<?php

namespace WooOrderCart\Monitoring;

use WooOrderCart\DatabaseTables\Checkout_TraceEvents;

class CheckoutTraceRepository {
    private const FALLBACK_OPTION_KEY = 'ipscmi_order_cart_checkout_trace_events';
    private static bool $legacy_import_checked = false;

    /**
     * @param array<string,mixed> $event
     */
    public static function append( array $event ): bool {
        global $wpdb;

        try {
            CheckoutMonitoringSchema::ensure_installed();

            if ( ! self::table_exists() ) {
                self::append_legacy_option( $event );
                return true;
            }

            self::safe_maybe_import_legacy_events();

            $flow_run_id = CheckoutFlowRunRepository::upsert_from_event( $event );
            $inserted = $wpdb->insert(
                self::table_name(),
                [
                    'event_uuid' => sanitize_key( (string) ( $event['id'] ?? '' ) ),
                    'flow_run_id' => $flow_run_id,
                    'trace_id' => sanitize_key( (string) ( $event['traceId'] ?? '' ) ),
                    'origin' => sanitize_key( (string) ( $event['origin'] ?? '' ) ),
                    'event' => sanitize_key( (string) ( $event['event'] ?? '' ) ),
                    'step' => sanitize_key( (string) ( $event['step'] ?? '' ) ),
                    'status' => sanitize_key( (string) ( $event['status'] ?? '' ) ),
                    'gateway_id' => sanitize_key( (string) ( $event['gatewayId'] ?? '' ) ),
                    'provider_key' => sanitize_key( (string) ( $event['providerKey'] ?? '' ) ),
                    'message' => sanitize_text_field( (string) ( $event['message'] ?? '' ) ),
                    'context_json' => wp_json_encode( is_array( $event['context'] ?? null ) ? $event['context'] : [] ),
                    'created_at' => self::normalize_mysql_datetime( (string) ( $event['createdAt'] ?? '' ) ),
                ],
                [ '%s', '%d', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s' ]
            );

            if ( false === $inserted ) {
                return false;
            }

            self::safe_prune_after_append();

            return true;
        } catch ( \Throwable $error ) {
            return false;
        }
    }

    /**
     * @return array<int,array<string,mixed>>
     */
    public static function recent( int $limit = 50 ): array {
        global $wpdb;

        $limit = max( 1, $limit );
        CheckoutMonitoringSchema::ensure_installed();

        if ( ! self::table_exists() ) {
            return array_values( array_slice( self::legacy_all(), 0, $limit ) );
        }

        self::maybe_import_legacy_events();

        $rows = $wpdb->get_results(
            $wpdb->prepare(
                'SELECT * FROM %i ORDER BY created_at DESC, id DESC LIMIT %d',
                self::table_name(),
                $limit
            ),
            ARRAY_A
        );

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

        return array_map( [ __CLASS__, 'map_row_to_event' ], $rows );
    }

    public static function clear(): void {
        global $wpdb;

        CheckoutMonitoringSchema::ensure_installed();

        if ( self::table_exists() ) {
            $wpdb->query( $wpdb->prepare( 'DELETE FROM %i', self::table_name() ) );
        }

        CheckoutFlowRunRepository::clear();
        update_option( self::FALLBACK_OPTION_KEY, [], false );
    }

    /**
     * @return array<string,mixed>
     */
    public static function summary( int $limit = 50 ): array {
        $events = self::recent( $limit );
        $summary = [
            'total' => count( $events ),
            'errors' => 0,
            'warnings' => 0,
            'frontend' => 0,
            'backend' => 0,
            'latestEventAt' => '',
            'gatewayCounts' => [],
        ];

        foreach ( $events as $event ) {
            $status = (string) ( $event['status'] ?? '' );
            $origin = (string) ( $event['origin'] ?? '' );
            $gateway_id = (string) ( $event['gatewayId'] ?? '' );

            if ( in_array( $status, [ 'error', 'failed', 'critical' ], true ) ) {
                $summary['errors']++;
            } elseif ( 'warning' === $status ) {
                $summary['warnings']++;
            }

            if ( 'frontend' === $origin ) {
                $summary['frontend']++;
            } else {
                $summary['backend']++;
            }

            if ( '' === $summary['latestEventAt'] && ! empty( $event['createdAt'] ) ) {
                $summary['latestEventAt'] = (string) $event['createdAt'];
            }

            if ( '' !== $gateway_id ) {
                if ( ! isset( $summary['gatewayCounts'][ $gateway_id ] ) ) {
                    $summary['gatewayCounts'][ $gateway_id ] = 0;
                }

                $summary['gatewayCounts'][ $gateway_id ]++;
            }
        }

        return $summary;
    }

    /**
     * @return array<int,array<string,mixed>>
     */
    private static function legacy_all(): array {
        $events = \WooOrderCart\Config\CartConfig::read_owned_option( self::FALLBACK_OPTION_KEY, [] );

        return is_array( $events ) ? array_values( $events ) : [];
    }

    public static function table_name(): string {
        return ( new Checkout_TraceEvents() )->get_name();
    }

    public static function table_exists(): bool {
        global $wpdb;

