Comment on top

src/life.cpp

@@ -1,17 +1,259 @@
-// This is the CPP file you will edit and turn in.
-// Also remove these comments here and add your own.
-// TODO: remove this comment header
+// A TUI implementation of Conway's Game of Life
+// Author: Love Billenius <lovbi127@student.liu.se>
+
 
-#include <iostream>
 #include "grid.h"
 #include "lifeutil.h"
+#include "unistd.h"
+#include <fstream>
+#include <iostream>
 #include <string>
 
+const char *const FORMAT_UNDERSCORE = "\033[4m";
+const char *const END_FORMATTING = "\033[0m";
+
+const int ANIMATION_SLEEP_MS = 100, ANIMATION_N_GENERATIONS = 20;
+
+void printWelcome() {
+    std::cout << "Welcome to the TDDD86 Game of Life,\n"
+              << "a simulation of the lifecycle of a bacteria colony.\n"
+              << "Cells (X) live and die by the following rules:\n"
+              << "  - A cell with 1 or fewer neighbours dies.\n"
+              << "  - Locations with 2 neighbours remain stable.\n"
+              << "  - Locations with 3 neighbours will create life.\n"
+              << "  - A cell with 4 or more neighbours dies." << std::endl;
+}
+
+std::string input(const char *message) {
+    if (message != nullptr)
+        std::cout << message;
+
+    std::cout << FORMAT_UNDERSCORE;
+    std::flush(std::cout);
+
+    std::string ret;
+    std::getline(std::cin, ret);
+    std::cout << END_FORMATTING;
+    return ret;
+}
+
+bool fileExists(const char *fileName) { return access(fileName, 0) == 0; }
+
+std::string fileRead(const std::string &filePath) {
+    std::ifstream file(filePath, std::ios::binary);
+    if (!file.is_open())
+        throw std::runtime_error("File couldn't be found");
+
+    std::string content;
+    const int BUF_LENGTH = 1024;
+    char buf[BUF_LENGTH];
+    while (file.read(buf, BUF_LENGTH))
+        content.append(buf, file.gcount());
+    content.append(buf, file.gcount());
+
+    if (!file.eof() && file.fail())
+        throw std::runtime_error("Error: Failed to read the file '" + filePath +
+                                 "'");
+
+    return content;
+}
+
+enum MenuAction { ANIMATE, TICK, QUIT };
+
+MenuAction askMenu() {
+    while (true) {
+        std::string userInput = input("a)nimate, t)ick, q)uit? ");
+        if (userInput == "a")
+            return MenuAction::ANIMATE;
+        else if (userInput == "t")
+            return MenuAction::TICK;
+        else if (userInput == "q")
+            return MenuAction::QUIT;
+        std::cout << "The input '" << userInput << "' is an invalid option!\n";
+    }
+}
+
+std::vector<std::string> split(const std::string &s, const char at) {
+    std::vector<std::string> ret;
+
+    size_t last = 0, idx;
+    while ((idx = s.find(at, last)) != std::string::npos) {
+        std::string sub = s.substr(last, idx - last);
+        ret.push_back(sub);
+        last = idx + 1;
+    }
+
+    ret.push_back(s.substr(last));
+    return ret;
+}
+
+enum Cell { ALIVE, DEAD };
+
+void gridPrint(Grid<Cell> &grid) {
+    std::stringstream ss;
+
+    for (int row = 0; row < grid.numRows(); row++) {
+        for (int col = 0; col < grid.numCols(); col++) {
+            char sign = grid.get(row, col) == Cell::ALIVE ? 'X' : '-';
+            ss << sign;
+        }
+        if (row == grid.numRows() - 1)
+            ss << std::endl;
+        else
+            ss << '\n';
+    }
+
+    std::cout << ss.str();
+}
+
+int gridAliveNeighbors(Grid<Cell> &grid, int row, int col) {
+    int alive = 0;
+    for (int rowDelta = -1; rowDelta <= 1; rowDelta++) {
+        int checkRow = row + rowDelta;
+        // Skip out of bounds
+        if (checkRow < 0 || checkRow >= grid.numRows())
+            continue;
+
+        for (int colDelta = -1; colDelta <= 1; colDelta++) {
+            // Don't check the original piece
+            if (rowDelta == 0 && colDelta == 0)
+                continue;
+            int checkCol = col + colDelta;
+            // Skip out of bounds
+            if (checkCol < 0 || checkCol >= grid.numCols())
+                continue;
+            if (grid.get(checkCol, checkRow) == Cell::ALIVE)
+                alive++;
+        }
+    }
+
+    return alive;
+}
+
+/**
+ * Run one Game of Life tick.
+ * Cells (X) live and die by the following rules:
+ *    - A cell with 1 or fewer neighbours dies.
+ *    - Locations with 2 neighbours remain stable.
+ *    - Locations with 3 neighbours will create life.
+ *    - A cell with 4 or more neighbours dies.
+ */
+void gridTick(Grid<Cell> &grid) {
+    Grid<Cell> nextGrid = grid;
+
+    for (int row = 0; row < grid.numRows(); row++) {
+        for (int col = 0; col < grid.numCols(); col++) {
+            int alive = gridAliveNeighbors(grid, row, col);
+
+            // A cell with 1 or fewer neighbours dies.
+            if (alive == 1)
+                nextGrid.set(row, col, Cell::DEAD);
+            // Locations with 2 neighbours remain stable.
+            else if (alive == 2)
+                nextGrid.set(row, col, grid.get(row, col));
+            // Locations with 3 neighbours will create life.
+            else if (alive == 3)
+                nextGrid.set(row, col, Cell::ALIVE);
+            // A cell with 4 or more neighbours dies.
+            else if (alive == 4)
+                nextGrid.set(row, col, Cell::DEAD);
+        }
+    }
+
+    grid = nextGrid;
+}
 
