import { FrontendPlugin, Extension, ExtensionDataRef, ExtensionAttachToSpec } from '../../wiring';
/**
 * The specification for this {@link AppNode} in the {@link AppTree}.
 *
 * @public
 * @remarks
 *
 * The specifications for a collection of app nodes is all the information needed
 * to build the tree and instantiate the nodes.
 */
export interface AppNodeSpec {
    readonly id: string;
    readonly attachTo: ExtensionAttachToSpec;
    readonly extension: Extension<unknown, unknown>;
    readonly disabled: boolean;
    readonly config?: unknown;
    readonly plugin?: FrontendPlugin;
    /**
     * @deprecated Use {@link AppNodeSpec.plugin} instead.
     */
    readonly source?: FrontendPlugin;
}
/**
 * The connections from this {@link AppNode} to other nodes.
 *
 * @public
 * @remarks
 *
 * The app node edges are resolved based on the app node specs, regardless of whether
 * adjacent nodes are disabled or not. If no parent attachment is present or
 */
export interface AppNodeEdges {
    readonly attachedTo?: {
        node: AppNode;
        input: string;
    };
    readonly attachments: ReadonlyMap<string, AppNode[]>;
}
/**
 * The instance of this {@link AppNode} in the {@link AppTree}.
 *
 * @public
 * @remarks
 *
 * The app node instance is created when the `factory` function of an extension is called.
 * Instances will only be present for nodes in the app that are connected to the root
 * node and not disabled
 */
export interface AppNodeInstance {
    /** Returns a sequence of all extension data refs that were output by this instance */
    getDataRefs(): Iterable<ExtensionDataRef<unknown>>;
    /** Get the output data for a single extension data ref */
    getData<T>(ref: ExtensionDataRef<T>): T | undefined;
}
/**
 * A node in the {@link AppTree}.
 *
 * @public
 */
export interface AppNode {
    /** The specification for how this node should be instantiated */
    readonly spec: AppNodeSpec;
    /** The edges from this node to other nodes in the app tree */
    readonly edges: AppNodeEdges;
    /** The instance of this node, if it was instantiated */
    readonly instance?: AppNodeInstance;
}
/**
 * The app tree containing all {@link AppNode}s of the app.
 *
 * @public
 */
export interface AppTree {
    /** The root node of the app */
    readonly root: AppNode;
    /** A map of all nodes in the app by ID, including orphaned or disabled nodes */
    readonly nodes: ReadonlyMap<string, AppNode>;
    /** A sequence of all nodes with a parent that is not reachable from the app root node */
    readonly orphans: Iterable<AppNode>;
}
/**
 * The API for interacting with the {@link AppTree}.
 *
 * @public
 */
export interface AppTreeApi {
    /**
     * Get the {@link AppTree} for the app.
     */
    getTree(): {
        tree: AppTree;
    };
    /**
     * Get all nodes in the app that are mounted at a given route path.
     */
    getNodesByRoutePath(sourcePath: string): {
        nodes: AppNode[];
    };
}
/**
 * The `ApiRef` of {@link AppTreeApi}.
 *
 * @public
 */
export declare const appTreeApiRef: import("@backstage/core-plugin-api").ApiRef<AppTreeApi>;