# pylint: disable=unexpected-keyword-arg
"""One-dimensional kernel density estimate plots."""
import warnings

import xarray as xr

from ..data import InferenceData
from ..rcparams import rcParams
from ..stats.density_utils import _fast_kde_2d, kde, _find_hdi_contours
from .plot_utils import get_plotting_function


def plot_kde(
    values,
    values2=None,
    cumulative=False,
    rug=False,
    label=None,
    bw="default",
    adaptive=False,
    quantiles=None,
    rotated=False,
    contour=True,
    hdi_probs=None,
    fill_last=False,
    figsize=None,
    textsize=None,
    plot_kwargs=None,
    fill_kwargs=None,
    rug_kwargs=None,
    contour_kwargs=None,
    contourf_kwargs=None,
    pcolormesh_kwargs=None,
    is_circular=False,
    ax=None,
    legend=True,
    backend=None,
    backend_kwargs=None,
    show=None,
    return_glyph=False,
    **kwargs
):
    """1D or 2D KDE plot taking into account boundary conditions.

    Parameters
    ----------
    values : array-like
        Values to plot
    values2 : array-like, optional
        Values to plot. If present, a 2D KDE will be estimated
    cumulative : bool
        If true plot the estimated cumulative distribution function. Defaults to False.
        Ignored for 2D KDE
    rug : bool
        If True adds a rugplot. Defaults to False. Ignored for 2D KDE
    label : string
        Text to include as part of the legend
    bw: float or str, optional
        If numeric, indicates the bandwidth and must be positive.
        If str, indicates the method to estimate the bandwidth and must be
        one of "scott", "silverman", "isj" or "experimental" when `is_circular` is False
        and "taylor" (for now) when `is_circular` is True.
        Defaults to "default" which means "experimental" when variable is not circular
        and "taylor" when it is.
    adaptive: bool, optional.
        If True, an adaptative bandwidth is used. Only valid for 1D KDE.
        Defaults to False.
    quantiles : list
        Quantiles in ascending order used to segment the KDE.
        Use [.25, .5, .75] for quartiles. Defaults to None.
    rotated : bool
        Whether to rotate the 1D KDE plot 90 degrees.
    contour : bool
        If True plot the 2D KDE using contours, otherwise plot a smooth 2D KDE.
        Defaults to True.
    hdi_probs : list
        Plots highest density credibility regions for the provided probabilities for a 2D KDE.
        Defaults to matplotlib chosen levels with no fixed probability associated.
    fill_last : bool
        If True fill the last contour of the 2D KDE plot. Defaults to False.
    figsize : tuple
        Figure size. If None it will be defined automatically.
    textsize: float
        Text size scaling factor for labels, titles and lines. If None it will be autoscaled based
        on figsize. Not implemented for bokeh backend.
    plot_kwargs : dict
        Keywords passed to the pdf line of a 1D KDE. See :meth:`mpl:matplotlib.axes.Axes.plot`
        or :meth:`bokeh:bokeh.plotting.figure.Figure.line` for a description of accepted values.
    fill_kwargs : dict
        Keywords passed to the fill under the line (use fill_kwargs={'alpha': 0} to disable fill).
        Ignored for 2D KDE
    rug_kwargs : dict
        Keywords passed to the rug plot. Ignored if rug=False or for 2D KDE
        Use `space` keyword (float) to control the position of the rugplot. The larger this number
        the lower the rugplot.
    contour_kwargs : dict
        Keywords passed to ax.contour to draw contour lines. Ignored for 1D KDE.
    contourf_kwargs : dict
        Keywords passed to ax.contourf to draw filled contours. Ignored for 1D KDE.
    pcolormesh_kwargs : dict
        Keywords passed to ax.pcolormesh. Ignored for 1D KDE.
    is_circular : {False, True, "radians", "degrees"}. Default False.
        Select input type {"radians", "degrees"} for circular histogram or KDE plot. If True,
        default input type is "radians". When this argument is present, it interprets `values`
        is a circular variable measured in radians and a circular KDE is used. Inputs in
        "degrees" will undergo an internal conversion to radians.
    ax: axes, optional
        Matplotlib axes or bokeh figures.
    legend : bool
        Add legend to the figure. By default True.
    backend: str, optional
        Select plotting backend {"matplotlib","bokeh"}. Default "matplotlib".
    backend_kwargs: bool, optional
        These are kwargs specific to the backend being used. For additional documentation
        check the plotting method of the backend.
    show : bool, optional
        Call backend show function.
    return_glyph : bool, optional
        Internal argument to return glyphs for bokeh

    Returns
    -------
    axes : matplotlib.Axes or bokeh.plotting.Figure
        Object containing the kde plot
    glyphs : list, optional
        Bokeh glyphs present in plot.  Only provided if ``return_glyph`` is True.

