# -*- 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.
    """
    feeding_types=[
            'breast milk',
            'formula',
            'fortified breast milk',
            'solid food',
        ]
    feeding_types_desc=[
            'Breast milk',
            'Formula',
            'Fortified breast milk',
            'Solid food',
        ]
    total_idx=len(feeding_types)+1 #+1 for aggregate total
    totals_list=list()
    for i in range(total_idx):
        totals_list.append({})
    for instance in instances:
        end = timezone.localtime(instance.end)
        date = end.date()
        if date not in totals_list[total_idx-1].keys():
            for item in totals_list:
                item[date]=0
        feeding_idx=feeding_types.index(instance.type)
        totals_list[feeding_idx][date]+= instance.amount or 0
        totals_list[total_idx-1][date]+= instance.amount or 0
    zeros = [0 for a in totals_list[total_idx-1].values()]
    
    #sum each feeding type for graph
    amounts_array=[]
    for i in range(total_idx):
        amounts_array.append([round(amount, 2) for amount in totals_list[i].values()])
    
    traces=[]
    for i in range(total_idx-1):
        traces.append(go.Bar(
            name=feeding_types_desc[i],
            x=list(totals_list[total_idx-1].keys()),
            y=amounts_array[i],
            text=amounts_array[i]

        ))

    traces.append(go.Bar(
        name=_('Total'),
        x=list(totals_list[total_idx-1].keys()),
        y=zeros,
        hoverinfo='text',
        textposition='outside',
        text=amounts_array[total_idx-1]
    ))


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