#!/bin/bash
#
# Copyright 2016-present the Material Components for iOS 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.

old_commit=""
new_commit=""
VERBOSE=0

usage() {
  echo "Usage: $0 -o [old commit] -n [new commit]]"
  echo
  echo "Example usage: $0 -o v2.0.0 -n develop"
}

while getopts "h?vo:n:" opt; do
  case "$opt" in
  h|\?)
      usage
      exit 0
      ;;
  v)  VERBOSE=1
      ;;
  o)  old_commit=$(git rev-list -n 1 $OPTARG)
      ;;
  n)  new_commit=$(git rev-list -n 1 $OPTARG)
      ;;
  esac
done

log() {
  if [ "$VERBOSE" -eq "1" ]; then
    echo "$@"
  fi
}

if [[ -z "$old_commit" || -z "$new_commit" ]]; then
  usage
  exit 0
fi

logger() {
  while read data; do
    log "$data"
  done
}

validate_commit() {
  git cat-file -t $1 >> /dev/null 2> /dev/null || { echo "$1 is not a valid commit."; exit 1; }
}

validate_commit $old_commit
validate_commit $new_commit

# Compute directories relative to the script's known location in scripts/
SCRIPTS_PATH="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

log "Installing objc-diff..."

"$SCRIPTS_PATH/install_objc_diff"  \
    2>&1 | logger || { echo "Failed to install objc-diff."; exit 1; }

objc_diff() {
  $($SCRIPTS_PATH/install_objc_diff -p) "$@"
}

TMP_PATH=$(mktemp -d)

OLD_ROOT_PATH="$TMP_PATH/old"
NEW_ROOT_PATH="$TMP_PATH/new"
"$SCRIPTS_PATH/temporary_clone_at_ref" "$OLD_ROOT_PATH" $old_commit
"$SCRIPTS_PATH/temporary_clone_at_ref" "$NEW_ROOT_PATH" $new_commit

old_header_search_paths=""
new_header_search_paths=""
for d in $NEW_ROOT_PATH/components/*/src; do
  folder=$(dirname $d)
  component=$(basename $folder)
  old_header_search_paths="$old_header_search_paths --oldargs -I$OLD_ROOT_PATH/components/$component/src/ "
  new_header_search_paths="$new_header_search_paths --newargs -I$NEW_ROOT_PATH/components/$component/src/ "
done

echo "## API diffs"
echo
echo "Auto-generated by running:"
echo
echo "    scripts/api_diff -o $old_commit -n $new_commit"


for d in $NEW_ROOT_PATH/components/*/src; do
  folder=$(dirname $d)
  component=$(basename $folder)

  echo
  echo "### $component"
  echo

  if [ ! -d "$OLD_ROOT_PATH/components/$component/src" ]; then
    echo "**New component.**"
    continue
  fi

  objc_diff \
    --xml \
    --sdk iphonesimulator \
    --old "$OLD_ROOT_PATH/components/$component/src" \
    --new "$NEW_ROOT_PATH/components/$component/src" \
    $old_header_search_paths \
    $new_header_search_paths | $SCRIPTS_PATH/objc_diff_xml_to_md $old_commit $new_commit components/$component/src
done

if [ ! -z "$TMP_PATH" ]; then
  log "Cleaning up..."
  rm -rf $TMP_PATH
fi