#!/bin/bash
#
# Check/enforce the validity of tags we apply

# WARNING:
# This file is maintained under $CVSROOT/CVSROOT/admin via CVS.
# All changes to the plaintext copy on the CVS server will be lost.

# $Id: tag-check,v 1.23 2008/04/14 16:37:37 ausil Exp $

# The root of the rpms directory on the filesystem
RPMSROOT="${CVSROOT}/rpms"
DEVELROOT="${CVSROOT}/devel"
REPOROOT="/repo/extras"

# $1 -- tagname
# $2 -- operation "add" for tag, "mov" for tag -F, and "del" for tag -d
# $3 -- repository
# $4->  file revision [file revision ...]

# parse arguments
TAGNAME=$1
shift
OPERATION=$1
shift
REPOSITORY=$1
shift
FILEREVS="$@"

# XXX: debug
#echo $@

# The repository must start with the $RPMSROOT or $DEVELROOT
if [ "${REPOSITORY##${RPMSROOT}}" = "${REPOSITORY}" ] ; then
    # not $RPMSROOT
    if [ "${REPOSITORY##${DEVELROOT}}" = "${REPOSITORY}" ] ; then
        # not $DEVELROOT either
        echo "ERROR: This script can only deal with modules from ${RPMSROOT} and ${DEVELROOT}" >&2
        exit -1
    fi
    ON_DEVEL="yes"
    # else, we are in the $DEVELROOT
    BRANCH="devel"
    MODDIR=$(echo "${REPOSITORY##${DEVELROOT}}" | sed -e 's,/, ,g')
    # extract the module name and the branch
    MODULE=$(echo ${MODDIR} | awk '{print $1}')
    SUBDIR=$(echo ${MODDIR} | awk '{print $2}')
else
    ON_RPMS="yes"
    # We expect the repositories to be (at least) 2 levels deep under $RPMSROOT
    # in the form of module_name/branch
    MODDIR=$(echo "${REPOSITORY##${RPMSROOT}}" | sed -e 's,/, ,g')
    # extract the module name and the branch
    MODULE=$(echo ${MODDIR} | awk '{print $1}')
    BRANCH=$(echo ${MODDIR} | awk '{print $2}')
    SUBDIR=$(echo ${MODDIR} | awk '{print $3}')
fi

# if we operate on a subdirectory of a particular branch these tag
# checks and operations do not apply
if [ -n "${BRANCH}" -a -n "${SUBDIR}" ] ; then
    exit 0
fi

# we better hope the CVSROOT is saved in the environment
TAGFILE="${CVSROOT}/tags/${MODULE}"

# check if we are operating in a branch
CheckBranch() {
    # we can not accept an empty branch for tagging 
    # (ie, don't tag in the root of the module)
    if [ -z "${BRANCH}" ] ; then
	echo "ERROR: creating module-wide tags is prohibited" >&2
	exit 2
    fi
}

# check the tag validity
VALID=0
# avoid getting into the 4Suite trap
CHECK_NAME="$(echo ${MODULE} | sed -e 's/\./_/g' -e 's/^[0-9]\+//g')"
case ${TAGNAME} in
    # show a list of all the tags
    show )
	if [ -f ${TAGFILE} ] ; then
	    echo "The following tags have been created for the module ${MODULE}"
	    cat ${TAGFILE}
	    echo
	else
	    echo "No tags have been found for the module ${MODULE}"
	    echo
	fi
	#echo "(the following error is caused intentionally to avoid creating a 'show' tag)">&2
	#exit 1
	exit 0
	;;

    setup-new-module )
	echo "WARNING: Your cvs-import.sh script is OUT OF DATE" >&2
	exit 0
	;;

    # we allow all operations on the private-* tags. Exit OK
    private-* )
	CheckBranch
	exit 0
	;;

    ${CHECK_NAME}-*-* )
	CheckBranch
        # check n-v-r format
        if echo "${TAGNAME}" | egrep '(.*)-([^-]+)-([^-]+)' >/dev/null 2>/dev/null ; then
	    VALID=1
	else
	    echo "ERROR: Tag ${TAGNAME} is not in name-version-release format" >&2
	    exit -1
	fi
	# check that the "n" matches the rpm name from the repository
	# It fucking blows that I have to write the same goddamn regex differently for egrep and sed
	TEST_NAME="$(echo ${TAGNAME} | sed -e 's/\(.*\)-\([^-]\+\)-\([^-]\+\)/\1/')"
	if [ "${TEST_NAME}" = "${CHECK_NAME}" ] ; then
	    VALID=1
	else
	    echo "ERROR: Tag ${TAGNAME} has not been created from package name ${MODULE}" >&2
	    exit -1
	fi
	;;

