//
// Created by erki on 30.04.21.
//

#include <catch2/catch.hpp>

#include "utility_fixedpoint.hpp"

using FP15 = Utility::FixedPoint<std::uint32_t, 15>;

TEST_CASE("FP constructors work appropriately.", "[utility],[fixed point]")
{
  SECTION("Empty FP constructs with data 0.")
  {
    FP15 fp;

    REQUIRE(fp.data == 0);
  }

  SECTION("FP with integral data constructors appropriately.")
  {
    FP15 fp(1);

    REQUIRE(fp.data == (1 << 15));
  }

  SECTION("FP assignment operators work appropriately.")
  {
    FP15 fp;
    fp = 15;

    REQUIRE(fp.data == (15 << 15));
  }

  SECTION("FP with floating point data constructors works appropriately.")
  {
    FP15 fp(1.5f);

    REQUIRE(fp.data == ((1 << 15) | (1 << 14)));

    FP15 fp2(1.5);

    REQUIRE(fp2.data == ((1 << 15) | (1 << 14)));
  }

  SECTION("FP assignment operators work with floating point data appropriately.")
  {
    FP15 fp;
    fp = 1.5f;

    REQUIRE(fp.data == ((1 << 15) | (1 << 14)));

    fp = 1.5;

    REQUIRE(fp.data == ((1 << 15) | (1 << 14)));
  }
}

TEST_CASE("FP comparison operators work appropriately.", "[utility],[fixed point]")
{
  SECTION("FPs compare equal with other FPs appropriately.")
  {
    const FP15 fp1(15);
    const FP15 fp2(15);

    REQUIRE(fp1 == fp2);

    const FP15 fp3(32);

    REQUIRE(fp1 != fp3);
  }

  SECTION("FPs compare equal with integers appropriately.")
  {
    const FP15 fp1(15);

    REQUIRE(fp1 == 15);
    REQUIRE(fp1 != 32);
  }

  SECTION("FPs compare equal with floats appropriately.")
  {
    const FP15 fp1(1.45f);

    REQUIRE(fp1 == 1.45f);
    REQUIRE(fp1 == 1.45);
  }

  SECTION("FPs compare lt and gt with other FPs appropriately.")
  {
    const FP15 fp(1.45f);
    const FP15 fp2(1.4525f);
    const FP15 fp3(1.4475f);

    REQUIRE(fp < fp2);
    REQUIRE(fp > fp3);
    REQUIRE(fp <= fp2);
    REQUIRE(fp >= fp3);

    REQUIRE(fp <= fp);
    REQUIRE(fp >= fp);
    REQUIRE(!(fp < fp));
    REQUIRE(!(fp > fp));
  }

  SECTION("FPs compare lt and gt with integers appropriately.")
  {
    const FP15 fp(15);

    REQUIRE(fp < 16);
    REQUIRE(fp > 14);
    REQUIRE(!(fp < 15));
    REQUIRE(!(fp > 15));

    REQUIRE(fp <= 15);
    REQUIRE(fp <= 16);
    REQUIRE(fp >= 15);
    REQUIRE(fp >= 14);
  }

  SECTION("FPs compare lt and gt with floating point numbers appropriately.")
  {
    const FP15 fp(45.75f);

    REQUIRE(fp < 45.80f);
    REQUIRE(fp > 45.70f);
    REQUIRE(!(fp < 45.75f));
    REQUIRE(!(fp > 45.75f));

    REQUIRE(fp <= 45.75f);
    REQUIRE(fp <= 45.80f);
    REQUIRE(fp >= 45.75f);
    REQUIRE(fp >= 45.70f);
  }
}

TEST_CASE("FP arithmetic operators work appropriately.", "[utility],[fixed point]")
{
  SECTION("FPs add with other FPs appropriately.")
  {
    const FP15 fp1(45.75f);
    const FP15 fp2(0.25f);

    REQUIRE((fp1 + fp2) == FP15(46));
  }

  SECTION("FPs subtract from other FPs appropriately.")
  {
    const FP15 fp1(45.75f);
    const FP15 fp2(0.75f);

    REQUIRE((fp1 - fp2) == FP15(45));
  }

  SECTION("FPs add with arithmetic types appropriately.")
  {
    const FP15 fp(45.75f);

    REQUIRE((fp + 10) == FP15(55.75f));
    REQUIRE((fp + 0.25f) == FP15(46));
  }

  SECTION("FPs subtract from arithmetic types appropriately.")
  {
    const FP15 fp(45.75f);

    REQUIRE((fp - 10) == FP15(35.75f));
    REQUIRE((fp - 0.75f) == FP15(45));
  }
}

TEMPLATE_TEST_CASE("FP converting back to integral values works appropriately.", "[utility],[fixed point]",
                   std::int8_t, std::int16_t, std::int32_t)
{
  using FP = Utility::FixedPoint<TestType, 4>;

  FP fp(4);

  REQUIRE(fp.template toValue<TestType>() == 4);
}

TEMPLATE_TEST_CASE("FP converting back to floating point values works appropriately.", "[utility],[fixed point]",
                   float, double)
{
  FP15 fp(TestType(4.45));

  REQUIRE(TestType(fp) == Approx(TestType(4.45)));
}

TEST_CASE("FP multiplication works appropriately.", "[utility],[fixed point]")
{
  SECTION("FP multiplies with other FPs appropriately.")
  {
    FP15 fp1(0.25);
    FP15 fp2(0.1);

    FP15 fp3 = fp1 * fp2;

    REQUIRE(fp3 == FP15(0.025));
  }

  SECTION("FP multiplies with real values appropriately.")
  {
    FP15 fp1(0.25);

    FP15 fp2 = fp1 * 0.1;

    REQUIRE(fp2 == FP15(0.025));
  }
}

TEST_CASE("FP division works appropriately.", "[utility],[fixed point]")
{
  SECTION("FP divides with other FPs appropriately.")
  {
    FP15 fp1(0.25);
    FP15 fp2(0.1);

    FP15 fp3 = fp1 / fp2;

    REQUIRE(fp3.data == FP15(2.5).data - 5);// Rounding errors, yay!
  }

  SECTION("FP divides with real values appropriately.")
  {
    FP15 fp1(0.25);

    FP15 fp3 = fp1 / 0.1;

    REQUIRE(fp3.data == FP15(2.5).data - 5);// Rounding errors, yay!
  }
}