Bash rc for generating a PS1 string... technically working, but not quite

ps1.rc

+
+_show_last_exit_smilie() {
+  # If the exit status of the last run command was a 0 (success), show a smile, otherwise a frown
+  exit_status=$?
+  if [[ "$exit_status" -ne 0 ]]; then
+    echo "${NORMAL}[${RED}:(${NORMAL}]"
+  else
+    echo "${NORMAL}[${GREEN}:)${NORMAL}]"
+  fi
+}
+
+
+# This function was modified from one found @ https://www.reddit.com/r/linux/comments/2uf5uu/this_is_my_bash_prompt_which_is_your_favorite/?st=jikgswh4&sh=371ba8bf
+_git_status() {
+  local unknown untracked stash clean ahead behind staged dirty diverged
+  unknown=$BLUE
+  untracked=$GREEN
+  stash=$GREEN
+  clean=$GREEN
+  ahead=$YELLOW
+  behind=$YELLOW
+  staged=$CYAN
+  dirty=$RED
+  diverged=$RED
+
+
+  branch=$(git rev-parse --abbrev-ref HEAD 2>/dev/null)
+  if [[ -n "$branch" ]]; then
+    git_status=$(git status 2> /dev/null)
+    # If nothing changes the color, we can spot unhandled cases.
+    color=$unknown
+    if [[ $git_status =~ 'Untracked files' ]]; then
+      color=$untracked
+      branch="${branch}?"
+    fi
+    if git stash show &>/dev/null; then
+      color=$stash
+      branch="${branch}+"
+    fi
+    if [[ $git_status =~ 'working directory clean' ]]; then
+      color=$clean
+    fi
+    if [[ $git_status =~ 'Your branch is ahead' ]]; then
+      color=$ahead
+      branch="${branch}>"
+    fi
+    if [[ $git_status =~ 'Your branch is behind' ]]; then
+      color=$behind
+      branch="${branch}<"
+    fi
+    if [[ $git_status =~ 'Changes to be committed' ]]; then
+      color=$staged
+    fi
+    if [[ $git_status =~ 'Changed but not updated' ||
+          $git_status =~ 'Changes not staged'      ||
+          $git_status =~ 'Unmerged paths' ]]; then
+      color=$dirty
+    fi
+    if [[ $git_status =~ 'Your branch'.+diverged ]]; then
+      color=$diverged
+      branch="${branch}!"
+    fi
+    echo -n "${NORMAL}|${color}${branch}${NORMAL}|"
+  fi
+}
+
+
+set_prompt() {
+  if [ $1 = yes ]; then
+    echo -n "${debian_chroot:+($debian_chroot)}${GREEN}\u${NORMAL}[${BLUE}\w${NORMAL}]$(_show_last_exit_smilie)$(_git_status)\$ "
+  else
+    echo -n "${debian_chroot:+($debian_chroot)}\u@\h:\w\$ "
+  fi
+}