import numpy as np
import matplotlib.pyplot as plt
import os
from glob import glob
from tqdm import tqdm
import sys

def Hbeta(D=np.array([]), beta=1.0):
    """
    Compute the perplexity and the P-row for a specific value of the
    precision of a Gaussian distribution.
    
    Args:
        D (numpy.ndarray): Distance array.
        beta (float): Precision of the Gaussian distribution.
        
    Returns:
        tuple: A tuple containing perplexity (H) and the P-row (P).
    """
    P = np.exp(-D.copy() * beta)
    sumP = sum(P)
    H = np.log(sumP) + beta * np.sum(D * P) / sumP
    P = P / sumP
    return H, P


def pca(X=np.array([]), no_dims=50):
    # Runs PCA on the NxD array X in order to reduce its dimensionality to no_dims dimensions.
    (n, d) = X.shape
    X = X - np.tile(np.mean(X, 0), (n, 1))
    (l, M) = np.linalg.eig(np.dot(X.T, X))
    Y = np.dot(X, M[:, 0:no_dims])
    return Y


def x2p(X=np.array([]), tol=1e-5, perplexity=30.0):
    """
        Performs a binary search to get P-values in such a way that each
        conditional Gaussian has the same perplexity.
    """
    (n, d) = X.shape
    sum_X = np.sum(np.square(X), 1)
    D = np.add(np.add(-2 * np.dot(X, X.T), sum_X).T, sum_X)
    P = np.zeros((n, n))
    beta = np.ones((n, 1))
    logU = np.log(perplexity)

    # Loop over all datapoints
    for i in range(n):
        if i % 100 == 0:
            print("Computing P-values for point %d of %d..." % (i, n))

        # Compute the Gaussian kernel and entropy for the current precision
        betamin = -np.inf
        betamax = np.inf
        Di = D[i, np.concatenate((np.r_[0:i], np.r_[i+1:n]))]
        (H, thisP) = Hbeta(Di, beta[i])

        # Evaluate whether the perplexity is within tolerance
        Hdiff = H - logU
        tries = 0
        while np.abs(Hdiff) > tol and tries < 50:
            # If not, increase or decrease precision
            if Hdiff > 0:
                betamin = beta[i].copy()
                if betamax == np.inf or betamax == -np.inf:
                    beta[i] = beta[i] * 2.
                else:
                    beta[i] = (beta[i] + betamax) / 2.
            else:
                betamax = beta[i].copy()
                if betamin == np.inf or betamin == -np.inf:
                    beta[i] = beta[i] / 2.
                else:
                    beta[i] = (beta[i] + betamin) / 2.

            # Recompute the values
            (H, thisP) = Hbeta(Di, beta[i])
            Hdiff = H - logU
            tries += 1

        # Set the final row of P
        P[i, np.concatenate((np.r_[0:i], np.r_[i+1:n]))] = thisP

    # Return final P-matrix
    print("Mean value of sigma: %f" % np.mean(np.sqrt(1 / beta)))
    return P


def tsne(X=np.array([]), no_dims=2, initial_dims=50, perplexity=30.0):
    """
        Runs t-SNE on the dataset in the NxD array X to reduce its
        dimensionality to no_dims dimensions. The syntaxis of the function is
        `Y = tsne.tsne(X, no_dims, perplexity), where X is an NxD NumPy array.
    """

    if isinstance(no_dims, float):
        print("Error: array X should have type float.")
        return -1
    if round(no_dims) != no_dims:
        print("Error: number of dimensions should be an integer.")
        return -1

    X = pca(X, initial_dims).real
    (n, d) = X.shape
    max_iter = 1000
    initial_momentum = 0.5
    final_momentum = 0.8
    eta = 500
    min_gain = 0.01
    Y = np.random.randn(n, no_dims)
    dY = np.zeros((n, no_dims))
    iY = np.zeros((n, no_dims))
    gains = np.ones((n, no_dims))

    # Compute P-values
    P = x2p(X, 1e-5, perplexity)
    P = P + np.transpose(P)
    P = P / np.sum(P)
    P = P * 4.
    P = np.maximum(P, 1e-12)

    for iter in range(max_iter):
        # Compute pairwise affinities
        sum_Y = np.sum(np.square(Y), 1)
        num = -2. * np.dot(Y, Y.T)
        num = 1. / (1. + np.add(np.add(num, sum_Y).T, sum_Y)) #
        num[range(n), range(n)] = 0.
        Q = num / np.sum(num)
        Q = np.maximum(Q, 1e-12)

        # Compute gradient
        PQ = P - Q
        for i in range(n):
            dY[i, :] = np.sum(np.tile(PQ[:, i] * num[:, i], (no_dims, 1)).T * (Y[i, :] - Y), 0)

