local _gitdir
local last_fetch
local diff

# exec 3>&1 4>&2
# trap 'exec 2>&4 1>&3' 0 1 2 3
# exec 1>>~/tmp/gitfetch.log 2>&1

cd $1


gitdir=$(git rev-parse --git-dir 2> /dev/null) || return 0
last_fetch=$(zstat +mtime $gitdir/FETCH_HEAD 2> /dev/null || echo 0)
let "diff = $(strftime %s) - $last_fetch"
if [ $diff -gt ${GIT_FETCH_INTERVAL:-30} ]; then
  setopt localoptions noshwordsplit

  # Sets `GIT_TERMINAL_PROMPT=0` to disable authentication prompt for Git fetch (Git 2.3+).
  export GIT_TERMINAL_PROMPT=0
  # Set SSH `BachMode` to disable all interactive SSH password prompting.
  export GIT_SSH_COMMAND="${GIT_SSH_COMMAND:-"ssh"} -o BatchMode=yes"

  local ref
  ref=$(command git symbolic-ref -q HEAD)
  local -a remote
  remote=($(command git for-each-ref --format='%(upstream:remotename) %(refname)' $ref))

  if [[ -z $remote[1] ]]; then
    # No remote specified for this branch, skip fetch.
    return 97
  fi

  # Default return code, which indicates Git fetch failure.
  local fail_code=99

  # Guard against all forms of password prompts. By setting the shell into
  # MONITOR mode we can notice when a child process prompts for user input
  # because it will be suspended. Since we are inside an async worker, we
  # have no way of transmitting the password and the only option is to
  # kill it. If we don't do it this way, the process will corrupt with the
  # async worker.
  setopt localtraps monitor

  # Make sure local HUP trap is unset to allow for signal propagation when
  # the async worker is flushed.
  trap - HUP

  trap '
    # Unset trap to prevent infinite loop
    trap - CHLD
    if [[ $jobstates = suspended* ]]; then
      # Set fail code to password prompt and kill the fetch.
      fail_code=98
      kill %%
    fi
  ' CHLD

  # Only fetch information for the current branch and avoid
  # fetching tags or submodules to speed up the process.
  command git -c gc.auto=0 fetch \
    --quiet \
    --no-tags \
    --recurse-submodules=yes \
    $remote &>/dev/null &
  wait $! || return $fail_code

  unsetopt monitor
fi

return 0

# vim: set ts=2 sw=2 tw=0 ft=sh :