# -*- coding: utf-8 -*-
from django.utils import timezone
from django.utils.translation import gettext as _

import plotly.offline as plotly
import plotly.graph_objs as go

from reports import utils


def feeding_amounts(instances):
    """
    Create a graph showing daily feeding amounts over time.
    :param instances: a QuerySet of Feeding instances.
    :returns: a tuple of the the graph's html and javascript.
    """
    totals = {}
    for instance in instances:
        end = timezone.localtime(instance.end)
        date = end.date()
        if date not in totals.keys():
            totals[date] = 0
        totals[date] += instance.amount or 0

    amounts = [round(amount, 2) for amount in totals.values()]
    trace = go.Bar(
        name=_('Total feeding amount'),
        x=list(totals.keys()),
        y=amounts,
        hoverinfo='text',
        textposition='outside',
        text=amounts
    )

    layout_args = utils.default_graph_layout_options()
    layout_args['title'] = _('<b>Total Feeding Amounts</b>')
    layout_args['xaxis']['title'] = _('Date')
    layout_args['xaxis']['rangeselector'] = utils.rangeselector_date()
    layout_args['yaxis']['title'] = _('Feeding amount')

    fig = go.Figure({
        'data': [trace],
        'layout': go.Layout(**layout_args)
    })
    output = plotly.plot(fig, output_type='div', include_plotlyjs=False)
    return utils.split_graph_output(output)