        # Perform the update
        if iter < 20:
            momentum = initial_momentum
        else:
            momentum = final_momentum
        gains = (gains + 0.2) * ((dY > 0.) != (iY > 0.)) + \
                (gains * 0.8) * ((dY > 0.) == (iY > 0.))
        gains[gains < min_gain] = min_gain
        iY = momentum * iY - eta * (gains * dY)
        Y = Y + iY
        Y = Y - np.tile(np.mean(Y, 0), (n, 1))

        # Compute current value of cost function
        if (iter + 1) % 10 == 0:
            C = np.sum(P * np.log(P / Q))
            print("Iteration %d: error is %f" % (iter + 1, C))
        if iter == 100:
            P = P / 4.

    return Y


import numpy as np
import matplotlib.pyplot as plt
import os
from glob import glob
from tqdm import tqdm
import sys

def Hbeta(D=np.array([]), beta=1.0):
    """
    Compute the perplexity and the P-row for a specific value of the
    precision of a Gaussian distribution.
    
    Args:
        D (numpy.ndarray): Distance array.
        beta (float): Precision of the Gaussian distribution.
        
    Returns:
        tuple: A tuple containing perplexity (H) and the P-row (P).
    """
    # Compute P-row and corresponding perplexity
    P = np.exp(-D.copy() * beta)
    sumP = np.sum(P)
    H = np.log(sumP) + beta * np.sum(D * P) / sumP
    P = P / sumP
    return H, P


def pca(X=np.array([]), no_dims=50):
    """
    Performs PCA on the NxD array X to reduce its dimensionality to no_dims dimensions.
    
    Args:
        X (numpy.ndarray): Input data array.
        no_dims (int): Number of dimensions to reduce to.
        
    Returns:
        numpy.ndarray: The reduced data array.
    """
    (n, d) = X.shape
    X = X - np.tile(np.mean(X, axis=0), (n, 1))
    (l, M) = np.linalg.eig(np.dot(X.T, X))
    Y = np.dot(X, M[:, 0:no_dims])
    return Y


def x2p(X=np.array([]), tol=1e-5, perplexity=30.0):
    """
    Performs a binary search to get P-values such that each
    conditional Gaussian has the same perplexity.
    
    Args:
        X (numpy.ndarray): Input data array.
        tol (float): Tolerance for the perplexity.
        perplexity (float): Desired perplexity.
        
    Returns:
        numpy.ndarray: The P-values matrix.
    """
    (n, d) = X.shape
    sum_X = np.sum(np.square(X), axis=1)
    D = np.add(np.add(-2 * np.dot(X, X.T), sum_X).T, sum_X)
    P = np.zeros((n, n))
    beta = np.ones((n, 1))
    logU = np.log(perplexity)

    # Loop over all data points
    for i in range(n):
        if i % 100 == 0:
            print(f"Computing P-values for point {i} of {n}...")

        # Compute the Gaussian kernel and entropy for the current precision
        betamin = -np.inf
        betamax = np.inf
        Di = D[i, np.concatenate((np.r_[0:i], np.r_[i+1:n]))]
        (H, thisP) = Hbeta(Di, beta[i])

        # Evaluate whether the perplexity is within tolerance
        Hdiff = H - logU
        tries = 0
        while np.abs(Hdiff) > tol and tries < 50:
            # If not, adjust precision
            if Hdiff > 0:
                betamin = beta[i].copy()
                if betamax in [np.inf, -np.inf]:
                    beta[i] *= 2
                else:
                    beta[i] = (beta[i] + betamax) / 2
            else:
                betamax = beta[i].copy()
                if betamin in [np.inf, -np.inf]:
                    beta[i] /= 2
                else:
                    beta[i] = (beta[i] + betamin) / 2

            # Recompute the values
            (H, thisP) = Hbeta(Di, beta[i])
            Hdiff = H - logU
            tries += 1

        # Set the final row of P
        P[i, np.concatenate((np.r_[0:i], np.r_[i+1:n]))] = thisP

    print("Mean value of sigma: %f" % np.mean(np.sqrt(1 / beta)))
    return P


def tsne(X=np.array([]), no_dims=2, initial_dims=50, perplexity=30.0):
    """
    Runs t-SNE on the dataset in the NxD array X to reduce its
    dimensionality to no_dims dimensions.

    Args:
        X (numpy.ndarray): Input data array.
        no_dims (int): Number of dimensions to reduce to.
        initial_dims (int): Number of initial dimensions.
        perplexity (float): Desired perplexity.
        
