import {
  decodePacket,
  decodePayload,
  encodePacket,
  encodePayload,
  Packet,
  createPacketDecoderStream,
  createPacketEncoderStream,
} from "..";
import * as expect from "expect.js";
import { areArraysEqual } from "./util";

describe("engine.io-parser (node.js only)", () => {
  describe("single packet", () => {
    it("should encode/decode a Buffer", (done) => {
      const packet: Packet = {
        type: "message",
        data: Buffer.from([1, 2, 3, 4]),
      };
      encodePacket(packet, true, (encodedPacket) => {
        expect(encodedPacket).to.eql(packet.data); // noop
        expect(decodePacket(encodedPacket)).to.eql(packet);
        done();
      });
    });

    it("should encode/decode a Buffer as base64", (done) => {
      const packet: Packet = {
        type: "message",
        data: Buffer.from([1, 2, 3, 4]),
      };
      encodePacket(packet, false, (encodedPacket) => {
        expect(encodedPacket).to.eql("bAQIDBA==");
        expect(decodePacket(encodedPacket, "nodebuffer")).to.eql(packet);
        done();
      });
    });

    it("should encode/decode an ArrayBuffer", (done) => {
      const packet: Packet = {
        type: "message",
        data: Int8Array.from([1, 2, 3, 4]).buffer,
      };
      encodePacket(packet, true, (encodedPacket) => {
        expect(encodedPacket === packet.data).to.be(true);
        const decodedPacket = decodePacket(encodedPacket, "arraybuffer");
        expect(decodedPacket.type).to.eql(packet.type);
        expect(decodedPacket.data).to.be.an(ArrayBuffer);
        expect(areArraysEqual(decodedPacket.data, packet.data)).to.be(true);
        done();
      });
    });

    it("should encode/decode an ArrayBuffer as base64", (done) => {
      const packet: Packet = {
        type: "message",
        data: Int8Array.from([1, 2, 3, 4]).buffer,
      };
      encodePacket(packet, false, (encodedPacket) => {
        expect(encodedPacket).to.eql("bAQIDBA==");
        const decodedPacket = decodePacket(encodedPacket, "arraybuffer");
        expect(decodedPacket.type).to.eql(packet.type);
        expect(decodedPacket.data).to.be.an(ArrayBuffer);
        expect(areArraysEqual(decodedPacket.data, packet.data)).to.be(true);
        done();
      });
    });

    it("should encode a typed array", (done) => {
      const packet: Packet = {
        type: "message",
        data: Int16Array.from([257, 258, 259, 260]),
      };
      encodePacket(packet, true, (encodedPacket) => {
        expect(encodedPacket === packet.data).to.be(true);
        done();
      });
    });

    it("should encode a typed array (with offset and length)", (done) => {
      const buffer = Int8Array.from([1, 2, 3, 4]).buffer;
      const data = new Int8Array(buffer, 1, 2);
      encodePacket({ type: "message", data }, true, (encodedPacket) => {
        expect(encodedPacket).to.eql(Buffer.from([2, 3]));
        done();
      });
    });

    it("should decode an ArrayBuffer as ArrayBuffer", () => {
      const encodedPacket = Int8Array.from([1, 2, 3, 4]).buffer;
      const decodedPacket = decodePacket(encodedPacket, "arraybuffer");
      expect(decodedPacket.type).to.eql("message");
      expect(decodedPacket.data).to.be.an(ArrayBuffer);
      expect(areArraysEqual(decodedPacket.data, encodedPacket)).to.be(true);
    });
  });

  describe("payload", () => {
    it("should encode/decode a string + Buffer payload", (done) => {
      const packets: Packet[] = [
        { type: "message", data: "test" },
        { type: "message", data: Buffer.from([1, 2, 3, 4]) },
      ];
      encodePayload(packets, (payload) => {
        expect(payload).to.eql("4test\x1ebAQIDBA==");
        expect(decodePayload(payload, "nodebuffer")).to.eql(packets);
        done();
      });
    });
  });

  if (typeof TransformStream === "function") {
    describe("createPacketEncoderStream", () => {
      it("should encode a binary packet (Buffer)", async () => {
        const stream = createPacketEncoderStream();

        const writer = stream.writable.getWriter();
        const reader = stream.readable.getReader();

        writer.write({
          type: "message",
          data: Buffer.of(1, 2, 3),
        });

        const header = await reader.read();
        expect(header.value).to.eql(Uint8Array.of(131));

        const payload = await reader.read();
        expect(payload.value).to.eql(Uint8Array.of(1, 2, 3));
      });
    });

    describe("createPacketDecoderStream", () => {
      it("should decode a binary packet (Buffer)", async () => {
        const stream = createPacketDecoderStream(1e6, "nodebuffer");

        const writer = stream.writable.getWriter();
        const reader = stream.readable.getReader();

        writer.write(Uint8Array.of(131, 1, 2, 3));

        const { value } = await reader.read();

        expect(value.type).to.eql("message");
        expect(Buffer.isBuffer(value.data)).to.be(true);
        expect(value.data).to.eql(Buffer.from([1, 2, 3]));
      });
    });
  }
});