# -*- coding: utf-8 -*-
"""
Created on Sat May 18 16:15:32 2024
@author: litav
"""


import numpy as np
import tensorflow as tf
import random
import os
import pandas as pd
import cv2
import matplotlib.pyplot as plt
from sklearn.model_selection import KFold
from tensorflow.keras.layers import Dense, Conv2D, MaxPooling2D, Flatten
from tensorflow.keras.optimizers import Adam
from tensorflow.keras.models import Sequential
from sklearn.metrics import accuracy_score, confusion_matrix, ConfusionMatrixDisplay
from tensorflow.keras.layers import Dropout
from tensorflow.keras.callbacks import EarlyStopping, ModelCheckpoint
from sklearn.metrics import precision_score, recall_score, f1_score, classification_report


# Suppress iCCP warning
import warnings
warnings.filterwarnings("ignore", category=UserWarning, message=".*iCCP:.*")

# Define data paths
train_real_folder = 'datasets/training_set/real/'
train_fake_folder = 'datasets/training_set/fake/'
test_real_folder = 'datasets/test_set/real/'
test_fake_folder = 'datasets/test_set/fake/'

# Load train image paths and labels
train_image_paths = []
train_labels = []

# Load train_real image paths and labels
for filename in os.listdir(train_real_folder):
    image_path = os.path.join(train_real_folder, filename)
    label = 0  # Real images have label 0
    train_image_paths.append(image_path)
    train_labels.append(label)

# Load train_fake image paths and labels
for filename in os.listdir(train_fake_folder):
    image_path = os.path.join(train_fake_folder, filename)
    label = 1  # Fake images have label 1
    train_image_paths.append(image_path)
    train_labels.append(label)

# Load test image paths and labels
test_image_paths = []
test_labels = []

# Load test_real image paths and labels
for filename in os.listdir(test_real_folder):
    image_path = os.path.join(test_real_folder, filename)
    label = 0  # Assuming test real images are all real (label 0)
    test_image_paths.append(image_path)
    test_labels.append(label)

# Load test_fake image paths and labels
for filename in os.listdir(test_fake_folder):
    image_path = os.path.join(test_fake_folder, filename)
    label = 1  # Assuming test fake images are all fake (label 1)
    test_image_paths.append(image_path)
    test_labels.append(label)

# Create DataFrames
train_dataset = pd.DataFrame({'image_path': train_image_paths, 'label': train_labels})
test_dataset = pd.DataFrame({'image_path': test_image_paths, 'label': test_labels})

# Function to preprocess images
def preprocess_image(image_path):
    """Loads, resizes, and normalizes an image."""
    image = cv2.imread(image_path)
    resized_image = cv2.resize(image, (128, 128))  # Target size defined here
    normalized_image = resized_image.astype(np.float32) / 255.0
    return normalized_image

# Preprocess all images and convert labels to numpy arrays
X = np.array([preprocess_image(path) for path in train_image_paths])
Y = np.array(train_labels)

# Define discriminator network
def build_discriminator(input_shape, dropout_rate=0.5):
    model = Sequential()
    model.add(Conv2D(32, (3, 3), activation='relu', input_shape=input_shape))
    model.add(MaxPooling2D((2, 2)))
    model.add(Conv2D(64, (3, 3), activation='relu'))
    model.add(MaxPooling2D((2, 2)))
    model.add(Conv2D(64, (3, 3), activation='relu'))
    model.add(Flatten())
    model.add(Dense(64, activation='relu'))
    model.add(Dropout(dropout_rate))  # Adding dropout layer
    model.add(Dense(1, activation='sigmoid'))
    return model

# Function to check if previous weights exist
def load_previous_weights(model, fold_number):
    weights_file = f'model_weights/model_fold_{fold_number}.weights.h5'
    if os.path.exists(weights_file):
        model.load_weights(weights_file)
        print(f"Loaded weights from {weights_file}")
    else:
        print("No previous weights found.")

# Function to save weights if current accuracy is higher
def save_updated_weights(model, fold_number, val_accuracy, best_accuracy):
    weights_file = f'model_weights/model_fold_{fold_number}.weights.h5'
    if val_accuracy > best_accuracy:
        model.save_weights(weights_file)
        print(f"Saved updated weights to {weights_file} with val_accuracy: {val_accuracy:.4f}")
        return val_accuracy
    else:
        print(f"Did not save weights for fold {fold_number} as val_accuracy {val_accuracy:.4f} is not better than {best_accuracy:.4f}")
        return best_accuracy

# Set parameters for cross-validation
kf = KFold(n_splits=4, shuffle=True, random_state=42)
batch_size = 32
epochs = 15

# Lists to store accuracy and loss for each fold
accuracy_per_fold = []
loss_per_fold = []
# Store the best accuracies for each fold
best_accuracies = [0] * kf.get_n_splits()


# Perform K-Fold Cross-Validation
for fold_number, (train_index, val_index) in enumerate(kf.split(X), 1):
    X_train, X_val = X[train_index], X[val_index]
    Y_train, Y_val = Y[train_index], Y[val_index]
    
