#! /bin/sh

# cl2patch version 1.2

# Copyright (C) 1998, Free Software Foundation

# This script is Free Software, and it can be copied, distributed and
# modified as defined in the GNU General Public License.  A copy of
# its license can be downloaded from http://www.gnu.org/copyleft/gpl.html

# Written by Alexandre Oliva <oliva@dcc.unicamp.br>

# usage: cl2patch [-D|-d DATE] [-r dir] [-a AUTHOR] -- \
#            [ mypatch.diff ... | < mypatch.diff ] | \
#        patch -p0

# -D  --old-date      use old date format as default; [default: YYYY-MM-DD]
# -d  --date=DATE     specify date for ChangeLog entries; [$DATE or now]
# -a  --author=AUTHOR specify author name; [$AUTHOR or unknown]
# -r  --rootdir=dir   create patch based on ChangeLog files exist in dir [.]
# -v  --version       print version information
# -h,-?  --help       print short or long help message

# This script translates a patch with ChangeLog entries in text format
# into one that appends these ChangeLog entries in the beginning of an
# existing ChangeLog file.  It accepts some common formats of
# submitting ChangeLog entries, like the ones below.  In particular,
# it accepts the output of clcleanup.

# for dir/ChangeLog:
# 	* test: this is a test
# Index: anotherdir/ChangeLog
# 	* test: yet another test

# The script identifies the beginning of ChangeLog entries with lines
# such as `Index: [.../]ChangeLog' or `for [.../]ChangeLog', and its
# end with another `Index:' or `for' line, or EOF.  Blank lines are
# added in the beginning and in the end of the ChangeLog entry, if
# necessary.

# By default, the ChangeLog entries are given the current date as
# their timestamp.  This default can be overridden by the environment
# variable DATE, and then by the command-line switch `-d'.

# If a root directory is specified (possibly in environment variable
# ROOTDIR), existing ChangeLog files will be looked for within that
# directory, the patch will be generated based on them, and some
# effort will be made to use the same date format.  Otherwise, the
# patches for ChangeLog files will be created in a way that GNU patch
# is likely to be able to install.  Automatic detection of date format
# depends on GNU date and GNU awk.

# If the author name is not specified, the contents of the environment
# variable AUTHOR will be used by default, or `unknown', if the
# variable is undefined.  If the ChangeLog entry specifies an author
# already, with a `from' or `by' line just after the beginning of the
# ChangeLog entry, it will override the default value.  If the author
# name ends up `unknown', a warning message will be printed in a way
# that Emacs can parse as compiler-errors.

