add a semi-functional TUI

Makefile

@@ -13,4 +13,4 @@ clean:
 	rm -f *.o
 
 all: todo.o main.o
-	$(CC) $(CFLAGS) todo.o main.o -o todd
+	$(CC) $(CFLAGS) todo.o main.o -lncurses -o todd

README.md

@@ -8,3 +8,4 @@ To build `todd` all you need to do is run `make`.
 ## 3rd Party
 Todd uses the following dependencies:
 - stb_ds - https://github.com/nothings/stb
+- ncurses - https://tldp.org/HOWTO/NCURSES-Programming-HOWTO/index.html

main.c

@@ -3,68 +3,206 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <ncurses.h>
 
 #define MAX_TODOS UINT_MAX
-#define SAVE_FILE "todos.todd"
+#define MAX_PATH_LENGTH 1024
 #define STB_DS_IMPLEMENTATION
 
+#define BORDERS_PAIR 1
+#define DEFAULT_PAIR 2
+#define COMPLETED_PAIR 3
+
 #include "3rd-party/stb-ds.h"
 
+char SAVE_FILE[MAX_PATH_LENGTH] = "todos.todd";
 TodoItem *todos = NULL;
 
 enum Command {
   ADD = 'a',
   MARK = 'm',
   PRINT = 'p',
-  REMOVE = 'r',
+  REMOVE = 'd',
   QUIT = 'q',
 
   WRITE_TO_FILE = 'w',
   LOAD_FROM_FILE = 'l',
+
+  UP = 'k',
+  DOWN = 'j',
 };
 
-void add_command_handler(void) {
+void clear_todos(void) {
+  for (int i = 0; i < arrlen(todos); i++) {
+    todo_free_item(&todos[i]);
+  }
+
+  arrfree(todos);
+}
+
+void initialize_curses(int *width, int *height) {
+  initscr();
+  curs_set(0);
+  int tw, th;
+  getmaxyx(stdscr, th, tw);
+
+  *width = tw;
+  *height = th;
+
+  start_color();
+  init_pair(BORDERS_PAIR, COLOR_BLACK, COLOR_WHITE); 
+  init_pair(DEFAULT_PAIR, COLOR_WHITE, COLOR_BLACK);
+  init_pair(COMPLETED_PAIR, COLOR_BLACK, COLOR_GREEN);
+  // turn off echoing of keys, and enter cbreak mode,
+  // where no buffering is performed on keyboard input
+  cbreak();
+  noecho();
+}
+
+void draw_header(int width) {
+  attron(COLOR_PAIR(BORDERS_PAIR));
+  move(0, 0);
+  addstr(" Todd");
+  for (int i = strlen("Todd"); i < width - 1; i++) {
+    addch(' ');
+  }
+}
+
+void draw_footer(int width, int height) {
+  move(height - 1, 0);
+  for (int i = 0; i < width - 1; i++) {
+    addch(' ');
+  }
+  attroff(COLOR_PAIR(BORDERS_PAIR));
+}
+
+void alert(const char *message, int terminal_width, int terminal_height) {
+  int window_height = 5;
+  int window_width = terminal_width - 4;
+  int window_y = terminal_height / 2 - 1;
+  int window_x = 2;
+
+  int message_x = (terminal_width - 4 - strlen(message)) / 2;
+  int message_y = 2;
+
+  // create a new window
+  WINDOW *alert_window = newwin(window_height, window_width, window_y, window_x);
+  // draw a border around the window
+  box(alert_window, 0, 0);
+  // print the message in the middle of the window
+  mvwprintw(alert_window, message_y, message_x, message);
+  // refresh the window
+  wrefresh(alert_window);
+  // wait for a key press
+  getch();
+
+  // delete the window
+  delwin(alert_window);
+}
+
+void input_string(int terminal_width, int terminal_height, char *buffer, int buffer_size) {
+  int window_height = 5;
+  int window_width = terminal_width - 4;
+  int window_y = terminal_height / 2 - 1;
+  int window_x = 2;
+
+  int message_x = strlen("Enter todo title: ") + 1;
+  int message_y = 2;
+
+  curs_set(1);
+  // create a new window
+  WINDOW *input_window = newwin(window_height, window_width, window_y, window_x);
+  // draw a border around the window
+  box(input_window, 0, 0);
+  // print the message in the middle of the window
+  mvwprintw(input_window, message_y, message_x, "Enter todo title: ");
+  // refresh the window
+  wrefresh(input_window);
+  // wait for a key press
+  echo();
+  mvwgetnstr(input_window, message_y, message_x + strlen("Enter todo title: "), buffer, buffer_size);
+  noecho();
+
+  // delete the window
+  delwin(input_window);
+  curs_set(0);
+}
+
+void display_todos(int width, int height, int current_line) {
+  int current_y = 1;
+  int current_index = current_line;
+  const char *padding = "...";
+  unsigned long title_length = 0;
+  unsigned long padding_length = strlen(padding);
+  
+  char *title = (char *)malloc(width);
+
+  attron(COLOR_PAIR(DEFAULT_PAIR));
+
+  // TODO: Use an offset or something
+
+  while(current_y < height - 2) {
+    // check if we're out of bounds
+    if (current_index >= arrlen(todos)) {
+      break;
+    }
+
+    // copy the title to the buffer
+    title_length = strlen(todos[current_index].title);
+    strncpy(title, todos[current_index].title, width - padding_length - 1);
+    // append the padding if needed
+    if (title_length > strlen(title)) {
+      strcat(title, padding);
+    }
+
+    // move to the correct line
+    move(current_y, 0);
+
+    // if the current todo is completed, print it as green
+    if (todos[current_index].completed) {
+      attroff(COLOR_PAIR(DEFAULT_PAIR));
+      attron(COLOR_PAIR(COMPLETED_PAIR));
+    }
+
+    // highlight the current line
+    if (current_index == current_line) {
+      attron(A_UNDERLINE);
+    }
+
+    printw("%d. %s", current_index + 1, title);
+
+    // increment the current y and index
+    current_y++;
+    current_index++;
+
+    attroff(A_UNDERLINE);
+    attroff(COLOR_PAIR(COMPLETED_PAIR));
+    attron(COLOR_PAIR(DEFAULT_PAIR));
+  }
+
+  free(title);
+}
+
+// Command handlers
+void add_command_handler(int width, int height) {
   char title[TODO_MAX_TITLE_LENGTH];
-  printf("Enter todo title: ");
-  fgets(title, TODO_MAX_TITLE_LENGTH - 1, stdin);
-  // remove the newline character from the buffer
-  title[strlen(title) - 1] = '\0';
+
+  input_string(width, height, title, TODO_MAX_TITLE_LENGTH);
 