    Examples
    --------
    Plot default KDE

    .. plot::
        :context: close-figs

        >>> import arviz as az
        >>> non_centered = az.load_arviz_data('non_centered_eight')
        >>> mu_posterior = np.concatenate(non_centered.posterior["mu"].values)
        >>> tau_posterior = np.concatenate(non_centered.posterior["tau"].values)
        >>> az.plot_kde(mu_posterior)


    Plot KDE with rugplot

    .. plot::
        :context: close-figs

        >>> az.plot_kde(mu_posterior, rug=True)

    Plot KDE with adaptive bandwidth

    .. plot::
        :context: close-figs

        >>> az.plot_kde(mu_posterior, adaptive=True)

    Plot KDE with a different bandwidth estimator

    .. plot::
        :context: close-figs

        >>> az.plot_kde(mu_posterior, bw="scott")

    Plot KDE with a bandwidth specified manually

    .. plot::
        :context: close-figs

        >>> az.plot_kde(mu_posterior, bw=0.4)

    Plot KDE for a circular variable

    .. plot::
        :context: close-figs

        >>> rvs = np.random.vonmises(mu=np.pi, kappa=2, size=500)
        >>> az.plot_kde(rvs, is_circular=True)


    Plot a cumulative distribution

    .. plot::
        :context: close-figs

        >>> az.plot_kde(mu_posterior, cumulative=True)



    Rotate plot 90 degrees

    .. plot::
        :context: close-figs

        >>> az.plot_kde(mu_posterior, rotated=True)


    Plot 2d contour KDE

    .. plot::
        :context: close-figs

        >>> az.plot_kde(mu_posterior, values2=tau_posterior)


    Plot 2d contour KDE, without filling and contour lines using viridis cmap

    .. plot::
        :context: close-figs

        >>> az.plot_kde(mu_posterior, values2=tau_posterior,
        ...             contour_kwargs={"colors":None, "cmap":plt.cm.viridis},
        ...             contourf_kwargs={"alpha":0});

    Plot 2d contour KDE, set the number of levels to 3.

    .. plot::
        :context: close-figs

        >>> az.plot_kde(
        ...     mu_posterior, values2=tau_posterior,
        ...     contour_kwargs={"levels":3}, contourf_kwargs={"levels":3}
        ... );

    Plot 2d contour KDE with 30%, 60% and 90% HDI contours.

    .. plot::
        :context: close-figs

        >>> az.plot_kde(mu_posterior, values2=tau_posterior, hdi_probs=[0.3, 0.6, 0.9])

    Plot 2d smooth KDE

    .. plot::
        :context: close-figs

        >>> az.plot_kde(mu_posterior, values2=tau_posterior, contour=False)

    See Also
    --------
    plot_kde : Compute and plot a kernel density estimate.

    """
    if isinstance(values, xr.Dataset):
        raise ValueError(
            "Xarray dataset object detected.Use plot_posterior, plot_density, plot_joint"
            "or plot_pair instead of plot_kde"
        )
    if isinstance(values, InferenceData):
        raise ValueError(
            " Inference Data object detected. Use plot_posterior "
            "or plot_pair instead of plot_kde"
        )

    if values2 is None:

        if bw == "default":
            if is_circular:
                bw = "taylor"
            else:
                bw = "experimental"

        grid, density = kde(values, is_circular, bw=bw, adaptive=adaptive, cumulative=cumulative)
        lower, upper = grid[0], grid[-1]

        if cumulative:
            density_q = density
        else:
            density_q = density.cumsum() / density.sum()

        # This is just a hack placeholder for now
        xmin, xmax, ymin, ymax, gridsize = [None] * 5
    else:
        gridsize = (128, 128) if contour else (256, 256)
        density, xmin, xmax, ymin, ymax = _fast_kde_2d(values, values2, gridsize=gridsize)

        if hdi_probs is not None:
            # Check hdi probs are within bounds (0, 1)
            if min(hdi_probs) <= 0 or max(hdi_probs) >= 1:
                raise ValueError("Highest density interval probabilities must be between 0 and 1")

            # Calculate contour levels and sort for matplotlib
            contour_levels = _find_hdi_contours(density, hdi_probs)
            contour_levels.sort()

            contour_level_list = [0] + list(contour_levels) + [density.max()]

            # Add keyword arguments to contour, contourf
            if contour_kwargs is None:
                contour_kwargs = {"levels": contour_level_list}
            else:
                if "levels" in contour_kwargs:
                    warnings.warn(
                        "Both 'levels' in contour_kwargs and 'hdi_probs' have been specified."
                        "Using 'hdi_probs' in favor of 'levels'.",
                        UserWarning,
                    )
                contour_kwargs["levels"] = contour_level_list

            if contourf_kwargs is None:
                contourf_kwargs = {"levels": contour_level_list}
            else:
                if "levels" in contourf_kwargs:
                    warnings.warn(
                        "Both 'levels' in contourf_kwargs and 'hdi_probs' have been specified."
                        "Using 'hdi_probs' in favor of 'levels'.",
                        UserWarning,
                    )
                contourf_kwargs["levels"] = contour_level_list

        lower, upper, density_q = [None] * 3

    kde_plot_args = dict(
        # Internal API
        density=density,
        lower=lower,
        upper=upper,
        density_q=density_q,
        xmin=xmin,
        xmax=xmax,
        ymin=ymin,
        ymax=ymax,
        gridsize=gridsize,
        # User Facing API that can be simplified
        values=values,
        values2=values2,
        rug=rug,
        label=label,
        quantiles=quantiles,
        rotated=rotated,
        contour=contour,
        fill_last=fill_last,
        figsize=figsize,
        textsize=textsize,
        plot_kwargs=plot_kwargs,
        fill_kwargs=fill_kwargs,
        rug_kwargs=rug_kwargs,
        contour_kwargs=contour_kwargs,
        contourf_kwargs=contourf_kwargs,
        pcolormesh_kwargs=pcolormesh_kwargs,
        is_circular=is_circular,
        ax=ax,
        legend=legend,
        backend_kwargs=backend_kwargs,
        show=show,
        return_glyph=return_glyph,
        **kwargs,
    )

    if backend is None:
        backend = rcParams["plot.backend"]
    backend = backend.lower()

    # TODO: Add backend kwargs
    plot = get_plotting_function("plot_kde", "kdeplot", backend)
    ax = plot(**kde_plot_args)

    return ax
