# -*- coding: utf-8 -*-
""" Controllers for building graphs using pandas library

"""
import base64
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt

from datetime import datetime
from gluon.storage import Storage
from graph_tools import (do_labels,
                         do_linechart,
                         do_stackedchart,
                         do_title,
                         savefig)
from pandas import DataFrame
from plugin_dbui import Selector
from reporting_tools import repr_team_project


TITLE_Y = "Number of publications"


def dashboard():
    """Return a pre-configure linechart for public used.
    Cumulative distribution for the publications are shown for
    the current year.

    """
    cfg = Storage()
    cfg.Graph_selectorCumulative = 'True'
    cfg.Graph_selectorId = ''
    cfg.Graph_selectorId_authors_roles = ''
    cfg.Graph_selectorId_graphs = ''
    cfg.Graph_selectorId_projects = ''
    cfg.Graphs_selectorId_teams = ''
    cfg.Graph_selectorTime = T('month')
    cfg.Graph_selectorYear_start = datetime.now().year
    cfg.Graph_selectorYear_end = ''

    request.vars.update(cfg)

    fields = ('cumulative','id_graphs', 'time', 'year_start','year_end')
    selector = Selector(virtdb.graph_selector, exclude_fields=fields)

    # figure layout
    fig, axes = plt.subplots(nrows=1, ncols=2, sharey=True)
    fig.subplots_adjust(wspace=0.1)

    # the cumulative sum of publications for the current year
    do_linechart(db.publications, selector, target=axes[0])
    do_labels(axes[0], "", T(TITLE_Y))

    # histogram of the number of publications per year
    selector.cumulative = False
    selector.time = T('year')
    selector.year_start = ''

    do_linechart(db.publications, selector, target=axes[1])
    do_labels(axes[1], "", "")

    # delegate the rendering to the view
    response.view = "graphs/index.html"
    return dict(data=savefig(fig, "svg"))


def index():
    """Generate graph showing the number of publication per month / year
    either as a linechart or as a stacked histograms.

    """
    fields = ('cumulative','id_graphs', 'time', 'year_start','year_end')
    selector = Selector(virtdb.graph_selector, exclude_fields=fields)

    # graph configuration
    graph = db.graphs[selector.id_graphs]

    # stacked chart
    if graph.stack_axis:
        ax = do_stackedchart(db.publications, selector, graph)

    # line char
    else:
        ax = do_linechart(db.publications, selector)

    do_labels(ax, "", T(TITLE_Y))
    do_title(ax, db, selector)

    # delegate the rendering to the view
    extension = request.extension
    fmt = "svg" if extension == "html" else extension

    # base64 string encoding
    data = savefig(ax.get_figure(), fmt)
    if fmt in ("pdf", "png"):
        data = base64.b64encode(data)

    return dict(data=data)