#!/bin/bash
#---------------------------------*- sh -*-------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | www.openfoam.com
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
#     Copyright (C) 2011-2016 OpenFOAM Foundation
#     Copyright (C) 2016 OpenCFD Ltd.
#------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM.
#
#     OpenFOAM is free software: you can redistribute it and/or modify it
#     under the terms of the GNU General Public License as published by
#     the Free Software Foundation, either version 3 of the License, or
#     (at your option) any later version.
#
#     OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
#     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
#     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
#     for more details.
#
#     You should have received a copy of the GNU General Public License
#     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
#
# Script
#     pre-commit-hook
#
# Description
#     pre-commit hook for git.
#     Copy or link this file as ".git/hooks/pre-commit"
#
#     Eg,
#     (
#         cd $WM_PROJECT_DIR/.git/hooks &&
#         ln -sf ../../bin/tools/pre-commit-hook pre-commit
#     )
#
#     Hook receives: empty
#
#     Checks for
#     - illegal code, e.g. <TAB>
#     - columns greater than 80 for *.[CH] files
#
# Note
#     Using "git commit --no-verify" it is possible to override the hook.
#
#     By supplying arguments to the hook, it can also be used to manually
#     test the specified files/directories for standards conformance.
#
#------------------------------------------------------------------------------

hookName="pre-commit"
headerSeparator="-----------------------------------"

die()
{
    echo "$hookName hook failure" 1>&2
    echo $headerSeparator 1>&2
    echo '' 1>&2
    echo "$@" 1>&2
    echo '' 1>&2
    exit 1
}

# Automatically upgrade copyrights in files.
# Disabled by default since some changes (eg, spelling) do not automatically
# imply an update copyright.
optCopyright=false

# Run all tests (do not exit on first failure)
optAll=false

#-----------------------------------------------------------------------------
# Check content that will be added by this commit.

if git rev-parse --verify HEAD > /dev/null 2>&1
then
    against=HEAD
else
    # Initial commit: diff against an empty tree object
    against=4b825dc642cb6eb9a060e54bf8d69288fbee4904
fi

# called manually with arguments for the files/directories to be tested?
if [ "$#" -gt 0 ]
then
    while [ "$#" -gt 0 ]
    do
        case "$1" in
        -h | -help)
            die "interactive usage: supply list of files/directories to check"
            ;;
        -copy)
            echo "$hookName: adjust copyright enabled" 1>&2
            optCopyright=true
            shift
            ;;
        -all)
            echo "$hookName: do all tests (no premature exit)" 1>&2
            optAll=true
            shift
            ;;
        *)
            break
            ;;
        esac
    done

    # obtain list of all specified files/directories
    fileList=$(git ls-files -- $@ 2>/dev/null)
else
    # list of all files to be committed
    fileList=$(git diff-index --cached --name-only $against --)
fi

#
# no files changed: can skip all the checks
# this usage can correspond to a 'git commit --amend'
#
[ -n "$fileList" ] || exit 0


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

exitCode=0

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

        exitCode=1
        if [ "$optAll" = true ]
        then
            return 0   # Continue to the next test
        else
            exit $exitCode
        fi
    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'")"
    msgBad="<TAB>"

    scope=$(gitScope $@)

    badFiles=$(
    for f in $fileList
    do
        case "$f" in
        # exclude potential makefiles
        (*[Mm]akefile* | wmake/rules/* | *.f* | *.v[cf]proj | *.pdf | *.png | *.html | *.gif | *.css | *.gz)
        ;;
        (*)
            fileType=`file -b $f`
            if [ "$fileType" != "data" ]
            then
                # 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"
            fi
        ;;
        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"
}


#
# check for non-standard code patterns
#
checkNonStandardCodePatterns()
{
    echo "$hookName: checking for non-standard code ..." 1>&2

    scope=$(gitScope $@)

    badFiles=$(
    for f in $fileList
    do
        # limit to *.[CH] files
        case "$f" in
        (*.[CH])
            # Directly report the incorrect markers
            git grep -n --color \
                -e '> >' -e '\bNULL\b' \
                $scope"$f"
        ;;
        esac
    done
    )

    dieOnBadFiles "$(cat<<MESSAGE
Please revise the files reported below for the following non-standard code:

  1. Spaced ending of multi-level template parameters are not allowed, such as:

      List<List<scalar> >

    which instead should be:

      List<List<scalar>>

  2. The use of the 'NULL' macro should be replaced by 'nullptr'

$headerSeparator
MESSAGE
    )"
}


#
# check that copyright date is current
#
checkCopyright()
{
    year=$(date +%Y)
    echo "$hookName: check copyright ..." 1>&2

    badFiles=$(
    for f in $fileList
    do
        startYear=`grep "Copyright.*OpenCFD" $f | sed 's/[^0-9]*\([0-9]*\).*/\1/g'`
        endYear=`grep "Copyright.*-.*OpenCFD" $f | sed 's/[^-]*-\([0-9]*\).*/\1/g'`
        #echo "startYear=$startYear endYear=$endYear"
        if [ -n "$startYear" ]
        then
            if [ -n "$endYear" ]
            then
                # Date is of type 2011-2012 OpenCFD Ltd.
                if [ "$year" != "$endYear" ]
                then
                    echo "Updated copyright for: $f" 1>&2
                    echo "$f"
                    sed -i -e "s/$startYear-$endYear OpenCFD/$startYear-$year OpenCFD/g" $f
                fi
            else
                # Date is of type 2011 OpenCFD Ltd.
                if [ "$year" != "$startYear" ]
                then
                    echo "$f"
                    echo "Updated copyright for: $f" 1>&2
                    sed -i -e "s/$startYear OpenCFD/$startYear-$year OpenCFD/g" $f
                fi
            fi
        fi
    done
    )

    dieOnBadFiles "Some copyright dates were automatically updated; Please check these before pushing"
}


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

# builtin whitespace check to avoid trailing space, including CR-LF endings
bad=$(git diff-index --cached --check $against --) || die "$bad"

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

# ensure code conforms to 80 columns max
checkLineLengthNonDirective

# check for non-standard code patterns
checkNonStandardCodePatterns

# Stop now if there were any errors
[ "$exitCode" = 0 ] || exit $exitCode

# check copyright date (normally disabled)
[ "$optCopyright" = true ] && checkCopyright

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