_order_total',
        );
        add_action( $cart_hooks[ $pos ] ?? $cart_hooks['before_tax'], array( $this, 'render_offers_row' ) );
        add_action( $chk_hooks[ $pos ] ?? $chk_hooks['before_tax'], array( $this, 'render_offers_row' ) );
        add_action( 'wp_enqueue_scripts',                     array( $this, 'enqueue_front' ) );
        add_action( 'wp_ajax_x_offer_apply',                  array( $this, 'ajax_apply' ) );
        add_action( 'wp_ajax_nopriv_x_offer_apply',           array( $this, 'ajax_apply' ) );
        add_action( 'wp_ajax_x_offer_get_offers',             array( $this, 'ajax_get_offers' ) );
        add_action( 'wp_ajax_nopriv_x_offer_get_offers',      array( $this, 'ajax_get_offers' ) );

        // Block (Store-API) checkout: expose offers + accept the selection.
        add_action( 'woocommerce_blocks_loaded', array( $this, 'register_store_api' ) );
    }

    /** Register the offers data + selection update on the Cart Store API (block checkout). */
    public function register_store_api(): void {
        if ( ! function_exists( 'woocommerce_store_api_register_endpoint_data' )
            || ! function_exists( 'woocommerce_store_api_register_update_callback' ) ) {
            return;
        }
        woocommerce_store_api_register_endpoint_data( array(
            'endpoint'        => 'cart',
            'namespace'       => 'extnify-offer',
            'data_callback'   => array( $this, 'store_api_data' ),
            'schema_callback' => array( $this, 'store_api_schema' ),
            'schema_type'     => ARRAY_A,
        ) );
        woocommerce_store_api_register_update_callback( array(
            'namespace' => 'extnify-offer',
            'callback'  => array( $this, 'store_api_update' ),
        ) );
    }

    /** Store API payload: eligible offers + mode + heading. */
    public function store_api_data(): array {
        $offers = ( function_exists( 'WC' ) && WC()->cart ) ? ( new Extnify_Offer_Offer() )->eligible_offers( WC()->cart ) : array();
        $cfg    = (array) get_option( 'extnify_offer', array() );
        return array(
            'offers'  => array_values( $offers ),
            'single'  => ( ( $cfg['offer_type'] ?? 'multiple' ) === 'single' ),
            'heading' => ! empty( $cfg['offer_heading'] ) ? (string) $cfg['offer_heading'] : __( 'Recommended Offers', 'extnify-offer' ),
        );
    }

    /** Store API schema. */
    public function store_api_schema(): array {
        return array(
            'offers'  => array( 'description' => __( 'Eligible offers for the current cart.', 'extnify-offer' ), 'type' => 'array', 'readonly' => true ),
            'single'  => array( 'description' => __( 'Single-selection mode.', 'extnify-offer' ), 'type' => 'boolean', 'readonly' => true ),
            'heading' => array( 'description' => __( 'Offers box heading.', 'extnify-offer' ), 'type' => 'string', 'readonly' => true ),
        );
    }

    /** Store API update: persist the shopper's selection (triggers a recalc). */
    public function store_api_update( $data ): void {
        $ids = isset( $data['offers'] ) ? array_map( 'intval', (array) $data['offers'] ) : array();
        ( new Extnify_Offer_Offer() )->set_chosen( $ids );
    }

    /** Enqueue the storefront offers-widget assets on cart/checkout only. */
    public function enqueue_front(): void {
        if ( ! function_exists( 'is_cart' ) || ! ( is_cart() || is_checkout() ) ) {
            return;
        }
        $base = EXTNIFY_OFFER_PLUGIN_URL;
        $path = EXTNIFY_OFFER_PLUGIN_PATH;
        $fb   = defined( 'EXTNIFY_OFFER_PLUGIN_VERSION' ) ? EXTNIFY_OFFER_PLUGIN_VERSION : '1.0.0';
        // Version assets by filemtime so a plain `cp` of a changed CSS/JS busts the cache
        // (matches the admin-asset convention); fall back to the plugin version.
        $ver  = function ( $rel ) use ( $path, $fb ) {
            return file_exists( $path . $rel ) ? filemtime( $path . $rel ) : $fb;
        };
        wp_enqueue_style( 'xoffer-front', $base . 'assets/css/front.css', array(), $ver( 'assets/css/front.css' ) );
        wp_enqueue_script( 'xoffer-front', $base . 'assets/js/front.js', array( 'jquery' ), $ver( 'assets/js/front.js' ), true );
        wp_localize_script( 'xoffer-front', 'XOfferFront', array(
            'ajax'  => admin_url( 'admin-ajax.php' ),
            'nonce' => wp_create_nonce( 'x_offer_front' ),
        ) );

