"""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

:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses

"""

__docformat__ = "restructuredtext en"

import os

import time

from simplejson import dumps

from logilab.common import flatten

from logilab.mtconverter import xml_escape

from cubicweb.utils import make_uid, UStringIO, datetime2ticks

from cubicweb.appobject import objectify_selector

from cubicweb.web.views import baseviews

@objectify_selector

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

    if not rset:

        return 0

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

@objectify_selector

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', 'Float'):

            return 0

    return 1

@objectify_selector

def second_column_is_number(cls, req, rset=None, *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=None, *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 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()

class FlotPlotWidget(PlotWidget):

    """PlotRenderer widget using Flot"""

    onload = u'''

%(plotdefs)s

jQuery.plot(jQuery("#%(figid)s"), [%(plotdata)s],

    {points: {show: true},

     lines: {show: true},

     grid: {hoverable: true},

     xaxis: {mode: %(mode)s}});

jQuery("#%(figid)s").bind("plothover", onPlotHover);

'''

    def __init__(self, labels, plots, timemode=False):

        self.labels = labels

        self.plots = plots # list of list of couples

        self.timemode = timemode

    def dump_plot(self, plot):

        # XXX for now, the only way that we have to customize properly

        #     datetime labels on tooltips is to insert an additional column

        #     cf. function onPlotHover in cubicweb.flot.js

        if self.timemode:

            plot = [(datetime2ticks(x), y, datetime2ticks(x)) for x,y in plot]

        return dumps(plot)

    def _render(self, req, width=500, height=400):

        # XXX IE requires excanvas.js

        req.add_js( ('jquery.flot.js', 'cubicweb.flot.js', 'excanvas.js') )

        figid = u'figure%s' % req.varmaker.next()

        plotdefs = []

        plotdata = []

        self.w(u'<div id="%s" style="width: %spx; height: %spx;"></div>' %

               (figid, width, height))

        for idx, (label, plot) in enumerate(zip(self.labels, self.plots)):

            plotid = '%s_%s' % (figid, idx)

            plotdefs.append('var %s = %s;' % (plotid, self.dump_plot(plot)))

            # XXX ugly but required in order to not crash my demo

            plotdata.append("{label: '%s', data: %s}" % (label.replace(u'&', u''), plotid))

        req.html_headers.add_onload(self.onload %

                                    {'plotdefs': '\n'.join(plotdefs),

                                     'figid': figid,

                                     'plotdata': ','.join(plotdata),

                                     'mode': self.timemode and "'time'" or 'null'})

class PlotView(baseviews.AnyRsetView):

    id = 'plot'

    title = _('generic plot')

    __select__ = at_least_two_columns() & all_columns_are_numbers()

    timemode = False

    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:]

        abscissa = [row[0] for row in self.rset]

        plots = []

        nbcols = len(self.rset.rows[0])

        for col in xrange(1, nbcols):

            data = [row[col] for row in self.rset]

            plots.append(filterout_nulls(abscissa, data))

        plotwidget = FlotPlotWidget(varnames, plots, timemode=self.timemode)

        plotwidget.render(self.req, width, height, w=self.w)

class TimeSeriePlotView(PlotView):

    __select__ = at_least_two_columns() & columns_are_date_then_numbers()

    timemode = True

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):

        id = 'piechart'

        pieclass = Pie

        __select__ = at_least_two_columns() & second_column_is_number()

        def _guess_vid(self, row):

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

            if self.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.rset):

                if value is not None:

                    vid = self._guess_vid(rowidx)

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

                                        value)

                    labels.append(label.encode(self.req.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):

        id = 'piechart3D'

        pieclass = Pie3D