From 13f5ecd846e6a891690a6fcb477d7d719020e1a4 Mon Sep 17 00:00:00 2001
From: Thomas Preisner <mail@tpreisner.de>
Date: Sun, 18 Sep 2022 18:01:32 +0200
Subject: [PATCH] zsh: display some info about vcs in current directory

---
 zsh/prompt.zsh | 27 +++++++++++++++-----
 zsh/vcs.zsh    | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++
 zshrc          |  1 +
 3 files changed, 91 insertions(+), 6 deletions(-)
 create mode 100644 zsh/vcs.zsh

diff --git a/zsh/prompt.zsh b/zsh/prompt.zsh
index c53daf9..1e9b4a7 100644
--- a/zsh/prompt.zsh
+++ b/zsh/prompt.zsh
@@ -18,6 +18,9 @@ setopt transient_rprompt # only show the rprompt on the current prompt
 # ===== set the prompt
 zshrc_prompt_precmd() {
 
+	# call vcs_info before every prompt
+	vcs_info
+
 	# regex to remove all zerospace elements. Used to calculate the width of
 	# the top prompt.
 	local zero='%([BSUBfksu]|([FB]|){*})'
@@ -52,6 +55,14 @@ zshrc_prompt_precmd() {
 	# username, green for normal users, red for root
 	local user="%(!.%F{red}.%F{green})%n%f"
 
+	# information about unstaged/staged changes in VCS in current directory
+	local vcs="${vcs_info_msg_0_}"
+	local vcs_width=${#${(S%%%)vcs//$~zero/}}
+	if [[ $vcs_width -ne 0 ]]; then
+		# add brackets if vcs is non-empty
+		vcs="${bracket_open}${vcs}${bracket_close}"
+	fi
+
 	# hostname, underlined if running on a remote system through SSH
 	local host="%F{green}%m%f"
 	if [[ -n $SSH_CONNECTION ]]; then
@@ -95,6 +106,7 @@ zshrc_prompt_precmd() {
 	# combine them to create the prompt
 	local top_left=""
 	local top_right="${bracket_open}${time}${bracket_close}"
+	local top_middle="${vcs}"
 	local bottom_left="${bracket_open}${user}%F{green}@%f${host}${bracket_close}${exitcode}${separator}${symbol}"
 	local bottom_right=
 
@@ -109,15 +121,16 @@ zshrc_prompt_precmd() {
 	local width_top_prefix=${#${(S%%%)top_prefix//$~zero/}}
 	local width_top_suffix=${#${(S%%%)top_suffix//$~zero/}}
 	local width_top_left=${#${(S%%%)top_left//$~zero/}}
+	local width_top_middle=${#${(S%%%)top_middle//$~zero/}}
 	local width_top_right=${#${(S%%%)top_right//$~zero/}}
 
 	# calculate the maximum width of ${top_left}:
-	# (-4 for brackets, -1 as spacing between top_left and top_right)
+	# (-4 for brackets and as spacing between top_left, top_middle and top_right)
 	local top_left_width_max=$((
 		COLUMNS - $width_top_prefix
-				- $width_top_left - 4
-				- 1
-				- $width_top_right
+				- $width_top_left - 2
+				- $width_top_middle
+				- $width_top_right - 2
 				- $width_top_suffix
 	))
 
@@ -129,12 +142,14 @@ zshrc_prompt_precmd() {
 	local width=$((
 		COLUMNS - width_top_prefix
 				- width_top_left
+				- width_top_middle
 				- width_top_right
 				- width_top_suffix
 	))
-	local top_separator="%F{cyan}${(pl:${width}::$dash:)}%f"
+	local top_left_separator="%F{cyan}${(pl:$((width / 2))::$dash:)}%f"
+	local top_right_separator="%F{cyan}${(pl:$((width / 2 + width % 2))::$dash:)}%f"
 
