import type { Actor, Recipient } from "../vocab/actor.ts";
import type { Activity, Hashtag, Object } from "../vocab/vocab.ts";
import type {
  ActorDispatcher,
  ActorHandleMapper,
  ActorKeyPairsDispatcher,
  AuthorizePredicate,
  CollectionCounter,
  CollectionCursor,
  CollectionDispatcher,
  InboxErrorHandler,
  InboxListener,
  NodeInfoDispatcher,
  ObjectAuthorizePredicate,
  ObjectDispatcher,
  SharedInboxKeyDispatcher,
} from "./callback.ts";
import type { Context, RequestContext } from "./context.ts";

/**
 * Options for {@link Federation.startQueue} method.
 * @since 1.0.0
 */
export interface FederationStartQueueOptions {
  /**
   * The signal to abort the task queue.
   */
  signal?: AbortSignal;
}

/**
 * An object that registers federation-related business logic and dispatches
 * requests to the appropriate handlers.
 *
 * It also provides a middleware interface for handling requests before your
 * web framework's router; see {@link Federation.fetch}.
 *
 * @since 0.13.0
 */
export interface Federation<TContextData> {
  /**
   * Manually start the task queue.
   *
   * This method is useful when you set the `manuallyStartQueue` option to
   * `true` in the {@link createFederation} function.
   * @param contextData The context data to pass to the context.
   * @param options Additional options for starting the queue.
   */
  startQueue(
    contextData: TContextData,
    options?: FederationStartQueueOptions,
  ): Promise<void>;

  /**
   * Create a new context.
   * @param baseUrl The base URL of the server.  The `pathname` remains root,
   *                and the `search` and `hash` are stripped.
   * @param contextData The context data to pass to the context.
   * @returns The new context.
   */
  createContext(baseUrl: URL, contextData: TContextData): Context<TContextData>;

  /**
   * Create a new context for a request.
   * @param request The request object.
   * @param contextData The context data to pass to the context.
   * @returns The new request context.
   */
  createContext(
    request: Request,
    contextData: TContextData,
  ): RequestContext<TContextData>;

  /**
   * Registers a NodeInfo dispatcher.
   * @param path The URI path pattern for the NodeInfo dispatcher.  The syntax
   *             is based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have no variables.
   * @param dispatcher A NodeInfo dispatcher callback to register.
   * @throws {RouterError} Thrown if the path pattern is invalid.
   */
  setNodeInfoDispatcher(
    path: string,
    dispatcher: NodeInfoDispatcher<TContextData>,
  ): void;

  /**
   * Registers an actor dispatcher.
   *
   * @example
   * ``` typescript
   * federation.setActorDispatcher(
   *   "/users/{identifier}",
   *   async (ctx, identifier) => {
   *     return new Person({
   *       id: ctx.getActorUri(identifier),
   *       // ...
   *     });
   *   }
   * );
   * ```
   *
   * @param path The URI path pattern for the actor dispatcher.  The syntax is
   *             based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one variable: `{identifier}`.
   * @param dispatcher An actor dispatcher callback to register.
   * @returns An object with methods to set other actor dispatcher callbacks.
   * @throws {RouterError} Thrown if the path pattern is invalid.
   */
  setActorDispatcher(
    path: `${string}{identifier}${string}` | `${string}{handle}${string}`,
    dispatcher: ActorDispatcher<TContextData>,
  ): ActorCallbackSetters<TContextData>;

  /**
   * Registers an object dispatcher.
   *
   * @typeParam TContextData The context data to pass to the {@link Context}.
   * @typeParam TObject The type of object to dispatch.
   * @typeParam TParam The parameter names of the requested URL.
   * @param cls The Activity Vocabulary class of the object to dispatch.
   * @param path The URI path pattern for the object dispatcher.  The syntax is
   *             based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one or more variables.
   * @param dispatcher An object dispatcher callback to register.
   */
  setObjectDispatcher<TObject extends Object, TParam extends string>(
    // deno-lint-ignore no-explicit-any
    cls: (new (...args: any[]) => TObject) & { typeId: URL },
    path:
      `${string}{${TParam}}${string}{${TParam}}${string}{${TParam}}${string}{${TParam}}${string}{${TParam}}${string}{${TParam}}${string}`,
    dispatcher: ObjectDispatcher<TContextData, TObject, TParam>,
  ): ObjectCallbackSetters<TContextData, TObject, TParam>;

