refactor: add game state abstraction

game_state.c

@@ -0,0 +1,72 @@
+#include "game_state.h"
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+char *word_bank[] = {
+  "hypothesis",
+  "science",
+  "usurp",
+  "conditional",
+  "passionate",
+  "orion",
+  NULL // sentinel value marking end
+};
+
+struct game_state {
+  char **curr_el;
+  unsigned short curr_letter_index;
+  unsigned short wins;
+};
+
+static struct game_state state;
+
+void init_game_state() {
+  state.curr_el = word_bank;
+  state.curr_letter_index = 0;
+  state.wins = 0;
+}
+
+// Gets the word at the current element. Will always return a valid non-null pointer to first char of the word
+char *get_curr_word() {
+  assert(state.curr_el != NULL);
+  assert((*state.curr_el) != NULL);
+  return *state.curr_el;
+}
+
+char get_curr_letter() {
+  char *word = get_curr_word();
+  return word[state.curr_letter_index];
+}
+
+int get_curr_letter_index() {
+  return state.curr_letter_index;
+}
+
+int get_wins() {
+  return state.wins;
+}
+
+// goes to the next word in the word bank, wrapping when necessary
+static void go_next_word() {
+  if (*(state.curr_el + 1) == NULL) {
+    state.curr_el = word_bank;
+  } else {
+    state.curr_el++;
+  }
+
+  state.wins++;
+  state.curr_letter_index = 0;
+}
+
+// handle either going to the next letter or next word if at the end 
+void next() {
+  size_t word_len = strlen(get_curr_word());
+  if (state.curr_letter_index >= word_len - 1) { // at last character
+    go_next_word();
+  } else {
+    state.curr_letter_index++;
+  }
+}