-	PROMPT="${top_prefix}${top_left}${top_separator}${top_right}${top_suffix}
+	PROMPT="${top_prefix}${top_left}${top_left_separator}${top_middle}${top_right_separator}${top_right}${top_suffix}
 ${bottom_prefix}${bottom_left} "
 
 	RPROMPT="${bottom_right}${bottom_suffix}"
diff --git a/zsh/vcs.zsh b/zsh/vcs.zsh
new file mode 100644
index 0000000..ef69f50
--- /dev/null
+++ b/zsh/vcs.zsh
@@ -0,0 +1,69 @@
+autoload -Uz vcs_info
+
+# only look for certain VCS
+zstyle ':vcs_info:*' enable git
+
+# check repository for changes so that they can be used in %u/%c
+# (this might be slow for bigger repositories)
+zstyle ':vcs_info:*' check-for-changes yes
+
+# display current branch (%b -> green), unstaged + staged changes (%u/%c -> green),
+# VCS (%s -> blue) and custom messages (%m).
+zstyle ':vcs_info:*' formats \
+	"%F{green}%b%u%c%F{default}:%F{blue}%s%F{default}%m"
+# during special actions (e.g. merge, rebase), also display those (%a -> red)
+zstyle ':vcs_info:*' actionformats \
+	"(%F{green}%b%u%c%F{default}/%F{red}%a%F{default}:%F{blue}%s%F{default}%m)"
+
+# set style for formats/actionformats when unstaged (%u) and staged (%c)
+# changes are detected in the repository
+# (check-for-changes must be true for this to work)
+zstyle ':vcs_info:*' unstagedstr '¹'
+zstyle ':vcs_info:*' stagedstr   '²'
+
+# force vcs_info to be run. this prevents running it later for performance reasons.
+# default to run vcs_info. will be prevented from running later if possible
+# (for speedup)
+zshrc_force_run_vcs_info=1
+
+# cache data
+zstyle ':vcs_info:*+pre-get-data:*' hooks pre-get-data
++vi-pre-get-data() {
+	# only git and mercurial support and need caching. ignore all other VCS
+	[[ $vcs != git && $vcs != hg ]] && return
+
+	# run vcs_info on startup, on directory change (or for other custom reasons)
+	if [[ -n $zshrc_force_run_vcs_info ]]; then
+		zshrc_force_run_vcs_info=
+		return
+	fi
+
+	# don't run vcs_info by default to speed up the shell
+	ret=1
+	case $(fc -ln $(($HISTCMD-1))) in
+		# vcs status might need an update after running git/hg
+		git* | g\ *)
+			ret=0
+			;;
+	esac
+}
+
+# display stash count
+function +vi-git-stashes() {
+	if [[ -s ${hook_com[base]/.git/refs/stash} ]]; then
+		local -a stashes
+		# "grep" output of git stash list via (M) and :#(...)
+		stashes=( ${(M)${(f)"$(git stash list 2>/dev/null)"}:#(*WIP*)} )
+
+		if [[ ${#stashes} -gt 0 ]]; then
+			hook_com[misc]+=" %F{yellow}${#stashes}s%F{default}"
+		fi
+	fi
+}
+zstyle ':vcs_info:git*+set-message:*' hooks git-stashes
+
+# enforce running vcs_info when changing directory
+prompt_chpwd() {
+	zshrc_force_run_vcs_info=1
+}
+chpwd_functions+=(prompt_chpwd)
diff --git a/zshrc b/zshrc
index d147f0b..a0c35fb 100644
--- a/zshrc
+++ b/zshrc
@@ -2,6 +2,7 @@
 source ~/.zsh/keybindings.zsh
 source ~/.zsh/setopt.zsh
 source ~/.zsh/general.zsh
+source ~/.zsh/vcs.zsh
 source ~/.zsh/prompt.zsh
 source ~/.zsh/completion.zsh
 source ~/.zsh/history.zsh