# (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 DataView class, and associated property traits and property
functions.
"""
from numpy import array, transpose

from traits.api import Bool, Enum, Instance, Property
from enable.api import color_table

from .abstract_overlay import AbstractOverlay
from .axis import PlotAxis
from .base_1d_mapper import Base1DMapper
from .base_2d_plot import Base2DPlot
from .data_range_2d import DataRange2D
from .grid import PlotGrid
from .linear_mapper import LinearMapper
from .log_mapper import LogMapper
from .plot_containers import OverlayPlotContainer


# -----------------------------------------------------------------------------
# Define new traits to condense the definition of some convenience
# properties in the Plot class
# -----------------------------------------------------------------------------


def get_mapper(self, attr_name):
    """Getter function used by OrientedMapperProperty."""
    if (attr_name, self.orientation) in [("x_mapper", "h"), ("y_mapper", "v")]:
        return self.index_mapper
    else:
        return self.value_mapper


def set_mapper(self, attr_name, new):
    """Setter function used by OrientedMapperProperty."""
    if (attr_name, self.orientation) in [("x_mapper", "h"), ("y_mapper", "v")]:
        self.index_mapper = new
    else:
        self.value_mapper = new


# Property that represents a mapper for an orientation.
OrientedMapperProperty = Property(get_mapper, set_mapper)


def get_axis(self, attr_name):
    """Getter function used by AxisProperty."""
    if (attr_name, self.orientation) in [
        ("index_axis", "h"),
        ("value_axis", "v"),
    ]:
        return self.x_axis
    else:
        return self.y_axis


def set_axis(self, attr_name, new):
    """Setter function used by AxisProperty."""
    if (attr_name, self.orientation) in [
        ("index_axis", "h"),
        ("value_axis", "v"),
    ]:
        self.x_axis = new
    else:
        self.y_axis = new


# Property that represents an axis.
AxisProperty = Property(get_axis, set_axis)


def get_grid(self, attr_name):
    """Getter function used by GridProperty."""
    if (attr_name, self.orientation) in [
        ("index_grid", "v"),
        ("value_grid", "h"),
    ]:
        return self.y_grid
    else:
        return self.x_grid


def set_grid(self, attr_name, new):
    """Setter function used by GridProperty."""
    if (attr_name, self.orientation) in [
        ("index_grid", "v"),
        ("value_grid", "h"),
    ]:
        self.y_grid = new
    else:
        self.y_grid = new


# Property that represents a grid for a particular orientation.
GridProperty = Property(get_grid, set_grid)


class DataView(OverlayPlotContainer):
    """Represents a mapping from 2-D data space into 2-D screen space.

    It can house renderers and other plot components, and otherwise behaves
    just like a normal PlotContainer.
    """

    #: The orientation of the index axis.
    orientation = Enum("h", "v")

    #: The default location of the origin  for new plots
    default_origin = Enum(
        "bottom left", "top left", "bottom right", "top right"
    )

    #: The origin reported to axes, etc
    origin = Property(observe="default_origin")

    # Whether our map_screen and map_data should treat screen-space
    # coords as being in our coordinate space or in our contained
    # coordinate space.

    #: The mapper to use for the index data.
    index_mapper = Instance(Base1DMapper)

    #: The mapper to use for value data.
    value_mapper = Instance(Base1DMapper)

    #: For x-y plots, the scale of the index axis.
    index_scale = Enum("linear", "log")

    #: For x-y plots, the scale of the index axis.
    value_scale = Enum("linear", "log")

    #: The range used for the index data.
    index_range = Property

    #: The range used for the value data.
    value_range = Property

    #: The 2-D data range whose x- and y-ranges are exposed as the
    #: **index_range** and **value_range** property traits. This allows
    #: supporting both XY plots and 2-D (image) plots.
    range2d = Instance(DataRange2D)

    #: Convenience property that offers access to whatever mapper corresponds
    #: to the X-axis.
    x_mapper = OrientedMapperProperty

    #: Convenience property that offers access to whatever mapper corresponds
    #: to the Y-axis
    y_mapper = OrientedMapperProperty

    # ------------------------------------------------------------------------
    # Axis and Grids
    # ------------------------------------------------------------------------

    #: The horizontal axis.  Its position relative to the plot
    #: area can be "top", "bottom", or "float".  The default position for a new
    #: x-axis is "bottom".
    #:
    #: TODO: For now, this is an instance of AbstractOverlay instead of PlotAxis
    #: because scales_axis.PlotAxis doesn't inherit from PlotAxis, but instead is a
    #: semi-reimplementation.  Thus, rather than making scales_axis.PlotAxis
    #: inherit a concrete class, I chose to loosen this trait by specifying
    #: a more general base class of PlotAxis.  This incurs lower risk of subtle
    #: and difficult-to-catch bugs being introduced by changes to the
    #: axis.PlotAxis class.  This same comment applies to the y_axis trait
    #: below.  --pwang
    #:x_axis = Instance(PlotAxis)
    x_axis = Instance(AbstractOverlay)

