<?php
/**
 * Reward Engine — calculates reward values and creates reward records.
 *
 * @package AdsdReferralCouponcoreEcosystem
 */

defined( 'ABSPATH' ) || exit;

class ADSD_RCC_Reward_Engine {

    private static ?ADSD_RCC_Reward_Engine $instance = null;

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

    /**
     * Generate rewards for a confirmed referral.
     * Respects the reward_recipient setting (sender/receiver/both).
     */
    public function generate_rewards_for_referral( int $referral_id ): void {
        $db       = ADSD_RCC_DB::instance();
        $settings = ADSD_RCC_Settings::instance();
        $referral = $db->get_referral( $referral_id );

        if ( ! $referral ) {
            return;
        }

        $recipient = $settings->reward_recipient();

        if ( in_array( $recipient, [ 'sender', 'both' ], true ) ) {
            $this->create_reward( $referral_id, (int) $referral->referrer_id, 'sender' );
        }

        if ( in_array( $recipient, [ 'receiver', 'both' ], true ) ) {
            $referee_id = (int) $referral->referee_id;
            if ( $referee_id > 0 ) {
                $this->create_reward( $referral_id, $referee_id, 'receiver' );
            }
        }

        // Update referral status
        $db->update_referral_status( $referral_id, 'rewarded', [
            'rewarded_at' => current_time( 'mysql', true ),
        ] );
    }

    /**
     * Create a single reward record for a user.
     */
    private function create_reward( int $referral_id, int $user_id, string $role ): void {
        $settings   = ADSD_RCC_Settings::instance();
        $db         = ADSD_RCC_DB::instance();
        $codegen    = ADSD_RCC_Code_Generator::instance();

        [ $type, $value ] = $this->calculate_reward( $settings, $role );

        $expiry_days = $settings->code_expiry_days();
        $expires_at  = $expiry_days > 0
            ? gmdate( 'Y-m-d H:i:s', strtotime( "+{$expiry_days} days" ) )
            : null;

        $code = $codegen->generate();

        $reward_id = $db->insert_reward( [
            'referral_id'  => $referral_id,
            'user_id'      => $user_id,
            'reward_code'  => $code,
            'reward_type'  => $type,
            'reward_value' => $value,
            'status'       => 'active',
            'expires_at'   => $expires_at,
        ] );

        if ( ! $reward_id ) {
            $db->log( 'reward_create_failed', $user_id, $referral_id, "Failed to create {$role} reward." );
            return;
        }

        $reward = $db->get_reward( $reward_id );
        $user   = get_user_by( 'id', $user_id );

        if ( $user && $reward ) {
            $this->send_reward_email( $user, $reward );
        }

        $db->log( 'reward_created', $user_id, $reward_id, "Reward created for {$role}.", [
            'code'  => $code,
            'type'  => $type,
            'value' => $value,
        ] );
    }

    /**
     * Calculate reward value based on settings and role.
     *
     * @return array [type, value]
     */
    private function calculate_reward( ADSD_RCC_Settings $s, string $role ): array {
        $recipient = $s->reward_recipient();

        // Separate sender/receiver settings when BOTH is active
        if ( $recipient === 'both' ) {
            $offer_key  = ( $role === 'sender' ) ? 'sender_offer_type' : 'receiver_offer_type';
            $offer_type = $s->get( $offer_key, 'automatic' );
        } else {
            $offer_type = $s->offer_type();
        }

        switch ( $offer_type ) {
            case 'automatic':
                $min   = (float) $s->get( ( $recipient === 'both' ) ? "{$role}_offer_min" : 'offer_min', 20 );
                $max   = (float) $s->get( ( $recipient === 'both' ) ? "{$role}_offer_max" : 'offer_max', 100 );
                // Use random_int for uniform distribution; multiply by 100 to get 2 decimal precision
                $value = round( random_int( (int) ( $min * 100 ), (int) ( $max * 100 ) ) / 100, 2 );
                return [ 'fixed', $value ];

            case 'manual':
                // In "both" mode use per-role fixed value; otherwise use the shared field
                $value = (float) $s->get( ( $recipient === 'both' ) ? "{$role}_offer_fixed" : 'offer_fixed', 50 );
                return [ 'fixed', $value ];

            case 'automatic_percent':
                $min   = (float) $s->get( ( $recipient === 'both' ) ? "{$role}_offer_min" : 'offer_min', 10 );
                $max   = (float) $s->get( ( $recipient === 'both' ) ? "{$role}_offer_max" : 'offer_max', 30 );
                $value = round( random_int( (int) ( $min * 100 ), (int) ( $max * 100 ) ) / 100, 2 );
                return [ 'percent', $value ];

            case 'manual_percent':
                // In "both" mode use per-role fixed %; otherwise use the shared field
                $value = (float) $s->get( ( $recipient === 'both' ) ? "{$role}_offer_percent_fixed" : 'offer_percent_fixed', 20 );
                return [ 'percent', $value ];

            default:
                return [ 'fixed', 50.0 ];
        }
    }

    /**
     * Format reward value for display.
     */
    public static function format_value( object $reward ): string {
        if ( $reward->reward_type === 'percent' ) {
            return number_format_i18n( (float) $reward->reward_value, 2 ) . '%';
        }

        if ( ADSD_RCC_Plugin::is_woocommerce_active() ) {
            return wc_price( (float) $reward->reward_value );
        }

        // Fallback when WooCommerce is not active — use generic currency symbol
        $symbol = function_exists( 'get_woocommerce_currency_symbol' ) ? get_woocommerce_currency_symbol() : '&#36;';
        return $symbol . number_format_i18n( (float) $reward->reward_value, 2 );
    }

    private function send_reward_email( WP_User $user, object $reward ): void {
        $mailer    = ADSD_RCC_Mailer::instance();
        $s         = ADSD_RCC_Settings::instance();

        $vars = [
            '{user_email}'   => $user->user_email,
            '{reward_code}'  => $reward->reward_code,
            '{reward_value}' => self::format_value( $reward ),
            '{expiry_date}'  => $reward->expires_at
                ? date_i18n( get_option( 'date_format' ), strtotime( $reward->expires_at ) )
                : __( 'No expiry', 'adsd-referral-couponcore' ),
            '{button_url}'   => $s->page_url( 'reward_list' ),
        ];

        $mailer->send( $user->user_email, 'reward_generated', $vars );
    }

    /**
     * Send reward-used notification.
     */
    public function send_used_email( WP_User $user, object $reward ): void {
        $vars = [
            '{user_email}'  => $user->user_email,
            '{reward_code}' => $reward->reward_code,
        ];
        ADSD_RCC_Mailer::instance()->send( $user->user_email, 'reward_used', $vars );
    }

    /**
     * Send reward-expired notification.
     */
    public function send_expired_email( WP_User $user, object $reward ): void {
        $vars = [
            '{user_email}'  => $user->user_email,
            '{reward_code}' => $reward->reward_code,
            '{expiry_date}' => $reward->expires_at
                ? date_i18n( get_option( 'date_format' ), strtotime( $reward->expires_at ) )
                : '',
            '{button_url}'  => ADSD_RCC_Settings::instance()->page_url( 'dashboard' ),
        ];
        ADSD_RCC_Mailer::instance()->send( $user->user_email, 'reward_expired', $vars );
    }
}