strict hard mode and help message

wordle

@@ -65,8 +65,9 @@ function select_random_word() {
 function set_options() {
   declare -g BORDER=1
   declare -g HARD_MODE=0
+  declare -g STRICT_HARD_MODE=0
 
-  while getopts "bw:Hh" OPT; do
+  while getopts "bw:HSh" OPT; do
     case "${OPT}" in
       b)
         BORDER=0
@@ -82,13 +83,28 @@ function set_options() {
       H)
 	      HARD_MODE=1
 	      ;;
+      S)
+        HARD_MODE=1
+        STRICT_HARD_MODE=1
+        ;;
       h)
-        exit # add help message
+        echo -e "Usage: <program_name> [OPTIONS]
+Play a game for Wordle
+Options:
+  -b        Toggle borderless mode
+  -w        Set target word
+  -H        Enable hard mode
+  -S        Enable strict hard mode (Cannot reuse grey letters)
+  -h        Show this help message and exit"
+
+        exit
         ;;
       *)
         ;;
     esac
   done
+
+  shift $((OPTIND - 1))
 }
 
 function init_board() {
@@ -161,7 +177,9 @@ function hard_mode_check() {
   declare GUESS=$1
 
   for (( i=0; i<WIDTH; i++ )); do
-    [[ "${POOL}" == *${GUESS:i:1}* ]] || return 2
+    if [[ "${STRICT_HARD_MODE}" == 1 ]]; then
+      [[ "${POOL}" == *${GUESS:i:1}* ]] || return 2
+    fi
 
     color_check "${GUESS:i:1}" $i && continue