    # Create and compile model
    input_dim = X_train.shape[1:]  # Dimensionality of the input images
    model = build_discriminator(input_dim)
    model.compile(loss='binary_crossentropy', optimizer=Adam(0.0002, 0.5), metrics=['accuracy'])
    
     # Load previous weights if they exist
    load_previous_weights(model, fold_number)
    
    # Define Early Stopping callback
    early_stopping = EarlyStopping(monitor='val_accuracy', patience=5, restore_best_weights=True)
    
    # Define ModelCheckpoint callback to save the best weights
    checkpoint = ModelCheckpoint(filepath=f'best_model_weights/model_fold_{fold_number}.best.weights.h5.keras', monitor='val_accuracy', save_best_only=True, mode='max')
    
    # Train the model with the callbacks
    history = model.fit(X_train, Y_train, epochs=epochs, batch_size=batch_size, verbose=2, 
                        validation_data=(X_val, Y_val), callbacks=[early_stopping, checkpoint])
    
    # Store the accuracy and loss for this folds
    average_val_accuracy = np.mean(history.history['val_accuracy'])
    accuracy_per_fold.append(average_val_accuracy)
    average_val_loss = np.mean(history.history['val_loss'])
    loss_per_fold.append(average_val_loss)
  
    # Save updated weights if accuracy is high
    best_accuracies[fold_number - 1] = save_updated_weights(model, fold_number, average_val_accuracy, best_accuracies[fold_number - 1])
 
    
    # Print fold accuracy
    print(f'Fold {fold_number} average accuracy: {average_val_accuracy*100:.2f}%')

# Print average accuracy across all folds
print(f'Average accuracy across all folds: {np.mean(accuracy_per_fold)*100:.2f}%')

# Load the model weights of the best model
best_model_index = np.argmax(accuracy_per_fold)
best_model_path = f'best_model_weights/model_fold_{best_model_index + 1}.best.weights.h5.keras'
model.load_weights(best_model_path)

# Evaluate the preprocessed test images using the best model
test_loss, test_accuracy = model.evaluate(np.array([preprocess_image(path) for path in test_image_paths]), np.array(test_labels))
print(f"\nTest Loss: {test_loss}, Test Accuracy: {test_accuracy}")

# Predict labels for the test set using the best model
predictions = model.predict(np.array([preprocess_image(path) for path in test_image_paths]))
predicted_labels = (predictions > 0.5).astype(int).flatten()

# Summarize the classification results
true_real_correct = np.sum((np.array(test_labels) == 0) & (predicted_labels == 0))
true_real_incorrect = np.sum((np.array(test_labels) == 0) & (predicted_labels == 1))
true_fake_correct = np.sum((np.array(test_labels) == 1) & (predicted_labels == 1))
true_fake_incorrect = np.sum((np.array(test_labels) == 1) & (predicted_labels == 0))

print("\nClassification Summary:")
print(f"Real images correctly classified: {true_real_correct}")
print(f"Real images incorrectly classified: {true_real_incorrect}")
print(f"Fake images correctly classified: {true_fake_correct}")
print(f"Fake images incorrectly classified: {true_fake_incorrect}")


# Print detailed classification report
print("\nClassification Report:")
print(classification_report(test_labels, predicted_labels, target_names=['Real', 'Fake']))

print(model.summary())


# Plot confusion matrix
cm = confusion_matrix(test_labels, predicted_labels)
disp = ConfusionMatrixDisplay(confusion_matrix=cm, display_labels=['Real', 'Fake'])
disp.plot(cmap=plt.cm.Blues)
plt.title("Confusion Matrix")
plt.show()

# Plot training & validation accuracy values
plt.figure(figsize=(12, 4))
plt.subplot(1, 2, 1)
plt.plot(history.history['accuracy'])
plt.plot(history.history['val_accuracy'])
plt.title('Model accuracy')
plt.ylabel('Accuracy')
plt.xlabel('Epoch')
plt.legend(['Train', 'Validation'], loc='upper left')
plt.xticks(np.arange(0, len(history.history['accuracy']), step=1), np.arange(1, len(history.history['accuracy']) + 1, step=1))


# Plot training & validation loss values
plt.subplot(1, 2, 2)
plt.plot(history.history['loss'])
plt.plot(history.history['val_loss'])
plt.title('Model loss')
plt.ylabel('Loss')
plt.xlabel('Epoch')
plt.legend(['Train', 'Validation'], loc='upper left')
plt.xticks(np.arange(0, len(history.history['loss']), step=1), np.arange(1, len(history.history['loss']) + 1, step=1))


plt.tight_layout()
plt.show()

# Plot validation accuracy and loss per fold
plt.figure(figsize=(12, 4))
plt.subplot(1, 2, 1)
plt.plot(range(1, kf.get_n_splits() + 1), accuracy_per_fold, marker='o')
plt.title('Validation Accuracy per Fold')
plt.xlabel('Fold')
plt.ylabel('Accuracy')

plt.subplot(1, 2, 2)
plt.plot(range(1, kf.get_n_splits() + 1), loss_per_fold, marker='o')
plt.title('Validation Loss per Fold')
plt.xlabel('Fold')
plt.ylabel('Loss')

plt.tight_layout()
plt