src/streamlit_app.py

import streamlit as st
import tensorflow as tf
import numpy as np
import time
import tensorflow.keras as keras
from tensorflow.keras.applications import VGG16
from tensorflow.keras.layers import Dense, Flatten
from tensorflow.keras.models import Model, load_model
from datasets import load_dataset
import matplotlib.pyplot as plt
from sklearn.model_selection import train_test_split
from sklearn.metrics import confusion_matrix, classification_report
import seaborn as sns
from huggingface_hub import HfApi
import os

# 📌 Percorso della cache
os.environ["HF_HOME"] = "/app/.cache"
os.environ["HF_DATASETS_CACHE"] = "/app/.cache"
HF_TOKEN = os.getenv("HF_TOKEN")

# 📌 Autenticazione Hugging Face
if HF_TOKEN:
    api = HfApi()
    user_info = api.whoami(HF_TOKEN)
    st.write(f"✅ Autenticato come {user_info.get('name', 'Utente sconosciuto')}")
else:
    st.warning("⚠️ Nessun token API trovato! Verifica il Secret nello Space.")

# 📌 Caricamento del dataset
st.write("🔄 Caricamento di 300 immagini da `tiny-imagenet`...")
dataset = load_dataset("zh-plus/tiny-imagenet", split="train")

image_list = []
label_list = []

for i, sample in enumerate(dataset):
    if i >= 300:  # Prende solo 300 immagini
        break
    image = tf.image.resize(sample["image"], (64, 64)) / 255.0  # Normalizzazione
    image_list.append(image.numpy())
    label_list.append(np.array(sample["label"]))  

X = np.array(image_list)
y = np.array(label_list)

# 📌 Suddivisione dataset: 80% training, 20% validation
X_train, X_val, y_train, y_val = train_test_split(X, y, test_size=0.2, random_state=42)

st.write(f"📊 **Training:** {X_train.shape[0]} immagini")
st.write(f"📊 **Validation:** {X_val.shape[0]} immagini")

# 📌 Checkbox per decidere se rifare il training
force_training = st.checkbox("🔄 Rifai il training anche se Silva.h5 esiste")

# 📌 Caricamento o training del modello
history = None  # 🛠 Inizializza history

if os.path.exists("Silva.h5") and not force_training:
    model = load_model("Silva.h5")
    st.write("✅ Modello `Silva.h5` caricato, nessun nuovo training necessario!")
else:
    st.write("🚀 Training in corso...")
    base_model = VGG16(weights="imagenet", include_top=False, input_shape=(64, 64, 3))
    for layer in base_model.layers:
        layer.trainable = False

    x = Flatten()(base_model.output)
    x = Dense(256, activation="relu")(x)
    x = Dense(128, activation="relu")(x)
    output = Dense(len(set(y_train)), activation="softmax")(x)

    model = Model(inputs=base_model.input, outputs=output)
    model.compile(optimizer="adam", loss="sparse_categorical_crossentropy", metrics=["accuracy"])

    history = model.fit(X_train, y_train, epochs=10, validation_data=(X_val, y_val))
    model.save("Silva.h5")
    st.write("✅ Modello salvato come `Silva.h5`!")

# 📌 Calcolo delle metriche sulla validazione
y_pred_val = np.argmax(model.predict(X_val), axis=1)
accuracy_val = np.mean(y_pred_val == y_val)
rmse_val = np.sqrt(np.mean((y_pred_val - y_val) ** 2))
report_val = classification_report(y_val, y_pred_val, output_dict=True)

recall_val = report_val["weighted avg"]["recall"]
precision_val = report_val["weighted avg"]["precision"]
f1_score_val = report_val["weighted avg"]["f1-score"]

st.write(f"📊 **Validation Accuracy:** {accuracy_val:.4f}")
st.write(f"📊 **Validation RMSE:** {rmse_val:.4f}")
st.write(f"📊 **Validation Precision:** {precision_val:.4f}")
st.write(f"📊 **Validation Recall:** {recall_val:.4f}")
st.write(f"📊 **Validation F1-Score:** {f1_score_val:.4f}")

# 📌 Bottone per generare la matrice di confusione sulla validazione
if st.button("🔎 Genera matrice di confusione per validazione"):
    conf_matrix_val = confusion_matrix(y_val, y_pred_val)
    fig, ax = plt.subplots(figsize=(10, 7))
    sns.heatmap(conf_matrix_val, annot=True, cmap="Blues", fmt="d", ax=ax)
    st.pyplot(fig)
    st.write("✅ Matrice di confusione generata!")

# 📌 Grafico per Loss e Accuracy con validazione
if history is not None:
    fig, ax = plt.subplots(1, 2, figsize=(12, 5))
    ax[0].plot(history.history["loss"], label="Training Loss")
    ax[0].plot(history.history["val_loss"], label="Validation Loss")
    ax[1].plot(history.history["accuracy"], label="Training Accuracy")
    ax[1].plot(history.history["val_accuracy"], label="Validation Accuracy")
    ax[0].set_title("Loss durante il training e validazione")
    ax[1].set_title("Accuracy durante il training e validazione")
    ax[0].legend()
    ax[1].legend()
    st.pyplot(fig)
else:
    st.warning("⚠️ Nessun training eseguito, impossibile mostrare il grafico!")

# 📌 Bottone per scaricare il modello
if os.path.exists("Silva.h5"):
    with open("Silva.h5", "rb") as f:
        st.download_button(
            label="📥 Scarica il modello Silva.h5",
            data=f,
            file_name="Silva.h5",
            mime="application/octet-stream"
        )

# 📌 Bottone per caricare il modello su Hugging Face
def upload_model():
    api.upload_file(
        path_or_fileobj="Silva.h5",
        path_in_repo="Silva.h5",
        repo_id="scontess/trainigVVG16",
        repo_type="space"
    )
    st.success("✅ Modello 'Silva.h5' caricato su Hugging Face!")

st.write("📥 Carica il modello Silva su Hugging Face")
if st.button("🚀 Carica Silva su Model Store"):
    upload_model()