// Gustav Sörnäs - gusso230

#include "grid.h"
#include "lifeutil.h"

#include <iostream>
#include <fstream>
#include <string>

/*
 * Ask for a file and read it, storing the initial state in `grid`.
 */
void askAndReadFile(Grid<bool> &grid) {
    std::string filepath;
    std::cout << "file: ";
    std::cin >> filepath;
    std::ifstream input;
    input.open(filepath);
    int h, w;
    input >> h >> w;
    grid.resize(h, w);

    for (int y = 0; y < grid.numRows(); y++) {
        std::string line;
        std::getline(input, line);
        for (int x = 0; x < grid.numCols(); x++) {
            grid.set(y, x, line[x] == 'X');
        }
    }
    input.close();
}

/*
 * Print a representation of the grid.
 * Alive cells show as 'X', dead show as '-'.
 */
void printGrid(const Grid<bool> &grid) {
    for (int y = 0; y < grid.numRows(); y++) {
        for (int x = 0; x < grid.numCols(); x++) {
            if (grid.get(y, x)) {
                std::cout << 'X';
            } else {
                std::cout << '-';
            }
        }
        std::cout << std::endl;
    }
}

/*
 * Return whether (x, y) is in bounds and alive.
 */
bool checkPoint(const Grid<bool> &grid, int y, int x) {
    return grid.inBounds(y, x) && grid.get(y, x) ? 1 : 0;
}

/*
 * Simulate the grid one time step and update it in-place.
 */
void simulate(Grid<bool> &grid) {
    Grid<bool> prevGrid(grid);
    for (int y = 0; y < grid.numRows(); y++) {
        for (int x = 0; x < grid.numCols(); x++) {
            int numNeighbours = 0;
            for (int dy = -1; dy <= 1; dy++) {
                for (int dx = -1; dx <= 1; dx++) {
                    if ((dx != 0 || dy != 0) && checkPoint(prevGrid, y+dy, x+dx)) {
                        numNeighbours++;
                    }
                }
            }
            if (numNeighbours < 2) {
                grid.set(y, x, false);
            } else if (numNeighbours == 2) {
                // Do nothing.
            } else if (numNeighbours == 3) {
                grid.set(y, x, true);
            } else {
                grid.set(y, x, false);
            }
        }
    }
}

int main() {
    Grid<bool> grid;
    askAndReadFile(grid);

    char prompt;
    bool running = true;
    while (running && (std::cout << "[a]nimate, [t]ick, [q]uit: ") && std::cin >> prompt) {
        switch (prompt) {
        case 'a':
            while (true) {
                clearConsole();
                std::cout << std::endl;
                printGrid(grid);
                pause(100);
                simulate(grid);
            }
        case 't':
            simulate(grid);
            printGrid(grid);
            break;
        case 'q':
            running = false;
            break;
        }
    }
}