# Copyright (c) 2017 Egor Tensin <Egor.Tensin@gmail.com>
# This file is part of the "VK scripts" project.
# For details, see https://github.com/egor-tensin/vk-scripts.
# Distributed under the MIT License.

import matplotlib.pyplot as plt
from matplotlib.ticker import AutoLocator, FuncFormatter, MaxNLocator
import numpy as np

class BarChartBuilder:
    _BAR_HEIGHT = .5

    THICK_BAR_HEIGHT = _BAR_HEIGHT
    THIN_BAR_HEIGHT = THICK_BAR_HEIGHT / 2

    def __init__(self, labels_align_middle=True):
        self._fig, self._ax = plt.subplots()
        self.labels_align_middle = labels_align_middle

    def set_title(self, title):
        self._ax.set_title(title)

    def _get_categories_axis(self):
        return self._ax.get_yaxis()

    def _get_values_axis(self):
        return self._ax.get_xaxis()

    def set_categories_axis_limits(self, start=None, end=None):
        self._ax.set_ylim(bottom=start, top=end)

    def set_values_axis_limits(self, start=None, end=None):
        self._ax.set_xlim(left=start, right=end)

    def enable_grid_for_categories(self):
        self._get_categories_axis().grid()

    def enable_grid_for_values(self):
        self._get_values_axis().grid()

    def get_categories_labels(self):
        return self._get_categories_axis().get_ticklabels()

    def get_values_labels(self):
        return self._get_values_axis().get_ticklabels()

    def set_value_label_formatter(self, fn):
        self._get_values_axis().set_major_formatter(FuncFormatter(fn))

    def any_values(self):
        self._get_values_axis().set_major_locator(AutoLocator())

    def only_integer_values(self):
        self._get_values_axis().set_major_locator(MaxNLocator(integer=True))

    @staticmethod
    def set_property(*args, **kwargs):
        plt.setp(*args, **kwargs)

    def _set_size(self, inches, dim=0):
        fig_size = self._fig.get_size_inches()
        assert len(fig_size) == 2
        fig_size[dim] = inches
        self._fig.set_size_inches(fig_size, forward=True)

    def set_width(self, inches):
        self._set_size(inches)

    def set_height(self, inches):
        self._set_size(inches, dim=1)

    def plot_bars(self, categories, values, inches_per_bar=THICK_BAR_HEIGHT):

        numof_bars = len(categories)

        if not numof_bars:
            self.set_height(2 * inches_per_bar)
            self._get_categories_axis().set_tick_params(labelleft=False)
            return []

        categories_axis_min = 0
        categories_axis_max = 2 * inches_per_bar * numof_bars

        self.set_height(categories_axis_max)
        self.set_categories_axis_limits(categories_axis_min, categories_axis_max)

        bar_offsets = 2 * inches_per_bar * np.arange(numof_bars) + inches_per_bar

        if self.labels_align_middle:
            self._get_categories_axis().set_ticks(bar_offsets)
        else:
            self._get_categories_axis().set_ticks(bar_offsets - inches_per_bar)

        self._get_categories_axis().set_ticklabels(categories)

        return self._ax.barh(bar_offsets, values, align='center',
                             height=inches_per_bar)

    @staticmethod
    def show():
        plt.show()

    def save(self, path):
        self._fig.savefig(path, bbox_inches='tight')

if __name__ == '__main__':
    import argparse
    parser = argparse.ArgumentParser()

    parser.add_argument('--categories', nargs='*', default=[],
                        help='categories')
    parser.add_argument('--values', nargs='*', type=float, default=[],
                        help='values')

    parser.add_argument('--output', '-o',
                        help='set output file path')

    parser.add_argument('--middle', action='store_true',
                        dest='labels_align_middle',
                        help='align labels to the middle of the bars')

    parser.add_argument('--integer-values', action='store_true',
                        dest='only_integer_values')
    parser.add_argument('--any-values', action='store_false',
                        dest='only_integer_values')

    parser.add_argument('--grid-categories', action='store_true')
    parser.add_argument('--grid-values', action='store_true')

    args = parser.parse_args()

    if len(args.categories) < len(args.values):
        parser.error('too many bar values')
    if len(args.categories) > len(args.values):
        args.values.extend([0.0] * (len(args.categories) - len(args.values)))

    builder = BarChartBuilder(labels_align_middle=args.labels_align_middle)

    if args.only_integer_values:
        builder.only_integer_values()
    else:
        builder.any_values()

    if args.grid_categories:
        builder.enable_grid_for_categories()
    if args.grid_values:
        builder.enable_grid_for_values()

    builder.plot_bars(args.categories, args.values)

    if args.output is None:
        builder.show()
    else:
        builder.save(args.output)