#include <stdio.h>
#include <stdbool.h>
#include "gameoflife.h"

// Convert 4 packed uint32 words into a 10x10 binary grid
void convert_words_to_grid(const uint32 words[4], int grid[10][10]) {
    for (int i = 0; i < 100; i++) {
        int word_index = i / 32;
        int bit_index  = i % 32;

        int row = i / 10;
        int col = i % 10;

        grid[row][col] = (words[word_index] >> bit_index) & 1;
    }
}

// Convert a 10x10 binary grid into 4 packed uint32 words
void convert_grid_to_words(const int grid[10][10], uint32 words[4]) {
    for (int w = 0; w < 4; w++) {
        words[w] = 0; // Clear buffer before OR-masking
    }

    for (int i = 0; i < 100; i++) {
        int word_index = i / 32;
        int bit_index  = i % 32;

        int row = i / 10;
        int col = i % 10;

        if (grid[row][col]) {
            words[word_index] |= (1U << bit_index);
        }
    }
}

void print_grid(const char *label, const int grid[10][10]) {
    printf("%s:\n", label);
    for (int row = 0; row < 10; row++) {
        for (int col = 0; col < 10; col++) {
            printf("%c ", grid[row][col] ? '#' : '.');
        }
        printf("\n");
    }
    printf("\n");
}

bool run_test_case(const char *test_name, const int input[10][10], const int expected[10][10]) {
    uint32 hw_in[4];
    uint32 hw_out[4] = {0, 0, 0, 0};
    int actual[10][10];

    convert_grid_to_words(input, hw_in);
    game_of_life_step(hw_in, hw_out);
    convert_words_to_grid(hw_out, actual);

    bool passed = true;
    for (int row = 0; row < 10; row++) {
        for (int col = 0; col < 10; col++) {
            if (actual[row][col] != expected[row][col]) {
                passed = false;
                break;
            }
        }
        if (!passed) break;
    }

    if (passed) {
        printf("[PASS] %s\n", test_name);
    } else {
        printf("[FAIL] %s\n", test_name);
        print_grid("Input", input);
        print_grid("Expected", expected);
        print_grid("Actual Output", actual);
    }

    return passed;
}

int main(void) {
    bool all_passed = true;

    // Test 1: Empty Grid (All 0s -> All 0s)
    const int t1_input[10][10] = {0};
    const int t1_expected[10][10] = {0};
    all_passed &= run_test_case("Test 1: All Zero Grid", t1_input, t1_expected);

    // Test 2: Still Life (2x2 Block & Tub)
    // A 2x2 block has every cell with 3 neighbors; no outside cell has 3. It must remain identical.
    const int t2_input[10][10] = {
        {0,0,0,0,0,0,0,0,0,0},
        {0,1,1,0,0,0,0,0,0,0},
        {0,1,1,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,1,0,0,0},
        {0,0,0,0,0,1,0,1,0,0},
        {0,0,0,0,0,0,1,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0}
    };
    all_passed &= run_test_case("Test 2: Still Life (Block and Tub remain static)", t2_input, t2_input);

    // Test 3: Oscillator (Blinker - Horizontal to Vertical)
    // Three cells in a row (horizontal) oscillate to three cells in a column (vertical).
    const int t3_input[10][10] = {
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,1,1,1,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0}
    };
    const int t3_expected[10][10] = {
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,1,0,0,0,0,0},
        {0,0,0,0,1,0,0,0,0,0},
        {0,0,0,0,1,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0}
    };
    all_passed &= run_test_case("Test 3: Oscillator (Blinker Horizontal -> Vertical)", t3_input, t3_expected);

    // Test 4: Toroidal Seam / Wrap-around Test
    // Place a Blinker horizontally straddling the right-to-left border: cells at [0][9], [0][0], [0][1].
    // Under toroidal rules, this horizontal line should flip to a vertical line at:
    // [9][0], [0][0], [1][0] (straddling the top-to-bottom border).
    const int t4_input[10][10] = {
        {1,1,0,0,0,0,0,0,0,1}, // row 0: cols 0, 1, and 9 are alive
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0}
    };
    const int t4_expected[10][10] = {
        {1,0,0,0,0,0,0,0,0,0}, // cell at [0][0]
        {1,0,0,0,0,0,0,0,0,0}, // cell at [1][0]
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {1,0,0,0,0,0,0,0,0,0}  // cell at [9][0] (wrapped from top!)
    };
    all_passed &= run_test_case("Test 4: Toroidal Seam Wrap-Around (Blinker across boundaries)", t4_input, t4_expected);

    // Test 5: Overpopulation Death (Dense 3x3 block)
    // A solid 3x3 box of live cells. The center has 8 neighbors (dies).
    // The 4 corners have 3 neighbors (survive).
    // The 4 edges have 5 neighbors (die).
    // The 4 adjacent external empty cells have 3 neighbors (birth).
    // Resulting shape should be an empty diamond / cross outline.
    const int t5_input[10][10] = {
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,1,1,1,0,0,0,0},
        {0,0,0,1,1,1,0,0,0,0},
        {0,0,0,1,1,1,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0}
    };
    const int t5_expected[10][10] = {
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,1,0,0,0,0,0}, // Birth at [2][4]
        {0,0,0,1,0,1,0,0,0,0}, // Corners survive, center edge dies
        {0,0,1,0,0,0,1,0,0,0}, // Birth at [4][2] & [4][6], center [4][4] dies of overpopulation (8)
        {0,0,0,1,0,1,0,0,0,0}, // Corners survive, center edge dies
        {0,0,0,0,1,0,0,0,0,0}, // Birth at [6][4]
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0},
        {0,0,0,0,0,0,0,0,0,0}
    };
    all_passed &= run_test_case("Test 5: Overpopulation & Birth (Solid 3x3 block)", t5_input, t5_expected);

    // Final result
    if (all_passed) {
        printf("\n*************************************\n");
        printf("ALL 5 UNIT TESTS PASSED SUCCESSFULLY! \n");
        printf("*************************************\n");
        return 0;
    } else {
        printf("\n[ERROR] One or more tests failed.\n");
        return 1;
    }
}