import { ErrorLike } from './errors';
import * as GQL from './schema/graphqlschema';
export declare type ID = string;
/**
 * A subset of the settings JSON Schema type containing the minimum needed by this library.
 */
export interface Settings {
    extensions?: {
        [extensionID: string]: boolean;
    };
    [key: string]: any;
    subjects?: never;
    merged?: never;
}
/**
 * A configuration subject is something that can have settings associated with it, such as a site ("global
 * settings"), an organization ("organization settings"), a user ("user settings"), etc.
 */
export declare type ConfigurationSubject = Pick<GQL.IConfigurationSubject, 'id' | 'settingsURL' | 'viewerCanAdminister'> & (Pick<GQL.IUser, '__typename' | 'username' | 'displayName'> | Pick<GQL.IOrg, '__typename' | 'name' | 'displayName'> | Pick<GQL.ISite, '__typename'>);
/**
 * A cascade of settings from multiple subjects, from lowest precedence to highest precedence, and the final
 * settings, merged in order of precedence from the settings for each subject in the cascade.
 *
 * Callers that need to represent the null/error states should use {@link ConfigurationCascade}.
 *
 * @template S the configuration subject type
 * @template C the settings type
 */
export interface ConfigurationCascade<S extends ConfigurationSubject = ConfigurationSubject, C extends Settings = Settings> {
    /**
     * The settings for each subject in the cascade, from lowest to highest precedence.
     */
    subjects: ConfiguredSubject<S, C>[];
    merged: C;
}
/**
 * A configuration cascade that also supports representing subjects with no settings or whose settings triggered an
 * error.
 *
 * Callers that don't need to represent the null/error states should use {@link ConfigurationCascade}.
 *
 * @template S the configuration subject type
 * @template C the settings type
 */
export interface ConfigurationCascadeOrError<S extends ConfigurationSubject, C extends Settings = Settings> extends Pick<ConfigurationCascade<S, C>, Exclude<keyof ConfigurationCascade<S, C>, 'subjects' | 'merged'>> {
    /**
     * The settings for each subject in the cascade, from lowest to highest precedence, null if there are none, or
     * an error.
     *
     * @see ConfigurationCascade#subjects
     */
    subjects: ConfiguredSubjectOrError<S, C>[] | ErrorLike | null;
    /**
     * The final settings (merged in order of precedence from the settings for each subject in the cascade), an
     * error (if any occurred while retrieving, parsing, or merging the settings), or null if there are no settings
     * from any of the subjects.
     *
     * @see ConfigurationCascade#merged
     */
    merged: C | ErrorLike | null;
}
/**
 * A subject and its settings.
 *
 * Callers that need to represent the null/error states should use {@link ConfiguredSubjectOrError}.
 *
 * @template S the configuration subject type
 * @template C the settings type
 */
export interface ConfiguredSubject<S extends ConfigurationSubject, C extends Settings = Settings> {
    /** The subject. */
    subject: S;
    /** The subject's settings. */
    settings: C;
}
/**
 * A subject and its settings, or null if there are no settings, or an error.
 *
 * Callers that don't need to represent the null/error states should use {@link ConfiguredSubject}.
 */
export interface ConfiguredSubjectOrError<S extends ConfigurationSubject, C extends Settings = Settings> extends Pick<ConfiguredSubject<S, C>, Exclude<keyof ConfiguredSubject<S, C>, 'settings'>> {
    /**
     * The subject's settings (if any), an error (if any occurred while retrieving or parsing the settings), or
     * null if there are no settings.
     */
    settings: C | ErrorLike | null;
}
/** A minimal subset of a GraphQL ConfigurationSubject type that includes only the single contents value. */
export interface SubjectConfigurationContents {
    latestSettings: {
        configuration: {
            contents: string;
        };
    } | null;
}
/** Converts a GraphQL ConfigurationCascade value to a value of this library's ConfigurationCascade type. */
export declare function gqlToCascade<S extends ConfigurationSubject, C extends Settings>({ subjects, }: {
    subjects: (S & SubjectConfigurationContents)[];
}): ConfigurationCascadeOrError<S, C>;
/** Converts a ConfigurationCascadeOrError to a ConfigurationCascade, returning the first error it finds. */
export declare function extractErrors(c: ConfigurationCascadeOrError<ConfigurationSubject, Settings>): ConfigurationCascade | ErrorLike;
/**
 * Deeply merges the settings without modifying any of the input values. The array is ordered from lowest to
 * highest precedence in the merge.
 *
 * TODO(sqs): In the future, this will pass a CustomMergeFunctions value to merge.
 */
export declare function mergeSettings<C extends Settings>(values: C[]): C | null;
export interface CustomMergeFunctions {
    [key: string]: (base: any, add: any) => any | CustomMergeFunctions;
}
/**
 * Deeply merges add into base (modifying base). The merged value for a key path can be customized by providing a
 * function at the same key path in custom.
 *
 * Most callers should use mergeSettings, which uses the set of CustomMergeFunctions that are required to properly
 * merge settings.
 */
export declare function merge(base: any, add: any, custom?: CustomMergeFunctions): void;
/**
 * The conventional ordering of extension configuration subject types in a list.
 */
export declare const SUBJECT_TYPE_ORDER: ConfigurationSubject['__typename'][];
export declare function subjectTypeHeader(nodeType: ConfigurationSubject['__typename']): string | null;
export declare function subjectLabel(subject: ConfigurationSubject): string;
/**
 * React partial props for components needing the configuration cascade.
 */
export interface ConfigurationCascadeProps<S extends ConfigurationSubject, C extends Settings> {
    configurationCascade: ConfigurationCascadeOrError<S, C>;
}