Preliminary support for EPUB3 output

The real change is that now there are 2 different ADOC_TOTALs, one for PDF
and one for EPUB. This is because the workarounds currently in place for
frontmatter styling don't work in EPUB output (because an EPUB can't
"include" a PDF).

At the moment, both of the ADOC_TOTALs are identical and the frontmatter bug
is still present in EPUB output, but at least the plumbing is in place to
make them different.

2 files changed, 56 insertions, 5 deletions

diff --git a/Gemfile b/Gemfile
index a988aa0..5604218 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,5 @@
 source "https://rubygems.org"
 gem "asciidoctor-pdf", git: "https://github.com/dressupgeekout/asciidoctor-pdf", branch: "2.3.4-charlotte"
+gem "asciidoctor-epub3", git: "https://github.com/dressupgeekout/asciidoctor-epub3", branch: "charlotte"
+gem "epubcheck-ruby"
 gem "rghost"
diff --git a/mk/willora.mk b/mk/willora.mk
index 12e8b9a..8606431 100644
--- a/mk/willora.mk
+++ b/mk/willora.mk
@@ -7,13 +7,16 @@ WILLORABASE?=	${.CURDIR}
 
 NAME?=		mybook
 PDF_OUT?=	${NAME}.pdf
-ADOC_TOTAL=	${NAME}.adoc
+PDF_ADOC_TOTAL=	${PDF_OUT}.adoc
+EPUB_OUT?=	${NAME}.epub
+EPUB_ADOC_TOTAL=${EPUB_OUT}.adoc
 
 BUNDLE?=	bundle
 THEME?=		poppy
 THEMEDIR?=	${WILLORABASE}/themes
 FONTDIR?=	${WILLORABASE}/fonts
 MEDIA?=		prepress
+PUBLISHER?=	WilloraPDF
 
 COLOPHON_OUT?=		colophon.pdf
 DEDICATION_OUT?=	dedication.pdf
@@ -23,13 +26,18 @@ CUSTOM_PDF_CONVERTER=	${WILLORABASE}/lib/willora_pdf_converter.rb
 
 ########## ########## ##########
 
+.PHONY: all
+all: ${PDF_OUT} ${EPUB_OUT}
+
+########## ########## ##########
+
 # XXX: Figure out why I can't do this:
 # 'asciidoctor-pdf -a optimize'
 # > GPL Ghostscript 9.50: Can't find initialization file gs_init.ps.
 # https://docs.asciidoctor.org/pdf-converter/latest/optimize-pdf/
 
 CLEANFILES+=	${PDF_OUT}
-${PDF_OUT}: ${THEMEDIR}/${THEME}-theme.yml ${CUSTOM_PDF_CONVERTER} ${ADOC_TOTAL} Gemfile.lock ${COLOPHON_OUT} ${DEDICATION_OUT} ${ACKNOWLEDGMENTS_OUT}
+${PDF_OUT}: ${THEMEDIR}/${THEME}-theme.yml ${CUSTOM_PDF_CONVERTER} ${PDF_ADOC_TOTAL} Gemfile.lock ${COLOPHON_OUT} ${DEDICATION_OUT} ${ACKNOWLEDGMENTS_OUT}
 	${BUNDLE} exec asciidoctor-pdf \
 		-v \
 		-r ${CUSTOM_PDF_CONVERTER} \
@@ -40,10 +48,10 @@ ${PDF_OUT}: ${THEMEDIR}/${THEME}-theme.yml ${CUSTOM_PDF_CONVERTER} ${ADOC_TOTAL}
 		-a pdf-themesdir=${THEMEDIR} \
 		-a media=${MEDIA} \
 		-a text-align=justify \
-		${ADOC_TOTAL}
+		${PDF_ADOC_TOTAL}
 
-CLEANFILES+=	${ADOC_TOTAL}
-${ADOC_TOTAL}: ${CHAPTERS}
+CLEANFILES+=	${PDF_ADOC_TOTAL}
+${PDF_ADOC_TOTAL}: ${CHAPTERS}
 	rm -f ${.TARGET}
 .for chapter in ${CHAPTERS}
 	dos2unix < ${chapter} | sed -E \
@@ -93,6 +101,47 @@ ${ACKNOWLEDGMENTS_OUT}: ${THEMEDIR}/${THEME}-acknowledgments-theme.yml ${ACKNOWL
 		-a media=print \
 		${ACKNOWLEDGMENTS_FILE}
 
+########## ########## ##########
+
+# XXX: '-a ebook-validate' doesn't work because:
+# > RUBYOPT=-d epubcheck
+# Exception `LoadError' at /usr/pkg/lib/ruby/3.0.0/rubygems.rb:1339 - cannot
+# 	load such file -- rubygems/defaults/ruby
+# Exception `LoadError' at
+# 	<internal:/usr/pkg/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85 -
+# 	cannot load such file -- rubygems/defaults/operating_system
+# Exception `LoadError' at
+# 	<internal:/usr/pkg/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:162 -
+# 	cannot load such file -- rubygems/defaults/operating_system
+# Failed to execute epubcheck
+
+CLEANFILES+=	${EPUB_OUT}
+${EPUB_OUT}: Gemfile.lock ${EPUB_ADOC_TOTAL}
+	${BUNDLE} exec asciidoctor-epub3 \
+		-v \
+		-d book \
+		-o ${.TARGET} \
+		-a producer="${PUBLISHER}" \
+		-a front-cover-image=${EPUB_COVER_FILE} \
+		-a ebook-format=epub3 \
+		-a media=${MEDIA} \
+		-a text-align=justify \
+		${EPUB_ADOC_TOTAL}
+
+# XXX Needs to be different from the PDF one
+CLEANFILES+=	${EPUB_ADOC_TOTAL}
+${EPUB_ADOC_TOTAL}: ${CHAPTERS}
+	rm -f ${.TARGET}
+.for chapter in ${CHAPTERS}
+	dos2unix < ${chapter} | sed -E \
+		-e 's,[[:space:]]--[[:space:]],\&\#8212;,g' \
+		-e 's,\&iuml;,\&\#239;,g' \
+		-e 's,\&eacute;,\&\#233;,g' >> ${.TARGET}
+	printf '\n\n' >> ${.TARGET}
+.endfor
+
+########## ########## ##########
+
 Gemfile.lock:
 	${BUNDLE} install