Add initial implementation of Flask app for AI text classification and requirements file

app.py

@@ -0,0 +1,145 @@
+from flask import Flask, request, jsonify, Response
+from transformers import AutoTokenizer, AutoModelForSequenceClassification
+import torch
+import torch.nn.functional as F
+import threading
+import time
+import queue
+from nltk.tokenize import sent_tokenize 
+import nltk
+try:
+    nltk.data.find('tokenizers/punkt')
+except LookupError:
+    nltk.download('punkt')
+
+
+app = Flask(__name__)
+
+
+model_name = "priyabrat/AI.or.Human.text.classification"
+tokenizer = AutoTokenizer.from_pretrained(model_name)
+model = AutoModelForSequenceClassification.from_pretrained(model_name)
+device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
+model.to(device).eval()
+
+labels = ["AI-generated", "Human-written"]
+lock = threading.Lock()
+
+
+sessions = {}
+queues = {}
+
+def classify_line(text):
+    with lock, torch.no_grad():
+        inputs = tokenizer(text, return_tensors="pt", truncation=True, padding=True, max_length=10000)
+        inputs = {k: v.to(device) for k, v in inputs.items()}
+        outputs = model(**inputs)
+        probs = F.softmax(outputs.logits, dim=-1)
+        pred = torch.argmax(probs, dim=-1).item()
+        confidence = probs[0][pred].item()
+        return {
+            "text": text.strip(),
+            "label": labels[pred],
+            "confidence": round(confidence * 100, 2)
+        }
+
+
+
+def background_worker(user_id, text):
+    sessions[user_id]['status'] = "processing"
+    if '\n' not in text:
+        lines = sent_tokenize(text)  
+    else:
+        lines = [line.strip() for line in text.strip().split('\n') if line.strip()]
+
+    result_count = 0
+
+    for i, line in enumerate(lines, 1):
+        result = classify_line(line)
+        result["line"] = i
+        queues[user_id].put(f"data: {result}\n\n")
+        result_count += 1
+        time.sleep(0.2)  
+
+    queues[user_id].put("event: done\ndata: Session complete\n\n")
+    sessions[user_id]['status'] = "done"
+
+    time.sleep(2)
+    del sessions[user_id]
+    del queues[user_id]
+
+    sessions[user_id]['status'] = "processing"
+    lines = [line.strip() for line in text.strip().split('\n') if line.strip()]
+    result_count = 0
+
+    for i, line in enumerate(lines, 1):
+        result = classify_line(line)
+        result["line"] = i
+        queues[user_id].put(f"data: {result}\n\n")
+        result_count += 1
+        time.sleep(0.2)  
+
+    queues[user_id].put("event: done\ndata: Session complete\n\n")
+    sessions[user_id]['status'] = "done"
+    time.sleep(2)
+    del sessions[user_id]
+    del queues[user_id]
+
+@app.route('/start-session', methods=['POST'])
+def start_session():
+    data = request.get_json()
+    user_id = data.get("user_id")
+    text = data.get("text")
+
+    if not user_id or not text:
+        return jsonify({"error": "user_id and text are required"}), 400
+
+    if user_id in sessions:
+        status = sessions[user_id]["status"]
+        return jsonify({"message": f"Session already exists", "status": status}), 409
+
+    sessions[user_id] = {"status": "pending"}
+    queues[user_id] = queue.Queue()
+    threading.Thread(target=background_worker, args=(user_id, text), daemon=True).start()
+
+    return jsonify({"message": "Session started", "status": "pending"}), 202
+
+@app.route('/stream/<user_id>')
+def stream(user_id):
+    if user_id not in sessions:
+        return jsonify({"error": "No active session for this user"}), 404
+
+    def event_stream():
+        while True:
+            try:
+                message = queues[user_id].get(timeout=60)
+                yield message
+                if "event: done" in message:
+                    break
+            except queue.Empty:
+                yield "event: timeout\ndata: No activity\n\n"
+                break
+
+    return Response(
+        event_stream(),
+        mimetype="text/event-stream",
+        headers={
+            "Cache-Control": "no-cache",
+            "Connection": "keep-alive",
+            "Access-Control-Allow-Origin": "*"
+        }
+    )
+@app.route('/status/<user_id>')
+def session_status(user_id):
+    if user_id not in sessions:
+        return jsonify({"status": "no_session"})
+    return jsonify({
+        "status": sessions[user_id]["status"]
+    })
+
+@app.route('/')
+def index():
+    return "alive yet !"
+
+if __name__ == '__main__':
+    app.run(debug=True, threaded=True,host='0.0.0.0', port=5000)

requirenments.txt

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+blinker==1.9.0
+certifi==2025.4.26
+charset-normalizer==3.4.2
+click==8.2.1
+colorama==0.4.6
+filelock==3.18.0
+Flask==3.1.1
+fsspec==2025.5.1
+huggingface-hub==0.32.3
+idna==3.10
+itsdangerous==2.2.0
+Jinja2==3.1.6
+joblib==1.5.1
+MarkupSafe==3.0.2
+mpmath==1.3.0
+networkx==3.4.2
+nltk==3.9.1
+numpy==2.2.6
+packaging==25.0
+PyYAML==6.0.2
+regex==2024.11.6
+requests==2.32.3
+safetensors==0.5.3
+sympy==1.14.0
+tokenizers==0.21.1
+torch==2.7.0
+tqdm==4.67.1
+transformers==4.52.4
+typing_extensions==4.13.2
+urllib3==2.4.0
+Werkzeug==3.1.3