From b072d919580bae3cd38fe08311d57ef4d31e2687 Mon Sep 17 00:00:00 2001
From: Jorge Morante <jorge@morante.eu>
Date: Sun, 2 Apr 2017 17:55:39 +0200
Subject: [PATCH] initial health check implementation

---
 README.md               |  4 +--
 scripts/health-check.sh | 77 +++++++++++++++++++++++++++++++++++++++++
 tmux-fingers.tmux       |  2 ++
 3 files changed, 81 insertions(+), 2 deletions(-)
 create mode 100755 scripts/health-check.sh

diff --git a/README.md b/README.md
index a79b6a4..18b2e11 100644
--- a/README.md
+++ b/README.md
@@ -39,9 +39,9 @@ While in **[fingers]** mode, you can use the following shortcuts:
 
 # Requirements
 
-* bash 4+
 * tmux 2.1+ ( 2.2 recommended )
-* gawk ( optional but recommended )
+* bash 4+
+* gawk
 
 # Installation
 
diff --git a/scripts/health-check.sh b/scripts/health-check.sh
new file mode 100755
index 0000000..65d9c8c
--- /dev/null
+++ b/scripts/health-check.sh
@@ -0,0 +1,77 @@
+#!/usr/bin/env bash
+
+CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+source $CURRENT_DIR/utils.sh
+source $CURRENT_DIR/debug.sh
+
+REQUIRED_BASH_MAJOR=4
+REQUIRED_TMUX_MAJOR=2
+RECOMMENDED_TMUX_MINOR=3
+HELP_LINK="https://github.com/Morantron/tmux-fingers/blob/master/docs/health-check.md"
+
+health_tmp=$(fingers_tmp)
+
+function is_tmux_ready() {
+  local num_windows=$(tmux list-windows | wc -l)
+
+  if [[ $num_windows -gt 0 ]]; then
+    echo 1
+  else
+    echo 0
+  fi
+}
+
+function program_exists() {
+  local prog="$1"
+
+  if [[ $(which "$prog" &> /dev/null) ]]; then
+    echo "0"
+  else
+    echo "1"
+  fi
+}
+
+function log_health() {
+  echo "$1" >> "$health_tmp"
+}
+
+function perform_health_check() {
+  local healthy=1
+
+  if [[ $(program_exists "gawk") = "0" ]]; then
+    log_health "* 'gawk' not found"
+    healthy=0
+  fi
+
+  BASH_MAJOR=$(echo "$BASH_VERSION" | grep -Eo "^[0-9]")
+
+  if [[ "$BASH_MAJOR" -lt "$REQUIRED_BASH_MAJOR" ]]; then
+    log_health "* Bash version \"$BASH_VERSION\" is too old."
+    healthy=0
+  fi
+
+  TMUX_VERSION=$(tmux -V | grep -Eio "[0-9]+(\.[0-9a-z])*$")
+  TMUX_MAJOR=$(echo "$TMUX_VERSION" | cut -f1 -d.)
+  TMUX_MINOR=$(echo "$TMUX_VERSION" | cut -f2 -d. | grep -Eo "[0-9]")
+
+  if [[ $TMUX_MAJOR -lt $REQUIRED_TMUX_MAJOR ]]; then
+    log_health "* tmux version \"$TMUX_VERSION\" is too old."
+    healthy=0
+  fi
+
+  if [[ $TMUX_MAJOR -eq $REQUIRED_TMUX_MAJOR ]] && [[ $TMUX_MINOR -lt $RECOMMENDED_TMUX_MINOR ]]; then
+    echo "* WARNING: tmux 2.2+ is recommended"
+  fi
+
+  if [[ $healthy -eq 0 ]]; then
+    while [[ $(is_tmux_ready) = 0 ]]; do
+      : # waiting for-tmux
+    done
+
+    tmux run "echo -e 'tmux-fingers health-check:\\n\\n'; cat $health_tmp"
+  fi
+
+  rm -rf "$health_tmp"
+}
+
+perform_health_check
diff --git a/tmux-fingers.tmux b/tmux-fingers.tmux
index 8f36124..940ee57 100755
--- a/tmux-fingers.tmux
+++ b/tmux-fingers.tmux
@@ -1,8 +1,10 @@
 #!/usr/bin/env bash
 
 CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
 DEFAULT_FINGERS_KEY="F"
 FINGERS_KEY=$(tmux show-option -gqv @fingers-key)
 FINGERS_KEY=${FINGERS_KEY:-$DEFAULT_FINGERS_KEY}
 
+tmux run -b "$CURRENT_DIR/scripts/health-check.sh"
 tmux bind-key $FINGERS_KEY run-shell "tmux capture-pane -p | $CURRENT_DIR/scripts/tmux-fingers.sh"