import { expect } from "chai";

import { DPT3 } from "../src/DPT3"
import { BufferLengthError } from "../src/errors/BufferLengthError";
import { InvalidValueError } from "../src/errors/InvalidValueError";

import { compareBuffers } from "./util"

let bufferDecZero = Buffer.from([0])
let bufferDecValue = Buffer.from([5])
let bufferIncZero = Buffer.from([8])
let bufferIncValue = Buffer.from([13])

let bufferEmpty = Buffer.from([])
let bufferBiggerSize = Buffer.from([1, 0])

describe("Test DPT003", (): void => {

  let dpt = new DPT3();

  it("Decode buffer dec-zero", async function () {
    const value = dpt.decoder(bufferDecZero)
    expect(value.data).is.equal(0);
    expect(value.decr_incr).is.equal(0);
  });

  it("Decode buffer dec-value", async function () {
    const value = dpt.decoder(bufferDecValue)
    expect(value.data).is.equal(5);
    expect(value.decr_incr).is.equal(0);
  });

  it("Decode buffer inc-zero", async function () {
    const value = dpt.decoder(bufferIncZero)
    expect(value.data).is.equal(0);
    expect(value.decr_incr).is.equal(1);
  });

  it("Decode buffer inc-value", async function () {
    const value = dpt.decoder(bufferIncValue)
    expect(value.data).is.equal(5);
    expect(value.decr_incr).is.equal(1);
  });

  it("Decode empty buffer", async function () {
    var testFunction = function () {
      const value = dpt.decoder(bufferEmpty)
    }
    expect(testFunction).to.throw(BufferLengthError);
  });

  it("Decode oversized buffer", async function () {
    var testFunction = function () {
      const value = dpt.decoder(bufferBiggerSize)
    }
    expect(testFunction).to.throw(BufferLengthError);
  });

  /* Encode tests */
  it("encode valid", async function () {
    expect(compareBuffers(dpt.encoder({ data: 0, decr_incr: 0 }), bufferDecZero)).is.true;
    expect(compareBuffers(dpt.encoder({ data: 5, decr_incr: 0 }), bufferDecValue)).is.true;
    expect(compareBuffers(dpt.encoder({ data: 0, decr_incr: 1 }), bufferIncZero)).is.true;
    expect(compareBuffers(dpt.encoder({ data: 5, decr_incr: 1 }), bufferIncValue)).is.true;
  });

  it("encode invalid", async function () {
    var testFunction = function () {
      const value = dpt.encoder({ data: 0, decr_incr: 3 })
    }
    expect(testFunction).to.throw(InvalidValueError);
  });

  it("encode undefined", async function () {
    var testFunction = function () {
      const value = dpt.encoder(undefined)
    }
    expect(testFunction).to.throw(InvalidValueError);
  });


});