(() => {
    if (typeof window === 'undefined') {
        return;
    }

    if (window.__tenantpilotUnhandledRejectionLoggerApplied) {
        return;
    }

    window.__tenantpilotUnhandledRejectionLoggerApplied = true;

    const recentKeys = new Map();

    const cleanupRecentKeys = (nowMs) => {
        for (const [key, timestampMs] of recentKeys.entries()) {
            if (nowMs - timestampMs > 5_000) {
                recentKeys.delete(key);
            }
        }
    };

    const isTransportEnvelope = (value) => {
        return value !== null
            && typeof value === 'object'
            && Object.prototype.hasOwnProperty.call(value, 'status')
            && Object.prototype.hasOwnProperty.call(value, 'body')
            && Object.prototype.hasOwnProperty.call(value, 'json')
            && Object.prototype.hasOwnProperty.call(value, 'errors');
    };

    const isCancellationReason = (reason) => {
        if (!isTransportEnvelope(reason)) {
            return false;
        }

        return reason.status === null
            && reason.body === null
            && reason.json === null
            && reason.errors === null;
    };

    const isPageHiddenOrInactive = () => {
        if (document.visibilityState !== 'visible') {
            return true;
        }

        return typeof document.hasFocus === 'function'
            ? document.hasFocus() === false
            : false;
    };

    const isExpectedBackgroundTransportFailure = (reason) => {
        if (isCancellationReason(reason)) {
            return true;
        }

        if (!isTransportEnvelope(reason) || !isPageHiddenOrInactive()) {
            return false;
        }

        return (reason.status === 419 && typeof reason.body === 'string' && reason.body.includes('Page Expired'))
            || (reason.status === 404 && typeof reason.body === 'string' && reason.body.includes('Not Found'));
    };

    const normalizeReason = (value, depth = 0) => {
        if (depth > 3) {
            return '[max-depth-reached]';
        }

        if (value instanceof Error) {
            return {
                type: 'Error',
                name: value.name,
                message: value.message,
                stack: value.stack,
            };
        }

        if (value === null || value === undefined) {
            return value;
        }

        if (typeof value === 'string' || typeof value === 'number' || typeof value === 'boolean') {
            return value;
        }

        if (Array.isArray(value)) {
            return value.slice(0, 10).map((item) => normalizeReason(item, depth + 1));
        }

        if (typeof value === 'object') {
            const result = {};
            const allowedKeys = [
                'message',
                'stack',
                'name',
                'type',
                'status',
                'body',
                'json',
                'errors',
                'reason',
                'code',
            ];

            for (const key of allowedKeys) {
                if (Object.prototype.hasOwnProperty.call(value, key)) {
                    result[key] = normalizeReason(value[key], depth + 1);
                }
            }

            if (Object.keys(result).length > 0) {
                return result;
            }

            const stringTag = Object.prototype.toString.call(value);

            return {
                type: stringTag,
                value: String(value),
            };
        }

        return String(value);
    };

    const toStableJson = (payload) => {
        try {
            return JSON.stringify(payload);
        } catch {
            return JSON.stringify({
                source: payload.source,
                href: payload.href,
                timestamp: payload.timestamp,
                reason: '[unserializable]',
            });
        }
    };

    window.addEventListener('unhandledrejection', (event) => {
        const normalizedReason = normalizeReason(event.reason);
        const payload = {
            source: 'window.unhandledrejection',
            href: window.location.href,
            timestamp: new Date().toISOString(),
            reason: normalizedReason,
        };

        if (isExpectedBackgroundTransportFailure(normalizedReason)) {
            event.preventDefault();

            return;
        }

        const dedupeKey = toStableJson({
            source: payload.source,
            href: payload.href,
            reason: payload.reason,
        });

        const payloadJson = toStableJson(payload);
        const nowMs = Date.now();

        cleanupRecentKeys(nowMs);

        if (recentKeys.has(dedupeKey)) {
            return;
        }

        recentKeys.set(dedupeKey, nowMs);

        console.error(`TenantPilot unhandled promise rejection ${payloadJson}`);
    });
})();