<?php
/**
 * Extnify Fee Rules (free) — WooCommerce cart-fee engine.
 *
 * Mirrors the OpenCart "X-Feepro" 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;

class XFee_Fee {

    /** 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 = false;

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

        // Global "Module Status" is the master switch (Global Settings → General).
        // When it is disabled, NO fees are applied — matching OpenCart. Absent =
        // enabled (so a fresh install with configured fees works out of the box).
        $global = (array) get_option( 'x_feepro', array() );
        $status = isset( $global['status'] ) ? (string) $global['status'] : '1';
        if ( '1' !== $status ) {
            $this->log( 'info', 'Module Status is disabled — no fees applied.' );
            return;
        }

        $model = new XFee_Model();
        $rows  = $model->getData();
        if ( empty( $rows ) ) {
            $this->log( 'info', 'No fee methods configured.' );
            return;
        }

        $subtotal  = (float) $cart->get_subtotal();
        $collected = array();

        // Heartbeat — with Debugging on, this appears on every cart/checkout calc,
        // so enabling Debug + one page load immediately shows the log is live.
        $this->log( 'debug', sprintf( 'Fee calculation started — %d method(s), subtotal %s.', count( $rows ), number_format( $subtotal, 2 ) ) );

        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'] : 'Fee #' . $id );

            if ( $m['status'] !== '1' ) {
                continue;
            }
            // Free supports only the flat rate type — a Pro-only type is skipped.
            if ( ! in_array( $m['rate_type'], self::$free_types, true ) ) {
                $this->log( 'warn', sprintf( '#%d "%s" skipped — rate type "%s" is a Pro feature.', $id, $name, $m['rate_type'] ) );
                continue;
            }
            // Rules gate (whole cart).
            if ( ! $this->rule_geo_zone( $m ) ) {
                $this->log( 'warn', sprintf( '#%d "%s" not applied — Shipping Zone rule did not match.', $id, $name ) );
                continue;
            }
            if ( ! $this->rule_payment( $m ) ) {
                $this->log( 'warn', sprintf( '#%d "%s" not applied — Payment Method rule did not match.', $id, $name ) );
                continue;
            }
            if ( ! $this->rule_shipping( $m ) ) {
                $this->log( 'warn', sprintf( '#%d "%s" not applied — Shipping Method rule did not match.', $id, $name ) );
                continue;
            }

            $cost = $this->parse_cost( (string) ( $m['cost'] ?? '' ), $subtotal );
            if ( 0.0 === $cost ) {
                $this->log( 'info', sprintf( '#%d "%s" resolved to 0 — not applied.', $id, $name ) );
                continue;
            }

            $label = ! empty( $m['name'] )
                ? $m['name']
                : ( ! empty( $m['display'] ) ? $m['display'] : __( 'Fee', 'extnify-fee' ) );

            $this->log( 'info', sprintf( '#%d "%s" applied — amount %s.', $id, $name, number_format( $cost, 2 ) ) );

            $taxable     = ! empty( $m['tax_class_id'] ) && 'none' !== $m['tax_class_id'];
            $collected[] = array(
                'id'         => $id,
                'label'      => $label,
                'amount'     => $cost,
                'taxable'    => $taxable,
                'tax_class'  => $taxable ? (string) $m['tax_class_id'] : '',
                'sort_order' => (int) ( $m['sort_order'] ?? 0 ),
            );
        }

        // Respect the per-method Sort Order.
        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'] );
        }
    }

    // ── 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 a flat amount; "N%" is a percentage of
     * the cart subtotal. Negative values are allowed (a discount). Both can be + or −.
     */
    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) ─────────────────────

    private function debug_enabled(): bool {
        $s = (array) get_option( 'x_feepro', array() );
        return isset( $s['debug'] ) && '1' === (string) $s['debug'];
    }

    /**
     * Append one entry to the debug log — only when Debugging is enabled.
     * Stored in the database (a capped transient), never written to a file.
     */
    private function log( string $level, string $message ): void {
        if ( ! $this->debug ) {
            return;
        }
        $entries = get_transient( 'x_feepro_debug_log' );
        if ( ! is_array( $entries ) ) {
            $entries = array();
        }
        $entries[] = array(
            'time'    => current_time( 'H:i:s' ),
            'level'   => strtolower( $level ),
            'message' => $message,
        );
        if ( count( $entries ) > 300 ) {
            $entries = array_slice( $entries, -300 );
        }
        set_transient( 'x_feepro_debug_log', $entries, WEEK_IN_SECONDS );
    }

    /** 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' => '',
        );
    }
}