rpclibrary/src/Types.ts

import * as I from "./Interfaces";
import { RPCSocket } from "./Frontend";

export type PioBindListener = (...args: any) => void
export type PioHookListener = GenericFunction

export type GenericFunction<Parameters extends any[] = any[], Result = any> = {(...args: Parameters): Result}

export type BackendHook<Func extends GenericFunction> =
    GenericFunction<
        [
            GenericFunction<
                Parameters<
                    AsFunction<
                        Parameters<Func>[0]
                    >
                >,
                void
            >,
            ...Tail<Parameters<Func>>
        ],
        ReturnType<Func>
    >


export type AccessFilter<InterfaceT extends RPCInterface = RPCInterface> = (sesame: string | undefined, exporter: I.RPCExporter<InterfaceT, keyof InterfaceT>) => Promise<boolean> | boolean
export type Visibility = "127.0.0.1" | "0.0.0.0"
export type ConnectionHandler = (socket: I.Socket) => void
export type ErrorHandler = (socket: I.Socket, error: any, rpcName: string, args: any[]) => void
export type CloseHandler = (socket: I.Socket) => void
export type SesameFunction = (sesame: string) => boolean
export type SesameConf = {
    sesame?: string | SesameFunction
}
export type FrontEndHandlerType = {
    'error': (e: any) => void
    'close': () => void
}
export type ClientConfig = SocketIOClient.ConnectOpts & {
    protocol?: 'http' | 'https',
    callTimeoutMs?: number
}
export type ExporterArray<InterfaceT extends RPCInterface = RPCInterface> = I.RPCExporter<RPCInterface<InterfaceT>, keyof InterfaceT>[]

export type ConnectedSocket<T extends RPCInterface = RPCInterface> = RPCSocket & AsyncIfc<T>

export type ServerConf<InterfaceT extends RPCInterface> = {
    accessFilter?: AccessFilter<InterfaceT>
    connectionHandler?: ConnectionHandler
    errorHandler?: ErrorHandler
    closeHandler?: CloseHandler
    throwOnUnknownRPC?: boolean
} & SesameConf

export type ResponseType = "Subscribe" | "Success" | "Error"
export type Outcome = "Success" | "Error"

export type Respose<T> = T & { result: Outcome }
export type SuccessResponse<T = {}> = Respose<T> & { result: "Success" }
export type ErrorResponse<T = {}> = Respose<T> & { result: "Error", message?: string }

export type RPCType = 'Hook' | 'Unhook' | 'Call'

export type CallRPC<Name, Func extends GenericFunction> = {
    name: Name
    call: Func
}

export type HookRPC<Name, Func extends GenericFunction> = {
    name: Name
    hook: BackendHook<Func>
    onCallback?: GenericFunction
    onDestroy?: HookCloseFunction<ReturnType<Func> extends Promise<infer T> ? T : ReturnType<Func>>
}

export type RPC<Name, Func extends GenericFunction> = HookRPC<Name, Func> | CallRPC<Name, Func> | Func

export type RPCInterface<Impl extends RPCInterface = {}> = {
    [grp in string]: {
        [rpc in string]: GenericFunction
    }
} & Impl

export type exportT = {
    [group in string]: {}
}

export type RPCDefinitions<Ifc extends RPCInterface> = {
    [grp in keyof Ifc]: ({
        [rpc in keyof Ifc[grp]]: RPC<rpc, Ifc[grp][rpc]>
    }[keyof Ifc[grp]])[]
}

export type BaseInfo = {
    name: string,
    owner: string,
    argNames: string[],
}

export type HookInfo<SubresT = {}> = BaseInfo & {
    type: 'Hook',
    generator: (socket?: I.Socket) => (...args: any[]) => SubresT
}

export type CallInfo = BaseInfo & {
    type: 'Call',
    call: GenericFunction
}

export type RpcInfo = HookInfo | CallInfo
export type ExtendedRpcInfo = RpcInfo & { uniqueName: string }

export type OnFunction = <T extends "error" | "close">(type: T, f: FrontEndHandlerType[T]) => void
export type HookCloseFunction<T> = (res: T, rpc: HookRPC<any, any>) => any


export type AsyncIfc<Ifc extends RPCInterface> = { [grp in keyof Ifc]: { [rpcname in keyof Ifc[grp]]: AsyncGenericFunction<Ifc[grp][rpcname]> } }

export type AsyncGenericFunction<F extends GenericFunction = GenericFunction> = F extends (...args: Parameters<F>) => infer R
    ? ((...args: Parameters<F>) => R extends Promise<any> ? R : Promise<R>)
    : Promise<any>

type Destroyable = { destroy: () => void }
export type Callback<Params extends any[] = []> =
    (this: Destroyable, ...args: Params) => void

type AsFunction<F> = F extends GenericFunction ? F : GenericFunction

type Last<Tuple extends any[]> = Tuple[ Subtract<Length<Tuple>, 1> ]
type Tail<T extends any[]> = T extends [any, ...infer R] ? R : any[]

type Length<T extends any[]> = 
    T extends { length: infer L } ? L : never;

type BuildTuple<L extends number, T extends any[] = []> = 
    T extends { length: L } ? T : BuildTuple<L, [...T, any]>;

type Subtract<A extends number, B extends number> = 
    BuildTuple<A> extends [...(infer U), ...BuildTuple<B>]
        ? Length<U>
        : never;