name=cl2patch
repeat="test $# -gt 0"
while $repeat; do
    case "$1" in
    -d|--date)
	shift
	DATE="$1"
	shift || { echo missing date >&2; exit 1; }
	;;
    --date=*)
        DATE=`echo "$1" | sed 's/[^=]*=//'`
	shift
	;;
    -D|--old-date)
	shift
	DATE=`date "+%a %b %e %T %Y" ${DATE+-d} ${DATE+"$DATE"}` ||
	{ echo failed to get current date >&2; exit 1; }
	;;
    -r|--rootdir)
	shift
	ROOTDIR="$1"
	shift || { echo missing root directory >&2; exit 1; }
	;;
    --rootdir=*)
	ROOTDIR=`echo "$1" | sed 's/[^=]*=//'`
	shift
	;;
    -a|--author)
	shift
	AUTHOR="$1"
	shift || { echo missing author name >&2; exit 1; }
	;;
    --author=*)
	AUTHOR=`echo "$1" | sed 's/[^=]*=//'`
	shift
	;;
    -v|--version)
	sed '/^# '$name' version /,/^# Written by/ { s/^# //; p; }; d' < $0
	exit 0
	;;
    -\?|-h)
	sed '/^# usage:/,/# -h/ { s/^# //; p; }; d' < $0 &&
	echo
	echo "run \`$name --help | more' for full usage"
	exit 0
	;;
    --help)
	sed '/^# '$name' version /,/^[^#]/ { /^[^#]/ d; s/^# //; p; }; d' < $0
	exit 0
	;;
    --)
	shift
	repeat=false
	;;
    *)
	repeat=false
	;;
    esac
done
SHORTDATE=`date "+%Y-%m-%d" ${DATE+-d} ${DATE+"$DATE"} 2>/dev/null` ||
SHORTDATE="$DATE"
LONGDATE=`date "+%a %b %e %T %Y" ${DATE+-d} ${DATE+"$DATE"} 2>/dev/null` ||
LONGDATE="$DATE"
if test x"${DATE+set}" != x"set"; then
    : ${DATE=`date "+%Y-%m-%d"`} ||
    { echo failed to get current date >&2; exit 1; }
fi
if test x"${AUTHOR+set}" != x"set"; then
    AUTHOR="unknown"
fi
printpatch='
    if (inchangelog > 1) { # print the patch only if we collected any data
	if (lastblank == 0) { # insert a missing blank line at the end
	    ++inchangelog;
	    entry=entry "\n+";
	}
	print preamble; # now print the patch
	print "@@ -1,1 +1," inchangelog+1 " @@";
	newfirstline=thisdate "  " author;
 	print "+" newfirstline entry;
	if (firstline[filename] != "") {
	    print " " firstline[filename];
	} else if (usablefirstline != 0)
	    system("sed s/\\^/\\ /\\;1q < "shfilename);
	else {
	    print ""; # this blank line will not match,
	    # but GNU patch will do The Right Thing (TM)
	}
	firstline[filename] = newfirstline;
	if (author == "unknown") {
	    warninglist[++ warning] = filename;
	}
    } else if (saveline != "") {
	print saveline;
    }
'
exec awk "
BEGIN { date=\"$DATE\"; author=\"$AUTHOR\";
	shortdate=\"$SHORTDATE\"; longdate=\"$LONGDATE\";
	rootdir=\"$ROOTDIR\"; firstline[\"\"] = \"\";
	} "'
/^Index:.*ChangeLog$/ || /^for .*ChangeLog:?/ {
    '"$printpatch"'
    saveline="";
    inchangelog=1; # start a new ChangeLog entry
    filename=$2;
    if (filename ~ /:$/) {
	filename = substr(filename, 1, length(filename)-1);
    }
    preamble="--- " filename "\n+++ " filename;
    if (rootdir != "") {
	shfilename = "\"" rootdir "/" filename "\"";
	usablefirstline=0;
	if (system("test -f " shfilename) != 0) {
	    thisdate=date;
	} else if (system("sed 1q < "shfilename" | grep \\^\\[0-9\\] > /dev/null") == 0) {
	    thisdate=shortdate; usablefirstline=1;
	} else if (system("sed 1q < "shfilename" | grep \\^\\[MTWF\\] > /dev/null") == 0) {
	    thisdate=longdate; usablefirstline=1;
	} else {
	    thisdate=date;
	}
    } else {
	thisdate=date;
    }
    entry="";
    print "Index: " filename;
    lastblank=0;
    next;
}
inchangelog == 1 && /^(>?[Ff]rom|[Bb]y) .*<.*@.*>/ { # author name
    author=substr($0, index($0, " "));
    # ugh!  awk on Solaris 2.5 will not parse match()
    while (index(author, " ") == 1)
        author=substr(author, 2);
    saveline=$0; # just in case this ends up failing
    next;
}
inchangelog == 1 && /[^ ]  [A-Za-z].*<.*@.*>/ { # author name
    author=$0;
    # ugh!  awk on Solaris 2.5 will not parse match()
    while (author !~ /^  [A-Za-z].*<.*@.*>/)
        author=substr(author, 2);
    author=substr(author, 3);
    saveline=$0; # just in case this ends up failing
    next;
}
inchangelog != 0 && lastblank == 0 && /^[ 	]*$/ {
# blank line in ChangeLog entry
    ++inchangelog;
    lastblank=1; # mark as blank
    entry=entry "\n+";
    next;
}
inchangelog != 0 && /^[ 	][ 	]*[^ 	]/ {
# non-blank ChangeLog line; insert it
    if (inchangelog == 1 && lastblank == 0) {
    # insert a blank line if the first line is not blank
	++inchangelog;
	entry=entry "\n+";
    }
    ++inchangelog;
    thisline=$0;
    while (thisline ~ /^[ 	]/)
	thisline=substr(thisline, 2);
    entry=entry "\n+	" thisline;
    lastblank=0;
    next;
}
inchangelog != 0 { # if we get here, this line cannot be part of the entry
    '"$printpatch"'
    saveline="";
    inchangelog = 0;
}
# anything else should be copied literally
{ print; }
END { # just in case the ChangeLog entry is at the end of file
    '"$printpatch"'
    if (warning > 0) {
	for (warning in warninglist) {
	    print warninglist[warning]":"1": unknown author" | "cat >&2"
	}
    }
}
' ${1+"$@"}