    Returns:
        numpy.ndarray: The reduced data array.
    """
    if isinstance(no_dims, float):
        print("Error: array X should have type float.")
        return -1
    if round(no_dims) != no_dims:
        print("Error: number of dimensions should be an integer.")
        return -1

    X = pca(X, initial_dims).real
    (n, d) = X.shape
    max_iter = 1000
    initial_momentum = 0.5
    final_momentum = 0.8
    eta = 500
    min_gain = 0.01
    Y = np.random.randn(n, no_dims)
    dY = np.zeros((n, no_dims))
    iY = np.zeros((n, no_dims))
    gains = np.ones((n, no_dims))

    # Compute P-values
    P = x2p(X, 1e-5, perplexity)
    P = P + np.transpose(P)  # Ensure symmetry
    P = P / np.sum(P)  # Normalize
    P = P * 4.  # Early exaggeration
    P = np.maximum(P, 1e-12)  # Avoid numerical issues

    for iter in range(max_iter):
        # Compute pairwise affinities
        sum_Y = np.sum(np.square(Y), axis=1)
        num = -2. * np.dot(Y, Y.T)
        num = 1. / (1. + np.add(np.add(num, sum_Y).T, sum_Y))
        num[np.arange(n), np.arange(n)] = 0.  # Avoid self-affinity
        Q = num / np.sum(num)
        Q = np.maximum(Q, 1e-12)  # Avoid numerical issues

        # Compute gradient
        PQ = P - Q
        for i in range(n):
            dY[i, :] = np.sum(np.tile(PQ[:, i] * num[:, i], (no_dims, 1)).T * (Y[i, :] - Y), axis=0)

        # Perform the update
        momentum = initial_momentum if iter < 20 else final_momentum
        gains = (gains + 0.2) * ((dY > 0.) != (iY > 0.)) + (gains * 0.8) * ((dY > 0.) == (iY > 0.))
        gains[gains < min_gain] = min_gain
        iY = momentum * iY - eta * (gains * dY)
        Y = Y + iY
        Y -= np.tile(np.mean(Y, axis=0), (n, 1))  # Center the data

        # Compute current value of cost function
        if (iter + 1) % 10 == 0:
            C = np.sum(P * np.log(P / Q))
            print(f"Iteration {iter + 1}: error is {C:.6f}")
        if iter == 100:
            P /= 4.  # Decrease early exaggeration

    return Y


if __name__ == '__main__':
    
    task = sys.argv[2]
    if sys.argv[1] == "gnss":
        task_class = {0: 3, 1: 5, 2: 7, 3: 9, 4: 11}
        colors = {0: "#1f77b4", 1: "#ff7f0e", 2: "#2ca02c", 3: "#d62728", 
                  4: "#9467bd", 5: "#8c564b", 6: "#e377c2", 7: "#7f7f7f", 
                  8: "#bcbd22", 9: "#17becf", 10: "#000000"}
    elif sys.argv[1] == "cifar":
        task_class = {0: 4, 1: 6, 2: 8, 3: 10}
        colors = {0: "#1f77b4", 1: "#ff7f0e", 2: "#2ca02c", 3: "#d62728", 
                  4: "#9467bd", 5: "#8c564b", 6: "#e377c2", 7: "#7f7f7f", 
                  8: "#bcbd22", 9: "#17becf"}
    else:
        raise Exception("Please provide the name of the dataset.")

    # Load embeddings and ground truth of a task
    emb_file = f"embeddings_{task}.npy"  
    ground_truth_file = f"predictions_{task}_tr_pr.npy"  
    points = np.load(emb_file)
    ground_truth = np.load(ground_truth_file)
    size = points.shape[1]
    labels = ground_truth[:, 0]

    # Check if t-SNE embeddings are already computed
    tsne_file = f"tsne_embeddings/emb_tsne_{task}.npy"
    if not os.path.isfile(tsne_file):
        tsne_embs = tsne(points, 2, size, 30.0)
        np.save(tsne_file, tsne_embs)

    tsne_embs = np.load(tsne_file, allow_pickle=True)
    x = tsne_embs
    print('t-SNE embeddings shape:', x.shape)
    y = labels
    colors_list = [colors[cy] for cy in y]

    # Plotting the t-SNE results
    plt.figure(figsize=(5, 4))
    for key, val in colors.items():
        if key == task_class[int(task)]:
            break
        cur_x = x[y == key]
        plt.scatter(cur_x[:, 0], cur_x[:, 1], s=8, color=val, label=f"Class: {key}")

    # Add legend and save the plot
    plt.legend(fontsize=10, loc="lower left", ncol=2, labelspacing=0.03, columnspacing=0.03,
               handletextpad=0.03)
    plt.tight_layout()
    plt.xticks([], [])
    plt.yticks([], [])
    plt.savefig(f"tsne_plots/tsne_{task}.pdf", dpi=1200)
    plt.close()