################################################################################
# DocBook pseudobuilder
################################################################################

import SCons.Util, SCons.Action
import xml.dom.minidom, re, os.path, sys

def maybeBytesToString(s):
    if isinstance(s, bytes):
        return s.decode('utf-8')
    return s

def prepareForWrite(s):
    try:
        if isinstance(s, unicode):
            return s.encode('utf-8')
    except NameError:
        pass
    return s

def generate(env) :
    # Location of stylesheets and catalogs
    docbook_dir = "#/BuildTools/DocBook"
    docbook_xsl_style_dir = env.Dir(docbook_dir + "/Stylesheets").abspath
    docbook_xml_catalog = env.File("catalog.xml").abspath
    if "DOCBOOK_XML_DIR" in env :
        docbook_xml_dir = env.Dir("$DOCBOOK_XML_DIR").abspath
    else :
        docbook_xml_dir = env.Dir("#/3rdParty/DocBook/XML").abspath
    if "DOCBOOK_XSL_DIR" in env :
        docbook_xsl_dir = env.Dir("$DOCBOOK_XSL_DIR").abspath
    else :
        docbook_xsl_dir = env.Dir("#/3rdParty/DocBook/XSL").abspath
    fop_fonts_dir = env.Dir(docbook_dir + "/Fonts").abspath

    # Generates a catalog from paths to external tools
    def buildCatalog(target, source, env) :
        catalog = """<?xml version='1.0'?>
<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog" prefer="public">
    <rewriteSystem 
            systemIdStartString="http://www.oasis-open.org/docbook/xml/4.5/" 
            rewritePrefix="%(docbook_xml_dir)s/" />
    <rewriteSystem 
            systemIdStartString="docbook-xsl:/" 
            rewritePrefix="%(docbook_xsl_dir)s/" />
</catalog>"""

        docbook_xml_dir = maybeBytesToString(source[0].get_contents())
        docbook_xsl_dir = maybeBytesToString(source[1].get_contents())
        if env["PLATFORM"] == "win32" :
            docbook_xml_dir = docbook_xml_dir.replace("\\","/")
            docbook_xsl_dir = docbook_xsl_dir.replace("\\","/")
        file = open(target[0].abspath, "w")
        file.write(catalog % {
                "docbook_xml_dir" : prepareForWrite(docbook_xml_dir),
                "docbook_xsl_dir" : prepareForWrite(docbook_xsl_dir),
            })
        file.close()

    # Generates a FOP config file
    def buildFopConfig(target, source, env) :
        fopcfg = """<fop version=\"1.0\">
    <renderers>
        <renderer mime=\"application/pdf\">
            <fonts>
                <directory recursive=\"true\">%(fonts_dir)s</directory>
            </fonts>
        </renderer>
    </renderers>
</fop>"""

        file = open(target[0].abspath, "w")
        file.write(fopcfg % {
                "fonts_dir" : source[0].get_contents()
            })
        file.close()

    # Builds a DocBook file
    def buildDocBook(env, source) :
        db_env = env.Clone()
        db_env["XMLCATALOGS"] = [docbook_xml_catalog]
        db_env["ENV"].update({"OS" : os.environ.get("OS", "")})

        db_env["XMLLINT"] = env.WhereIs("xmllint")
        db_env["XSLT"] = env.WhereIs("xsltproc")
        db_env["FO"] = env.WhereIs("fop")

        if not db_env["XMLLINT"] or not db_env["XSLT"] :
            return

        # PDF generation
        if db_env["FO"] :
            fo = db_env.XSLT(os.path.splitext(source)[0] + ".fo", source, 
                    XSLTSTYLESHEET = db_env["DOCBOOK_XSL_FO"])
            pdf = db_env.FO(fo)

        # HTML generation
        db_env.XSLT(os.path.splitext(source)[0] + ".html", source, 
                XSLTSTYLESHEET = db_env["DOCBOOK_XSL_HTML"])

    # Import tools
    env.Tool("FO", toolpath = [docbook_dir + "/SCons"])
    env.Tool("XSLT", toolpath = [docbook_dir + "/SCons"])

    # Catalog file generation
    env.Command("catalog.xml", [env.Value(docbook_xml_dir), env.Value(docbook_xsl_dir)], SCons.Action.Action(buildCatalog, cmdstr = "$GENCOMSTR"))

    # FO config file generation
    env["FOCFG"] = env.File("fop.cfg").abspath
    env.Command("fop.cfg", [env.Value(fop_fonts_dir)], SCons.Action.Action(buildFopConfig, cmdstr = "$GENCOMSTR"))

    # DocBook stylesheets
    env["DOCBOOK_XSL_FO"] = docbook_xsl_style_dir + "/fo/docbook.xsl"
    env["DOCBOOK_XSL_HTML"] = docbook_xsl_style_dir + "/html/docbook.xsl"
    env.AddMethod(buildDocBook, "DocBook")

def exists(env) :
    return True