app.py

import torch
from transformers import ViTImageProcessor, ViTForImageClassification
from fastai.learner import load_learner
from fastai.vision.core import PILImage
from PIL import Image
import matplotlib.pyplot as plt
import numpy as np
import gradio as gr
import io
import base64

# 🔹 Cargar modelo ViT desde Hugging  Face
MODEL_NAME = "ahishamm/vit-base-HAM-10000-sharpened-patch-32"
feature_extractor = ViTImageProcessor.from_pretrained(MODEL_NAME)
model_vit = ViTForImageClassification.from_pretrained(MODEL_NAME)
model_vit.eval()

# 🔹 Cargar modelos Fast.ai desde archivos locales
model_malignancy = load_learner("ada_learn_malben.pkl")
model_norm2000 = load_learner("ada_learn_skin_norm2000.pkl")

# 🔹 Clases y niveles de riesgo
CLASSES = [
    "Queratosis actínica / Bowen", "Carcinoma células basales",
    "Lesión queratósica benigna", "Dermatofibroma",
    "Melanoma maligno", "Nevus melanocítico", "Lesión vascular"
]
RISK_LEVELS = {
    0: {'level': 'Moderado', 'color': '#ffaa00', 'weight': 0.6},
    1: {'level': 'Alto', 'color': '#ff4444', 'weight': 0.8},
    2: {'level': 'Bajo', 'color': '#44ff44', 'weight': 0.1},
    3: {'level': 'Bajo', 'color': '#44ff44', 'weight': 0.1},
    4: {'level': 'Crítico', 'color': '#cc0000', 'weight': 1.0},
    5: {'level': 'Bajo', 'color': '#44ff44', 'weight': 0.1},
    6: {'level': 'Bajo', 'color': '#44ff44', 'weight': 0.1}
}

def analizar_lesion_combined(img):
    # 🔹 Convertir imagen para Fastai
    img_fastai = PILImage.create(img)

    # 🔹 ViT prediction
    inputs = feature_extractor(img, return_tensors="pt")
    with torch.no_grad():
        outputs = model_vit(**inputs)
        probs_vit = outputs.logits.softmax(dim=-1).cpu().numpy()[0]
    pred_idx_vit = int(np.argmax(probs_vit))
    pred_class_vit = CLASSES[pred_idx_vit]
    confidence_vit = probs_vit[pred_idx_vit]

    # 🔹 Fast.ai models
    pred_fast_malignant, _, probs_fast_mal = model_malignancy.predict(img_fastai)
    prob_malignant = float(probs_fast_mal[1])  # 1 = maligno

    pred_fast_type, _, probs_fast_type = model_norm2000.predict(img_fastai)

    # 🔹 Gráfico ViT
    colors_bars = [RISK_LEVELS[i]['color'] for i in range(7)]
    fig, ax = plt.subplots(figsize=(8, 3))
    ax.bar(CLASSES, probs_vit*100, color=colors_bars)
    ax.set_title("Probabilidad ViT por tipo de lesión")
    ax.set_ylabel("Probabilidad (%)")
    ax.set_xticks(np.arange(len(CLASSES)))  # evita warning
    ax.set_xticklabels(CLASSES, rotation=45, ha='right')
    ax.grid(axis='y', alpha=0.2)
    plt.tight_layout()
    buf = io.BytesIO()
    plt.savefig(buf, format="png")
    plt.close(fig)
    img_bytes = buf.getvalue()
    img_b64 = base64.b64encode(img_bytes).decode("utf-8")
    html_chart = f'<img src="data:image/png;base64,{img_b64}" style="max-width:100%"/>'

    # 🔹 Informe HTML
    informe = f"""
    <div style="font-family:sans-serif; max-width:800px; margin:auto">
    <h2>🧪 Diagnóstico por 3 modelos de IA</h2>
    <table style="border-collapse: collapse; width:100%; font-size:16px">
        <tr><th style="text-align:left">🔍 Modelo</th><th>Resultado</th><th>Confianza</th></tr>
        <tr><td>🧠 ViT (transformer)</td><td><b>{pred_class_vit}</b></td><td>{confidence_vit:.1%}</td></tr>
        <tr><td>🧬 Fast.ai (clasificación)</td><td><b>{pred_fast_type}</b></td><td>N/A</td></tr>
        <tr><td>⚠️ Fast.ai (malignidad)</td><td><b>{"Maligno" if prob_malignant > 0.5 else "Benigno"}</b></td><td>{prob_malignant:.1%}</td></tr>
    </table>
    <br>
    <b>🩺 Recomendación automática:</b><br>
    """

    # 🔹 Recomendación basada en ViT + malignidad
    cancer_risk_score = sum(probs_vit[i] * RISK_LEVELS[i]['weight'] for i in range(7))
    if prob_malignant > 0.7 or cancer_risk_score > 0.6:
        informe += "🚨 <b>CRÍTICO</b> – Derivación urgente a oncología dermatológica"
    elif prob_malignant > 0.4 or cancer_risk_score > 0.4:
        informe += "⚠️ <b>ALTO RIESGO</b> – Consulta con dermatólogo en 7 días"
    elif cancer_risk_score > 0.2:
        informe += "📋 <b>RIESGO MODERADO</b> – Evaluación programada (2-4 semanas)"
    else:
        informe += "✅ <b>BAJO RIESGO</b> – Seguimiento de rutina (3-6 meses)"

    informe += "</div>"

    return informe, html_chart

# 🔹 Interfaz Gradio
demo = gr.Interface(
    fn=analizar_lesion_combined,
    inputs=gr.Image(type="pil", label="Sube una imagen de la lesión"),
    outputs=[gr.HTML(label="Informe combinado"), gr.HTML(label="Gráfico ViT")],
    title="Detector de Lesiones Cutáneas (ViT + Fast.ai)",
    description="Comparación entre ViT transformer (HAM10000) y dos modelos Fast.ai entrenados sobre distintos datasets.",
    flagging_mode="never"
)

if __name__ == "__main__":
    demo.launch()