// SPDX-FileCopyrightText: 2024 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#include <catch2/catch_all.hpp>
#include "../common/DiffractionGeometry.h"
#include <iostream>

TEST_CASE("RecipToDetector_1", "[LinearAlgebra][Coord]") {
    DiffractionExperiment x(DetectorGeometry(8, 2));
    x.BeamX_pxl(1024).BeamY_pxl(1024).DetectorDistance_mm(120);

    float pos_x = 512, pos_y = 512;

    auto recip = DetectorToRecip(x, pos_x, pos_y);
    auto [proj_x, proj_y] = RecipToDector(x, recip);
    REQUIRE(proj_x == Catch::Approx(pos_x));
    REQUIRE(proj_y == Catch::Approx(pos_y));
    REQUIRE((recip - DetectorToRecip(x, proj_x, proj_y)).Length() < 0.00000001f);
    REQUIRE(DistFromEwaldSphere(x, recip) < 4e-4);
}

TEST_CASE("RecipToDetector_2", "[LinearAlgebra][Coord]") {
    DiffractionExperiment x(DetectorGeometry(8, 2));
    x.BeamX_pxl(1024).BeamY_pxl(1024).DetectorDistance_mm(120);
    float pos_x = 1023, pos_y = 1023;

    auto recip = DetectorToRecip(x, pos_x, pos_y);
    auto [proj_x, proj_y] = RecipToDector(x, recip);
    REQUIRE(proj_x == Catch::Approx(pos_x));
    REQUIRE(proj_y == Catch::Approx(pos_y));
    REQUIRE((recip - DetectorToRecip(x, proj_x, proj_y)).Length() < 0.00000001f);
    REQUIRE(DistFromEwaldSphere(x, recip) < 4e-4);
}

TEST_CASE("RecipToDetector_3", "[LinearAlgebra][Coord]") {
    DiffractionExperiment x(DetectorGeometry(8, 2));
    x.BeamX_pxl(1024).BeamY_pxl(1024).DetectorDistance_mm(120);
    float pos_x = 30, pos_y = 30;

    auto recip = DetectorToRecip(x, pos_x, pos_y);
    auto [proj_x, proj_y] = RecipToDector(x, recip);
    REQUIRE(proj_x == Catch::Approx(pos_x));
    REQUIRE(proj_y == Catch::Approx(pos_y));
    REQUIRE((recip - DetectorToRecip(x, proj_x, proj_y)).Length() < 0.00000001f);
    REQUIRE(DistFromEwaldSphere(x, recip) < 4e-4);
}

TEST_CASE("Phi","") {
    DiffractionExperiment x(DetectorGeometry(8, 2, 8, 36));
    x.DetectorDistance_mm(75).IncidentEnergy_keV(WVL_1A_IN_KEV);
    x.BeamX_pxl(1000).BeamY_pxl(1000);

    REQUIRE(Phi(x, 2000, 1000) == Catch::Approx(0.0));
    REQUIRE(Phi(x, 1000, 2000) == Catch::Approx(M_PI_2));
    REQUIRE(Phi(x, 2000, 2000) == Catch::Approx(M_PI_4));
}

TEST_CASE("Cos2Theta","") {
    DiffractionExperiment x(DetectorGeometry(8, 2, 8, 36));
    x.DetectorDistance_mm(75).IncidentEnergy_keV(WVL_1A_IN_KEV);
    x.BeamX_pxl(1000).BeamY_pxl(1000);

    // det distance == 1000 pixel
    // theta = 30 deg
    // tan(2 * theta) = sqrt(3)
    REQUIRE(CosTwoTheta(x, 1000, 1000 * (1.0 + sqrt(3))) == Catch::Approx(0.5f));
}

TEST_CASE("PxlToRes","") {
    DiffractionExperiment x(DetectorGeometry(8, 2, 8, 36));
    x.DetectorDistance_mm(75).IncidentEnergy_keV(WVL_1A_IN_KEV);

    // sin(theta) = 1/2
    // theta = 30 deg
    // tan(2 * theta) = sqrt(3)
    REQUIRE(PxlToRes(x, 0, 1000 * sqrt(3)) == Catch::Approx(1.0));

    // sin(theta) = 1/4
    // theta = 14.47 deg
    // tan(2 * theta) = 0.55328333517

    REQUIRE(PxlToRes(x, 1000 * 0.55328333517 * cosf(1), 1000 * 0.55328333517 * sinf(1)) == Catch::Approx(2.0));
}

TEST_CASE("ResToPxl","") {
    DiffractionExperiment x(DetectorGeometry(8, 2, 8, 36));
    x.DetectorDistance_mm(75).IncidentEnergy_keV(WVL_1A_IN_KEV);

    // sin(theta) = 1/2
    // theta = 30 deg
    // tan(2 * theta) = sqrt(3)
    REQUIRE(ResToPxl(x, 1.0) == Catch::Approx(1000 * sqrt(3)));

    // sin(theta) = 1/4
    // theta = 14.47 deg
    // tan(2 * theta) = 0.55328333517
    REQUIRE(ResToPxl(x, 2.0) == Catch::Approx(1000 * 0.55328333517));
}

TEST_CASE("SolidAngleCorrection","") {
    DiffractionExperiment x;
    x.IncidentEnergy_keV(WVL_1A_IN_KEV);
    x.BeamX_pxl(1000).BeamY_pxl(1000).DetectorDistance_mm(75);

    REQUIRE(CalcAzIntSolidAngleCorr(x, 0.0) == 1.0f);
    REQUIRE(CalcAzIntSolidAngleCorr(x, 2 * M_PI) == Catch::Approx(0.5f * 0.5f * 0.5f));

    // theta = 30 deg
    // cos (2 * theta) = 1/2
    REQUIRE(CalcAzIntSolidAngleCorr(x, 1000, 1000) == 1.0f);
    REQUIRE(CalcAzIntSolidAngleCorr(x, 1000 * (1.0 + sqrt(3)), 1000) == Catch::Approx(0.5f * 0.5f * 0.5f));
}

TEST_CASE("PolarizationCorrection","") {
    DiffractionExperiment x;
    x.IncidentEnergy_keV(WVL_1A_IN_KEV);
    x.BeamX_pxl(1000).BeamY_pxl(1000).DetectorDistance_mm(75);

    // Circular polarization 0.5*(1+cos(2theta)^2)
    x.PolarizationFactor(0);
    REQUIRE(CalcAzIntPolarizationCorr(x, 1000 * (1.0 + sqrt(3)), 1000, 0) == Catch::Approx(0.5f * (1 + 0.5f * 0.5f)));
    REQUIRE(CalcAzIntPolarizationCorr(x, 1000, 1000 * (1.0 + sqrt(3)), 0) == Catch::Approx(0.5f * (1 + 0.5f * 0.5f)));

    // Horizontal polarization
    x.PolarizationFactor(1);

    // No correction in vertical direction
    REQUIRE(CalcAzIntPolarizationCorr(x, 1000, 1000 * (1.0 + sqrt(3)), 1) == Catch::Approx(1.0f));
    REQUIRE(CalcAzIntPolarizationCorr(x, 1000, 1000 * (1.0 - sqrt(3)), 1) == Catch::Approx(1.0f));

    // cos(2*theta)^2 in horizontal direction
    REQUIRE(CalcAzIntPolarizationCorr(x, 1000 * (1.0 + sqrt(3)), 1000, 1) == Catch::Approx(0.5f * 0.5f));
    REQUIRE(CalcAzIntPolarizationCorr(x, 1000 * (1.0 - sqrt(3)), 1000, 1) == Catch::Approx(0.5f * 0.5f));
}