mybuddy/reports/graphs/sleep_pattern.py

# -*- coding: utf-8 -*-
from collections import OrderedDict

from django.utils import timezone, formats
from django.utils.translation import gettext as _

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

from core.utils import duration_string

from reports import utils

from datetime import timedelta

ASLEEP_COLOR = 'rgb(35, 110, 150)'
AWAKE_COLOR = 'rgba(255, 255, 255, 0)'


def sleep_pattern(sleeps):
    """
    Create a graph showing blocked out periods of sleep during each day.
    :param sleeps: a QuerySet of Sleep instances.
    :returns: a tuple of the the graph's html and javascript.
    """
    last_end_time = None
    adjustment = None

    days = _init_days(sleeps.first().start, sleeps.last().end)

    for sleep in sleeps:
        start_time = timezone.localtime(sleep.start)
        end_time = timezone.localtime(sleep.end)
        start_date = start_time.date().isoformat()
        end_date = end_time.date().isoformat()
        duration = sleep.duration

        # Check if the previous entry crossed midnight (see below).
        if adjustment:
            _add_adjustment(adjustment, days)
            last_end_time = timezone.localtime(adjustment['end_time'])
            adjustment = None

        # If the dates do not match, set up an adjustment for the next day.
        if end_time.date() != start_time.date():
            adj_start_time = end_time.replace(hour=0, minute=0, second=0)
            adjustment = {
                'column': end_date,
                'start_time': adj_start_time,
                'end_time': end_time,
                'duration': end_time - adj_start_time
            }

            # Adjust end_time for the current entry.
            end_time = end_time.replace(
                year=start_time.year, month=start_time.month,
                day=start_time.day, hour=23, minute=59, second=0)
            duration = end_time - start_time

        if not last_end_time:
            last_end_time = start_time.replace(hour=0, minute=0, second=0)

        # Awake time.
        days[start_date].append({
            'time': (start_time - last_end_time).seconds / 60,
            'label': None
        })

        # Asleep time.
        days[start_date].append({
            'time': duration.seconds / 60,
            'label': _format_label(duration, start_time, end_time)}
        )

        # Update the previous entry duration if an offset change occurred.
        # This can happen when an entry crosses a daylight savings time change.
        if start_time.utcoffset() != end_time.utcoffset():
            diff = start_time.utcoffset() - end_time.utcoffset()
            duration -= timezone.timedelta(seconds=diff.seconds)
            yesterday = (end_time - timezone.timedelta(days=1))
            yesterday = yesterday.date().isoformat()
            days[yesterday][len(days[yesterday]) - 1] = {
                'time': duration.seconds / 60,
                'label': _format_label(duration, start_time, end_time)
            }

        last_end_time = end_time

    # Handle any left over adjustment (if the last entry crossed midnight).
    if adjustment:
        _add_adjustment(adjustment, days)

    # Create dates for x-axis using a 12:00:00 time to ensure correct
    # positioning of bars (covering entire day).
    dates = []
    for time in list(days.keys()):
        dates.append('{} 12:00:00'.format(time))

    traces = []
    color = AWAKE_COLOR

    # Set iterator and determine maximum iteration for dates.
    i = 0
    max_i = 0
    for date_times in days.values():
        max_i = max(len(date_times), max_i)
    while i < max_i:
        y = {}
        text = {}
        for date in days.keys():
            try:
                y[date] = days[date][i]['time']
                text[date] = days[date][i]['label']
            except IndexError:
                y[date] = None
                text[date] = None
        i += 1
        traces.append(go.Bar(
            x=dates,
            y=list(y.values()),
            hovertext=list(text.values()),
            # `hoverinfo` is deprecated but if we use the new `hovertemplate`
            # the "filler" areas for awake time get a hover that says "null"
            # and there is no way to prevent this currently with Plotly.
            hoverinfo='text',
            marker={'color': color},
            showlegend=False,
        ))
        if color == AWAKE_COLOR:
            color = ASLEEP_COLOR
        else:
            color = AWAKE_COLOR

    layout_args = utils.default_graph_layout_options()
    layout_args['margin']['b'] = 100

    layout_args['barmode'] = 'stack'
    layout_args['bargap'] = 0
    layout_args['hovermode'] = 'closest'
    layout_args['title'] = _('<b>Sleep Pattern</b>')
    layout_args['height'] = 800

    layout_args['xaxis']['title'] = _('Date')
    layout_args['xaxis']['tickangle'] = -65
    layout_args['xaxis']['tickformat'] = '%b %e\n%Y'
    layout_args['xaxis']['ticklabelmode'] = 'period'
    layout_args['xaxis']['rangeselector'] = utils.rangeselector_date()

    start = timezone.localtime().strptime('12:00 AM', '%I:%M %p')
    ticks = OrderedDict()
    ticks[0] = start.strftime('%I:%M %p')
    for i in range(0, 60*24, 30):
        ticks[i] = formats.time_format(start + timezone.timedelta(minutes=i),
                                       'TIME_FORMAT')

    layout_args['yaxis']['title'] = _('Time of day')
    layout_args['yaxis']['range'] = [24*60, 0]
    layout_args['yaxis']['tickmode'] = 'array'
    layout_args['yaxis']['tickvals'] = list(ticks.keys())
    layout_args['yaxis']['ticktext'] = list(ticks.values())
    layout_args['yaxis']['tickfont'] = {'size': 10}

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


def _init_days(first_day, last_day):
    period = (last_day.date() - first_day.date()).days + 1
    def new_day(d): return (first_day + timedelta(days=d)).date().isoformat()
    return {new_day(day): [] for day in range(period)}


def _add_adjustment(adjustment, days):
    """
    Adds "adjustment" data for entries that cross midnight.
    :param adjustment: Column, start time, end time, and duration of entry.
    :param blocks: List of days
    """
    column = adjustment.pop('column')
    # Fake (0) entry to keep the color switching logic working.
    days[column].append({'time': 0, 'label': 0})

    # Real adjustment entry.
    days[column].append({
        'time': adjustment['duration'].seconds / 60,
        'label': _format_label(**adjustment)
    })


def _format_label(duration, start_time, end_time):
    """
    Formats a time block label.
    :param duration: Duration.
    :param start_time: Start time.
    :param end_time: End time.
    :return: Formatted string with duration, start, and end time.
    """
    return 'Asleep {} ({} to {})'.format(
                duration_string(duration),
                formats.time_format(start_time, 'TIME_FORMAT'),
                formats.time_format(end_time, 'TIME_FORMAT'))