type callModule = typeof import("libkmodule").callModule;
type connectModule = typeof import("libkmodule").connectModule;
type logErr = typeof import("libkmodule").logErr;
type log = typeof import("libkmodule").log;

import type { ErrTuple, DataFn } from "@siaweb/libweb";
import EventEmitter from "eventemitter2";

type callModuleBound = (method: string, data?: any) => Promise<ErrTuple>;
type connectModuleBound = (
  method: string,
  data: any,
  receiveUpdate: DataFn
) => [sendUpdate: DataFn, response: Promise<ErrTuple>];

let callModule: callModule;
let connectModule: connectModule;
let log: log;
let logErr: logErr;

export interface ModuleBag {
  callModule: callModule;
  connectModule: connectModule;
  log: log;
  logErr: logErr;
}

export interface ModuleBagBound extends ModuleBag {
  callModule: callModuleBound;
  connectModule: connectModuleBound;
}

export abstract class Client extends EventEmitter {
  private _callModule?: callModuleBound;

  get callModule(): callModuleBound {
    return this._callModule as callModuleBound;
  }

  private _log?: log;

  get log(): log {
    return this._log as log;
  }

  private _logErr?: logErr;

  get logErr(): logErr {
    return this._logErr as logErr;
  }

  private _connectModule?: connectModuleBound;

  get connectModule(): connectModuleBound {
    return this._connectModule as connectModuleBound;
  }

  public async loadLibs(module: string): Promise<void> {
    if (this._callModule && this._connectModule) {
      return;
    }

    const moduleBag = await this.loadBound(module);
    this._callModule = async (...args) => {
      const ret = await moduleBag.callModule(...args);
      this.handleError(ret);
      return ret;
    };
    this._connectModule = moduleBag.connectModule;
    this._log = log;
    this._logErr = logErr;
  }

  public async loadBound(module: string): Promise<ModuleBagBound> {
    return (await load(module)) as ModuleBagBound;
  }

  protected handleError(ret: ErrTuple): void {
    if (ret[1]) {
      throw new Error(ret[1]);
    }
  }

  protected handleErrorOrReturn(ret: ErrTuple): any {
    this.handleError(ret);
    return ret[0];
  }

  protected async callModuleReturn(method: string, data?: any): Promise<any> {
    const ret = await this.callModule(method, data);

    return ret[0];
  }
}

export async function load(
  module?: string
): Promise<ModuleBag | ModuleBagBound> {
  if (callModule && connectModule) {
    if (module) {
      return {
        callModule: callModule.bind(undefined, module),
        connectModule: connectModule.bind(undefined, module),
        log,
        logErr,
      } as ModuleBagBound;
    }
    return {
      callModule,
      connectModule,
      log,
      logErr,
    } as ModuleBag;
  }

  const pkg =
    typeof window !== "undefined" && window?.document
      ? await import("libkernel")
      : await import("libkmodule");

  callModule = pkg.callModule;
  connectModule = pkg.connectModule;
  // @ts-ignore
  log = pkg.log;
  // @ts-ignore
  logErr = pkg.logErr;

  return load(module);
}

type ClientConstructor<U> = new (...args: any[]) => U;

export const factory = function <T extends Client = Client>(
  type: ClientConstructor<T>,
  module: string
) {
  return function (...args: any): T {
    return new Proxy<T>(new type(...args), {
      get(target: T, property: string) {
        let desc = Object.getOwnPropertyDescriptor(
          target?.constructor?.prototype,
          property
        );
        if (!desc?.get) {
          const prop = target[property as keyof T];

          if (typeof prop !== "function") {
            return prop;
          }
        }

        return async (...args: any[]): Promise<any> => {
          await target.loadLibs(module);

          if (desc?.get) {
            return target[property as keyof T];
          }

          return (target[property as keyof T] as Function)(...args);
        };
      },
    });
  };
};

export async function maybeGetAsyncProperty(object: any) {
  if (typeof object === "function") {
    object = object();
  }

  if (isPromise(object)) {
    object = await object;
  }

  return object;
}

export function isPromise(obj: Promise<any>) {
  return (
    !!obj &&
    (typeof obj === "object" || typeof obj === "function") &&
    typeof obj.then === "function"
  );
}