app.py

"""Flask web app exposing the student data analysis chatbot.

Run locally:
    python app.py            # then open http://localhost:5000

For PythonAnywhere, point the WSGI configuration at wsgi.py instead.
"""

import os
import secrets

from flask import Flask, jsonify, render_template, request

from chatbot.engine import MAX_INPUT_LENGTH, respond

app = Flask(__name__)
app.config["SECRET_KEY"] = os.environ.get("SECRET_KEY", secrets.token_hex(32))


@app.after_request
def add_security_headers(response):
    response.headers["X-Content-Type-Options"] = "nosniff"
    response.headers["X-Frame-Options"] = "DENY"
    response.headers["Referrer-Policy"] = "no-referrer"
    return response


@app.route("/")
def index():
    return render_template("index.html")


@app.route("/api/suggestions")
def suggestions():
    """Curated example questions shown as quick-reply chips in the UI."""
    return jsonify(
        {
            "suggestions": [
                "How many students are there?",
                "Who has the highest total score?",
                "Who has the lowest total score?",
                "What is the average total score?",
                "How many female students are there?",
                "How many male students are there?",
                "Who has the highest attendance?",
                "Who has the lowest attendance?",
                "What is the average quiz score?",
                "How many students got grade A?",
                "What percentage of students passed?",
                "Show the grade distribution",
            ]
        }
    )


@app.route("/api/chat", methods=["POST"])
def chat():
    """Handle one chat message. Returns JSON: {"reply": "..."}."""
    data = request.get_json(silent=True) or {}
    message = data.get("message")

    if not isinstance(message, str) or not message.strip():
        return jsonify({"error": "Message must not be empty."}), 400

    if len(message) > MAX_INPUT_LENGTH:
        return jsonify({"error": f"Message too long (maximum {MAX_INPUT_LENGTH} characters)."}), 400

    return jsonify({"reply": respond(message)})


@app.route("/health")
def health():
    return jsonify({"status": "ok"})


if __name__ == "__main__":
    port = int(os.environ.get("PORT", 5000))
    app.run(host="0.0.0.0", port=port, debug=False)