        $table = self::table_name();

        return $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $table ) ) === $table;
    }

    /**
     * @param array<string,mixed> $event
     */
    private static function append_legacy_option( array $event ): void {
        $events = self::legacy_all();
        array_unshift( $events, $event );
        $events = array_slice( $events, 0, CheckoutTraceConfig::max_events() );

        update_option( self::FALLBACK_OPTION_KEY, $events, false );
    }

    private static function maybe_import_legacy_events(): void {
        if ( self::$legacy_import_checked ) {
            return;
        }

        self::$legacy_import_checked = true;
        $legacy_events = self::legacy_all();

        if ( [] === $legacy_events ) {
            return;
        }

        global $wpdb;

        $has_rows = (int) $wpdb->get_var( $wpdb->prepare( 'SELECT COUNT(1) FROM %i', self::table_name() ) );
        if ( $has_rows > 0 ) {
            return;
        }

        foreach ( array_reverse( $legacy_events ) as $legacy_event ) {
            if ( ! is_array( $legacy_event ) ) {
                continue;
            }

            $flow_run_id = CheckoutFlowRunRepository::upsert_from_event( $legacy_event );
            $wpdb->insert(
                self::table_name(),
                [
                    'event_uuid' => sanitize_key( (string) ( $legacy_event['id'] ?? '' ) ),
                    'flow_run_id' => $flow_run_id,
                    'trace_id' => sanitize_key( (string) ( $legacy_event['traceId'] ?? '' ) ),
                    'origin' => sanitize_key( (string) ( $legacy_event['origin'] ?? '' ) ),
                    'event' => sanitize_key( (string) ( $legacy_event['event'] ?? '' ) ),
                    'step' => sanitize_key( (string) ( $legacy_event['step'] ?? '' ) ),
                    'status' => sanitize_key( (string) ( $legacy_event['status'] ?? '' ) ),
                    'gateway_id' => sanitize_key( (string) ( $legacy_event['gatewayId'] ?? '' ) ),
                    'provider_key' => sanitize_key( (string) ( $legacy_event['providerKey'] ?? '' ) ),
                    'message' => sanitize_text_field( (string) ( $legacy_event['message'] ?? '' ) ),
                    'context_json' => wp_json_encode( is_array( $legacy_event['context'] ?? null ) ? $legacy_event['context'] : [] ),
                    'created_at' => self::normalize_mysql_datetime( (string) ( $legacy_event['createdAt'] ?? '' ) ),
                ],
                [ '%s', '%d', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s' ]
            );
        }

        self::prune_to_max_events();
        CheckoutFlowRunRepository::prune_to_max_runs( CheckoutTraceConfig::max_events() );
    }

    private static function safe_maybe_import_legacy_events(): void {
        try {
            self::maybe_import_legacy_events();
        } catch ( \Throwable $error ) {
            self::$legacy_import_checked = true;
        }
    }

    private static function safe_prune_after_append(): void {
        try {
            self::prune_to_max_events();
            CheckoutFlowRunRepository::prune_to_max_runs( CheckoutTraceConfig::max_events() );
        } catch ( \Throwable $error ) {
            return;
        }
    }

    private static function prune_to_max_events(): void {
        global $wpdb;

        if ( ! self::table_exists() ) {
            return;
        }

        $max_events = CheckoutTraceConfig::max_events();

        $wpdb->query(
            $wpdb->prepare(
                'DELETE FROM %i WHERE id NOT IN (SELECT id FROM (SELECT id FROM %i ORDER BY created_at DESC, id DESC LIMIT %d) AS ips_trace_keep)',
                self::table_name(),
                self::table_name(),
                $max_events
            )
        );
    }

    /**
     * @param array<string,mixed> $row
     * @return array<string,mixed>
     */
    private static function map_row_to_event( array $row ): array {
        $context = json_decode( (string) ( $row['context_json'] ?? '' ), true );

        return [
            'id' => (string) ( $row['event_uuid'] ?? '' ),
            'traceId' => (string) ( $row['trace_id'] ?? '' ),
            'event' => (string) ( $row['event'] ?? '' ),
            'step' => (string) ( $row['step'] ?? '' ),
            'status' => (string) ( $row['status'] ?? '' ),
            'origin' => (string) ( $row['origin'] ?? '' ),
            'gatewayId' => (string) ( $row['gateway_id'] ?? '' ),
            'providerKey' => (string) ( $row['provider_key'] ?? '' ),
            'message' => (string) ( $row['message'] ?? '' ),
            'createdAt' => self::mysql_to_iso( (string) ( $row['created_at'] ?? '' ) ),
            'context' => is_array( $context ) ? $context : [],
        ];
    }

    private static function normalize_mysql_datetime( string $value ): string {
        $timestamp = strtotime( $value );

        if ( false === $timestamp ) {
            return current_time( 'mysql', true );
        }

        return gmdate( 'Y-m-d H:i:s', $timestamp );
    }

    private static function mysql_to_iso( string $value ): string {
        $timestamp = strtotime( $value . ' UTC' );

        if ( false === $timestamp ) {
            return gmdate( 'c' );
        }

        return gmdate( 'c', $timestamp );
    }
}