  /**
   * Registers an object dispatcher.
   *
   * @typeParam TContextData The context data to pass to the {@link Context}.
   * @typeParam TObject The type of object to dispatch.
   * @typeParam TParam The parameter names of the requested URL.
   * @param cls The Activity Vocabulary class of the object to dispatch.
   * @param path The URI path pattern for the object dispatcher.  The syntax is
   *             based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one or more variables.
   * @param dispatcher An object dispatcher callback to register.
   */
  setObjectDispatcher<TObject extends Object, TParam extends string>(
    // deno-lint-ignore no-explicit-any
    cls: (new (...args: any[]) => TObject) & { typeId: URL },
    path:
      `${string}{${TParam}}${string}{${TParam}}${string}{${TParam}}${string}{${TParam}}${string}{${TParam}}${string}`,
    dispatcher: ObjectDispatcher<TContextData, TObject, TParam>,
  ): ObjectCallbackSetters<TContextData, TObject, TParam>;

  /**
   * Registers an object dispatcher.
   *
   * @typeParam TContextData The context data to pass to the {@link Context}.
   * @typeParam TObject The type of object to dispatch.
   * @typeParam TParam The parameter names of the requested URL.
   * @param cls The Activity Vocabulary class of the object to dispatch.
   * @param path The URI path pattern for the object dispatcher.  The syntax is
   *             based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one or more variables.
   * @param dispatcher An object dispatcher callback to register.
   */
  setObjectDispatcher<TObject extends Object, TParam extends string>(
    // deno-lint-ignore no-explicit-any
    cls: (new (...args: any[]) => TObject) & { typeId: URL },
    path:
      `${string}{${TParam}}${string}{${TParam}}${string}{${TParam}}${string}{${TParam}}${string}`,
    dispatcher: ObjectDispatcher<TContextData, TObject, TParam>,
  ): ObjectCallbackSetters<TContextData, TObject, TParam>;

  /**
   * Registers an object dispatcher.
   *
   * @typeParam TContextData The context data to pass to the {@link Context}.
   * @typeParam TObject The type of object to dispatch.
   * @typeParam TParam The parameter names of the requested URL.
   * @param cls The Activity Vocabulary class of the object to dispatch.
   * @param path The URI path pattern for the object dispatcher.  The syntax is
   *             based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one or more variables.
   * @param dispatcher An object dispatcher callback to register.
   */
  setObjectDispatcher<TObject extends Object, TParam extends string>(
    // deno-lint-ignore no-explicit-any
    cls: (new (...args: any[]) => TObject) & { typeId: URL },
    path:
      `${string}{${TParam}}${string}{${TParam}}${string}{${TParam}}${string}`,
    dispatcher: ObjectDispatcher<TContextData, TObject, TParam>,
  ): ObjectCallbackSetters<TContextData, TObject, TParam>;

  /**
   * Registers an object dispatcher.
   *
   * @typeParam TContextData The context data to pass to the {@link Context}.
   * @typeParam TObject The type of object to dispatch.
   * @typeParam TParam The parameter names of the requested URL.
   * @param cls The Activity Vocabulary class of the object to dispatch.
   * @param path The URI path pattern for the object dispatcher.  The syntax is
   *             based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one or more variables.
   * @param dispatcher An object dispatcher callback to register.
   */
  setObjectDispatcher<TObject extends Object, TParam extends string>(
    // deno-lint-ignore no-explicit-any
    cls: (new (...args: any[]) => TObject) & { typeId: URL },
    path: `${string}{${TParam}}${string}{${TParam}}${string}`,
    dispatcher: ObjectDispatcher<TContextData, TObject, TParam>,
  ): ObjectCallbackSetters<TContextData, TObject, TParam>;

  /**
   * Registers an object dispatcher.
   *
   * @typeParam TContextData The context data to pass to the {@link Context}.
   * @typeParam TObject The type of object to dispatch.
   * @typeParam TParam The parameter names of the requested URL.
   * @param cls The Activity Vocabulary class of the object to dispatch.
   * @param path The URI path pattern for the object dispatcher.  The syntax is
   *             based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one or more variables.
   * @param dispatcher An object dispatcher callback to register.
   */
  setObjectDispatcher<TObject extends Object, TParam extends string>(
    // deno-lint-ignore no-explicit-any
    cls: (new (...args: any[]) => TObject) & { typeId: URL },
    path: `${string}{${TParam}}${string}`,
    dispatcher: ObjectDispatcher<TContextData, TObject, TParam>,
  ): ObjectCallbackSetters<TContextData, TObject, TParam>;

