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type ExtraData = Record<string, null | boolean | string | number | undefined>;
interface CreateArgBase {	name: string;	extra?: ExtraData;}
interface NoParent extends CreateArgBase {	kind: "no-parent";	service: string;}
interface FromRequest extends CreateArgBase {	kind: "request";	parent: Request;	service: string;}
interface FromSpan extends CreateArgBase {	kind: "span";	parent: Span;}
class Span {	spans: Span[]; // all the spans	service: string; // the service the span is from	name: string; // role of the span	startTime: number; // when the span starts	duration?: number; // known when complete	spanId: string; // uniquely identifies the span	traceId: string; // identifies which trace the span belongs to	parentId?: string; // the parent span that created this span	extra?: ExtraData; // extra data that might be helpful.
	constructor(arg: NoParent | FromRequest | FromSpan) {		this.name = arg.name;		this.startTime = Date.now();		this.spanId = crypto.randomUUID();		this.extra = arg.extra;		if (arg.kind === "span") {			this.spans = arg.parent.spans;			this.service = arg.parent.service;			this.traceId = arg.parent.traceId;			this.parentId = arg.parent.spanId;		} else if (arg.kind === "request") {			this.spans = [];			this.service = arg.service;			this.traceId = arg.parent.headers.get("x-trace-id") ?? crypto.randomUUID();			this.parentId = arg.parent.headers.get("x-parent-id") ?? undefined;		} else {			this.spans = [];			this.service = arg.service;			this.traceId = crypto.randomUUID();		}		this.spans.push(this);	}
	hcJSON() {		return {			time: new Date(this.startTime).toISOString(),			data: {				// https://docs.honeycomb.io/getting-data-in/tracing/send-trace-data/#opentelemetry				name: this.name,				"service.name": this.service,				duration_ms: this.duration,				"trace.span_id": this.spanId,				"trace.trace_id": this.traceId,				"trace.parent_id": this.parentId,				...this.extra,			},		};	}}
interface CreateArg extends CreateArgBase {	skip?: boolean;	service?: string;	parent?: Request | Span | null;}
export function create({ skip, name, service, parent, extra }: CreateArg): Span | null {	if (skip || (parent === null && !service)) return null; // short circuit	if (parent instanceof Span) {		return new Span({ kind: "span", name, parent, extra });	}	if (!service) throw new Error("service must be provided when parent is not a span");	if (new URL(`http://localhost/${service}`).pathname.slice(1) !== service) {		console.warn("consider using a service name that is url friendly");	}	if (parent instanceof Request) {		return new Span({ kind: "request", name, service, parent, extra });	}	return new Span({ kind: "no-parent", name, service, extra });}
interface EventArg extends CreateArgBase {	parent: Span | null;}
export function event({ name, parent, extra }: EventArg) {	if (parent) {		new Span({			kind: "span",			name,			parent,			extra: { ...extra, "meta.annotation_type": "span_event" },		});	}}
export function link(parent: Span | null, to: Span | null) {	if (parent && to) {		new Span({			kind: "span",			name: "link",			parent,			extra: {				"meta.annotation_type": "link",				"trace.link.span_id": to.spanId,				"trace.link.trace_id": to.traceId,			},		});	}}
export function propagate(span: Span | null, headers: Headers) {	if (!span) return;	headers.set("x-trace-id", span.traceId);	headers.set("x-parent-id", span.spanId);}
export function extra(span: Span | null, extra: ExtraData) {	if (!span) return;	span.extra = { ...span.extra, ...extra };}
export function end(span: Span | null, extra?: ExtraData) {	if (!span) return;	span.duration = Date.now() - span.startTime;	span.extra = { ...span.extra, ...extra };}
interface HCReqArg {	apiKey: string;	span: Span;}
export function honeycombRequest({ apiKey, span }: HCReqArg) {	return new Request(`https://api.honeycomb.io/1/batch/${span.service}`, {		method: "POST",		headers: {			"x-honeycomb-team": apiKey,			"content-type": "application/json",		},		body: JSON.stringify(span.spans.map((s) => s.hcJSON())),	});}