#include "gtest/gtest.h"
#include "../Metrics.h"


namespace mdlp {
    class TestMetrics: public Metrics, public testing::Test {
    public:
        labels_t y;
        samples_t X;
        indices_t indices;
        precision_t precision = 0.000001;

        TestMetrics(): Metrics(y, indices) {}
        void SetUp()
        {
            y = { 1, 1, 1, 1, 1, 2, 2, 2, 2, 2 };
            indices = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
            setData(y, indices);
        }
    };
    TEST_F(TestMetrics, NumClasses)
    {
        y = { 1, 1, 1, 1, 1, 1, 1, 1, 2, 1 };
        EXPECT_EQ(1, computeNumClasses(4, 8));
        EXPECT_EQ(2, computeNumClasses(0, 10));
        EXPECT_EQ(2, computeNumClasses(8, 10));
    }
    TEST_F(TestMetrics, Entropy)
    {
        EXPECT_EQ(1, entropy(0, 10));
        EXPECT_EQ(0, entropy(0, 5));
        y = { 1, 1, 1, 1, 1, 1, 1, 1, 2, 1 };
        setData(y, indices);
        ASSERT_NEAR(0.468996, entropy(0, 10), precision);
    }
    TEST_F(TestMetrics, InformationGain)
    {
        ASSERT_NEAR(1, informationGain(0, 5, 10), precision);
        ASSERT_NEAR(1, informationGain(0, 5, 10), precision); // For cache
        y = { 1, 1, 1, 1, 1, 1, 1, 1, 2, 1 };
        setData(y, indices);
        ASSERT_NEAR(0.108032, informationGain(0, 5, 10), precision);
    }
}