<?php
/**
 * Extnify Offer Rules (free) — WooCommerce cart-fee engine.
 *
 * Mirrors the OpenCart "X-Offerpro" FREE feature set:
 *   • Rules (a fee applies only when ALL active rules pass):
 *       - Shipping Zone  — customer's shipping address falls in a chosen WC zone
 *       - Payment Method — customer chose one of the selected gateways
 *       - Shipping Method — customer chose one of the selected shipping methods
 *     Each rule is "For Any" (…_all = '1') unless specific items are selected.
 *   • Amount (rate_type = flat only): a plain number, or a percentage of the cart
 *     subtotal ("N%"). A NEGATIVE value is a discount.
 *
 * Anything else (tiered ranges, percentage bases, product/category rules, min/max,
 * equations, …) is Pro and simply ignored here. Delivered via WC()->cart->add_fee().
 */
defined( 'ABSPATH' ) || exit;

require_once __DIR__ . '/../system/extnify-core/traits/debug-log.php';

class Extnify_Offer_Offer {

    use Extnify_Debug_Log;

    /** Free understands only the flat rate type. */
    private static $free_types = array( 'flat' );

    /** Whether the global Debugging setting is on (computed per calculation). */
    private $debug = null;

    /**
     * Apply every matching fee to the cart. Called once per totals calculation.
     */
    public function apply( WC_Cart $cart ): void {
        $this->debug = $this->debug_enabled();

        $eligible = $this->build_eligible( $cart );
        if ( empty( $eligible ) ) {
            return;
        }
        // Offers only apply when CHOSEN by the customer (defaults auto-apply once).
        $chosen = $this->chosen_offers( $eligible );

        $collected = array();
        foreach ( $eligible as $e ) {
            if ( ! in_array( $e['id'], $chosen, true ) ) {
                $this->log( 'info', sprintf( '#%d "%s" eligible but not selected — not applied.', $e['id'], $e['label'] ) );
                continue;
            }
            $collected[] = $e;
        }
        usort( $collected, function ( $a, $b ) { return $a['sort_order'] <=> $b['sort_order']; } );
        foreach ( $collected as $e ) {
            // add_fee( name, amount, taxable, tax_class ). Negative amount = discount.
            $cart->add_fee( $e['label'], $e['amount'], $e['taxable'], $e['tax_class'] );
        }
    }

    /**
     * Compute every ELIGIBLE offer (passes rules + a non-zero flat amount). Returns
     * records {id,label,amount,taxable,tax_class,sort_order,select}. Shared by apply()
     * and eligible_offers(). Honors Module Status.
     */
    private function build_eligible( WC_Cart $cart ): array {
        $global = (array) get_option( 'extnify_offer', array() );
        if ( '1' !== ( isset( $global['status'] ) ? (string) $global['status'] : '1' ) ) {
            $this->log( 'info', 'Module Status is disabled — no offers applied.' );
            return array();
        }
        $rows = ( new Extnify_Offer_Model() )->getData();
        if ( empty( $rows ) ) {
            return array();
        }
        $subtotal = (float) $cart->get_subtotal();
        $eligible = array();
        foreach ( $rows as $row ) {
            $m    = array_merge( $this->defaults(), (array) $row['method_data'] );
            $id   = (int) $row['id'];
            $name = ! empty( $m['display'] ) ? $m['display'] : ( ! empty( $m['name'] ) ? $m['name'] : 'Offer #' . $id );

