import cv2
import numpy as np
from skimage.feature.texture import graycomatrix, graycoprops
from skimage.feature import local_binary_pattern, hog

from sklearn.svm import SVC
from sklearn.model_selection import train_test_split, GridSearchCV
from sklearn.metrics import accuracy_score, classification_report, precision_score, confusion_matrix
from sklearn.preprocessing import StandardScaler

def rgb_histogram(image, bins=256):
    hist_features = []
    for i in range(3):
        hist, _ = np.histogram(image[:, :, i], bins=bins, range=(0, 256), density=True)
        hist_features.append(hist)
    return np.concatenate(hist_features)

def hu_moments(image):
    gray = cv2.cvtColor(image, cv2.COLOR_RGB2GRAY)
    moments = cv2.moments(gray)
    hu_moments = cv2.HuMoments(moments).flatten()
    return hu_moments

def glcm_features(image, distances=[1], angles=[0], levels=256, symmetric=True, normed=True):
    gray = cv2.cvtColor(image, cv2.COLOR_RGB2GRAY)
    glcm = graycomatrix(gray, distances=distances, angles=angles, levels=levels, symmetric=symmetric, normed=normed)
    contrast = graycoprops(glcm, 'contrast').flatten()
    dissimilarity = graycoprops(glcm, 'dissimilarity').flatten()
    homogeneity = graycoprops(glcm, 'homogeneity').flatten()
    energy = graycoprops(glcm, 'energy').flatten()
    correlation = graycoprops(glcm, 'correlation').flatten()
    asm = graycoprops(glcm, 'ASM').flatten()
    return np.concatenate([contrast, dissimilarity, homogeneity, energy, correlation, asm])

def local_binary_pattern_features(image, P=8, R=1):
    gray = cv2.cvtColor(image, cv2.COLOR_RGB2GRAY)
    lbp = local_binary_pattern(gray, P, R, method='uniform')
    (hist, _) = np.histogram(lbp.ravel(), bins=np.arange(0, P + 3), range=(0, P + 2), density=True)
    return hist

def extract_features_from_image(image):
    hist_features = rgb_histogram(image, bins=64)
    hu_features = hu_moments(image)
    glcm_features_vector = glcm_features(image)
    lbp_features = local_binary_pattern_features(image)
    gray = cv2.cvtColor(image, cv2.COLOR_RGB2GRAY)
    hog_features = hog(
        gray,
        orientations=8,
        pixels_per_cell=(32, 32),
        cells_per_block=(2, 2),
        visualize=False,
        feature_vector=True
    )
    color_moments_features = []
    for channel in cv2.split(image):
        color_moments_features.append(np.mean(channel))
        color_moments_features.append(np.std(channel))
    color_moments_features = np.array(color_moments_features)
    edges = cv2.Canny(gray, 50, 150)
    edge_density = np.sum(edges > 0) / edges.size
    edge_features = np.array([edge_density])
    image_features = np.concatenate([
        hist_features,
        hu_features,
        glcm_features_vector,
        lbp_features,
        hog_features,
        color_moments_features,
        edge_features
    ])
    return image_features

def perform_pca(data, num_components):
    mean = np.mean(data, axis=0)
    std_dev = np.std(data, axis=0)
    data_standardized = (data - mean) / std_dev
    covariance_matrix = np.cov(data_standardized, rowvar=False)
    eigenvalues, eigenvectors = np.linalg.eig(covariance_matrix)
    sorted_indices = np.argsort(eigenvalues)[::-1]
    sorted_eigenvalues = eigenvalues[sorted_indices]
    sorted_eigenvectors = eigenvectors[:, sorted_indices]
    top_k_eigenvectors = sorted_eigenvectors[:, :num_components]
    data_reduced = np.dot(data_standardized, top_k_eigenvectors)
    data_reduced = np.real(data_reduced)
    return data_reduced

def train_svm_model(features, labels, test_size=0.2, use_grid_search=False, use_precision_optimization=False):
    if labels.ndim > 1 and labels.shape[1] > 1:
        labels = np.argmax(labels, axis=1)
    X_train, X_test, y_train, y_test = train_test_split(
        features, labels, test_size=test_size, random_state=42,
        stratify=labels
    )
    scaler = StandardScaler()
    X_train_scaled = scaler.fit_transform(X_train)
    X_test_scaled = scaler.transform(X_test)
    if use_grid_search:
        print("Grid Search...")
        param_grid = {
            'C': [0.1, 1, 10, 100, 1000],
            'kernel': ['rbf', 'linear', 'poly'],
            'gamma': ['scale', 'auto', 0.001, 0.01, 0.1],
            'class_weight': ['balanced', None],
            'degree': [2, 3, 4]
        }
        svm = SVC(random_state=42, probability=True)
        scoring = 'precision_weighted' if use_precision_optimization else 'accuracy'
        grid_search = GridSearchCV(
            svm, param_grid,
            cv=5,
            scoring=scoring,
            n_jobs=-1,
            verbose=1
        )
        grid_search.fit(X_train_scaled, y_train)
        svm_model = grid_search.best_estimator_
        print(f"\nbest params: {grid_search.best_params_}")
        print(f"   CV Score: {grid_search.best_score_:.4f}")
    else:
        svm_model = SVC(
            kernel='rbf',
            C=10,
            gamma='scale',
            class_weight='balanced',
            random_state=42,
            probability=True
        )
        svm_model.fit(X_train_scaled, y_train)
    y_pred = svm_model.predict(X_test_scaled)
    accuracy = accuracy_score(y_test, y_pred)
    print(f'Test Accuracy: {accuracy:.2f}')
    if use_precision_optimization:
        precision_weighted = precision_score(y_test, y_pred, average='weighted', zero_division=0)
        precision_macro = precision_score(y_test, y_pred, average='macro', zero_division=0)
        print(f'Test Precision (Weighted): {precision_weighted:.4f}')
        print(f'Test Precision (Macro): {precision_macro:.4f}')
        print(f'\nClassification Report:')
        print(classification_report(y_test, y_pred, zero_division=0))
        results = {
            'model': svm_model,
            'scaler': scaler,
            'accuracy': accuracy,
            'precision_weighted': precision_weighted,
            'precision_macro': precision_macro,
            'y_test': y_test,
            'y_pred': y_pred
        }
        if use_grid_search:
            results['best_params'] = grid_search.best_params_
            results['cv_score'] = grid_search.best_score_
        return svm_model, results
    return svm_model