# (C) Copyright 2005-2021 Enthought, Inc., Austin, TX
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD
# license included in LICENSE.txt and may be redistributed only under
# the conditions described in the aforementioned license. The license
# is also available online at http://www.enthought.com/licenses/BSD.txt
#
# Thanks for using Enthought open source!

""" Defines the LabelAxis class.
"""
# Major library imports
from traceback import print_exc
from numpy import array, float64, inf, searchsorted, take, unique

# Enthought library imports
from traits.api import ArrayOrNone, Str, List, Float

# Local, relative imports
from .axis import PlotAxis
from .label import Label


class LabelAxis(PlotAxis):
    """An axis whose ticks are labeled with text instead of numbers."""

    #: List of labels to use on tick marks.
    labels = List(Str)

    #: The angle of rotation of the label.
    label_rotation = Float(0)

    #: List of indices of ticks
    positions = ArrayOrNone()

    def _compute_tick_positions(self, gc, component=None):
        """Calculates the positions for the tick marks.

        Overrides PlotAxis.
        """
        if self.mapper is None:
            self._reset_cache()
            self._cache_valid = True
            return

        datalow = self.mapper.range.low
        datahigh = self.mapper.range.high
        screenhigh = self.mapper.high_pos
        screenlow = self.mapper.low_pos

        if (
            (datalow == datahigh)
            or (screenlow == screenhigh)
            or (datalow in [inf, -inf])
            or (datahigh in [inf, -inf])
        ):
            self._reset_cache()
            self._cache_valid = True
            return

        if not self.tick_generator:
            return

        # Get a set of ticks from the tick generator.
        tick_list = array(
            self.tick_generator.get_ticks(
                datalow, datahigh, datalow, datahigh, self.tick_interval
            ),
            float64,
        )

        # Find all the positions in the current range.
        pos_index = []
        pos = []
        pos_min = None
        pos_max = None
        for i, position in enumerate(self.positions):
            if datalow <= position <= datahigh:
                pos_max = (
                    max(position, pos_max) if pos_max is not None else position
                )
                pos_min = (
                    min(position, pos_min) if pos_min is not None else position
                )
                pos_index.append(i)
                pos.append(position)
        if len(pos_index) == 0:
            # No positions currently visible.
            self._tick_positions = []
            self._tick_label_positions = []
            self._tick_label_list = []
            return

        # Use the ticks generated by the tick generator as a guide for selecting
        # the positions to be displayed.
        tick_indices = unique(searchsorted(pos, tick_list))
        tick_indices = tick_indices[tick_indices < len(pos)]
        tick_positions = take(pos, tick_indices)
        self._tick_label_list = take(
            self.labels, take(pos_index, tick_indices)
        )

        if datalow > datahigh:
            raise RuntimeError(
                "DataRange low is greater than high; unable to compute axis ticks."
            )

        mapped_label_positions = [
            (
                (self.mapper.map_screen(pos) - screenlow)
                / (screenhigh - screenlow)
            )
            for pos in tick_positions
        ]
        self._tick_positions = [
            self._axis_vector * tickpos + self._origin_point
            for tickpos in mapped_label_positions
        ]
        self._tick_label_positions = self._tick_positions

    def _compute_labels(self, gc):
        """Generates the labels for tick marks.

        Overrides PlotAxis.
        """
        try:
            self.ticklabel_cache = []
            for text in self._tick_label_list:
                ticklabel = Label(
                    text=text,
                    font=self.tick_label_font,
                    color=self.tick_label_color,
                    rotate_angle=self.label_rotation,
                )
                self.ticklabel_cache.append(ticklabel)

            self._tick_label_bounding_boxes = [
                array(ticklabel.get_bounding_box(gc), float64)
                for ticklabel in self.ticklabel_cache
            ]
        except:
            print_exc()