#!/bin/bash -ue
# Copyright 2019 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# This script runs `cros lint` on everything it's handed.

if [[ $# -eq 0 ]]; then
  echo "No files were given to lint." >&2
  echo "Usage: $0 file1 file2 ..." >&2
  exit 1
fi

cros=cros

if ! type "${cros}" >&/dev/null; then
  echo "${cros} isn't on your \$PATH. Please either enter a chroot, or place" \
    "depot_tools on your \$PATH." >&2
  exit 1
fi

lint_args=( "$@" )

# Trys to lint our sources. If `cros` tooling isn't properly found, returns. If
# anything else happens, this will exit the script with the exit code of
# `cros`.
try_lint() {
  local output last_exit_code cros_binary

  cros_binary="$1"

  set +e
  output="$("${cros_binary}" lint -- "${lint_args[@]}" 2>&1)"
  last_exit_code="$?"
  set -e

  # `cros` exits with 127 specifically if it failed due to not finding a Chrome
  # OS checkout.
  if [[ "${last_exit_code}" -ne 127 ]]; then
    if [[ -n "${output}" ]]; then
      echo "${output}"
    fi
    exit "${last_exit_code}"
  fi
}

try_lint "${cros}"

# If the user's given us a root directory to fall back on, try that
if [[ -n "${CHROMEOS_ROOT_DIRECTORY:-}" ]]; then
  user_cros="${CHROMEOS_ROOT_DIRECTORY}/chromite/bin/cros"
  if [[ -x "${user_cros}" ]]; then
    try_lint "${user_cros}"
  fi
fi

# So, `cros` outside of the chroot defers to other tools inside of Chromite. If
# `cros` couldn't find the real `cros` tool, we fall back to pylint on each
# Python file. It appears that `cros` uses depot_tools' pylint configuration, so
# this should get us most of the way there, and is probably the best we can
# reasonably expect to do for users who want to develop without the source
# tree.
echo "WARNING: No Chrome OS checkout detected, and no viable CrOS tree" >&2
echo "found; falling back to python-only linting. If you have a Chrome OS" >&2
echo "checkout, please either develop from inside of the source tree, or" >&2
echo "set \$CHROMEOS_ROOT_DIRECTORY to the root of it." >&2

python_files=()
for file in "$@"; do
  if [[ "${file}" == *.py ]]; then
    python_files+=( "${file}" )
  fi
done

if [[ "${#python_files[@]}" -eq 0 ]]; then
  exit 0
fi

# We saw `cros` above, so assume that `pylint` is in our PATH (depot_tools
# packages it, and provides a reasonable default config).
pylint "${python_files[@]}"