#!/usr/bin/env retro

This tool is intended to be used to create an epub version of the
standard documentation.

An epub is just a .zip file containing a bunch of XHTML files and
a few files containing metadata.

Our structure will look like:

    Book Root Directory
      |-- META-INF directory
      |         `-- container.xml
      |-- mimetype
      |-- content.opf
      |-- toc.ncx
      |-- stylesheet.css
      |-- cover.xhtml
      |-- toc.xhtml
      |-- chapterAA.xhtml
      |-- ...
      `-- chapterZZ.xhtml


Begin by defining some helper functions for writing to a
file.

~~~
'tools/book-chapters.retro include

'FID var
:file:s:put [ @FID file:write ] s:for-each ;
:file:nl    ASCII:CR @FID file:write ;
:unix:mkdir 'mkdir_-p_%s s:format unix:system ;
~~~

Create the directories needed.

~~~
'STEP:_Create_directories s:put nl
'epub unix:mkdir
'epub/META-INF unix:mkdir
~~~

Then create the `mimetype` file. This is supposed to be written
without a trailing newline.

~~~
'STEP:_Generate_`mimetype` s:put nl
'application/epub+zip 'epub/mimetype file:spew
~~~

Then create `META-INF/container.xml`.

~~~
'STEP:_Generate_`container.xml` s:put nl
'epub/META-INF/container.xml file:open-for-writing !FID

  '<?xml_version="1.0"?> file:s:put file:nl
  '<container_version="1.0"_ file:s:put
  'xmlns="urn:oasis:names:tc:opendocument:xmlns:container"> file:s:put file:nl
  '<rootfiles> file:s:put file:nl
  '<rootfile_full-path="content.opf"_ file:s:put
  'media-type="application/oebps-package+xml"/> file:s:put file:nl
  '</rootfiles> file:s:put file:nl
  '</container> file:s:put file:nl

@FID file:close
~~~

Create `content.opf`. This will need to lest all of the files
that are used in the book.

Manifest:

'____<item_href="chap01.xhtml"_id="chap01_page"_media-type="application/xhtml+xml"/> file:s:put file:nl

Spine:

'____<itemref_idref="chap01_page"_linear="yes"/> file:s:put file:nl

~~~
'STEP:_Generate_`content.opf` s:put nl
'epub/content.opf file:open-for-writing !FID

'<?xml_version="1.0"_encoding="utf-8"_standalone="yes"?> file:s:put file:nl
'<package_xmlns="http://www.idpf.org/2007/opf"_unique-identifier="BookID"_version="2.0"> file:s:put file:nl
'__<metadata_xmlns:dc="http://purl.org/dc/elements/1.1/"_xmlns:opf="http://www.idpf.org/2007/opf"> file:s:put file:nl
'____<dc:title>RETRO_Forth_:_User_Manual</dc:title> file:s:put file:nl
'____<dc:identifier_id="BookID"_opf:scheme="CustomID">...bookid...</dc:identifier> file:s:put file:nl
'__</metadata> file:s:put file:nl

'__<manifest> file:s:put file:nl
#0 TOC [ over swap '____<item_href="chapters/%s.html"_id="CHAPTEr%n"_media-type="application/xhtml+xml"/> s:format file:s:put file:nl n:inc ] a:for-each
drop
'__</manifest> file:s:put file:nl

'__<spine_toc="ncx"> file:s:put file:nl
(spine)
'__</spine> file:s:put file:nl

'__<guide> file:s:put file:nl
'__</guide> file:s:put file:nl

'</package> file:s:put file:nl
@FID file:close
~~~

# Generate the Chapters

~~~
'STEP:_Convert_chapters_to_XHTML s:put nl
'retro_tools/book-chapters-to-xhtml.retro unix:system
~~~

# Assemble the pieces

~~~
'STEP:_Relocate_files s:put nl
'epub unix:chdir
'cp_-r_../chapters_. unix:system
~~~

# Zip Everything

~~~
'STEP:_Create_epub s:put nl
'zip_-0Xq_../book.epub_mimetype unix:system
'zip_-Xr9Dq_../book.epub_content.opf unix:system
'zip_-Xr9Dq_../book.epub_chapters unix:system
'.. unix:chdir
~~~

# Clean Up

Cleanup is the final step. Remove the temporary epub directory

~~~
'STEP:_Cleanup s:put nl
'rm_-rf_epub unix:system
~~~