  /**
   * Registers an inbox dispatcher.
   *
   * @param path The URI path pattern for the inbox dispatcher.  The syntax is
   *             based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one variable: `{identifier}`, and must match
   *             the inbox listener path.
   * @param dispatcher An inbox dispatcher callback to register.
   * @throws {@link RouterError} Thrown if the path pattern is invalid.
   */
  setInboxDispatcher(
    path: `${string}{identifier}${string}` | `${string}{handle}${string}`,
    dispatcher: CollectionDispatcher<
      Activity,
      RequestContext<TContextData>,
      TContextData,
      void
    >,
  ): CollectionCallbackSetters<
    RequestContext<TContextData>,
    TContextData,
    void
  >;

  /**
   * Registers an outbox dispatcher.
   *
   * @example
   * ``` typescript
   * federation.setOutboxDispatcher(
   *   "/users/{identifier}/outbox",
   *   async (ctx, identifier, options) => {
   *     let items: Activity[];
   *     let nextCursor: string;
   *     // ...
   *     return { items, nextCursor };
   *   }
   * );
   * ```
   *
   * @param path The URI path pattern for the outbox dispatcher.  The syntax is
   *             based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one variable: `{identifier}`.
   * @param dispatcher An outbox dispatcher callback to register.
   * @throws {@link RouterError} Thrown if the path pattern is invalid.
   */
  setOutboxDispatcher(
    path: `${string}{identifier}${string}` | `${string}{handle}${string}`,
    dispatcher: CollectionDispatcher<
      Activity,
      RequestContext<TContextData>,
      TContextData,
      void
    >,
  ): CollectionCallbackSetters<
    RequestContext<TContextData>,
    TContextData,
    void
  >;

  /**
   * Registers a following collection dispatcher.
   * @param path The URI path pattern for the following collection.  The syntax
   *             is based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one variable: `{identifier}`.
   * @param dispatcher A following collection callback to register.
   * @returns An object with methods to set other following collection
   *          callbacks.
   * @throws {RouterError} Thrown if the path pattern is invalid.
   */
  setFollowingDispatcher(
    path: `${string}{identifier}${string}` | `${string}{handle}${string}`,
    dispatcher: CollectionDispatcher<
      Actor | URL,
      RequestContext<TContextData>,
      TContextData,
      void
    >,
  ): CollectionCallbackSetters<
    RequestContext<TContextData>,
    TContextData,
    void
  >;

  /**
   * Registers a followers collection dispatcher.
   * @param path The URI path pattern for the followers collection.  The syntax
   *             is based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one variable: `{identifier}`.
   * @param dispatcher A followers collection callback to register.
   * @returns An object with methods to set other followers collection
   *          callbacks.
   * @throws {@link RouterError} Thrown if the path pattern is invalid.
   */
  setFollowersDispatcher(
    path: `${string}{identifier}${string}` | `${string}{handle}${string}`,
    dispatcher: CollectionDispatcher<
      Recipient,
      Context<TContextData>,
      TContextData,
      URL
    >,
  ): CollectionCallbackSetters<Context<TContextData>, TContextData, URL>;

  /**
   * Registers a liked collection dispatcher.
   * @param path The URI path pattern for the liked collection.  The syntax
   *             is based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one variable: `{identifier}`.
   * @param dispatcher A liked collection callback to register.
   * @returns An object with methods to set other liked collection
   *          callbacks.
   * @throws {@link RouterError} Thrown if the path pattern is invalid.
   */
  setLikedDispatcher(
    path: `${string}{identifier}${string}` | `${string}{handle}${string}`,
    dispatcher: CollectionDispatcher<
      Object | URL,
      RequestContext<TContextData>,
      TContextData,
      void
    >,
  ): CollectionCallbackSetters<
    RequestContext<TContextData>,
    TContextData,
    void
  >;

  /**
   * Registers a featured collection dispatcher.
   * @param path The URI path pattern for the featured collection.  The syntax
   *             is based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one variable: `{identifier}`.
   * @param dispatcher A featured collection callback to register.
   * @returns An object with methods to set other featured collection
   *          callbacks.
   * @throws {@link RouterError} Thrown if the path pattern is invalid.
   */
  setFeaturedDispatcher(
    path: `${string}{identifier}${string}` | `${string}{handle}${string}`,
    dispatcher: CollectionDispatcher<
      Object,
      RequestContext<TContextData>,
      TContextData,
      void
    >,
  ): CollectionCallbackSetters<
    RequestContext<TContextData>,
    TContextData,
    void
  >;

