# This runs in a new shell
readonly MODULE=${1}
readonly DIR=${2}
readonly URL=${3}
readonly TYPE=${4}
readonly REV=${5}
readonly -i QUIET=${6}
readonly CLEAR_LINE=$'\E[2K\r'
(( ! QUIET )) && print -Rn ${CLEAR_LINE}"Updating ${MODULE} …"
if ! builtin cd ${DIR} 2>/dev/null; then
  print -u2 -PR ${CLEAR_LINE}"%F{red}✗ %B${MODULE}:%b Not installed%f"
  return 1
fi
if [[ ${PWD} != $(command git rev-parse --show-toplevel 2>/dev/null) ]]; then
  # Not in repo root. Will not try to update.
  return 0
fi
if [[ ${URL} != $(command git config --get remote.origin.url) ]]; then
  print -u2 -PR ${CLEAR_LINE}"%F{red}✗ %B${MODULE}:%b URL does not match. Expected ${URL}. Will not try to update.%f"
  return 1
fi
if [[ ${TYPE} == tag ]]; then
  if [[ ${REV} == $(command git describe --tags --exact-match 2>/dev/null) ]]; then
    (( ! QUIET )) && print -PR ${CLEAR_LINE}"%F{green}✓%f %B${MODULE}:%b Already up to date"
    return 0
  fi
fi
if ! ERR=$(command git fetch -pq origin ${REV} 2>&1); then
  print -u2 -PR ${CLEAR_LINE}"%F{red}✗ %B${MODULE}:%b Error during git fetch%f"$'\n'${(F):-  ${(f)^ERR}}
  return 1
fi
if [[ ${TYPE} == branch ]]; then
  LOG_REV=${REV}@{u}
else
  LOG_REV=${REV}
fi
LOG=$(command git log --graph --color --format='%C(yellow)%h%C(reset) %s %C(cyan)(%cr)%C(reset)' ..${LOG_REV} 2>/dev/null)
if ! ERR=$(command git checkout -q ${REV} -- 2>&1); then
  print -u2 -PR ${CLEAR_LINE}"%F{red}✗ %B${MODULE}:%b Error during git checkout%f"$'\n'${(F):-  ${(f)^ERR}}
  return 1
fi
if [[ ${TYPE} == branch ]]; then
  if ! OUT=$(command git merge --ff-only --no-progress -n 2>&1); then
    print -u2 -PR ${CLEAR_LINE}"%F{red}✗ %B${MODULE}:%b Error during git merge%f"$'\n'${(F):-  ${(f)^OUT}}
    return 1
  fi
  # keep just first line of OUT
  OUT=${OUT%%($'\n'|$'\r')*}
else
  OUT="Updating to ${TYPE} ${REV}"
fi
if ERR=$(command git submodule update --init --recursive -q 2>&1); then
  if (( ! QUIET )); then
    [[ -n ${LOG} ]] && OUT=${OUT}$'\n'${(F):-  ${(f)^LOG}}
    print -PR ${CLEAR_LINE}"%F{green}✓%f %B${MODULE}:%b ${OUT}"
  fi
else
  print -u2 -PR ${CLEAR_LINE}"%F{red}✗ %B${MODULE}:%b Error during git submodule update%f"$'\n'${(F):-  ${(f)^ERR}}
  return 1
fi