# Copyright (C) 2007-2009  Internet Systems Consortium, Inc. ("ISC")
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
# OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
# PERFORMANCE OF THIS SOFTWARE.

# $Id$

# Generic GNUmakefile for use with xml2rfc.

# Default targets

all:: text

# Where to find citations, etcetera.
#
# We use XML_LIBRARY for the search path for compatability with xml2rfc.
# Since we expand all file inclusions before xml2rfc ever sees them,
# this isn't really necessary, we could use, eg, RFC2629TOOLS_PATH.
#
# Since xmllint and xsltproc can take URLs as pathname components
# (using space rather than colon as a separator), what I'd really
# -like- to do here is allow that, but all the fun GNU make vpath
# stuff would break, with good reason, so for now we're stuck with
# local files.
#
# It would not be hard, however, to write a script that did all the
# XSLT preprocessing using URLs pointing to, eg, a Subversion
# repository, it just wouldn't work like a Makefile.

ifndef RFC2629TOOLS_BASE
RFC2629TOOLS_BASE := ${HOME}/rfc2629tools
endif

ifndef XML_LIBRARY
XML_LIBRARY := ${RFC2629TOOLS_BASE}
XML_LIBRARY += ${RFC2629TOOLS_BASE}/xml
XML_LIBRARY += ${RFC2629TOOLS_BASE}/xml/rfc
XML_LIBRARY += ${RFC2629TOOLS_BASE}/xml/draft
XML_LIBRARY += ${RFC2629TOOLS_BASE}/xml/rfc2629xslt
endif

__EMPTY :=
__SPACE	:= ${__EMPTY} ${__EMPTY}
__PATH   = $(subst ${__SPACE},:,$(strip $(1)))

export XML_LIBRARY := $(call __PATH, . ${XML_LIBRARY})

vpath %.xml  ${XML_LIBRARY}
vpath %.xsl  ${XML_LIBRARY}
vpath %.xslt ${XML_LIBRARY}

XSLTPROC := xsltproc --path ${XML_LIBRARY}
XMLLINT  := xmllint  --path ${XML_LIBRARY}

# Whether to keep xml:base attributes from XInclude processing.

ifndef KEEP_XINCLUDE_ATTRIBUTES
  KEEP_XINCLUDE_ATTRIBUTES = 1
endif

# Rules to expand file inclusions for every XML file in this directory
# with a docName attribute.  We support both xml2rfc <?rfc include="foo"?>
# and XInclude inclusion.
#
# NB: we freeze the XML as docName.xml, so the source file can't have
# that name.  Since the docName attribute includes the draft version
# number, which you probably don't want in the name of the source file
# anyway, this is unlikely to be a serious restriction, except perhaps
# for the RFC Editor (and the RFC Editor knows where to find me...).

define RULES
  ifneq ($(1),$(2).xml)
    TARGETS += $(2)
    SOURCES += $(1)
    $(2).xml : $(1) $(3) ; ${XSLTPROC} --xinclude --param keep_xinclude_attributes ${KEEP_XINCLUDE_ATTRIBUTES} -o $(2).xml expand-rfc2629-pi-rfc-include.xsl $(1)
  else
    SKIPPED += $(1)
  endif
endef

# Generate the above rules for every XML file with a docName attribute.

GENERATE = $(if $(2),$(eval $(call RULES,$(1),$(firstword $(2)),$(sort $(filter-out $(firstword $(2)),$(2))))))
EXTRACT  = $(shell 2>/dev/null ${XSLTPROC} --novalid GNUmakefile-helper.xsl $(1))
$(foreach F,$(wildcard *.xml),$(call GENERATE,${F},$(strip $(call EXTRACT,${F}))))

# Locate the DTD if we can

DTD := $(wildcard ${RFC2629TOOLS_BASE}/xml/rfc2629xslt/rfc2629.dtd)
ifeq (${DTD},)
  DTD :=
else
  DTD := --dtd=${DTD}
endif

# Rules to run xml2rfc on the frozen XML

%.txt : %.xml
	xml2rfc   ${DTD} $< $@

%.html : %.xml
	xml2html  ${DTD} $< $@

%.nr : %.xml
	xml2nroff ${DTD} $< $@

# Force cleanup after xml2rfc errors

.DELETE_ON_ERROR:

