<?php

namespace WooOrderCart\Monitoring;

class CheckoutPpcpTraceProbe {
    private static ?self $instance = null;

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

    private function __construct() {
        if ( ! CheckoutTraceConfig::is_enabled() ) {
            return;
        }

        add_action( 'woocommerce_paypal_payments_create_order_request_started', [ $this, 'capture_create_order_request' ], 10, 1 );
        add_action( 'woocommerce_paypal_payments_paypal_order_created', [ $this, 'capture_paypal_order_created' ], 10, 1 );
        add_action( 'woocommerce_paypal_payments_approve_order_request_started', [ $this, 'capture_approve_order_request' ], 10, 1 );
        add_filter( 'ppcp_create_order_request_body_data', [ $this, 'capture_create_order_body' ], 20, 3 );
    }

    /**
     * @param array<string,mixed> $data
     */
    public function capture_create_order_request( array $data ): void {
        $this->record_ppcp_event( 'ppcp_native_create_order_request_started', 'create_order', $data );
    }

    /**
     * @param mixed $order
     */
    public function capture_paypal_order_created( $order ): void {
        $trace_id = $this->get_trace_id();

        if ( '' === $trace_id ) {
            return;
        }

        $paypal_order_id = is_object( $order ) && method_exists( $order, 'id' ) ? (string) $order->id() : '';

        CheckoutTraceService::record(
            [
                'traceId' => $trace_id,
                'event' => 'ppcp_native_paypal_order_created',
                'step' => 'payment',
                'status' => 'success',
                'origin' => 'backend',
                'gatewayId' => 'ppcp-gateway',
                'providerKey' => 'ppcp',
                'context' => [
                    'stage' => 'create_order',
                    'has_paypal_order_id' => '' !== trim( $paypal_order_id ),
                    'paypal_order_id_length' => strlen( trim( $paypal_order_id ) ),
                    'cart_summary' => $this->summarize_cart(),
                    'ppcp_session_summary' => $this->summarize_ppcp_session(),
                ],
            ]
        );
    }

    /**
     * @param array<string,mixed> $data
     */
    public function capture_approve_order_request( array $data ): void {
        $this->record_ppcp_event( 'ppcp_native_approve_order_request_started', 'approve_order', $data );
    }

    /**
     * @param array<string,mixed> $data
     * @param mixed               $payment_method
     * @param mixed               $request_data
     * @return array<string,mixed>
     */
    public function capture_create_order_body( array $data, $payment_method = '', $request_data = [] ): array {
        $trace_id = $this->get_trace_id();

        if ( '' === $trace_id ) {
            return $data;
        }

        try {
            $request_data = is_array( $request_data ) ? $request_data : [];
            $payment_method = sanitize_key( (string) $payment_method );
            $funding_source = sanitize_key( (string) ( $request_data['funding_source'] ?? '' ) );
            $callback_url = $this->extract_order_update_callback_url( $data );
            $callback_summary = CheckoutPpcpShippingCallbackTraceProbe::remember_trace_for_callback_url(
                $callback_url,
                $trace_id,
                [
                    'payment_method' => $payment_method,
                    'funding_source' => $funding_source,
                ]
            );

            CheckoutTraceService::record(
                [
                    'traceId' => $trace_id,
                    'event' => 'ppcp_native_create_order_body_prepared',
                    'step' => 'payment',
                    'status' => 'info',
                    'origin' => 'backend',
                    'gatewayId' => 'ppcp-gateway',
                    'providerKey' => 'ppcp',
                    'context' => array_merge(
                        $this->summarize_create_order_body( $data, $payment_method, $request_data ),
                        $callback_summary
                    ),
                ]
            );
        } catch ( \Throwable $error ) {
            unset( $error );
        }

        return $data;
    }

    /**
     * @param array<string,mixed> $data
     */
    private function record_ppcp_event( string $event, string $stage, array $data ): void {
        $trace_id = $this->get_trace_id();

        if ( '' === $trace_id ) {
            return;
        }

        CheckoutTraceService::record(
            [
                'traceId' => $trace_id,
                'event' => $event,
                'step' => 'payment',
                'status' => 'start',
                'origin' => 'backend',
                'gatewayId' => 'ppcp-gateway',
                'providerKey' => 'ppcp',
                'context' => $this->build_trace_context( $stage, $data ),
            ]
        );
    }

