# -*- coding: utf-8 -*-
from django.db.models import Count, Sum
from django.db.models.functions import TruncDate
from django.utils.translation import gettext as _

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

from core.utils import duration_parts

from reports import utils


def tummytime_duration(instances):
    """
    Create a graph showing total duration of tummy time instances per day.

    :param instances: a QuerySet of TummyTime instances.
    :returns: a tuple of the the graph's html and javascript.
    """
    totals = instances.annotate(date=TruncDate('start')) \
        .values('date') \
        .annotate(count=Count('id')) \
        .annotate(sum=Sum('duration')) \
        .order_by('-date')

    sums = []
    for total in totals:
        sums.append(total['sum'])

    trace_avg = go.Bar(
        name=_('Total duration'),
        x=list(totals.values_list('date', flat=True)),
        y=[td.seconds/60 for td in sums],
        hoverinfo='text',
        text=[_duration_string_ms(td) for td in sums]
    )
    trace_count = go.Scatter(
        name=_('Number of sessions'),
        mode='markers',
        x=list(totals.values_list('date', flat=True)),
        y=list(totals.values_list('count', flat=True)),
        yaxis='y2',
        hoverinfo='y'
    )

    layout_args = utils.default_graph_layout_options()
    layout_args['title'] = _('<b>Total Tummy Time Durations</b>')
    layout_args['xaxis']['title'] = _('Date')
    layout_args['xaxis']['rangeselector'] = utils.rangeselector_date()
    layout_args['yaxis']['title'] = _('Total duration (minutes)')
    layout_args['yaxis2'] = dict(layout_args['yaxis'])
    layout_args['yaxis2']['title'] = _('Number of sessions')
    layout_args['yaxis2']['overlaying'] = 'y'
    layout_args['yaxis2']['side'] = 'right'

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


def _duration_string_ms(duration):
    """
    Format a "short" duration string with only minutes and seconds. This is
    intended to fit better in smaller spaces on a graph.
    :returns: a string of the form Xm.
    """
    h, m, s = duration_parts(duration)
    return '{}m{}s'.format(m, s)