#!/bin/bash

# Copyright (C) 2014 Google Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

# Script to check whether the local dirty commits are changing files
# which do not have an updated copyright.
#
# The script will determine your current remote branch and local
# branch, from which it will extract the commits to analyze.
# Afterwards, for each commit, it will see which files are being
# modified and, for each file, it will check the copyright.

function join {
    local IFS="$1"
    shift
    echo "$*"
}

# Determine the tracking branch for the current branch
readonly REMOTE=$(git branch -vv | grep -e "^\*" | sed -e "s/ \+/ /g" | awk '{ print $4 }' | grep "\[" | tr -d ":[]")

if [ -z "$REMOTE" ]
then
    echo check_copyright: failed to get remote branch
    exit 1
fi

# Determine which commits have no been pushed (i.e, diff between the
# remote branch and the current branch)
COMMITS=$(git log --pretty=format:'%h' ${REMOTE}..HEAD)

if [ -z "$COMMITS" ]
then
    echo check_copyright: there are no commits to check
    exit 0
fi

# for each commit, check its files
for commit in $(echo $COMMITS | tac -s " ")
do
    FILES=$(git diff-tree --no-commit-id --name-only -r $commit)

    if [ -z "$FILES" ]
    then
	echo check_copyright: commit \"$commit\" has no files to check
    else
	# for each file, check if it is in the 'lib' or 'src' dirs
	# and, if so, check the copyright
	for file in $FILES
	do
	    DIR=$(echo $file | cut -d "/" -f 1)

	    if [ "$DIR" = lib -o "$DIR" = src ]
	    then
		COPYRIGHT=$(grep "Copyright (C)" $file)
		YEAR=$(date +%G)

		if [ -z "$COPYRIGHT" ]
		then
		    echo check_copyright: commit \"$commit\" misses \
			copyright for \"$file\"
		elif ! echo $COPYRIGHT | grep -o $YEAR > /dev/null
		then
		    echo check_copyright: commit \"$commit\" misses \
			\"$YEAR\" copyright for \"$file\"
		fi
	    fi
	done
    fi
done