from xml.etree.ElementTree import QName, fromstring

from pysixt.standard.xhtml_xslfo.transformer import XHTML2FOTransformer

from pysixt.utils.xslfo.standard import cm

from pysixt.utils.xslfo import SimplePageMaster

from pysixt.standard.xhtml_xslfo.default_styling import default_styles

from pysixt.standard.xhtml_xslfo import XHTML_NS

class ReportTransformer(XHTML2FOTransformer):

    """

    Class transforming an XHTML input tree into a FO document

    displaying reports (one report for each <div class="contentmain">

    element in the input tree.

    """

    def __init__(self, section,

                 page_width=21.0, page_height=29.7,

                 margin_top=1.0, margin_bottom=1.0,

                 margin_left=1.0, margin_right=1.0,

                 header_footer_height=0.75,

                 standard_font_size=11.0, default_lang=u"fr" ):

        """

        Initializes a transformer turning an XHTML input tree

        containing <div class="contentmain"> elements representing

        main content sections into a FO output tree displaying the

        reports.

        page_width: float - width of the page (in cm)

        page_height: float - height of the page (in cm)

        margin_top: float - top margin of the page (in cm)

        margin_bottom: float - bottom margin of the page (in cm)

        margin_left: float - left margin of the page (in cm)

        margin_right: float - right margin of the page (in cm)

        header_footer_height: float - height of the header or the footer of the

                              page that the page number (if any) will be

                              inserted in.

        standard_font_size: float - standard size of the font (in pt)

        default_lang: u"" - default language (used for hyphenation)

        """

        self.section = section

        self.page_width = page_width

        self.page_height = page_height

        self.page_tmargin = margin_top

        self.page_bmargin = margin_bottom

        self.page_lmargin = margin_left

        self.page_rmargin = margin_right

        self.hf_height = header_footer_height

        self.font_size = standard_font_size

        self.lang = default_lang

        XHTML2FOTransformer.__init__(self)

    def define_pagemasters(self):

        """

        Defines the page masters for the FO output document.

        """

        pm = SimplePageMaster(u"page-report")

        pm.set_page_dims( self.page_width*cm, self.page_height*cm )

        pm.set_page_margins({u'top'   : self.page_tmargin*cm,

                             u'bottom': self.page_bmargin*cm,

                             u'left'  : self.page_lmargin*cm,

                             u'right' : self.page_rmargin*cm })

        pm.add_peripheral_region(u"end",self.hf_height)

        dims = {}

        dims[u"bottom"] = self.hf_height + 0.25

        pm.set_main_region_margins(dims)

        return [pm]

    def _visit_report(self, in_elt, _out_elt, params):

        """

        Specific visit function for the input <div> elements whose class is

        "report". The _root_visit method of this class selects these input

        elements and asks the process of these elements with this specific

        visit function.

        """

        ps = self.create_pagesequence(u"page-report")

        props = { u"force-page-count": u"no-force",

                  u"initial-page-number": u"1",

                  u"format": u"1", }

        self._output_properties(ps,props)

        sc = self.create_staticcontent(ps, u"end")

        sc_bl = self.create_block(sc)

        attrs = { u"hyphenate": u"false", }

        attrs[u"font-size"] = u"%.1fpt" %(self.font_size*0.7)

        attrs[u"language"] = self.lang

        attrs[u"text-align"] = u"center"

        self._output_properties(sc_bl,attrs)

        sc_bl.text = u"Page" + u" " # ### Should be localised!

        pn = self.create_pagenumber(sc_bl)

        pn.tail = u"/"

        lpn = self.create_pagenumbercitation( sc_bl,

                                              u"last-block-of-report-%d" % params[u"context_pos"]

                                              )

        fl = self.create_flow(ps,u"body")

        bl = self.create_block(fl)

        # Sets on the highest block element the properties of the XHTML body

        # element. These properties (at the least the inheritable ones) will

        # be inherited by all the future FO elements.

        bodies = list(self.in_tree.getiterator(QName(XHTML_NS,u"body")))

        if len(bodies) > 0:

            attrs = self._extract_properties([bodies[0]])

        else:

            attrs = default_styles[u"body"].copy()

        attrs[u"font-size"] = u"%.1fpt" %self.font_size

        attrs[u"language"] = self.lang

        self._output_properties(bl,attrs)

        # Processes the report content

        self._copy_text(in_elt,bl)

        self._process_nodes(in_elt.getchildren(),bl)

        # Inserts an empty block at the end of the report in order to be able

        # to compute the last page number of this report.

        last_bl = self.create_block(bl)

        props = { u"keep-with-previous": u"always", }

        props[u"id"] = u"last-block-of-report-%d" % params[u"context_pos"]

        self._output_properties(last_bl,props)

    def _root_visit(self):

        """

        Visit function called when starting the process of the input tree.

        """

        content = [ d for d in self.in_tree.getiterator(QName(XHTML_NS,u"div"))

                    if d.get(u"id") == self.section ]

        # Asks the process of the report elements with a specific visit

        # function

        self._process_nodes(content, self.fo_root,

                            with_function=self._visit_report)