  /**
   * Registers a featured tags collection dispatcher.
   * @param path The URI path pattern for the featured tags collection.
   *             The syntax is based on URI Template
   *             ([RFC 6570](https://tools.ietf.org/html/rfc6570)).  The path
   *             must have one variable: `{identifier}`.
   * @param dispatcher A featured tags collection callback to register.
   * @returns An object with methods to set other featured tags collection
   *          callbacks.
   * @throws {@link RouterError} Thrown if the path pattern is invalid.
   */
  setFeaturedTagsDispatcher(
    path: `${string}{identifier}${string}` | `${string}{handle}${string}`,
    dispatcher: CollectionDispatcher<
      Hashtag,
      RequestContext<TContextData>,
      TContextData,
      void
    >,
  ): CollectionCallbackSetters<
    RequestContext<TContextData>,
    TContextData,
    void
  >;

  /**
   * Assigns the URL path for the inbox and starts setting inbox listeners.
   *
   * @example
   * ``` typescript
   * federation
   *   .setInboxListeners("/users/{identifier}/inbox", "/inbox")
   *   .on(Follow, async (ctx, follow) => {
   *     const from = await follow.getActor(ctx);
   *     if (!isActor(from)) return;
   *     // ...
   *   })
   *   .on(Undo, async (ctx, undo) => {
   *     // ...
   *   });
   * ```
   *
   * @param inboxPath The URI path pattern for the inbox.  The syntax is based
   *                  on URI Template
   *                  ([RFC 6570](https://tools.ietf.org/html/rfc6570)).
   *                  The path must have one variable: `{identifier}`, and must
   *                  match the inbox dispatcher path.
   * @param sharedInboxPath An optional URI path pattern for the shared inbox.
   *                        The syntax is based on URI Template
   *                        ([RFC 6570](https://tools.ietf.org/html/rfc6570)).
   *                        The path must have no variables.
   * @returns An object to register inbox listeners.
   * @throws {RouteError} Thrown if the path pattern is invalid.
   */
  setInboxListeners(
    inboxPath: `${string}{identifier}${string}` | `${string}{handle}${string}`,
    sharedInboxPath?: string,
  ): InboxListenerSetters<TContextData>;

  /**
   * Handles a request related to federation.  If a request is not related to
   * federation, the `onNotFound` or `onNotAcceptable` callback is called.
   *
   * Usually, this method is called from a server's request handler or
   * a web framework's middleware.
   *
   * @param request The request object.
   * @param parameters The parameters for handling the request.
   * @returns The response to the request.
   */
  fetch(
    request: Request,
    options: FederationFetchOptions<TContextData>,
  ): Promise<Response>;
}

/**
 * Additional settings for the actor dispatcher.
 *
 * ``` typescript
 * const federation = createFederation<void>({ ... });
 * federation
 *   .setActorDispatcher("/users/{identifier}", async (ctx, identifier) => {
 *     // ...
 *   })
 *   .setKeyPairsDispatcher(async (ctxData, identifier) => {
 *     // ...
 *   });
 * ```
 */
export interface ActorCallbackSetters<TContextData> {
  /**
   * Sets the key pairs dispatcher for actors.
   * @param dispatcher A callback that returns the key pairs for an actor.
   * @returns The setters object so that settings can be chained.
   * @since 0.10.0
   */
  setKeyPairsDispatcher(
    dispatcher: ActorKeyPairsDispatcher<TContextData>,
  ): ActorCallbackSetters<TContextData>;

  /**
   * Sets the callback function that maps a WebFinger username to
   * the corresponding actor's identifier.  If it's omitted, the identifier
   * is assumed to be the same as the WebFinger username, which makes your
   * actors have the immutable handles.  If you want to let your actors change
   * their fediverse handles, you should set this dispatcher.
   * @since 0.15.0
   */
  mapHandle(
    mapper: ActorHandleMapper<TContextData>,
  ): ActorCallbackSetters<TContextData>;

  /**
   * Specifies the conditions under which requests are authorized.
   * @param predicate A callback that returns whether a request is authorized.
   * @returns The setters object so that settings can be chained.
   * @since 0.7.0
   */
  authorize(
    predicate: AuthorizePredicate<TContextData>,
  ): ActorCallbackSetters<TContextData>;
}

/**
 * Additional settings for an object dispatcher.
 */
export interface ObjectCallbackSetters<
  TContextData,
  TObject extends Object,
  TParam extends string,
> {
  /**
   * Specifies the conditions under which requests are authorized.
   * @param predicate A callback that returns whether a request is authorized.
   * @returns The setters object so that settings can be chained.
   * @since 0.7.0
   */
  authorize(
    predicate: ObjectAuthorizePredicate<TContextData, TParam>,
  ): ObjectCallbackSetters<TContextData, TObject, TParam>;
}