 int main() {
+    printWelcome();
 
-    // TODO: Finish the program!
+    std::string inputFile;
+    while (true) {
+        inputFile = input("Grid input file name? ");
+        if (fileExists(inputFile.c_str()))
+            break;
+        std::cout << "File '" << inputFile << "' doesn't exist!" << std::endl;
+    }
+    std::string fileContents;
+    try {
+        fileContents = fileRead(inputFile);
+    } catch (std::exception &e) {
+        std::cerr << "Failed to read file: " << e.what() << std::endl;
+        return 1;
+    }
+    std::vector<std::string> lines = split(fileContents, '\n');
+    if (lines.size() <= 2) {
+        std::cerr << "No column, row header, in the file!" << std::endl;
+        return 1;
+    }
+    int headerRows, headerColumns;
+    try {
+        headerRows = std::stoi(lines[0]);
+        headerColumns = std::stoi(lines[1]);
+    } catch (const std::invalid_argument &e) {
+        std::cerr << "Column or row wasn't a number" << std::endl;
+        return 1;
+    } catch (const std::out_of_range &e) {
+        std::cerr << "Column or row was too large" << std::endl;
+        return 1;
+    }
 
-    std::cout << "Have a nice Life! "  << std::endl;
+    int possibleRows = lines.size() - 2;
+    if (possibleRows < headerRows) {
+        std::cerr << "There's less rows (" << possibleRows
+                  << ") than described in the header! (" << headerRows << ')'
+                  << std::endl;
+        return 1;
+    }
+
+    Grid<Cell> grid(headerColumns, headerRows);
+    for (int x = 0; x < headerRows; x++) {
+        std::string &row = lines[x + 2];
+        if (headerColumns > row.size()) {
+            std::cerr << "There's less columns (" << row.size()
+                      << "), than described in the header! (" << headerRows << ')'
+                      << std::endl;
+            return 1;
+        }
+
+        for (int y = 0; y < headerColumns; y++) {
+            char sign = row[y];
+
+            switch (sign) {
+            case '-':
+                grid.set(x, y, Cell::DEAD);
+                break;
+            case 'X':
+                grid.set(x, y, Cell::ALIVE);
+                break;
+            default:
+                std::cerr << "Invalid option '" << sign << "' in grid description!"
+                          << std::endl;
+                return 1;
+            }
+        }
+    }
+    gridPrint(grid);
+
+    MenuAction action;
+    while ((action = askMenu()) != MenuAction::QUIT) {
+        // We don't have to handle QUIT, since we do in the while check
+        switch (action) {
+        case MenuAction::TICK:
+            gridTick(grid);
+            gridPrint(grid);
+            break;
+        case MenuAction::ANIMATE:
+            for (int i = 0; i < ANIMATION_N_GENERATIONS; i++) {
+                gridTick(grid);
+                clearConsole();
+                gridPrint(grid);
+                pause(ANIMATION_SLEEP_MS);
+            }
+
+            break;
+        }
+    }
+
+    std::cout << "Have a nice Life!" << std::endl;
     return 0;
 }