            if ( $m['status'] !== '1' ) {
                continue;
            }
            if ( ! in_array( $m['rate_type'], self::$free_types, true ) ) {
                continue; // Pro rate type
            }
            if ( ! $this->rule_geo_zone( $m ) || ! $this->rule_payment( $m ) || ! $this->rule_shipping( $m ) ) {
                continue;
            }
            $cost = $this->parse_cost( (string) ( $m['cost'] ?? '' ), $subtotal );
            if ( 0.0 === $cost ) {
                continue;
            }
            $taxable    = ! empty( $m['tax_class_id'] ) && 'none' !== $m['tax_class_id'];
            $label      = ! empty( $m['name'] ) ? $m['name'] : ( ! empty( $m['display'] ) ? $m['display'] : __( 'Offer', 'extnify-offer' ) );
            $eligible[] = array(
                'id'         => $id,
                'label'      => $label,
                'amount'     => $cost,
                'taxable'    => $taxable,
                'tax_class'  => $taxable ? (string) $m['tax_class_id'] : '',
                'sort_order' => (int) ( $m['sort_order'] ?? 0 ),
                'select'     => ! empty( $m['select'] ),
            );
        }
        return $eligible;
    }

    /** Public list for the storefront "Recommended Offers" widget. */
    public function eligible_offers( WC_Cart $cart ): array {
        $eligible = $this->build_eligible( $cart );
        if ( empty( $eligible ) ) {
            return array();
        }
        $chosen = $this->chosen_offers( $eligible );
        $out    = array();
        foreach ( $eligible as $e ) {
            $out[] = array(
                'id'          => $e['id'],
                'title'       => $e['label'],
                'amount'      => (float) $e['amount'],
                'amount_html' => function_exists( 'wc_price' ) ? wp_strip_all_tags( wc_price( (float) $e['amount'] ) ) : number_format( (float) $e['amount'], 2 ),
                'selected'    => in_array( $e['id'], $chosen, true ),
                'sort_order'  => (int) $e['sort_order'],
            );
        }
        usort( $out, function ( $a, $b ) { return $a['sort_order'] <=> $b['sort_order']; } );
        return $out;
    }

    /** single | multiple offer-selection mode (default multiple). */
    private function offer_type(): string {
        $cfg = (array) get_option( 'extnify_offer', array() );
        return ( ( $cfg['offer_type'] ?? 'multiple' ) === 'single' ) ? 'single' : 'multiple';
    }

    /**
     * Offer ids to APPLY: the session's chosen set, plus any eligible offer flagged
     * "Default Select?" auto-added once. After the shopper interacts (xoffer_touched)
     * their selection is authoritative. Single mode keeps one.
     * @param array $eligible records with id/select
     * @return int[]
     */
    private function chosen_offers( array $eligible ): array {
        $session = ( function_exists( 'WC' ) && WC()->session ) ? WC()->session : null;
        $raw_c   = $session ? $session->get( 'xoffer_chosen' ) : array();
        $raw_p   = $session ? $session->get( 'xoffer_preset' ) : array();
        $chosen  = is_array( $raw_c ) ? array_map( 'intval', $raw_c ) : array();
        $preset  = is_array( $raw_p ) ? array_map( 'intval', $raw_p ) : array();

        if ( $session && $session->get( 'xoffer_touched' ) ) {
            return array_values( array_unique( $chosen ) );
        }
        $single  = 'single' === $this->offer_type();
        $changed = false;
        foreach ( $eligible as $e ) {
            if ( empty( $e['select'] ) || in_array( $e['id'], $preset, true ) ) {
                continue;
            }
            $preset[] = $e['id'];
            $changed  = true;
            if ( $single && ! empty( $chosen ) ) {
                continue;
            }
            $chosen[] = $e['id'];
        }
        if ( $single && count( $chosen ) > 1 ) {
            $chosen  = array( (int) $chosen[0] );
            $changed = true;
        }
        if ( $changed && $session ) {
            $session->set( 'xoffer_chosen', array_values( array_unique( $chosen ) ) );
            $session->set( 'xoffer_preset', array_values( array_unique( $preset ) ) );
        }
        return array_values( array_unique( $chosen ) );
    }

