/**
 * Copyright 2023 Fluence Labs Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { promises as fs } from "fs";

import { compileFromPath } from "@fluencelabs/aqua-api";
import {
  FunctionCallDef,
  JSONArray,
  JSONValue,
  ServiceDef,
} from "@fluencelabs/interfaces";
import { Subject, Subscribable } from "rxjs";

import { ClientPeer, makeClientPeerConfig } from "../clientPeer/ClientPeer.js";
import { ClientConfig, RelayOptions } from "../clientPeer/types.js";
import { callAquaFunction } from "../compilerSupport/callFunction.js";
import { ServiceImpl } from "../compilerSupport/types.js";
import { IConnection } from "../connection/interfaces.js";
import { DEFAULT_CONFIG, FluencePeer } from "../jsPeer/FluencePeer.js";
import {
  CallServiceResultType,
  ParticleContext,
} from "../jsServiceHost/interfaces.js";
import { JsServiceHost } from "../jsServiceHost/JsServiceHost.js";
import { WrapFnIntoServiceCall } from "../jsServiceHost/serviceUtils.js";
import { KeyPair } from "../keypair/index.js";
import { IMarineHost } from "../marine/interfaces.js";
import { loadMarineDeps } from "../marine/loader.js";
import { MarineBackgroundRunner } from "../marine/worker/index.js";
import { Particle } from "../particle/Particle.js";

export const registerHandlersHelper = (
  peer: FluencePeer,
  particle: Particle,
  handlers: Record<
    string,
    Record<string, (args: JSONArray) => CallServiceResultType | undefined>
  >,
) => {
  Object.entries(handlers).forEach(([serviceId, service]) => {
    Object.entries(service).forEach(([fnName, fn]) => {
      peer.internals.regHandler.forParticle(
        particle.id,
        serviceId,
        fnName,
        WrapFnIntoServiceCall(fn),
      );
    });
  });
};

export type CompiledFnCall = (
  peer: FluencePeer,
  args: PassedArgs,
) => Promise<unknown>;
export type CompiledFile = {
  functions: { [key: string]: CompiledFnCall };
  services: { [key: string]: ServiceDef };
};

interface FunctionInfo {
  script: string;
  funcDef: FunctionCallDef;
}

/**
 * Type for callback passed as aqua function argument
 */
export type ArgCallbackFunction = ServiceImpl[string];

/**
 * Arguments passed to Aqua function
 */
export type PassedArgs = { [key: string]: JSONValue | ArgCallbackFunction };

export const compileAqua = async (aquaFile: string): Promise<CompiledFile> => {
  await fs.access(aquaFile);

  const compilationResult = await compileFromPath({
    filePath: aquaFile,
  });

  if (compilationResult.errors.length > 0) {
    throw new Error(
      "Aqua compilation failed. Error: " + compilationResult.errors.join("/n"),
    );
  }

  const functions = Object.entries(compilationResult.functions)
    .map(([name, fnInfo]: [string, FunctionInfo]) => {
      const callFn = (peer: FluencePeer, args: PassedArgs) => {
        const def = fnInfo.funcDef;

        const isReturnTypeVoid =
          def.arrow.codomain.tag === "nil" ||
          def.arrow.codomain.items.length === 0;

        return callAquaFunction({
          script: fnInfo.script,
          config: {},
          peer: peer,
          args,
          fireAndForget: isReturnTypeVoid,
        });
      };

      return { [name]: callFn };
    })
    .reduce((agg, obj) => {
      return { ...agg, ...obj };
    }, {});

  return {
    functions,
    services: compilationResult.services,
  };
};

class NoopConnection implements IConnection {
  start(): Promise<void> {
    return Promise.resolve();
  }

  stop(): Promise<void> {
    return Promise.resolve();
  }

  getRelayPeerId(): string {
    return "nothing_here";
  }
  supportsRelay(): boolean {
    return true;
  }
  particleSource: Subscribable<Particle> = new Subject<Particle>();

  sendParticle(): Promise<void> {
    return Promise.resolve();
  }
}

export class TestPeer extends FluencePeer {
  constructor(keyPair: KeyPair, connection: IConnection, marine: IMarineHost) {
    const jsHost = new JsServiceHost();

    super(DEFAULT_CONFIG, keyPair, marine, jsHost, connection);
  }
}

export const mkTestPeer = async () => {
  const kp = await KeyPair.randomEd25519();
  const conn = new NoopConnection();

  const marineDeps = await loadMarineDeps("/");
  const marine = new MarineBackgroundRunner(...marineDeps);

  return new TestPeer(kp, conn, marine);
};

export const withPeer = async (action: (p: FluencePeer) => Promise<void>) => {
  const p = await mkTestPeer();

  try {
    await p.start();
    await action(p);
  } finally {
    await p.stop();
  }
};

export const withClient = async (
  relay: RelayOptions,
  config: ClientConfig,
  action: (client: ClientPeer) => Promise<void>,
) => {
  const { keyPair, peerConfig, relayConfig } = await makeClientPeerConfig(
    relay,
    config,
  );

  const marineDeps = await loadMarineDeps("/");
  const marine = new MarineBackgroundRunner(...marineDeps);

  const client = new ClientPeer(peerConfig, relayConfig, keyPair, marine);

  try {
    await client.connect();
    await action(client);
  } finally {
    await client.disconnect();
  }
};

export const makeTestTetraplet = (
  initPeerId: string,
  serviceId: string,
  fnName: string,
): ParticleContext => {
  return {
    particleId: "",
    timestamp: 0,
    ttl: 0,
    initPeerId: initPeerId,
    signature: new Uint8Array([]),
    tetraplets: [
      [
        {
          peer_pk: initPeerId,
          function_name: fnName,
          service_id: serviceId,
          lens: "",
        },
      ],
    ],
  };
};