app.py

import os
import gradio as gr
import numpy as np
from PIL import Image
import tensorflow as tf
from tensorflow.keras import layers, models

print("Building model architecture...")

# 1. Rebuild the exact backbone used in training
base_model = tf.keras.applications.MobileNetV2(
    input_shape=(224, 224, 3),
    include_top=False,
    weights="imagenet"
)
base_model.trainable = False

# 2. Rebuild the exact head used in training (Functional API)
inputs = tf.keras.Input(shape=(224, 224, 3))
x = base_model(inputs, training=False)
x = layers.GlobalAveragePooling2D()(x)

# --- The Missing Layers ---
x = layers.BatchNormalization()(x)
x = layers.Dense(256, activation="relu")(x) # This matches your trained (1280, 256) weights
x = layers.BatchNormalization()(x)
x = layers.Dropout(0.5)(x)
x = layers.Dense(128, activation="relu")(x)
x = layers.BatchNormalization()(x)
x = layers.Dropout(0.4)(x)
# --------------------------

outputs = layers.Dense(2, activation="softmax")(x)

model = models.Model(inputs, outputs)

print("Loading weights...")
# Now the shapes match perfectly
model.load_weights("model.keras") 
print("Model ready!")

LABELS = ["preserved", "looted"]
IMG_SIZE = (224, 224)

def preprocess(img: Image.Image):
    img = img.convert("RGB").resize(IMG_SIZE)
    arr = np.array(img) / 255.0
    arr = np.expand_dims(arr, 0).astype(np.float32)
    return arr

def predict(image: Image.Image):
    if image is None:
        return None, "No image uploaded."
    x = preprocess(image)
    probs = model.predict(x)[0]
    
    result = {LABELS[0]: float(probs[0]), LABELS[1]: float(probs[1])}
    idx = int(np.argmax(probs))
    summary = f"Prediction: **{LABELS[idx]}** ({float(probs[idx]):.1%} confidence)"
    
    return result, summary

iface = gr.Interface(
    fn=predict,
    inputs=gr.Image(type="pil", label="Upload photo"),
    outputs=[gr.Label(num_top_classes=2), gr.Textbox(label="Summary")],
    title="Preserved vs Looted Classifier",
    description="Upload a photo to classify archeological sites."
)

if __name__ == "__main__":
    iface.launch(server_name="0.0.0.0", server_port=int(os.environ.get("PORT", 7860)))