/**
 * Dexcom Developer API client (sandbox + production).
 * Docs: https://developer.dexcom.com/docs/dexcomv2/overview
 *
 * v0.1 ships:
 * - OAuth authorize URL builder
 * - Token exchange (auth_code → access_token)
 * - EGV (estimated glucose value) read
 * - Mock mode when no token is present
 */
import { type DexcomEnv } from "../constants.js";
import type { GlucoseReading } from "./glucose-engine.js";
export interface DexcomTokens {
    access_token: string;
    refresh_token: string;
    expires_at: string;
    scope: string;
}
export interface DexcomClientOptions {
    env?: DexcomEnv;
    clientId?: string;
    clientSecret?: string;
    redirectUri?: string;
    fetchImpl?: typeof fetch;
    accessToken?: string;
}
export declare class DexcomClient {
    readonly env: DexcomEnv;
    readonly baseUrl: string;
    readonly clientId?: string;
    readonly clientSecret?: string;
    readonly redirectUri?: string;
    readonly accessToken?: string;
    private readonly fetchImpl;
    constructor(opts?: DexcomClientOptions);
    hasAuth(): boolean;
    buildAuthorizeUrl(state?: string, scope?: string): string;
    exchangeAuthCode(code: string): Promise<DexcomTokens>;
    getEgvs(startDate: string, endDate: string): Promise<GlucoseReading[]>;
}