index.py

import json
import calculator as calc
import str_parser as parser
from flask import Flask, render_template, request
from flask_cors import CORS, cross_origin

app = Flask(__name__, static_url_path="/")
cors = CORS(app)
app.config["CORS_HEADERS"] = "Content-Type"

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

@app.route("/calculate", methods=["POST"])
@cross_origin()
def calculate():
    """
    Calculates the tangent equation of a function at a given point.
    """
    data = request.get_json()
    try:  # Load the request data
        fcn = str(data["fcn"])
        x = str(data["x"])
        y = str(data["y"])
        output = str(data["output"])
    except (KeyError, TypeError):
        return json.dumps({"error": "Error accessing data from request."}), 400

    # Validate the data
    if fcn is None or x is None or y is None or output not in ["exact", "decimal"]:
        return json.dumps({"error": "Invalid request data"}), 400

    # Parse data to sympy expressions
    try:
        if "y" not in fcn:
            fcn = f"y - ({fcn})"  # The dependent variable, y, is required.
        fcn = parser.parse(fcn)
        x = parser.parse(x)
        y = parser.parse(y)
    except Exception as e:
        return json.dumps({"error": f"Error parsing data: {e}"}), 400

    # Calculate the tangent equation
    dy_dx, lines = calc.calculate(fcn, x, y, output == "exact")
    if isinstance(lines, Exception):
        return json.dumps({"error": f"Error calculating tangent equation: {lines}", "dy_dx": str(dy_dx)}), 500

    return json.dumps({"dy_dx": str(dy_dx), "lines": [vars(line) for line in lines]}), 200

if __name__ == "__main__":
    app.run(threaded=True)