    #: The vertical axis.  Its position relative to the plot
    #: area can be "left", "right", or "float".  The default position for a new
    #: y-axis is "left".
    #:y_axis = Instance(PlotAxis)
    y_axis = Instance(AbstractOverlay)

    #: The grid that intersects the x-axis, i.e., a set of vertical lines.
    x_grid = Instance(PlotGrid)

    #: The grid that intersects the y-axis, i.e., a set of horizontal lines.
    y_grid = Instance(PlotGrid)

    #: Whether to automatically create the x_axis and y_axis if they were not
    #: already set by the caller.
    auto_axis = Bool(True)

    #: Whether to automatically create the x_grid and y_grid if they were not
    #: already set by the caller.
    auto_grid = Bool(True)

    #: Convenience property for accessing the index axis, which can be X or Y,
    #: depending on **orientation**.
    index_axis = AxisProperty
    #: Convenience property for accessing the value axis, which can be Y or X,
    #: depending on **orientation**.
    value_axis = AxisProperty
    #: Convenience property for accessing the index grid, which can be horizontal
    #: or vertical, depending on **orientation**.
    index_grid = GridProperty
    #: Convenience property for accessing the value grid, which can be vertical
    #: or horizontal, depending on **orientation**.
    value_grid = GridProperty

    # ------------------------------------------------------------------------
    # Appearance
    # ------------------------------------------------------------------------

    #: Background color (overrides Enable Component)
    bgcolor = "white"

    #: Padding defaults.
    padding_top = 50
    padding_bottom = 50
    padding_left = 50
    padding_right = 50

    border_visible = True

    # ------------------------------------------------------------------------
    # Public methods
    # ------------------------------------------------------------------------

    def __init__(self, **kwtraits):
        super().__init__(**kwtraits)
        self._init_components()

        # If we are not resizable, we will not get a bounds update upon layout,
        # so we have to manually update our mappers
        if self.resizable == "":
            self._update_mappers()

    def map_screen(self, data_array):
        """Maps an array of data points to screen space and returns an array
        of screen space points.
        """
        # data_array is Nx2 array
        if len(data_array) == 0:
            return []
        x_ary, y_ary = transpose(data_array)
        sx = self.index_mapper.map_screen(x_ary)
        sy = self.value_mapper.map_screen(y_ary)
        if self.orientation == "h":
            return transpose(array((sx, sy)))
        else:
            return transpose(array((sy, sx)))

    def map_data(self, screen_pt):
        """Maps a screen space point into the 2D data space of this plot.
        (Note that this differs from the BaseXYPlot implementation, which by
        default only maps into the 1D index space.)
        """
        # At some point it would be good to change the DataView to use
        # the GridMapper, and then use its map_data() method.
        x, y = screen_pt
        return array(
            (self.index_mapper.map_data(x), self.value_mapper.map_data(y))
        )

    # ------------------------------------------------------------------------
    # Private methods
    # ------------------------------------------------------------------------

    def _init_components(self):
        # Since this is called after the HasTraits constructor, we have to make
        # sure that we don't blow away any components that the caller may have
        # already set.

        if not self.range2d:
            self.range2d = DataRange2D()

        if not self.index_mapper:
            if self.index_scale == "linear":
                imap = LinearMapper(range=self.range2d.x_range)
            else:
                imap = LogMapper(range=self.range2d.x_range)
            self.index_mapper = imap

        if not self.value_mapper:
            if self.value_scale == "linear":
                vmap = LinearMapper(range=self.range2d.y_range)
            else:
                vmap = LogMapper(range=self.range2d.y_range)
            self.value_mapper = vmap

        # make sure the grid and bgcolor are not the same color

        grid_color = "lightgray"
        if color_table[self.bgcolor] == color_table[grid_color]:
            grid_color = "white"

        if not self.x_grid and self.auto_grid:
            self.x_grid = PlotGrid(
                mapper=self.x_mapper,
                orientation="vertical",
                line_color=grid_color,
                line_style="dot",
                component=self,
            )
        if not self.y_grid and self.auto_grid:
            self.y_grid = PlotGrid(
                mapper=self.y_mapper,
                orientation="horizontal",
                line_color=grid_color,
                line_style="dot",
                component=self,
            )

        if not self.x_axis and self.auto_axis:
            self.x_axis = PlotAxis(
                mapper=self.x_mapper, orientation="bottom", component=self
            )

        if not self.y_axis and self.auto_axis:
            self.y_axis = PlotAxis(
                mapper=self.y_mapper, orientation="left", component=self
            )

