#include <iostream>
#include <functional>
#include "tools/matrix.h"
#include "tools/math.h"
#include "simplex.h"

bool check_eq(double a, double b,
                          double relativeEpsilon = 0.0001) {
    double diff = std::abs(a - b);
    a = std::abs(a);
    b = std::abs(b);
    double largest = (b > a) ? b : a;

    return diff <= largest * relativeEpsilon;
}

int TEST_GENERAL_CASE() {
    std::cout << "----------------------------RUNNING_TEST_GENERAL_CASE----------------------------" << std::endl;

    Vector C = {5, 4};
    Matrix A = {
        {6, 4},
        {1, 2},
        {-1, 1},
        {0, 1}
    };
    Vector b = {24, 6, 1, 2};

    auto result = simplex(C, A, b);

    if (!(result.state == bounded)) {
        std::string state_name;
        switch (result.state) {
        case unsolvable:
            state_name = "unsolvable";
            break;
        case unbounded:
            state_name = "unbounded";
            break;
        default:
            state_name = "bounded";
            break;
        }
        std::cout << "Incorrect state type. Expected bounded. Got " << state_name << std::endl;
        return 0;
    }

    if (!check_eq(result.objective_function_value, 21)) {
        std::cout << "Incorrect objective function value. Expected 21. Got "
                  << result.objective_function_value << std::endl;
        return 0;
    }

    if (!( check_eq(result.solution[0],3) && check_eq(result.solution[1], 1.5) )) {
        std::cout << "Incorrect desire variables. Expected 3 and 1.5. Got "
                  << result.solution;
        return 0;
    }

    return 1;
}

int TEST_MINIMIZE_CASE() {
    std::cout << "----------------------------RUNNING_TEST_MINIMIZE_CASE----------------------------" << std::endl;

    Vector C = {-2, 2, -6};
    Matrix A = {
        {2, 1, -2},
        {1, 2, 4},
        {1, -1, 2}
    };
    Vector b = {24, 23, 10};

    auto result = simplex(C, A, b, 0.01, false);

    if (!(result.state == bounded)) {
        std::string state_name;
        switch (result.state) {
        case unsolvable:
            state_name = "unsolvable";
            break;
        case unbounded:
            state_name = "unbounded";
            break;
        default:
            state_name = "bounded";
            break;
        }
        std::cout << "Incorrect state type. Expected bounded. Got " << state_name << std::endl;
        return 0;
    }

    if (!check_eq(result.objective_function_value, -30.75)) {
        std::cout << "Incorrect objective function value. Expected -30.75. Got "
                  << result.objective_function_value << std::endl;
        return 0;
    }

    if (!( check_eq(result.solution[0], 0) && check_eq(result.solution[1], 0.75)
        && check_eq(result.solution[2],5.375)
    )) {
        std::cout << "Incorrect desire variables. Expected 3 and 1.5. Got "
                  << result.solution;
        return 0;
    }

    return 1;
}

int TEST_WITH_SLACK_CASE() {
    std::cout << "----------------------------RUNNING_TEST_WITH_SLACK_CASE----------------------------" << std::endl;

    Vector C = {5, 4};
    Matrix A = {
        {6, 4, 1},
        {1, 2, 0},
        {-1, 1, 0},
        {0, 1, 0}
    };
    Vector b = {24, 6, 1, 2};

    auto result = simplex(C, A, b);

    if (!(result.state == bounded)) {
        std::string state_name;
        switch (result.state) {
        case unsolvable:
            state_name = "unsolvable";
            break;
        case unbounded:
            state_name = "unbounded";
            break;
        default:
            state_name = "bounded";
            break;
        }
        std::cout << "Incorrect state type. Expected bounded. Got " << state_name << std::endl;
        return 0;
    }

    if (result.objective_function_value != 21) {
        std::cout << "Incorrect objective function value. Expected 21. Got "
                  << result.objective_function_value << std::endl;
        return 0;
    }

    if (!((result.solution[0] == 3) || (result.solution[1] == 1.5))) {
        std::cout << "Incorrect desire variables. Expected 3 and 1.5. Got "
                  << result.solution[0] << result.solution[1];
        return 0;
    }

    return 1;
}

int TEST_UNBOUNDED_CASE() {
    std::cout << "----------------------------RUNNING_TEST_UNBOUNDED_CASE----------------------------" << std::endl;

    Vector C = {2, 1};
    Matrix A = {
        {1, -1},
        {2, 0}
    };
    Vector b = {10, 40};

    auto result = simplex(C, A, b);

    if (!(result.state == unbounded)) {
        std::string state_name;
        switch (result.state) {
        case unsolvable:
            state_name = "unsolvable";
            break;
        case unbounded:
            state_name = "unbounded";
            break;
        default:
            state_name = "bounded";
            break;
        }
        std::cout << "Incorrect state type. Expected unbounded. Got " << state_name << std::endl;
        return 0;
    }

    return 1;
}

int TEST_UNSOLVABLE_CASE() {
    std::cout << "----------------------------RUNNING_TEST_UNSOLVABLE_CASE----------------------------" << std::endl;

    Vector C = {5, 4};
    Matrix A = {
        {6, 4},
        {1, 2},
        {-1, 1},
        {0, 1}
    };
    Vector b = {-24, 6, 1, 2};

    auto result = simplex(C, A, b);

    if (!(result.state == unsolvable)) {
        std::string state_name;
        switch (result.state) {
        case unsolvable:
            state_name = "unsolvable";
            break;
        case unbounded:
            state_name = "unbounded";
            break;
        default:
            state_name = "bounded";
            break;
        }
        std::cout << "Incorrect state type. Expected unsolvable. Got " << state_name << std::endl;
        return 0;
    }

    return 1;
}

int main() {

    std::vector<std::function<int(void)>> tests = {
        TEST_GENERAL_CASE,
        TEST_MINIMIZE_CASE,
        TEST_WITH_SLACK_CASE,
        TEST_UNBOUNDED_CASE,
        TEST_UNSOLVABLE_CASE
    };

    int counter = 0;

    for (auto& test : tests) {
        counter += test();
    }

    std::cout << "----------------------------RESULTS----------------------------" << std::endl;
    std::cout << "Total number of tests: " << tests.size() << std::endl;
    std::cout << "Total number of passed tests: " << counter << std::endl;

    return 0;
}