# copyright 2003-2012 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr

#

# This file is part of CubicWeb.

#

# CubicWeb is free software: you can redistribute it and/or modify it under the

# terms of the GNU Lesser General Public License as published by the Free

# Software Foundation, either version 2.1 of the License, or (at your option)

# any later version.

#

# CubicWeb is distributed in the hope that it will be useful, but WITHOUT

# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more

# details.

#

# You should have received a copy of the GNU Lesser General Public License along

# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.

"""basic plot views"""

from logilab.common.registry import objectify_predicate

from logilab.mtconverter import xml_escape

from cubicweb.utils import UStringIO

from cubicweb.predicates import multi_columns_rset

from cubicweb.web.views import baseviews

@objectify_predicate

def all_columns_are_numbers(cls, req, rset=None, *args, **kwargs):

    """accept result set with at least one line and two columns of result

    all columns after second must be of numerical types"""

    for etype in rset.description[0]:

        if etype not in ('Int', 'BigInt', 'Float'):

            return 0

    return 1

@objectify_predicate

def second_column_is_number(cls, req, rset=None, *args, **kwargs):

    etype = rset.description[0][1]

    if etype not  in ('Int', 'BigInt', 'Float'):

        return 0

    return 1

@objectify_predicate

def columns_are_date_then_numbers(cls, req, rset=None, *args, **kwargs):

    etypes = rset.description[0]

    if etypes[0] not in ('Date', 'Datetime', 'TZDatetime'):

        return 0

    for etype in etypes[1:]:

        if etype not in ('Int', 'BigInt', 'Float'):

            return 0

    return 1

def filterout_nulls(abscissa, plot):

    filtered = []

    for x, y in zip(abscissa, plot):

        if x is None or y is None:

            continue

        filtered.append( (x, y) )

    return sorted(filtered)

class PlotWidget(object):

    # XXX refactor with cubicweb.web.views.htmlwidgets.HtmlWidget

    def _initialize_stream(self, w=None):

        if w:

            self.w = w

        else:

            self._stream = UStringIO()

            self.w = self._stream.write

    def render(self, *args, **kwargs):

        w = kwargs.pop('w', None)

        self._initialize_stream(w)

        self._render(*args, **kwargs)

        if w is None:

            return self._stream.getvalue()

    def _render(self, *args, **kwargs):

        raise NotImplementedError

try:

    from GChartWrapper import Pie, Pie3D

except ImportError:

    pass

else:

    class PieChartWidget(PlotWidget):

        def __init__(self, labels, values, pieclass=Pie, title=None):

            self.labels = labels

            self.values = values

            self.pieclass = pieclass

            self.title = title

        def _render(self, width=None, height=None):

            piechart = self.pieclass(self.values)

            piechart.label(*self.labels)

            if width is not None:

                height = height or width

                piechart.size(width, height)

            if self.title:

                piechart.title(self.title)

            self.w(u'<img src="%s" />' % xml_escape(piechart.url))

    class PieChartView(baseviews.AnyRsetView):

        __regid__ = 'piechart'

        pieclass = Pie

        paginable = False

        __select__ = multi_columns_rset() & second_column_is_number()

        def _guess_vid(self, row):

            etype = self.cw_rset.description[row][0]

            if self._cw.vreg.schema.eschema(etype).final:

                return 'final'

            return 'textincontext'

        def call(self, title=None, width=None, height=None):

            labels = []

            values = []

            for rowidx, (_, value) in enumerate(self.cw_rset):

                if value is not None:

                    vid = self._guess_vid(rowidx)

                    label = '%s: %s' % (self._cw.view(vid, self.cw_rset, row=rowidx, col=0),

                                        value)

                    labels.append(label.encode(self._cw.encoding))

                    values.append(value)

            pie = PieChartWidget(labels, values, pieclass=self.pieclass,

                                 title=title)

            if width is not None:

                height = height or width

            pie.render(width, height, w=self.w)

    class PieChart3DView(PieChartView):

        __regid__ = 'piechart3D'

        pieclass = Pie3D