#!/bin/bash
#---------------------------------*- sh -*-------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | www.openfoam.com
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
#     Copyright (C) 2011 OpenFOAM Foundation
#------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
#
# Script
#     pre-receive-hook
#
# Description
#     pre-receive hook for git.
#     Copy or link this file as ".git/hooks/pre-receive"
#
#     Eg,
#     (
#         cd $WM_PROJECT_DIR/.git/hooks &&
#         ln -sf ../../bin/tools/pre-receive-hook pre-receive
#     )
#
#     Hook receives: <old-sha1> <new-sha1> <ref-name>
#
#     Checks for
#     - illegal code, e.g. <TAB>
#     - columns greater than 80 for *.[CH] files
#
#------------------------------------------------------------------------------
hookName="pre-receive"
die()
{
    echo "$hookName hook failure" 1>&2
    echo '-----------------------------------' 1>&2
    echo '' 1>&2
    echo "$@" 1>&2
    echo '' 1>&2
    exit 1
}

#-----------------------------------------------------------------------------

unset fileList
unset badFiles
# join list of files with this amount of space
Indent="    "

#
# report bad files and die if there are any
#
dieOnBadFiles()
{
    if [ -n "$badFiles" ]
    then
        echo "$hookName hook failure" 1>&2
        echo '-----------------------------------' 1>&2
        echo "$@" 1>&2
        echo '' 1>&2
        echo "File(s):" 1>&2
        echo "$badFiles" 1>&2
        echo ''  1>&2
        exit 1
    fi
}


#
# qualify 'git grep' to check cached value or from a specific commit
#
gitScope()
{
    if [ "$#" -gt 0 ]
    then
        echo "$1:"
    else
        echo "--cached -- "
    fi
}


#
# check for bad strings, characters, etc
#
checkIllegalCode()
{
    echo "$hookName: check bad strings/characters etc ..." 1>&2

    reBad="("$'\t'"|"$'\r\n'")"
    msgBad="<TAB> or DOS-line-endings"

    scope=$(gitScope $@)

    badFiles=$(
    for f in $fileList
    do
        case "$f" in
        # exclude potential makefiles
        (*[Mm]akefile* | wmake/rules/*)
        ;;
        (*)
            # parse line numbers from grep output:
            #        <lineNr>:   contents
            lines=$(git grep -E -hn -e "$reBad" $scope"$f" |
                sed -e 's@:.*@@' |
                tr '\n' ' '
            )
            [ -n "$lines" ] && echo "$Indent$f -- lines: $lines"
        ;;
        esac
    done
    )

    dieOnBadFiles "Remove/correct bad '$msgBad' references"
}


#
# limit line length to 80-columns
#
checkLineLength()
{
    echo "$hookName: check line lengths ..." 1>&2

    scope=$(gitScope $@)

    badFiles=$(
    for f in $fileList
    do
        # limit to *.[CH] files
        case "$f" in
        (*.[CH])
            # parse line numbers from grep output:
            #        <lineNr>:   contents
            lines=$(git grep -hn -e '^.\{81,\}' $scope"$f" |
                sed -e 's@:.*@@' |
                tr '\n' ' '
            )
            [ -n "$lines" ] && echo "$Indent$f -- lines: $lines"
        ;;
        esac
    done
    )

    dieOnBadFiles "Limit code to 80 columns before pushing"
}


#
# limit line length to 80-columns, except C++ comment lines
#
checkLineLengthNonComments()
{
    echo "$hookName: check line lengths ..." 1>&2

    scope=$(gitScope $@)

    badFiles=$(
    for f in $fileList
    do
        # limit to *.[CH] files
        case "$f" in
        (*.[CH])
            # parse line numbers from grep output:
            #        <lineNr>:   contents
            lines=$(git grep -hn -e '^.\{81,\}' \
                --and --not -e '^ *//' \
                $scope"$f" |
                sed -e 's@:.*@@' |
                tr '\n' ' '
            )
            [ -n "$lines" ] && echo "$Indent$f -- lines: $lines"
        ;;
        esac
    done
    )

    dieOnBadFiles "Limit code to 80 columns before pushing"
}


#
# limit line length to 80-columns, except #directive lines
#
checkLineLengthNonDirective()
{
    echo "$hookName: check line lengths ..." 1>&2

    scope=$(gitScope $@)

    badFiles=$(
    for f in $fileList
    do
        # limit to *.[CH] files
        case "$f" in
        (*.[CH])
            # parse line numbers from grep output:
            #        <lineNr>:   contents
            lines=$(git grep -hn -e '^.\{81,\}' \
                --and --not -e '^ *#' \
                $scope"$f" |
                sed -e 's@:.*@@' |
                tr '\n' ' '
            )
            [ -n "$lines" ] && echo "$Indent$f -- lines: $lines"
        ;;
        esac
    done
    )

    dieOnBadFiles "Limit code to 80 columns before pushing"
}


#------------------------------------------------------------------------------
# Main code : do all checks
#

while read oldSHA1 newSHA1 refName
do
    unset fileList rawFileList

    if [ "$newSHA1" = 0 ]
    then
        # ref to be deleted
        continue
    elif [ "$oldSHA1" = 0 ]
    then
        # ref to be created
        rawFileList=$(git diff-tree --root $newSHA1)
    else
        # normal changes
        rawFileList=$(git diff --name-only $oldSHA1..$newSHA1)
    fi

    #
    # no files changed: can skip all the checks
    #
    [ -n "$rawFileList" ] || continue

    fileList=$(
    for f in $rawFileList
    do
        git cat-file -e $newSHA1:$f > /dev/null 2>&1 && echo "$f"
    done
    )

    # check for illegal code, e.g. <TAB>, etc
    checkIllegalCode $newSHA1

    # ensure code conforms to 80 columns max
    checkLineLengthNonDirective $newSHA1

done


exit 0
#------------------------------------------------------------------------------