# -*- coding: utf-8 -*-
from __future__ import unicode_literals

from django.utils import timezone

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

from core.utils import duration_parts

from reports import utils


def sleep_totals(instances):
    """
    Create a graph showing total time sleeping for each day.
    :param instances: a QuerySet of Sleep instances.
    :returns: a tuple of the the graph's html and javascript.
    """
    totals = {}
    for instance in instances:
        start = timezone.localtime(instance.start)
        end = timezone.localtime(instance.end)
        if start.date() not in totals.keys():
            totals[start.date()] = timezone.timedelta(seconds=0)
        if end.date() not in totals.keys():
            totals[end.date()] = timezone.timedelta(seconds=0)

        # Account for dates crossing midnight.
        if start.date() != end.date():
            totals[start.date()] += end.replace(
                year=start.year, month=start.month, day=start.day,
                hour=23, minute=59, second=59) - start
            totals[end.date()] += end - start.replace(
                year=end.year, month=end.month, day=end.day, hour=0, minute=0,
                second=0)
        else:
            totals[start.date()] += instance.duration

    trace = go.Bar(
        name='Total sleep',
        x=list(totals.keys()),
        y=[td.seconds/3600 for td in totals.values()],
        hoverinfo='text',
        textposition='outside',
        text=[_duration_string_short(td) for td in totals.values()]
    )

    layout_args = utils.default_graph_layout_options()
    layout_args['barmode'] = 'stack'
    layout_args['title'] = '<b>Sleep Totals</b>'
    layout_args['xaxis']['title'] = 'Date'
    layout_args['xaxis']['rangeselector'] = utils.rangeselector_date()
    layout_args['yaxis']['title'] = 'Hours of sleep'

    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)


def _duration_string_short(duration):
    """
    Format a "short" duration string without seconds precision. This is
    intended to fit better in smaller spaces on a graph.
    :returns: a string of the form XhXm.
    """
    h, m, s = duration_parts(duration)
    return '{}h{}m'.format(h, m)