    /**
     * @param array<string,mixed> $data
     * @return array<string,mixed>
     */
    private function build_trace_context( string $stage, array $data ): array {
        $form = $this->resolve_form_data( $data );
        $paypal_order_id = (string) ( $data['order_id'] ?? $data['orderID'] ?? $data['orderId'] ?? '' );

        return [
            'stage' => $stage,
            'request_keys' => $this->sanitize_keys( array_keys( $data ), 40 ),
            'request_context' => sanitize_key( (string) ( $data['context'] ?? '' ) ),
            'payment_method' => sanitize_key( (string) ( $data['payment_method'] ?? 'ppcp-gateway' ) ),
            'funding_source' => sanitize_key( (string) ( $data['funding_source'] ?? '' ) ),
            'has_paypal_order_id' => '' !== trim( $paypal_order_id ),
            'paypal_order_id_length' => strlen( trim( $paypal_order_id ) ),
            'form_summary' => $this->summarize_form_data( $form ),
            'cart_summary' => $this->summarize_cart(),
            'customer_summary' => $this->summarize_customer(),
            'ppcp_session_summary' => $this->summarize_ppcp_session(),
        ];
    }

    /**
     * @param array<string,mixed> $data
     * @param array<string,mixed> $request_data
     * @return array<string,mixed>
     */
    private function summarize_create_order_body( array $data, string $payment_method, array $request_data ): array {
        $purchase_units = $this->trace_list( $this->read_trace_path( $data, [ 'purchase_units' ] ) );
        $payment_source = $this->trace_map( $this->read_trace_path( $data, [ 'payment_source' ] ) );
        $paypal_source = $this->trace_map( $this->read_trace_path( $data, [ 'payment_source', 'paypal' ] ) );
        $experience_context = $this->trace_map( $this->read_trace_path( $data, [ 'payment_source', 'paypal', 'experience_context' ] ) );
        $callback_config = $this->trace_map( $this->read_trace_path( $data, [ 'payment_source', 'paypal', 'experience_context', 'order_update_callback_config' ] ) );
        $callback_events = $this->trace_list( $this->read_trace_path( $callback_config, [ 'callback_events' ] ) );

        return [
            'stage' => 'create_order_body',
            'payment_method' => $payment_method,
            'funding_source' => sanitize_key( (string) ( $request_data['funding_source'] ?? '' ) ),
            'request_data_keys' => $this->sanitize_keys( array_keys( $request_data ), 20 ),
            'intent' => sanitize_key( (string) ( $data['intent'] ?? '' ) ),
            'purchase_unit_count' => count( $purchase_units ),
            'purchase_unit_summary' => $this->summarize_purchase_units( $purchase_units ),
            'has_payment_source' => [] !== $payment_source,
            'payment_source_keys' => $this->sanitize_keys( array_keys( $payment_source ), 8 ),
            'has_paypal_source' => [] !== $paypal_source,
            'paypal_source_keys' => $this->sanitize_keys( array_keys( $paypal_source ), 12 ),
            'experience_context_keys' => $this->sanitize_keys( array_keys( $experience_context ), 16 ),
            'shipping_preference' => sanitize_key( (string) ( $experience_context['shipping_preference'] ?? '' ) ),
            'has_order_update_callback_config' => [] !== $callback_config,
            'callback_event_count' => count( $callback_events ),
            'callback_events' => $this->sanitize_keys( $callback_events, 8 ),
        ];
    }

    /**
     * @param array<int,mixed> $purchase_units
     * @return array<int,array<string,mixed>>
     */
    private function summarize_purchase_units( array $purchase_units ): array {
        $summaries = [];

        foreach ( array_slice( $purchase_units, 0, 4 ) as $purchase_unit ) {
            $purchase_unit = $this->trace_map( $purchase_unit );

            if ( [] === $purchase_unit ) {
                continue;
            }

            $shipping = $this->trace_map( $this->read_trace_path( $purchase_unit, [ 'shipping' ] ) );
            $shipping_options = $this->trace_list( $this->read_trace_path( $shipping, [ 'options' ] ) );
            $amount = $this->trace_map( $this->read_trace_path( $purchase_unit, [ 'amount' ] ) );