   TodoItem item = todo_create_item(title);
   arrput(todos, item);
 }
 
-void mark_command_handler(void) {
-  int op_index = -1;
-  do {
-    printf("Enter todo index: ");
-    op_index = getc(stdin) - '0';
-    getc(stdin); // remove the newline character from the buffer
-  } while (op_index < 0 || op_index >= arrlen(todos));
-
-  TodoItem item = todos[op_index];
+void mark_command_handler(int index) {
+  TodoItem item = todos[index];
 
   todo_mark_item(&item, !item.completed);
 
-  todos[op_index] = item;
+  todos[index] = item;
 }
 
-void print_command_handler(void) {
-  for (int i = 0; i < arrlen(todos); i++) {
-    printf("%d. ", i);
-    todo_print_item(&todos[i]);
-  }
-}
-
-void remove_command_handler(void) {
-  int op_index = -1;
-  do {
-    printf("Enter todo index: ");
-    op_index = getc(stdin) - '0';
-    getc(stdin); // remove the newline character from the buffer
-  } while (op_index < 0 || op_index >= arrlen(todos));
-
-  arrdel(todos, op_index);
+void remove_command_handler(int index) {
+  arrdel(todos, index);
 }
 
 void write_to_file_handler(void) {
@@ -85,6 +223,9 @@ void write_to_file_handler(void) {
 }
 
 void load_from_file_handler(void) {
+  // clear the current todos
+  clear_todos();
+
   FILE *file = fopen(SAVE_FILE, "rb");
   char magic[5] = {'\0'};
   int todos_count = 0;
@@ -126,47 +267,73 @@ void load_from_file_handler(void) {
   }
 }
 
-int main(void) {
-  char cmd;
+int main(int argc, char **argv) {
+  int terminal_width = 0;
+  int terminal_height = 0;
+  int key = 0;
+  int running = 1;
+  int current_line = 0;
 
-  do {
-    printf("Enter command: ");
-    cmd = getc(stdin);
-    getc(stdin); // remove the newline character from the buffer
+  // set the save file path if provided
+  if (argc > 1 && strlen(argv[1]) < MAX_PATH_LENGTH) {
+    strncpy(SAVE_FILE, argv[1], MAX_PATH_LENGTH);
+  }
 
-    switch (cmd) {
-    case ADD:
-      add_command_handler();
-      break;
-    case MARK:
-      mark_command_handler();
-      break;
-    case PRINT:
-      print_command_handler();
-      break;
-    case REMOVE:
-      remove_command_handler();
+  initialize_curses(&terminal_width, &terminal_height);
+
+  while (running) {
+    clear();
+    draw_header(terminal_width);
+    draw_footer(terminal_width, terminal_height);
+    display_todos(terminal_width, terminal_height, current_line);
+    refresh();
+
+    // wait for a key press
+    key = getch();
+
+    // handle the key press
+    switch (key) {
+      case LOAD_FROM_FILE:
+        load_from_file_handler();
+        alert("Loaded!", terminal_width, terminal_height);
         break;
       case WRITE_TO_FILE:
         write_to_file_handler();
+        alert("Saved!", terminal_width, terminal_height);
         break;
-    case LOAD_FROM_FILE:
-      load_from_file_handler();
+      case ADD:
+        add_command_handler(terminal_width, terminal_height);
+        break;
+      case MARK:
+        mark_command_handler(current_line);
+        break;
+      case REMOVE:
+        remove_command_handler(current_line);
+        if (current_line >= arrlen(todos)) {
+          current_line = arrlen(todos) - 1;
+        }
         break;
       case QUIT:
+        running = 0;
         break;
-    default:
-      printf("Invalid command\n");
+      case UP:
+        current_line--;
+        if (current_line < 0) {
+          current_line = 0;
+        }
+        break;
+      case DOWN:
+        current_line++;
+        if (current_line >= arrlen(todos)) {
+          current_line = arrlen(todos) - 1;
+        }
         break;
     }
-
-  } while (cmd != QUIT);
-
-  for (int i = 0; i < arrlen(todos); i++) {
-    todo_free_item(&todos[i]);
   }
 
-  arrfree(todos);
+  endwin();
+
+
 
   return 0;
 }