#!/bin/bash

# Runs the specified command (provided by the first argument) in all tmux panes
# in every window.  If an application is currently running in a given pane
# (e.g., vim), it is suspended and then resumed so the command can be run.
all-panes()
{
  all-panes-bg_ "$1" &
}

# The actual implementation of `all-panes` that runs in a background process.
# This prevents the function from being suspended when we press ^z in each pane.
all-panes-bg_()
{
  # Assign the argument to something readable
  local COMMAND=$1

  # Remember which window/pane we were originally at
  local ORIG_WINDOW_INDEX=`tmux display-message -p '#I'`
  local ORIG_PANE_INDEX=`tmux display-message -p '#P'`

  # Loop through the windows
  for WINDOW in `tmux list-windows -F '#I'`; do
    # Select the window
    tmux select-window -t $WINDOW

    # Remember the window's current pane sync setting
    local ORIG_PANE_SYNC=`tmux show-window-options | grep '^synchronize-panes' | awk '{ print $2 }'`

    # Send keystrokes to all panes within the current window simultaneously
    tmux set-window-option synchronize-panes on

    # Send the escape key in case we are in a vim-like program.  This is
    # repeated because the send-key command is not waiting for vim to complete
    # its action...  And sending a `sleep 1` command seems to screw up the loop.
    for i in {1..25}; do tmux send-keys 'C-['; done

    # Temporarily suspend any GUI that's running
    tmux send-keys C-z

    # If no GUI was running, kill any input the user may have typed on the
    # command line to avoid A) concatenating our command with theirs, and
    # B) accidentally running a command the user didn't want to run
    # (e.g., rm -rf ~).
    tmux send-keys C-c

    # Run the command and switch back to the GUI if there was any
    tmux send-keys "$COMMAND; fg 2>/dev/null; echo -n" C-m

    # Restore the window's original pane sync setting
    if [[ -n "$ORIG_PANE_SYNC" ]]; then
      tmux set-window-option synchronize-panes "$ORIG_PANE_SYNC"
    else
      tmux set-window-option -u synchronize-panes
    fi
  done

  # Select the original window and pane
  tmux select-window -t $ORIG_WINDOW_INDEX
  tmux select-pane -t $ORIG_PANE_INDEX
}