"""basic plot views

:organization: Logilab

:copyright: 2007-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL.

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

"""

__docformat__ = "restructuredtext en"

import os

import time

from simplejson import dumps

from logilab.common import flatten

from logilab.mtconverter import html_escape

from cubicweb.utils import make_uid

from cubicweb.vregistry import objectify_selector

from cubicweb.web.views import baseviews

@objectify_selector

def at_least_two_columns(cls, req, rset, *args, **kwargs):

    if not rset:

        return 0

    return len(rset.rows[0]) >= 2

@objectify_selector

def all_columns_are_numbers(cls, req, rset, *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', 'Float'):

            return 0

    return 1

@objectify_selector

def second_column_is_number(cls, req, rset, *args, **kwargs):

    etype = rset.description[0][1]

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

        return 0

    return 1

@objectify_selector

def columns_are_date_then_numbers(cls, req, rset, *args, **kwargs):

    etypes = rset.description[0]

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

        return 0

    for etype in etypes[1:]:

        if etype not in ('Int', '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 PlotView(baseviews.AnyRsetView):

    id = 'plot'

    title = _('generic plot')

    __select__ = at_least_two_columns() & all_columns_are_numbers()

    def call(self, width=500, height=400):

        # prepare data

        rqlst = self.rset.syntax_tree()

        # XXX try to make it work with unions

        varnames = [var.name for var in rqlst.children[0].get_selected_variables()][1:]

class TimeSeriePlotView(PlotView):

    __select__ = at_least_two_columns() & columns_are_date_then_numbers()

try:

    from GChartWrapper import Pie, Pie3D

except ImportError:

    pass

else:

    class PieChartView(baseviews.AnyRsetView):

        id = 'piechart'

        pieclass = Pie

        __select__ = at_least_two_columns() & second_column_is_number()

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

            piechart = self.pieclass([(row[1] or 0) for row in self.rset])

            labels = ['%s: %s' % (row[0].encode(self.req.encoding), row[1])

                      for row in self.rset]

            piechart.label(*labels)

            if width is not None:

                height = height or width

                piechart.size(width, height)

            if title:

                piechart.title(title)

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

    class PieChart3DView(PieChartView):

        id = 'piechart3D'

        pieclass = Pie3D