        // Block (Store-API) checkout widget — renders only when the Blocks runtime
        // is present; harmlessly no-ops on classic checkout.
        if ( function_exists( 'is_checkout' ) && is_checkout() && wp_script_is( 'wc-blocks-checkout', 'registered' ) ) {
            wp_enqueue_script(
                'xoffer-blocks',
                $base . 'assets/js/blocks.js',
                array( 'wc-blocks-checkout', 'wp-element', 'wp-plugins', 'wp-data', 'wp-i18n' ),
                $ver( 'assets/js/blocks.js' ),
                true
            );
        }
    }

    /** Render the "Recommended Offers" box with the eligible offers (radio/checkbox). */
    /**
     * Render the offers chooser as a row inside the cart/checkout totals table, styled like
     * the Shipment row (label cell + radio/checkbox options). The chosen offer is applied as
     * a real fee by the engine (correct tax + recorded on the order); front.js hides that
     * fee's own line so this row is the single place offers appear.
     */
    public function render_offers_row(): void {
        if ( ! function_exists( 'WC' ) || ! WC()->cart || WC()->cart->is_empty() ) {
            return;
        }
        $offers = ( new Extnify_Offer_Offer() )->eligible_offers( WC()->cart );
        if ( empty( $offers ) ) {
            return;
        }
        $cfg     = (array) get_option( 'extnify_offer', array() );
        $single  = ( ( $cfg['offer_type'] ?? 'multiple' ) === 'single' );
        $heading = ! empty( $cfg['offer_heading'] ) ? (string) $cfg['offer_heading'] : __( 'Recommended Offers', 'extnify-offer' );
        $input   = $single ? 'radio' : 'checkbox';

        $html = '<tr class="xoffer-offers"><th>' . esc_html( $heading ) . '</th><td><ul class="xoffer-list">';
        foreach ( $offers as $o ) {
            $html .= sprintf(
                '<li class="xoffer-item"><label><input type="%s" class="xoffer-pick" name="extnify_offer_pick%s" value="%d" %s /> <span class="xoffer-name">%s</span> <span class="xoffer-amount">%s</span></label></li>',
                esc_attr( $input ),
                $single ? '' : '[]',
                (int) $o['id'],
                checked( ! empty( $o['selected'] ), true, false ),
                esc_html( $o['title'] ),
                esc_html( $o['amount_html'] )
            );
        }
        $html .= '</ul></td></tr>';
        echo $html; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped per-field above
    }

    /** AJAX: save the shopper's offer selection. */
    public function ajax_apply(): void {
        check_ajax_referer( 'x_offer_front', 'nonce' );
        $ids  = isset( $_POST['offers'] ) ? array_map( 'intval', (array) wp_unslash( $_POST['offers'] ) ) : array(); // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- intval cast
        $kept = ( new Extnify_Offer_Offer() )->set_chosen( $ids );
        if ( WC()->cart ) {
            WC()->cart->calculate_totals();
        }
        wp_send_json_success( array( 'selected' => $kept ) );
    }

    /** AJAX: list eligible offers. */
    public function ajax_get_offers(): void {
        check_ajax_referer( 'x_offer_front', 'nonce' );
        $offers = WC()->cart ? ( new Extnify_Offer_Offer() )->eligible_offers( WC()->cart ) : array();
        wp_send_json_success( array( 'offers' => $offers ) );
    }

    /**
     * Apply matching fees to the cart. WooCommerce fires this during totals
     * calculation (cart + checkout); the fee engine owns all the logic.
     */
    public function calculate_fees( $cart ): void {
        if ( is_admin() && ! defined( 'DOING_AJAX' ) ) {
            return;
        }
        if ( ! $cart instanceof WC_Cart || $cart->is_empty() ) {
            return;
        }
        ( new Extnify_Offer_Offer() )->apply( $cart );
    }

}