    /** Save the shopper's selection (sanitized, single-trimmed) + mark touched. */
    public function set_chosen( array $ids ): array {
        $ids = array_values( array_unique( array_map( 'intval', $ids ) ) );
        if ( 'single' === $this->offer_type() && count( $ids ) > 1 ) {
            $ids = array( $ids[0] );
        }
        if ( function_exists( 'WC' ) && WC()->session ) {
            WC()->session->set( 'xoffer_chosen', $ids );
            WC()->session->set( 'xoffer_touched', '1' );
        }
        return $ids;
    }

    // ── Rules ───────────────────────────────────────────────────────────────

    /** Shipping Zone: customer's address falls in one of the selected WC zones. */
    private function rule_geo_zone( array $m ): bool {
        if ( ( $m['geo_zone_all'] ?? '1' ) == '1' || empty( $m['geo_zone'] ) ) {
            return true;
        }
        $matched = WC_Shipping_Zones::get_zone_matching_package( $this->address_package() );
        if ( ! $matched ) {
            return false;
        }
        return in_array( (string) $matched->get_id(), array_map( 'strval', (array) $m['geo_zone'] ), true );
    }

    /** Payment Method: the chosen gateway is one of the selected ones. */
    private function rule_payment( array $m ): bool {
        if ( ( $m['payment_all'] ?? '1' ) == '1' || empty( $m['payment'] ) ) {
            return true;
        }
        $chosen = WC()->session ? (string) WC()->session->get( 'chosen_payment_method' ) : '';
        if ( '' === $chosen ) {
            return false;
        }
        return in_array( $chosen, array_map( 'strval', (array) $m['payment'] ), true );
    }

    /** Shipping Method: one of the chosen shipping methods is in the selected list. */
    private function rule_shipping( array $m ): bool {
        if ( ( $m['shipping_all'] ?? '1' ) == '1' || empty( $m['shipping'] ) ) {
            return true;
        }
        $chosen = WC()->session ? (array) WC()->session->get( 'chosen_shipping_methods' ) : array();
        if ( empty( $chosen ) ) {
            return false;
        }
        $want = array_map( 'strval', (array) $m['shipping'] );
        foreach ( $chosen as $rate_id ) {
            // $rate_id is like "flat_rate:3" — match both the full id and its base method id.
            $base = strtok( (string) $rate_id, ':' );
            if ( in_array( (string) $rate_id, $want, true ) || in_array( (string) $base, $want, true ) ) {
                return true;
            }
        }
        return false;
    }

    /** A minimal shipping package built from the customer's destination address. */
    private function address_package(): array {
        $c = WC()->customer;
        return array(
            'destination' => array(
                'country'  => $c ? $c->get_shipping_country() : '',
                'state'    => $c ? $c->get_shipping_state() : '',
                'postcode' => $c ? $c->get_shipping_postcode() : '',
                'city'     => $c ? $c->get_shipping_city() : '',
            ),
        );
    }

    // ── Amount ──────────────────────────────────────────────────────────────

    /**
     * Cost string → amount. A plain number is flat; "N%" is a percentage of the
     * cart subtotal. Negative values are allowed (a discount).
     */
    private function parse_cost( string $str, float $subtotal ): float {
        $str = trim( $str );
        if ( '' === $str ) {
            return 0.0;
        }
        if ( '%' === substr( $str, -1 ) ) {
            return (float) rtrim( $str, '%' ) * $subtotal / 100.0;
        }
        return (float) $str;
    }

    // ── Debug log (gated by the global Debugging setting) ─────────────────────

    protected function debug_option_key(): string { return 'extnify_offer'; }
    protected function debug_log_key(): string    { return 'extnify_offer_debug_log'; }

    /** The free subset of a method's fields. */
    private function defaults(): array {
        return array(
            'status'       => '1',
            'rate_type'    => 'flat',
            'cost'         => '',
            'geo_zone_all' => '1',
            'geo_zone'     => array(),
            'payment_all'  => '1',
            'payment'      => array(),
            'shipping_all' => '1',
            'shipping'     => array(),
            'name'         => '',
            'display'      => '',
            'sort_order'   => 0,
            'tax_class_id' => '',
            'select'       => '',
        );
    }
}