/**
 * Additional settings for a collection dispatcher.
 *
 * @typeParam TContext The type of the context.  {@link Context} or
 *                     {@link RequestContext}.
 * @typeParam TContextData The context data to pass to the {@link Context}.
 * @typeParam TFilter The type of filter for the collection.
 */
export interface CollectionCallbackSetters<
  TContext extends Context<TContextData>,
  TContextData,
  TFilter,
> {
  /**
   * Sets the counter for the collection.
   * @param counter A callback that returns the number of items in the collection.
   * @returns The setters object so that settings can be chained.
   */
  setCounter(
    counter: CollectionCounter<TContextData, TFilter>,
  ): CollectionCallbackSetters<TContext, TContextData, TFilter>;

  /**
   * Sets the first cursor for the collection.
   * @param cursor The cursor for the first item in the collection.
   * @returns The setters object so that settings can be chained.
   */
  setFirstCursor(
    cursor: CollectionCursor<TContext, TContextData, TFilter>,
  ): CollectionCallbackSetters<TContext, TContextData, TFilter>;

  /**
   * Sets the last cursor for the collection.
   * @param cursor The cursor for the last item in the collection.
   * @returns The setters object so that settings can be chained.
   */
  setLastCursor(
    cursor: CollectionCursor<TContext, TContextData, TFilter>,
  ): CollectionCallbackSetters<TContext, TContextData, TFilter>;

  /**
   * Specifies the conditions under which requests are authorized.
   * @param predicate A callback that returns whether a request is authorized.
   * @returns The setters object so that settings can be chained.
   * @since 0.7.0
   */
  authorize(
    predicate: AuthorizePredicate<TContextData>,
  ): CollectionCallbackSetters<TContext, TContextData, TFilter>;
}

/**
 * Registry for inbox listeners for different activity types.
 */
export interface InboxListenerSetters<TContextData> {
  /**
   * Registers a listener for a specific incoming activity type.
   *
   * @param type A subclass of {@link Activity} to listen to.
   * @param listener A callback to handle an incoming activity.
   * @returns The setters object so that settings can be chained.
   */
  on<TActivity extends Activity>(
    // deno-lint-ignore no-explicit-any
    type: new (...args: any[]) => TActivity,
    listener: InboxListener<TContextData, TActivity>,
  ): InboxListenerSetters<TContextData>;

  /**
   * Registers an error handler for inbox listeners.  Any exceptions thrown
   * from the listeners are caught and passed to this handler.
   *
   * @param handler A callback to handle an error.
   * @returns The setters object so that settings can be chained.
   */
  onError(
    handler: InboxErrorHandler<TContextData>,
  ): InboxListenerSetters<TContextData>;

  /**
   * Configures a callback to dispatch the key pair for the authenticated
   * document loader of the {@link Context} passed to the shared inbox listener.
   *
   * @param dispatcher A callback to dispatch the key pair for the authenticated
   *                   document loader.
   * @returns The setters object so that settings can be chained.
   * @since 0.11.0
   */
  setSharedKeyDispatcher(
    dispatcher: SharedInboxKeyDispatcher<TContextData>,
  ): InboxListenerSetters<TContextData>;
}

/**
 * Parameters of {@link Federation.fetch} method.
 *
 * @typeParam TContextData The context data to pass to the {@link Context}.
 * @since 0.6.0
 */
export interface FederationFetchOptions<TContextData> {
  /**
   * The context data to pass to the {@link Context}.
   */
  contextData: TContextData;

  /**
   * A callback to handle a request when the route is not found.
   * If not provided, a 404 response is returned.
   * @param request The request object.
   * @returns The response to the request.
   */
  onNotFound?: (request: Request) => Response | Promise<Response>;

  /**
   * A callback to handle a request when the request's `Accept` header is not
   * acceptable.  If not provided, a 406 response is returned.
   * @param request The request object.
   * @returns The response to the request.
   */
  onNotAcceptable?: (request: Request) => Response | Promise<Response>;

  /**
   * A callback to handle a request when the request is unauthorized.
   * If not provided, a 401 response is returned.
   * @param request The request object.
   * @returns The response to the request.
   * @since 0.7.0
   */
  onUnauthorized?: (request: Request) => Response | Promise<Response>;
}