export interface GitHubRelease {
    tag_name: string;
    body: string;
    html_url: string;
    published_at?: string | null;
    draft?: boolean;
    prerelease?: boolean;
}
export interface GitHubRepoMeta {
    stargazers_count: number;
    forks_count: number;
    archived: boolean;
    pushed_at: string | null;
    open_issues_count: number;
    created_at: string | null;
    license: {
        spdx_id: string | null;
        name: string | null;
    } | null;
    owner: {
        login: string;
        type: string;
    };
}
export interface IssueStats {
    /** null when the Search API call failed (rate-limited or network error). */
    open: number | null;
    /** null when the Search API call failed (rate-limited or network error). */
    closed: number | null;
    /** closed / (open + closed); null when either count is unavailable. */
    closeRatio: number | null;
    /** Median days-to-close over recent closed issues; null when unavailable. */
    medianDaysToClose: number | null;
}
export interface GitHubUser {
    public_repos: number | null;
    created_at: string | null;
}
export declare class GitHubClient {
    private readonly headers;
    constructor(token?: string);
    fetchReleases(owner: string, repo: string): Promise<GitHubRelease[]>;
    fetchChangelog(owner: string, repo: string): Promise<string | null>;
    repoExists(owner: string, repo: string): Promise<boolean>;
    /** Fetch repository metadata (stars, activity, license, owner). null on failure. */
    fetchRepo(owner: string, repo: string): Promise<GitHubRepoMeta | null>;
    /**
     * Publisher/owner account signals: public-repo count and account creation
     * date, used to gauge maintainer scale and account age. null on failure
     * (non-fatal — repo metrics still stand without it).
     */
    fetchUser(login: string): Promise<GitHubUser | null>;
    /**
     * Issue dynamics via the GitHub Search API: open vs closed counts, close
     * ratio, and median days-to-close over recent closed issues. Returns null
     * when both counts are unavailable (Search API is rate-limited more strictly
     * than the core API). PRs are excluded via `type:issue`.
     */
    fetchIssueStats(owner: string, repo: string): Promise<IssueStats | null>;
    private searchIssueCount;
    private medianDaysToCloseRecent;
    /**
     * Files > 1 MB come back with `content === ""` and a `download_url` pointing
     * at raw.githubusercontent.com. Fall back to fetching that raw URL so the
     * changelog isn't silently truncated to the empty string.
     */
    private decodeChangelogContents;
}