#!/bin/bash
#
# Copyright 2016 Istio Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
################################################################################
#
ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"

CLANG_VERSION_REQUIRED="14.0.0"
CLANG_DIRECTORY="${HOME}/clang-${CLANG_VERSION_REQUIRED}"
CLANG_FORMAT=$(command -v clang-format)
CLANG_VERSION="$(${CLANG_FORMAT} -version 2>/dev/null | cut -d ' ' -f 3 | cut -d '-' -f 1)"
# Try system clang first.
if [[ ! -x "${CLANG_FORMAT}" || "${CLANG_VERSION}" != "${CLANG_VERSION_REQUIRED}" ]]; then
  CLANG_FORMAT="${CLANG_DIRECTORY}/bin/clang-format"
  # Try cached clang second.
  CLANG_VERSION="$(${CLANG_FORMAT} -version 2>/dev/null | cut -d ' ' -f 3 | cut -d '-' -f 1)"
  if [[ ! -x "${CLANG_FORMAT}" || "${CLANG_VERSION}" != "${CLANG_VERSION_REQUIRED}" ]]; then
    # Install required clang version to a folder and cache it.
    if [ "$(uname)" == "Darwin" ]; then
      CLANG_BIN="x86_64-darwin-apple.tar.xz"
    elif [[ "$(uname -s)" =~ Linux* ]]; then
      if [ "$(uname -m)" == "aarch64" ]; then
        CLANG_BIN="aarch64-linux-gnu.tar.xz"
      else
        CLANG_BIN="x86_64-linux-gnu-ubuntu-18.04.tar.xz"
      fi
    else
      echo "Unsupported environment." ; exit 1 ;
    fi

    LLVM_URL_PREFIX="https://github.com/llvm/llvm-project/releases/download/llvmorg"
    echo "Downloading clang-format: ${LLVM_URL_PREFIX}-${CLANG_VERSION_REQUIRED}/clang+llvm-${CLANG_VERSION_REQUIRED}-${CLANG_BIN}"
    echo "Installing required clang-format ${CLANG_VERSION_REQUIRED} to ${CLANG_DIRECTORY}"

    mkdir -p "${CLANG_DIRECTORY}"
    curl -L --silent --show-error --retry 10 \
      "${LLVM_URL_PREFIX}-${CLANG_VERSION_REQUIRED}/clang+llvm-${CLANG_VERSION_REQUIRED}-${CLANG_BIN}" \
      | tar Jx -C "${CLANG_DIRECTORY}" --strip=1 \
    || { echo "Could not install required clang-format. Skip formatting." ; exit 1 ; }
  fi
fi

BUILDIFIER=$(command -v buildifier)
if [[ ! -x "${BUILDIFIER}" ]]; then
  BUILDIFIER="${HOME}/bin/buildifier"
  if [[ ! -x "${BUILDIFIER}" ]]; then

    if [ "$(uname)" == "Darwin" ]; then
      BUILDIFIER_BIN="buildifier-darwin-amd64"
    elif [[ "$(uname -s)" =~ Linux* ]]; then
      if [ "$(uname -m)" == "aarch64" ]; then
        BUILDIFIER_BIN="buildifier-linux-arm64"
      else
        BUILDIFIER_BIN="buildifier-linux-amd64"
      fi
    else
      echo "Unsupported environment." ; exit 1 ;
    fi

    echo "Downloading buildifier"

    mkdir -p "${HOME}/bin"
    curl --silent --show-error --retry 10 --location \
      "https://github.com/bazelbuild/buildtools/releases/download/v6.1.2/${BUILDIFIER_BIN}" \
      -o "${BUILDIFIER}" \
    || { echo "Could not install required buildifier. Skip formatting." ; exit 1 ; }
    chmod +x "${BUILDIFIER}"
  fi
fi

echo "Checking file format ..."

pushd "${ROOT}" > /dev/null || exit 1

SOURCE_FILES=()
while IFS='' read -r line; do SOURCE_FILES+=("$line"); done < <(git ls-tree -r HEAD --name-only | grep -E '\.(h|c|cc|proto)$')

"${CLANG_FORMAT}" -i "${SOURCE_FILES[@]}" \
  || { echo "Could not run clang-format." ; exit 1 ; }

CHANGED_SOURCE_FILES=()
while IFS='' read -r line; do CHANGED_SOURCE_FILES+=("$line"); done < <(git diff HEAD --name-only | grep -E '\.(h|c|cc|proto)$')

BAZEL_FILES=()
while IFS='' read -r line; do BAZEL_FILES+=("$line"); done < <(git ls-tree -r HEAD --name-only | grep -E '(\.bzl|BUILD|WORKSPACE)$' |grep -v 'extensions_build_config.bzl')

"${BUILDIFIER}" "${BAZEL_FILES[@]}" \
  || { echo "Could not run buildifier." ; exit 1 ; }

CHANGED_BAZEL_FILES=()
while IFS='' read -r line; do CHANGED_BAZEL_FILES+=("$line"); done < <(git diff HEAD --name-only | grep -E '(\.bzl|BUILD|WORKSPACE)$')

if [[ "${#CHANGED_SOURCE_FILES}" -ne 0 ]]; then
  echo -e "Source file(s) not formatted:\n${CHANGED_SOURCE_FILES[*]}"
fi
if [[ "${#CHANGED_BAZEL_FILES}" -ne 0 ]]; then
  echo -e "Bazel file(s) not formatted:\n${CHANGED_BAZEL_FILES[*]}"
fi
if [[ "${#CHANGED_SOURCE_FILES}" -ne 0 || "${#CHANGED_BAZEL_FILES}" -ne 0 ]]; then
  exit 1
fi
echo "All files are properly formatted."

popd || exit 1