"""
=========================================================
Gradio Demo to plot multi-class SGD on the iris dataset
=========================================================

Plot decision surface of multi-class SGD on iris dataset.
The hyperplanes corresponding to the three one-versus-all (OVA) classifiers
are represented by the dashed lines.

Created by Syed Affan <saffand03@gamil.com>

"""

import gradio as gr
import numpy as np
import matplotlib.pyplot as plt
from sklearn import datasets
from sklearn.linear_model import SGDClassifier
from sklearn.inspection import DecisionBoundaryDisplay
import matplotlib.cm

def make_plot(alpha,max_iter,Standardize):
# import some data to play with
    iris = datasets.load_iris()
    fig = plt.figure()

# we only take the first two features. We could
# avoid this ugly slicing by using a two-dim dataset
    X = iris.data[:, :2]
    y = iris.target
    colors = "bry"

# shuffle
    idx = np.arange(X.shape[0])
    np.random.seed(13)
    np.random.shuffle(idx)
    X = X[idx]
    y = y[idx]

# standardize
    if Standardize:
        mean = X.mean(axis=0)
        std = X.std(axis=0)
        X = (X - mean) / std


    clf = SGDClassifier(alpha=alpha, max_iter=max_iter).fit(X, y)
    accuracy = clf.score(X,y)
    acc = f'## The Accuracy on the entire dataset: {accuracy}'
    #fig,ax = subplots()
    ax = plt.gca()
    DecisionBoundaryDisplay.from_estimator(
        clf,
        X,
        cmap=matplotlib.cm.Paired,
        ax=ax,
        response_method="predict",
        xlabel=iris.feature_names[0],
        ylabel=iris.feature_names[1],
    )
    plt.axis("tight")

# Plot also the training points
    for i, color in zip(clf.classes_, colors):
        idx = np.where(y == i)
        plt.scatter(
            X[idx, 0],
            X[idx, 1],
            c=color,
            label=iris.target_names[i],
            cmap=matplotlib.cm.Paired,
            edgecolor="black",
            s=20,
        )
    plt.title("Decision surface of multi-class SGD")
    plt.axis("tight")

# Plot the three one-against-all classifiers
    xmin, xmax = plt.xlim()
    ymin, ymax = plt.ylim()
    coef = clf.coef_
    intercept = clf.intercept_


    def plot_hyperplane(c, color):
        def line(x0):
            return (-(x0 * coef[c, 0]) - intercept[c]) / coef[c, 1]

        plt.plot([xmin, xmax], [line(xmin), line(xmax)], ls="--", color=color)


    for i, color in zip(clf.classes_, colors):
        plot_hyperplane(i, color)
    plt.legend()

    
    return fig,acc

demo = gr.Interface(
    title = 'Plot multi-class SGD on the iris dataset',
    fn = make_plot,
    inputs = [gr.Slider(0.0001,5,step = 0.001,value = 0.001),
        gr.Slider(1,1000,step=10,value=100),
        gr.Checkbox(value=True)],
    outputs = [gr.Plot(),gr.Markdown()]
        ).launch()