            $summaries[] = [
                'reference_id_length' => strlen( trim( (string) ( $purchase_unit['reference_id'] ?? '' ) ) ),
                'has_amount' => [] !== $amount,
                'currency_code' => sanitize_key( (string) ( $amount['currency_code'] ?? '' ) ),
                'has_shipping' => [] !== $shipping,
                'shipping_keys' => $this->sanitize_keys( array_keys( $shipping ), 12 ),
                'shipping_option_count' => count( $shipping_options ),
            ];
        }

        return $summaries;
    }

    /**
     * @param array<string,mixed> $data
     */
    private function extract_order_update_callback_url( array $data ): string {
        $callback_url = $this->read_trace_path(
            $data,
            [ 'payment_source', 'paypal', 'experience_context', 'order_update_callback_config', 'callback_url' ]
        );

        if ( ! is_scalar( $callback_url ) ) {
            return '';
        }

        return trim( (string) $callback_url );
    }

    /**
     * @param mixed             $value
     * @param array<int,string> $path
     * @return mixed|null
     */
    private function read_trace_path( $value, array $path ) {
        foreach ( $path as $key ) {
            if ( is_array( $value ) && array_key_exists( $key, $value ) ) {
                $value = $value[ $key ];
                continue;
            }

            if ( is_object( $value ) && property_exists( $value, $key ) ) {
                $value = $value->{$key};
                continue;
            }

            return null;
        }

        return $value;
    }

    /**
     * @param mixed $value
     * @return array<string|int,mixed>
     */
    private function trace_map( $value ): array {
        if ( is_array( $value ) ) {
            return $value;
        }

        if ( is_object( $value ) ) {
            return get_object_vars( $value );
        }

        return [];
    }

    /**
     * @param mixed $value
     * @return array<int,mixed>
     */
    private function trace_list( $value ): array {
        if ( is_array( $value ) ) {
            return array_values( $value );
        }

        if ( is_object( $value ) ) {
            return array_values( get_object_vars( $value ) );
        }

        return [];
    }

    private function get_trace_id(): string {
        $trace_id = isset( $_SERVER['HTTP_X_IPS_CHECKOUT_TRACE'] )
            ? sanitize_key( wp_unslash( $_SERVER['HTTP_X_IPS_CHECKOUT_TRACE'] ) )
            : '';

        if ( '' === $trace_id && isset( $_SERVER['HTTP_X_IPS_CHECKOUT_TRACE_ID'] ) ) {
            $trace_id = sanitize_key( wp_unslash( $_SERVER['HTTP_X_IPS_CHECKOUT_TRACE_ID'] ) );
        }

        return sanitize_key( $trace_id );
    }

    /**
     * @param array<string,mixed> $data
     * @return array<string,mixed>
     */
    private function resolve_form_data( array $data ): array {
        if ( isset( $data['form'] ) && is_array( $data['form'] ) ) {
            return $data['form'];
        }

        $form_encoded = (string) ( $data['form_encoded'] ?? '' );
        if ( '' === $form_encoded ) {
            return [];
        }

        $form = [];
        parse_str( $form_encoded, $form );

        return is_array( $form ) ? $form : [];
    }

    /**
     * @param array<string,mixed> $form
     * @return array<string,mixed>
     */
    private function summarize_form_data( array $form ): array {
        $keys = $this->sanitize_keys( array_keys( $form ), 40 );
        $billing_keys = $this->filter_prefixed_keys( $keys, 'billing_' );
        $shipping_keys = $this->filter_prefixed_keys( $keys, 'shipping_' );