# 2-up Postscript, for proofreading

PS_UNDERLAY := -uDRAFT

%.ps : %.txt
	a2ps -2 ${PS_UNDERLAY} -o $@ $<

# Targets

TEXT	:= $(addsuffix .txt,  ${TARGETS})
NROFF	:= $(addsuffix .nr,   ${TARGETS})
HTML	:= $(addsuffix .html, ${TARGETS})
PS	:= $(addsuffix .ps,   ${TARGETS})
XML	:= $(addsuffix .xml,  ${TARGETS})

text:	${TEXT}
nroff:	${NROFF}
html:	${HTML}
ps:	${PS}
xml:	${XML}

clean::
	rm -f ${TEXT} ${NROFF} ${HTML} ${PS} ${XML}

ifeq (,${TARGETS})
OOPS := $(filter-out $(addsuffix .xml,${TARGETS}),${SKIPPED})
all::
ifneq (,${OOPS})
	@echo 'Skipped files: ${OOPS}'
	@echo ''
endif
	@echo "I couldn't find anything to build.  Either I had trouble parsing your files,"
	@echo 'or you forgot the docName attribute on the <rfc/> element (oops).'
	@echo 'Running "make lint" to check for parse errors.'
	@echo ''
all:: lint
endif

# Julian's reference checker

define CHECK_REFERENCES
  check-references::
	@echo Checking references in $(1) ; \
	 ${XSLTPROC} --novalid --xinclude expand-rfc2629-pi-rfc-include.xsl $(1) 2>/dev/null | \
	 ${XSLTPROC} --novalid check-references.xslt -
endef

$(foreach S,${SOURCES},$(eval $(call CHECK_REFERENCES,${S})))

# Julian's dependency plotter

define GEN_REFERENCE_GRAPH
  gen-reference-graph::
	@echo Checking references in $(1) ; \
	 ${XSLTPROC} --novalid --xinclude expand-rfc2629-pi-rfc-include.xsl $(1) 2>/dev/null | \
	 ${XSLTPROC} --novalid gen-reference-graph.xslt - | \
	 dot -Tps2 | ps2pdf - $(basename $(1)).reference-graph.pdf
endef

$(foreach S,${SOURCES},$(eval $(call GEN_REFERENCE_GRAPH,${S})))

# Lint checker

lint:
	${XMLLINT} --noout *.xml

# Lint references

lint-references:
	find $(subst :, ,${XML_LIBRARY}) -type f -name 'reference.*.xml' | \
	xargs ${XMLLINT} --noout

# Validation against the RFC2629 DTD.  Mostly works, but quirky.
#
# This doesn't work at all with <?rfc include="" ?> because xmllint
# doesn't understand that.  We could run xmllint on the expanded XML,
# but then the error messages would refer to the expanded XML rather
# than the original source, which would be annoying.
#
# Validation does mostly work with XInclude, but it spits out a lot of
# "No declaration for attribute base of element" errors when used with
# XInclude, due to a bad interaction between XInclude and the DTD.
# See:
#
# http://lists.oasis-open.org/archives/docbook/200211/msg00040.html
# http://sources.redhat.com/ml/docbook-apps/2003-q4/msg00072.html
#
# The fix is to add xml:base as an allowed attribute for any element
# that could usefully contain an XInclude (ie, all of them).  Adding
# the xmlns:xi attribute to the DTD as well would make it possible to
# for validation to work with the xi namespace defined in the <rfc/>
# element; as it is, one has to define it in each XInclude element to
# avoid validation errors.

validate:
	${XMLLINT} --noout --dtdvalid rfc2629.dtd --xinclude ${SOURCES}

relaxng:
	${XMLLINT} --noout --relaxng rfc2629.rng --xinclude ${SOURCES}


# rfcdiff against immediately previous version of a draft.  This looks in
# both the current directory and ${DRAFTDIR}, if the latter is defined.

diff::

define DIFF
ifeq ($(findstring -00,$1),)
  _F0 := $(shell echo $1 | awk 'BEGIN {FS = OFS = "-"} {$$NF = sprintf("%02d", -1 + $$NF); print}').txt
ifdef DRAFTDIR
  _F1 := $$(firstword $$(wildcard $${DRAFTDIR}/$${_F0} $${_F0}))
else
  _F1 := $${_F0}
endif
  _F2 := $1.txt
  _F3 := $(shell echo $1 | awk 'BEGIN {FS = "-"} {printf "%s-from-%02d.diff.html\n", $$0, -1 + $$NF}')

ifneq ($${_F1},)
  HTML += $${_F3}

  diff:: $${_F3}

  $${_F3} : $${_F1} $${_F2}
	rfcdiff --stdout $${_F1} $${_F2} >$${_F3}.tmp
	mv $${_F3}.tmp $${_F3}
endif
endif
endef

$(foreach T,${TARGETS},$(eval $(call DIFF,${T})))

all:: diff