#!/usr/bin/env bash
  
  # Copyright 2017 University of Southern California (Author: Dogan Can)
  
  # See ../../COPYING for clarification regarding multiple authors
  #
  # 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
  #
  # THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  # KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
  # WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
  # MERCHANTABLITY OR NON-INFRINGEMENT.
  # See the Apache 2 License for the specific language governing permissions and
  # limitations under the License.
  
  
  # Kaldi versioning is loosely based on the semantic versioning scheme. This
  # script tries to work out the version string from the partial version number
  # specified in src/.version along with the recent git history. By convention
  # src/.version specifies the first two components (MAJOR.MINOR) of the version
  # number. The third component (PATCH) is determined by counting how many
  # commits there are that are newer than than the last commit modifiying
  # src/.version. If there are uncommitted changes in the src/ directory, then
  # the version string is extended with a suffix (~N) specifiying the number of
  # files with uncommitted changes. The last component of the version string is
  # the abbreviated hash of the HEAD commit. If git history is not available or
  # if the file src/.short_version exists, then the version string defaults to
  # the number specified in src/.version.
  
  set -e
  
  # Change working directory to the directory where this script is located.
  cd "$(dirname ${BASH_SOURCE[0]})"
  
  # Read the partial version number specified in the first line of src/.version.
  version=$(head -1 ../.version)
  
  if [ -e ../.short_version ]; then
    echo "$0: File src/.short_version exists."
    echo "$0: Stopping the construction of full version number from git history."
  elif ! [[ $version =~ ^[0-9][0-9]*.[0-9][0-9]*$ ]]; then
    echo "$0: The version number \"$version\" specified in src/.version is not" \
         "in MAJOR.MINOR format."
    echo "$0: Stopping the construction of full version number from git history."
  elif ! which git >&/dev/null; then
    echo "$0: Git is not installed."
    echo "$0: Using the version number \"$version\" specified in src/.version."
  elif [ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" != true ]; then
    echo "$0: Git history is not available."
    echo "$0: Using the version number \"$version\" specified in src/.version."
  else
    # Figure out patch number.
    version_commit=$(git log -1 --pretty=oneline ../.version | awk '{print $1}')
    patch_number=$(git rev-list ${version_commit}..HEAD | wc -l | awk '{print $1}')
    version="$version.$patch_number"
  
    # Check for uncommitted changes in src/.
    uncommitted_changes=$(git diff-index HEAD -- .. | wc -l | awk '{print $1}')
    if [ $uncommitted_changes -gt 0 ]; then
      # Add suffix ~N if there are N files in src/ with uncommitted changes
      version="$version~$uncommitted_changes"
    fi
  
    # Figure out HEAD commit SHA-1.
    head_commit=$(git log -1 --pretty=oneline | awk '{print $1}')
    head_commit_short=$(git log -1 --oneline --abbrev=4 | awk '{print $1}')
    version="$version-${head_commit_short}"
  fi
  
  # Empty version number is not allowed.
  if [ -z "$version" ]; then
    version="?"
  fi
  
  # Write version info to a temporary file.
  temp=$(mktemp /tmp/temp.XXXXXX)
  trap 'rm -f "$temp"' EXIT
  echo "// This file was automatically created by ./get_version.sh." > $temp
  echo "// It is only included by ./kaldi-error.cc." >> $temp
  echo "#define KALDI_VERSION \"$version\"" >> $temp
  if [ -n "$head_commit" ]; then
    echo "#define KALDI_GIT_HEAD \"$head_commit\"" >> $temp
  fi
  
  # Overwrite ./version.h with the temporary file if they are different.
  if ! cmp -s $temp version.h; then
    cp $temp version.h
    chmod 644 version.h
  fi
  exit 0