        return [
            'total_key_count' => count( $keys ),
            'billing_key_count' => count( $billing_keys ),
            'shipping_key_count' => count( $shipping_keys ),
            'has_payment_method' => isset( $form['payment_method'] ),
            'has_billing_email' => isset( $form['billing_email'] ),
            'has_billing_phone' => isset( $form['billing_phone'] ),
            'has_billing_country' => isset( $form['billing_country'] ),
            'has_shipping_country' => isset( $form['shipping_country'] ),
            'has_shipping_postcode' => isset( $form['shipping_postcode'] ),
            'has_shipping_city' => isset( $form['shipping_city'] ),
            'has_shipping_address_1' => isset( $form['shipping_address_1'] ),
            'billing_address' => $this->summarize_form_address( $form, 'billing_' ),
            'shipping_address' => $this->summarize_form_address( $form, 'shipping_' ),
            'address_relation' => $this->summarize_form_address_relation( $form ),
            'billing_keys' => array_slice( $billing_keys, 0, 10 ),
            'shipping_keys' => array_slice( $shipping_keys, 0, 10 ),
        ];
    }

    /**
     * @return array<string,mixed>
     */
    private function summarize_cart(): array {
        if ( ! function_exists( 'WC' ) || ! WC() || ! WC()->cart ) {
            return [
                'available' => false,
            ];
        }

        $chosen_shipping_methods = [];
        if ( WC()->session && method_exists( WC()->session, 'get' ) ) {
            $chosen_shipping_methods = WC()->session->get( 'chosen_shipping_methods', [] );
        }

        if ( ! is_array( $chosen_shipping_methods ) ) {
            $chosen_shipping_methods = [];
        }

        $cart_hash = method_exists( WC()->cart, 'get_cart_hash' ) ? (string) WC()->cart->get_cart_hash() : '';

        return [
            'available' => true,
            'needs_shipping' => (bool) WC()->cart->needs_shipping(),
            'needs_payment' => (bool) WC()->cart->needs_payment(),
            'item_count' => (int) WC()->cart->get_cart_contents_count(),
            'shipping_total' => (float) WC()->cart->get_shipping_total(),
            'cart_total' => (float) WC()->cart->get_total( 'edit' ),
            'currency' => function_exists( 'get_woocommerce_currency' )
                ? sanitize_key( (string) get_woocommerce_currency() )
                : '',
            'cart_hash_length' => strlen( $cart_hash ),
            'chosen_shipping_methods_count' => count( $chosen_shipping_methods ),
            'has_chosen_shipping_methods' => [] !== $chosen_shipping_methods,
            'chosen_shipping_method_keys' => $this->summarize_shipping_method_keys( $chosen_shipping_methods ),
            'shipping_packages' => $this->summarize_wc_shipping_packages(),
        ];
    }

    /**
     * @return array<string,mixed>
     */
    private function summarize_customer(): array {
        if ( ! function_exists( 'WC' ) || ! WC() || ! WC()->customer ) {
            return [
                'available' => false,
            ];
        }

        $customer = WC()->customer;

        return [
            'available' => true,
            'is_logged_in' => is_user_logged_in(),
            'has_billing_country' => '' !== trim( (string) $customer->get_billing_country() ),
            'has_billing_postcode' => '' !== trim( (string) $customer->get_billing_postcode() ),
            'has_billing_city' => '' !== trim( (string) $customer->get_billing_city() ),
            'has_billing_state' => '' !== trim( (string) $customer->get_billing_state() ),
            'has_billing_address_1' => '' !== trim( (string) $customer->get_billing_address_1() ),
            'has_billing_phone' => '' !== trim( (string) $customer->get_billing_phone() ),
            'has_billing_email' => '' !== trim( (string) $customer->get_billing_email() ),
            'has_shipping_country' => '' !== trim( (string) $customer->get_shipping_country() ),
            'has_shipping_postcode' => '' !== trim( (string) $customer->get_shipping_postcode() ),
            'has_shipping_city' => '' !== trim( (string) $customer->get_shipping_city() ),
            'has_shipping_state' => '' !== trim( (string) $customer->get_shipping_state() ),
            'has_shipping_address_1' => '' !== trim( (string) $customer->get_shipping_address_1() ),
            'has_calculated_shipping' => method_exists( $customer, 'has_calculated_shipping' )
                ? (bool) $customer->has_calculated_shipping()
                : false,
        ];
    }