    # -------------------------------------------------------------------------
    # Event handlers
    # -------------------------------------------------------------------------

    def _update_mappers(self):

        x = self.x
        x2 = self.x2
        y = self.y
        y2 = self.y2

        if self.x_mapper is not None:
            if "left" in self.origin:
                self.x_mapper.low_pos = x
                self.x_mapper.high_pos = x2
            else:
                self.x_mapper.low_pos = x2
                self.x_mapper.high_pos = x

        if self.y_mapper is not None:
            if "bottom" in self.origin:
                self.y_mapper.low_pos = y
                self.y_mapper.high_pos = y2
            else:
                self.y_mapper.low_pos = y2
                self.y_mapper.high_pos = y

        self.invalidate_draw()

    def _bounds_changed(self, old, new):
        super()._bounds_changed(old, new)
        self._update_mappers()

    def _bounds_items_changed(self, event):
        super()._bounds_items_changed(event)
        self._update_mappers()

    def _position_changed(self, old, new):
        super()._position_changed(old, new)
        self._update_mappers()

    def _position_items_changed(self, event):
        super()._position_items_changed(event)
        self._update_mappers()

    def _origin_changed(self):
        self._update_mappers()

    def _orientation_changed(self):
        # Change our grid and axis mappers so that they correspond to the
        # new mapper configuration.  Using the self.x_mapper and self.y_mapper
        # properties will grab the correct mappers corresponding to our new
        # orientation.
        if self.x_grid is not None:
            self.x_grid.mapper = self.x_mapper
        if self.y_grid is not None:
            self.y_grid.mapper = self.y_mapper
        if self.x_axis is not None:
            self.x_axis.mapper = self.x_mapper
        if self.y_axis is not None:
            self.y_axis.mapper = self.y_mapper
        self._update_mappers()
        for renderer in self.components:
            if hasattr(renderer, "orientation"):
                renderer.orientation = self.orientation

    def _index_mapper_changed(self, old, new):
        if new is not None:
            if new.range is not None:
                # Add the range's datasources to our range
                for source in new.range.sources:
                    self.index_range.add(source)
            new.range = self.index_range
        if self.index_axis:
            self.index_axis.mapper = new
        if self.index_grid:
            self.index_grid.mapper = new

    def _value_mapper_changed(self, old, new):
        if new is not None:
            if new.range is not None:
                # Add the range's datasources to our range
                for source in new.range.sources:
                    self.value_range.add(source)
            new.range = self.value_range
        if self.value_axis:
            self.value_axis.mapper = new
        if self.value_grid:
            self.value_grid.mapper = new

    def _bgcolor_changed(self):
        self.invalidate_draw()

    def _x_grid_changed(self, old, new):
        self._underlay_change_helper(old, new)

    def _y_grid_changed(self, old, new):
        self._underlay_change_helper(old, new)

    def _x_axis_changed(self, old, new):
        self._underlay_change_helper(old, new)

    def _y_axis_changed(self, old, new):
        self._underlay_change_helper(old, new)

    def _underlay_change_helper(self, old, new):
        if old in self.underlays:
            self.underlays.remove(old)
        if new is not None:
            self.underlays.append(new)

    def _overlay_change_helper(self, old, new):
        if old in self.overlays:
            self.overlays.remove(old)
        if new is not None:
            self.overlays.append(new)

    def _range2d_changed(self, old, new):
        if new is not None:
            if self.index_mapper is not None:
                self.index_mapper.range = new.x_range
            if self.value_mapper is not None:
                self.value_mapper.range = new.y_range
        else:
            self.index_mapper.range = None
            self.value_mapper.range = None
        if old is not None:
            for datasource in old.sources[:]:
                old.remove(datasource)
                if new is not None:
                    new.add(datasource)
        for renderer in self.components:
            if hasattr(renderer, "range2d"):
                renderer.range2d = new
            elif isinstance(renderer, Base2DPlot):
                renderer.index_range = new
            else:
                if hasattr(renderer, "index_range"):
                    setattr(renderer, "index_range", self.index_range)
                if hasattr(renderer, "value_range"):
                    setattr(renderer, "value_range", self.value_range)

    def _range2d_default(self):
        """ Default trait initializer for the range2d trait """
        return DataRange2D()

    # ------------------------------------------------------------------------
    # Property getters and setters
    # ------------------------------------------------------------------------

    def _get_index_range(self):
        return self.range2d.x_range

    def _set_index_range(self, newrange):
        self._handle_range_changed("index", self.range2d.x_range, newrange)
        self.range2d.x_range = newrange

    def _get_value_range(self):
        return self.range2d.y_range

    def _set_value_range(self, newrange):
        self._handle_range_changed("value", self.range2d.y_range, newrange)
        self.range2d.y_range = newrange

    def _handle_range_changed(self, name, old, new):
        mapper = getattr(self, name + "_mapper")
        if mapper.range == old:
            mapper.range = new
        if old is not None:
            for datasource in old.sources[:]:
                old.remove(datasource)
                if new is not None:
                    new.add(datasource)
        range_name = name + "_range"
        for renderer in self.components:
            if hasattr(renderer, range_name):
                setattr(renderer, range_name, new)

    def _get_origin(self):
        # FIXME:
        return self.default_origin