[prompt] magicmace: add theme

Closes #69

modules/prompt/functions/prompt_magicmace_setup

@@ -0,0 +1 @@
+../themes/magicmace.zsh-theme

modules/prompt/themes/magicmace.zsh-theme

@@ -0,0 +1,100 @@
+#
+# magicmace theme
+# Ideas and code taken from:
+#   xero's zsh prompt <http://code.xero.nu/dotfiles>
+#   eriner's eriner prompt <https://github.com/Eriner/zim/blob/master/modules/prompt/themes/eriner.zsh-theme>
+#
+
+# Global variables
+function {
+  COLOR_ROOT="%F{red}"
+  COLOR_USER="%F{cyan}"
+  COLOR_NORMAL="%F{white}"
+  COLOR_ERROR="%F{red}"
+
+  if [[ "$EUID" -ne "0" ]]; then
+    USER_LEVEL="${COLOR_USER}"
+  else
+    USER_LEVEL="${COLOR_ROOT}"
+  fi
+}
+
+# Status:
+# - was there an error?
+# - are there background jobs?
+# - are we in a ranger session?
+prompt_status() {
+  local symbols=""
+
+  [[ ${RETVAL} -ne 0 ]]          && symbols+='${COLOR_ERROR}${RETVAL}${COLOR_NORMAL}'  # 'e' for error.
+  [[ $(jobs -l | wc -l) -gt 0 ]] && symbols+='b' # 'b' for background.
+  [[ ${RANGER_LEVEL} -ne 0 ]]    && symbols+='r' # 'r' for... you guessed it!
+
+  [[ -n ${symbols} ]] && print -Pn "─${COLOR_NORMAL}${symbols}${COLOR_USER}─"
+}
+
+prompt_git() {
+  local ico_dirty='*'
+  local ico_ahead='🠙'
+  local ico_behind='🠛'
+  local ico_diverged='⥮'
+  local git_info=""
+
+  is_dirty() {
+    test -n "$(git status --porcelain --ignore-submodules)"
+  }
+
+  vcs_info
+  git_info=${vcs_info_msg_0_} # branch name
+  if [[ -n ${git_info} ]]; then
+
+    if is_dirty; then
+      git_info+=${ico_dirty}
+    fi
+
+    stat=$(git status 2> /dev/null | command sed -n 2p)
+    case "${stat}" in
+      *ahead*)    git_info+=${ico_ahead}    ;;
+      *behind*)   git_info+=${ico_behind}   ;;
+      *diverged*) git_info+=${ico_diverged} ;;
+      *);;
+    esac
+
+    print -Pn \
+    "${USER_LEVEL}─[${COLOR_NORMAL}${git_info}${USER_LEVEL}]"
+  fi
+}
+
+prompt_magicmace_precmd() {
+  # While it would be apt to have this as a local variable in prompt_status(),
+  # $? (returned value) and ${(%):-%?} ("The return status of the last command
+  # executed just before the prompt") both change before executing the function.
+  # Is this perhaps because prompt_status _is_ here?
+  # We could also just set $? as an argument, and thus get our nifty local variable,
+  # but that's stretching it, and makes the code harder to read.
+  RETVAL=$?
+
+  PROMPT='${USER_LEVEL}$(prompt_status)[${COLOR_NORMAL}$(short_pwd)${USER_LEVEL}]$(prompt_git)── -%f '
+}
+
+prompt_magicmace_setup() {
+  autoload -Uz colors && colors
+  autoload -Uz add-zsh-hook
+  autoload -Uz vcs_info
+
+  prompt_opts=(cr subst percent)
+
+  zstyle ':vcs_info:*' enable git
+  zstyle ':vcs_info:*' check-for-changes false
+  zstyle ':vcs_info:*' use-simple true
+  # Only export branch name, as that is the only data we need.
+  zstyle ':vcs_info:*' max-exports 1
+  zstyle ':vcs_info:git*' formats '%b'
+
+  # Call git directly, ignoring aliases under the same name.
+  zstyle ':vcs_info:git:*:-all-' command =git
+
+  add-zsh-hook precmd prompt_magicmace_precmd
+}
+
+prompt_magicmace_setup "$@"