    /**
     * @return array<string,mixed>
     */
    private function summarize_ppcp_session(): array {
        if ( ! function_exists( 'WC' ) || ! WC() || ! WC()->session || ! method_exists( WC()->session, 'get' ) ) {
            return [
                'available' => false,
            ];
        }

        $session = WC()->session->get( 'ppcp' );

        if ( ! is_array( $session ) ) {
            return [
                'available' => true,
                'present' => null !== $session,
                'type' => is_object( $session ) ? 'object' : gettype( $session ),
            ];
        }

        $checkout_form = isset( $session['checkout_form'] ) && is_array( $session['checkout_form'] )
            ? $session['checkout_form']
            : [];

        return [
            'available' => true,
            'present' => [] !== $session,
            'has_order' => isset( $session['order'] ),
            'has_funding_source' => isset( $session['funding_source'] ) && '' !== trim( (string) $session['funding_source'] ),
            'has_checkout_form' => [] !== $checkout_form,
            'checkout_form_key_count' => count( $checkout_form ),
            'checkout_form_summary' => $this->summarize_form_data( $checkout_form ),
        ];
    }

    /**
     * @param array<string,mixed> $form
     * @return array<string,mixed>
     */
    private function summarize_form_address( array $form, string $prefix ): array {
        $country = $this->normalize_country_code( (string) ( $form[ $prefix . 'country' ] ?? '' ) );
        $state = $this->normalize_state_code( (string) ( $form[ $prefix . 'state' ] ?? '' ) );
        $postcode = trim( (string) ( $form[ $prefix . 'postcode' ] ?? '' ) );
        $city = trim( (string) ( $form[ $prefix . 'city' ] ?? '' ) );
        $address_1 = trim( (string) ( $form[ $prefix . 'address_1' ] ?? '' ) );
        $address_2 = trim( (string) ( $form[ $prefix . 'address_2' ] ?? '' ) );
        $first_name = trim( (string) ( $form[ $prefix . 'first_name' ] ?? '' ) );
        $last_name = trim( (string) ( $form[ $prefix . 'last_name' ] ?? '' ) );
        $email = trim( (string) ( $form[ $prefix . 'email' ] ?? '' ) );
        $phone = trim( (string) ( $form[ $prefix . 'phone' ] ?? '' ) );

        return [
            'present' => '' !== $country
                || '' !== $postcode
                || '' !== $city
                || '' !== $address_1
                || '' !== $address_2
                || '' !== $first_name
                || '' !== $last_name
                || '' !== $email
                || '' !== $phone,
            'country' => $country,
            'has_postcode' => '' !== $postcode,
            'postcode_length' => strlen( $postcode ),
            'has_city' => '' !== $city,
            'city_length' => strlen( $city ),
            'has_state' => '' !== $state,
            'state_length' => strlen( $state ),
            'has_address_1' => '' !== $address_1,
            'has_address_2' => '' !== $address_2,
            'has_name' => '' !== $first_name || '' !== $last_name,
            'has_email' => '' !== $email,
            'has_phone' => '' !== $phone,
        ];
    }

    /**
     * @param array<string,mixed> $form
     * @return array<string,mixed>
     */
    private function summarize_form_address_relation( array $form ): array {
        $billing_country = $this->normalize_country_code( (string) ( $form['billing_country'] ?? '' ) );
        $shipping_country = $this->normalize_country_code( (string) ( $form['shipping_country'] ?? '' ) );
        $billing_state = $this->normalize_state_code( (string) ( $form['billing_state'] ?? '' ) );
        $shipping_state = $this->normalize_state_code( (string) ( $form['shipping_state'] ?? '' ) );
        $billing_postcode = trim( (string) ( $form['billing_postcode'] ?? '' ) );
        $shipping_postcode = trim( (string) ( $form['shipping_postcode'] ?? '' ) );

        return [
            'country_matches' => '' !== $billing_country
                && '' !== $shipping_country
                && $billing_country === $shipping_country,
            'state_matches' => '' !== $billing_state
                && '' !== $shipping_state
                && $billing_state === $shipping_state,
            'postcode_length_matches' => '' !== $billing_postcode
                && '' !== $shipping_postcode
                && strlen( $billing_postcode ) === strlen( $shipping_postcode ),
            'billing_has_state' => '' !== $billing_state,
            'shipping_has_state' => '' !== $shipping_state,
        ];
    }

