Make the prompt generator more dynamic

dotlib/prompt.sh

@@ -1,3 +1,30 @@
+setup-prompt() {
+  local last_res=$? color=$PS1_color_green
+  PS1="\w "
+
+  if [[ -d .git ]]; then
+    PS1+="$(command git branch --show-current) "
+  fi
+
+  if [[ -v SSH_CLIENT ]]; then
+    PS1+="$PS1_hostname "
+  fi
+
+  if (( last_res )); then
+    color=$PS1_color_red
+  fi
+
+
+  PS1+="\[$color\][$last_res]\[$PS1_color_reset\] $PS1_prompt_sym "
+}
+
+PS1_prompt_sym=λ
+PS1_hostname=${HOSTNAME-"$(hostname)"}
+PS1_color_red=$(tput setaf 1)
+PS1_color_green=$(tput setaf 2)
+PS1_color_reset=$(tput sgr0)
+PROMPT_COMMAND+=(setup-prompt)
+
 read -r month day < <(date "+%m %d")
 
 if (( 10#$month == 3 && 10#$day < 18 )); then
@@ -7,7 +34,7 @@ if (( 10#$month == 3 && 10#$day < 18 )); then
     printf "Only %d days left until Saint Patrick's day!\n" "$(( 17 - 10#$day ))"
   fi
 
-  prompt_sym=🍀
+  PS1_prompt_sym=🍀
 elif (( 10#$month == 10 )); then
   if (( 31 - 10#$day == 0 )); then
     printf 'Have a spooky halloween!\n'
@@ -15,7 +42,7 @@ elif (( 10#$month == 10 )); then
     printf 'Only %d days left until Halloween!\n' "$(( 31 - 10#$day ))"
   fi
 
-  prompt_sym=🎃
+  PS1_prompt_sym=🎃
 elif (( 10#$month == 12 && 10#$day < 26 )); then
   if (( 25 - 10#$day == 0 )); then
     printf 'Merry Christmas!\n'
@@ -23,22 +50,5 @@ elif (( 10#$month == 12 && 10#$day < 26 )); then
     printf 'Only %d days left until Christmas!\n' "$(( 25 - 10#$day ))"
   fi
 
-  prompt_sym=🌲
+  PS1_prompt_sym=🌲
 fi
-
-setup-prompt() {
-  if [[ -d .git ]]; then
-    git_branch="$(command git branch --show-current) "
-  else
-    git_branch=""
-  fi
-}
-
-PROMPT_COMMAND+=(setup-prompt)
-PS1='\w $git_branch'
-
-if [[ -v SSH_CLIENT ]]; then
-  PS1+='${HOSTNAME-"$(hostname)"} '
-fi
-
-PS1+='${prompt_sym-λ} '