import tensorflow as tf
from tensorflow.keras.preprocessing.image import ImageDataGenerator
from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import Conv2D, MaxPooling2D, Flatten, Dense, Dropout
import matplotlib.pyplot as plt
from tensorflow.keras.applications import MobileNetV2
from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import Dense, Dropout, GlobalAveragePooling2D
from tensorflow.keras.preprocessing.image import ImageDataGenerator
from sklearn.metrics import classification_report, roc_auc_score, roc_curve, auc
from sklearn.utils.class_weight import compute_class_weight
from sklearn.metrics import roc_auc_score
from tensorflow.keras.callbacks import EarlyStopping
from tensorflow.keras import regularizers
from tensorflow.keras.preprocessing import image
from tensorflow.keras.applications.mobilenet_v2 import preprocess_input
import numpy as np
import cv2


def predict_pneumonia(img_path, model, class_labels):
    # Preprocess the image
    img = image.load_img(img_path, target_size=(224, 224))  
    img_array = image.img_to_array(img)  
    img_array = np.expand_dims(img_array, axis=0)  
    img_array = img_array / 255.0  

    # Make a prediction
    predictions = model.predict(img_array)
    predicted_class_idx = np.argmax(predictions, axis=1)[0]  
    predicted_class = class_labels[predicted_class_idx]  
    print(f"Prediction: {predicted_class} (Confidence: {predictions[0][predicted_class_idx]:.2f})")
    return predicted_class


    class_labels = {0: 'Normal', 1: 'Pneumonia'}

    import os

base_path = "/kaggle/input/chest-xray-pneumonia/chest_xray"
print(os.listdir(base_path)) 

train_dir = "/kaggle/input/chest-xray-pneumonia/chest_xray/train"
val_dir = "/kaggle/input/chest-xray-pneumonia/chest_xray/val"
test_dir = "/kaggle/input/chest-xray-pneumonia/chest_xray/test"

train_datagen = ImageDataGenerator(rescale=1.0/255, rotation_range=20, zoom_range=0.2, horizontal_flip=True,shear_range=0.2
    )
val_datagen = ImageDataGenerator(rescale=1.0/255)
test_datagen = ImageDataGenerator(rescale=1.0/255)

train_generator = train_datagen.flow_from_directory(
    train_dir, target_size=(224, 224), batch_size=32, class_mode='binary'
)
val_generator = val_datagen.flow_from_directory(
    val_dir, target_size=(224, 224), batch_size=32, class_mode='binary'
)
test_generator = test_datagen.flow_from_directory(
    test_dir, target_size=(224, 224), batch_size=32, class_mode='binary'
)

from tensorflow.keras.applications import MobileNetV2


base_model = MobileNetV2(weights='/kaggle/input/mobile-v2-1-0-224/mobilenet_v2_weights_tf_dim_ordering_tf_kernels_1.0_224_no_top.h5', 
                         include_top=False, input_shape=(224, 224, 3))
base_model.trainable = False

from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import Flatten, Dense, Dropout


model = Sequential([
    base_model,
    Flatten(),
    Dense(128, activation='relu'),  
    Dropout(0.5),  
    Dense(1, activation='sigmoid')  
])

model.compile(optimizer='adam', loss='binary_crossentropy', metrics=['accuracy'])

import os


print("Train directory content:", os.listdir(train_dir))
print("Validation directory content:", os.listdir(val_dir))
print("Test directory content:", os.listdir(test_dir))

class_weights = compute_class_weight(
    class_weight='balanced',
    classes=np.unique(train_generator.classes),
    y=train_generator.classes
)


class_weights = {i: weight for i, weight in enumerate(class_weights)}


if 1 in class_weights:
    class_weights[1] = class_weights[1] * 2  


history = model.fit(
    train_generator,
    steps_per_epoch=train_generator.samples // train_generator.batch_size,
    validation_data=val_generator,
    validation_steps=val_generator.samples // val_generator.batch_size,
    epochs=10,  #
    class_weight=class_weights  
)

test_loss, test_acc = model.evaluate(test_generator)
print(f"Test Accuracy: {test_acc:.2f}")

plt.figure(figsize=(10, 5))
plt.subplot(1, 2, 1)
plt.plot(history.history['accuracy'], label='Train Accuracy')
plt.plot(history.history['val_accuracy'], label='Validation Accuracy')
plt.legend()
plt.title('Accuracy')

plt.subplot(1, 2, 2)
plt.plot(history.history['loss'], label='Train Loss')
plt.plot(history.history['val_loss'], label='Validation Loss')
plt.legend()
plt.title('Loss')

plt.show()

true_labels = test_generator.classes
predicted_probs = model.predict(test_generator, steps=test_generator.samples // test_generator.batch_size + 1)
predicted_labels = np.argmax(predicted_probs, axis=1)

import numpy as np
from sklearn.metrics import classification_report


test_generator.reset()  
predictions = model.predict(test_generator, steps=test_generator.samples // test_generator.batch_size + 1)


predicted_labels = (predictions > 0.5).astype(int)


true_labels = test_generator.classes

# Step 3: Classification report
report = classification_report(true_labels, predicted_labels, target_names=['Normal', 'Pneumonia'])

print("Classification Report:")
print(report)

true_labels = test_generator.classes


predicted_probs = model.predict(test_generator)


roc_auc = roc_auc_score(true_labels, predicted_probs)
print(f"ROC-AUC Score: {roc_auc:.2f}")

true_labels = test_generator.classes


predicted_probs = model.predict(test_generator)



fpr, tpr, _ = roc_curve(true_labels, predicted_probs)


roc_auc = auc(fpr, tpr)


plt.figure()
plt.plot(fpr, tpr, color='darkorange', lw=2, label=f"ROC curve (area = {roc_auc:.2f})")
plt.plot([0, 1], [0, 1], color='navy', lw=2, linestyle='--')
plt.xlabel('False Positive Rate')
plt.ylabel('True Positive Rate')
plt.title('Receiver Operating Characteristic')
plt.legend(loc="lower right")
plt.show()

img_path = '/kaggle/input/chest-xray-pneumonia/chest_xray/val/PNEUMONIA/person1951_bacteria_4882.jpeg'  # Path to the X-ray image
predicted_class = predict_pneumonia(img_path, model, class_labels)
print(f"The X-ray image is classified as: {predicted_class}")