    /**
     * @param array<int,string|mixed> $shipping_methods
     * @return array<int,string>
     */
    private function summarize_shipping_method_keys( array $shipping_methods ): array {
        $keys = [];

        foreach ( $shipping_methods as $method ) {
            if ( ! is_scalar( $method ) ) {
                continue;
            }

            $method_key = explode( ':', (string) $method )[0] ?? '';
            $method_key = sanitize_key( $method_key );

            if ( '' !== $method_key ) {
                $keys[] = $method_key;
            }
        }

        return array_slice( array_values( array_unique( $keys ) ), 0, 4 );
    }

    /**
     * @return array<int,array<string,mixed>>
     */
    private function summarize_wc_shipping_packages(): array {
        if ( ! function_exists( 'WC' ) || ! WC() || ! WC()->shipping() || ! method_exists( WC()->shipping(), 'get_packages' ) ) {
            return [];
        }

        $packages = WC()->shipping()->get_packages();

        if ( ! is_array( $packages ) ) {
            return [];
        }

        $summaries = [];

        foreach ( array_slice( $packages, 0, 4 ) as $index => $package ) {
            if ( ! is_array( $package ) ) {
                continue;
            }

            $rates = isset( $package['rates'] ) && is_array( $package['rates'] ) ? $package['rates'] : [];
            $destination = isset( $package['destination'] ) && is_array( $package['destination'] ) ? $package['destination'] : [];
            $rate_method_keys = [];

            foreach ( array_slice( $rates, 0, 8 ) as $rate ) {
                $method_id = is_object( $rate ) && method_exists( $rate, 'get_method_id' )
                    ? (string) $rate->get_method_id()
                    : '';
                $method_id = sanitize_key( $method_id );

                if ( '' !== $method_id ) {
                    $rate_method_keys[] = $method_id;
                }
            }

            $summaries[] = [
                'package_index' => (int) $index,
                'rate_count' => count( $rates ),
                'rate_method_keys' => array_values( array_unique( $rate_method_keys ) ),
                'destination' => [
                    'country' => $this->normalize_country_code( (string) ( $destination['country'] ?? '' ) ),
                    'has_state' => '' !== $this->normalize_state_code( (string) ( $destination['state'] ?? '' ) ),
                    'has_postcode' => '' !== trim( (string) ( $destination['postcode'] ?? '' ) ),
                    'has_city' => '' !== trim( (string) ( $destination['city'] ?? '' ) ),
                    'has_address_1' => '' !== trim( (string) ( $destination['address_1'] ?? '' ) ),
                ],
            ];
        }

        return $summaries;
    }

    private function normalize_country_code( string $value ): string {
        $normalized = strtoupper( preg_replace( '/[^A-Z]/', '', $value ) ?: '' );

        return substr( $normalized, 0, 2 );
    }

    private function normalize_state_code( string $value ): string {
        $normalized = strtoupper( preg_replace( '/[^A-Z0-9_-]/', '', $value ) ?: '' );

        return substr( $normalized, 0, 16 );
    }

    /**
     * @param array<int,string|int> $keys
     * @return array<int,string>
     */
    private function sanitize_keys( array $keys, int $limit ): array {
        $sanitized = [];

        foreach ( $keys as $key ) {
            $normalized = sanitize_key( (string) $key );

            if ( '' === $normalized ) {
                continue;
            }

            $sanitized[] = $normalized;
        }

        return array_slice( array_values( array_unique( $sanitized ) ), 0, max( 1, $limit ) );
    }

    /**
     * @param array<int,string> $keys
     * @return array<int,string>
     */
    private function filter_prefixed_keys( array $keys, string $prefix ): array {
        return array_values(
            array_filter(
                $keys,
                static fn( string $key ): bool => 0 === strpos( $key, $prefix )
            )
        );
    }
}