app.py

import streamlit as st
from PIL import Image
import torch
import torch.nn as nn
from torchvision import transforms
import os
from dotenv import load_dotenv
from groq import Groq

# Load environment variables
load_dotenv()

# Page settings
st.set_page_config(page_title="🌿 Leaf Disease Detector", layout="wide")
st.markdown("<h1 style='text-align: center;'>🌿 Plant Leaf Disease Detection</h1>", unsafe_allow_html=True)
st.markdown("<p style='text-align: center;'>Upload a leaf image to detect plant diseases and get treatment guidance.</p>", unsafe_allow_html=True)
st.markdown("---")

# Initialize Groq client
try:
    api_key = os.getenv("GROQ_API_KEY")
    client = Groq(api_key=api_key)
except Exception as e:
    st.error(f"Failed to initialize Groq client: {str(e)}")
    client = None

# Dummy CNN model
class PlantDiseaseModel(nn.Module):
    def __init__(self, num_classes=28):
        super(PlantDiseaseModel, self).__init__()
        self.features = nn.Sequential(
            nn.Conv2d(3, 32, 3, padding=1), nn.ReLU(), nn.MaxPool2d(2, 2),
            nn.Conv2d(32, 64, 3, padding=1), nn.ReLU(), nn.MaxPool2d(2, 2),
            nn.Conv2d(64, 128, 3, padding=1), nn.ReLU(), nn.MaxPool2d(2, 2),
        )
        self.classifier = nn.Sequential(
            nn.Linear(128 * 32 * 32, 512), nn.ReLU(), nn.Dropout(0.5),
            nn.Linear(512, num_classes)
        )

    def forward(self, x):
        x = self.features(x)
        x = x.view(x.size(0), -1)
        x = self.classifier(x)
        return x

@st.cache_resource
def load_model():
    model = PlantDiseaseModel()
    model.eval()
    return model

model = load_model()

# Preprocessing
def preprocess_image(image):
    transform = transforms.Compose([
        transforms.Resize((256, 256)),
        transforms.ToTensor(),
        transforms.Normalize([0.485, 0.456, 0.406],
                             [0.229, 0.224, 0.225]),
    ])
    return transform(image).unsqueeze(0)

# Disease classes
disease_classes = [
    "Healthy", "Apple Scab", "Apple Black Rot", "Apple Cedar Rust", 
    "Cherry Powdery Mildew", "Corn Gray Leaf Spot", "Corn Common Rust", 
    "Grape Black Rot", "Grape Esca", "Grape Leaf Blight", 
    "Orange Huanglongbing", "Peach Bacterial Spot", "Pepper Bacterial Spot", 
    "Potato Early Blight", "Potato Late Blight", "Raspberry Healthy", 
    "Soybean Healthy", "Squash Powdery Mildew", "Strawberry Leaf Scorch", 
    "Tomato Bacterial Spot", "Tomato Early Blight", "Tomato Late Blight", 
    "Tomato Leaf Mold", "Tomato Septoria Leaf Spot", "Tomato Spider Mites", 
    "Tomato Target Spot", "Tomato Yellow Leaf Curl Virus", "Tomato Mosaic Virus"
]

# Predict class
def classify_disease(image):
    try:
        img_tensor = preprocess_image(image)
        with torch.no_grad():
            outputs = model(img_tensor)
        _, predicted = torch.max(outputs, 1)
        class_idx = predicted.item()
        return disease_classes[class_idx % len(disease_classes)]
    except Exception as e:
        st.error(f"Error during classification: {str(e)}")
        return "Unknown"

# Fetch disease info
def get_disease_info(disease_name):
    if not client:
        return {
            "description": "API not available. Check GROQ_API_KEY.",
        }

    try:
        if disease_name.lower() == "healthy":
            return {
                "description": "The plant appears to be healthy. No treatment is needed.",
            }

        response = client.chat.completions.create(
            messages=[
                {"role": "system", "content": "You are a plant pathologist assistant."},
                {"role": "user", "content": f"Describe {disease_name} in plants including symptoms, treatment, and prevention."}
            ],
            model="llama-3.3-70b-versatile",
            temperature=0.3,
            max_tokens=1024
        )
        return {"description": response.choices[0].message.content}
    except Exception as e:
        st.error(f"Error fetching disease info: {str(e)}")
        return {
            "description": "Unable to fetch disease info. Please try again later.",
        }

# Main app
def main():
    uploaded_file = st.file_uploader("📷 Upload a leaf image", type=["jpeg", "png", "jpg"])

    if uploaded_file:
        filename = uploaded_file.name.lower()
        if not (filename.endswith(".jpg") or filename.endswith(".jpeg") or filename.endswith(".png")):
            st.error("Only JPG, JPEG, and PNG files are allowed.")
            st.stop()

        try:
            image = Image.open(uploaded_file).convert("RGB")
            st.image(image, caption="Uploaded Leaf Image", width=400)

            if st.button("🔍 Predict Disease"):
                with st.spinner("Analyzing..."):
                    disease_name = classify_disease(image)
                    info = get_disease_info(disease_name)

                    st.markdown("---")
                    st.subheader("🔬 Prediction Results")

                    col1, col2 = st.columns([1, 2])
                    with col1:
                        status = "✅ Healthy" if disease_name.lower() == "healthy" else "⚠️ Diseased"
                        st.markdown(f"**Status:** {status}")
                        st.markdown(f"**Detected Disease:** `{disease_name}`")

                    with col2:
                        st.markdown("**📋 Disease Info:**")
                        st.markdown(info["description"])
        except Exception as e:
            st.error(f"Error processing image: {str(e)}")

if __name__ == "__main__":
    main()