    # branch starting tags
    RHL-8-start | RHL-9-start | \
    OLPC-2-start | OLPC-3-start | \
    EL-4-start | EL-5-start | \
    FC-1-start | FC-2-start | FC-3-start | FC-4-start | FC-5-start | \
    FC-6-start | F-7-start | F-8-start | F-9-start )
        # Adding these tags is allowed without any further checks.
        # Moving and deleting are prohibited
	CheckBranch
        if [ "${OPERATION}" = "add" ] ; then
	    exit 0
	else
	    echo "ERROR: Tag operation '${OPERATION}' is not allowed on tag ${TAGNAME}" >&2
	    exit -2
	fi
	# noop
        VALID=1
	;;
    
    # branch spliting tags - these ones sit on the devel branch to tell
    # us where various releases have split away from the trunk
    RHL-8-split | RHL-9-split | \
    OLPC-2-split | OLPC-3-split | \
    EL-4-split | EL-5-split | \
    FC-1-split | FC-2-split | FC-3-split | FC-4-split | FC-5-split | \
    FC-6-split | F-7-split | F-8-split | F-9-split )
        # Adding these tags is allowed without any further checks.
        # Moving and deleting are prohibited
	CheckBranch
        if [ "${OPERATION}" = "add" ] ; then
	    exit 0
	else
	    echo "ERROR: Tag operation '${OPERATION}' is not allowed on tag ${TAGNAME}" >&2
	    exit -2
	fi
	# noop
        VALID=1
	;;

    * )
	VALID=0
	;;
esac

# in theory this should be a noop, but who knows how the above case
# statement will grow...
if [ ${VALID} -eq 0 ] ; then
    echo "ERROR: Tag ${TAGNAME} is not in a valid tag format" >&2
    exit -1
fi

# we better hope the CVSROOT is saved in the environment
TAGFILE="${CVSROOT}/tags/${MODULE}"

AddTag() {
    # add this tag
    echo "${TAGNAME}:${BRANCH}:${USER}:$(date '+%s')" >> ${TAGFILE}
}

case ${OPERATION} in
    del )
        # first, we don't allow removal of regular tags. The special cases
        # should have been handled in the case statement above
	if [ "${OPERATION}" = "del" ] ; then
	    echo "ERROR: Tag removal not allowed for tag ${TAGNAME}"
	    exit -3
	fi
	;;

    add )
	# check that this is indeed a new tag.       
	if [ ! -f ${TAGFILE} ] ; then    
	    touch ${TAGFILE}
	    chmod 664 ${TAGFILE}
	    AddTag
	    exit 0
	fi
	# extract what we have already in the tags file
	OLDTAG=$(egrep "^${TAGNAME}:" ${TAGFILE} 2>/dev/null | cut -d':' -f1-2 | sort | uniq)
	if [ -z "${OLDTAG}" ] ; then
	    # nothing there, we don't have the tag
	    AddTag
	    exit 0
	fi
	# for the cvs import we hardcode this to allow everything we need
	if [ "${USER}" = "cvsdist" ] ; then
	    echo "WARNING: allowing illegal tagging for import's sake"
	    exit 0
	fi
	# try to be hepful in the error messages
	if egrep "^${TAGNAME}:${BRANCH}:" ${TAGFILE} >/dev/null 2>/dev/null ; then
            # tag exists, operation DENIED
	    echo "ERROR: Tag ${TAGNAME} has been already created." >&2
	    echo "The following tags have been created so far" >&2
	else	
	    echo "ERROR: The tag ${TAGNAME} is already applied on a different branch" >&2
	    echo "ERROR: You can not forcibly move tags between branches" >&2
	fi
	cat ${TAGFILE} >&2
	exit -4
	;;

    mov )
        # check that we have this tag first. We are stricter than regular CVS,
        # because we do not allow to forcibly create a new tag through a mov
        # operation. In this case 'mov' will only move an actual tag, not
        # create a new one. if it does not exist
	if [ ! -f ${TAGFILE} ] ; then
	    echo "ERROR: No tags are available for module ${MODULE}" >&2
	    exit -4
	fi
	# check that this tagname is available for the same branch
	if egrep "^${TAGNAME}:${BRANCH}:" ${TAGFILE} >/dev/null 2>/dev/null ; then
	    # tag exists, for now we record every time it gets re-applied
	    echo "${TAGNAME}:${BRANCH}:${USER}:$(date '+%s')" >> ${TAGFILE}
	else
	    # try to be helpful in the error message
	    if egrep "^${TAGNAME}:" ${TAGFILE} >/dev/null 2>/dev/null ; then
		# does it exist at all?
		echo "ERROR: The tag ${TAGNAME} is already applied on a different branch" >&2
		echo "ERROR: You can not forcibly move tags between branches" >&2
		exit -4
	    fi
	    # else, the tag does not exist at all
	    echo "ERROR: Tag ${TAGNAME} does not exist for module ${MODULE}" >&2
	    echo "ERROR: You can not move it around unless you create it first" >&2
	    exit -4
	fi
	;;

    * )
	echo "ERROR: Unknown operation ${OPERATION} for tag ${TAGNAME}" >&2
	exit -5
	;;

esac

exit 0