import time

from simplejson import dumps

from cubicweb.utils import make_uid

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):

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

@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()

    mode = 'null' # null or time, meant for jquery.flot.js

    def _build_abscissa(self):

        return [row[0] for row in self.rset]

    def _build_data(self, abscissa, plot):

        return filterout_nulls(abscissa, plot)

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

        # XXX add excanvas.js if IE

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

        # prepare data

        abscissa = self._build_abscissa()

        plots = []

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

        for col in xrange(1, nbcols):

            plots.append([row[col] for row in self.rset])

        # plot data

        plotuid = 'plot%s' % make_uid('foo')

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

               (plotuid, width, height))

        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:]

        plotdefs = []

        plotdata = []

        for idx, (varname, plot) in enumerate(zip(varnames, plots)):

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

            data = self._build_data(abscissa, plot)

            plotdefs.append('var %s = %s;' % (plotid, dumps(data)))

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

        self.req.html_headers.add_onload('''

%(plotdefs)s

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

    {points: {show: true},

     lines: {show: true},

     grid: {hoverable: true},

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

jQuery('#%(plotuid)s').bind('plothover', onPlotHover);

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

       'plotuid': plotuid,

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

       'mode': self.mode})

class TimeSeriePlotView(PlotView):

    id = 'plot'

    title = _('generic plot')

    __select__ = at_least_two_columns() & columns_are_date_then_numbers()

    mode = '"time"'

    def _build_abscissa(self):

        abscissa = [time.mktime(row[0].timetuple()) * 1000

                    for row in self.rset]

        return abscissa

    def _build_data(self, abscissa, plot):

        data = []

        # XXX find a way to get rid of the 3rd column and find 'mode' in JS

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

            data.append( (x, y, x) )

        return data

        __select__ = at_least_two_columns() & second_column_is_number()