import streamlit as st
import math

st.title("🧮 Advanced Calculator")

tab1, tab2, tab3 = st.tabs(["Basic Operations", "Scientific Functions", "Trigonometry"])

with tab1:
    st.header("Basic Operations")
    num1 = st.number_input("Enter first number", key="basic_num1")
    num2 = st.number_input("Enter second number", key="basic_num2")
    operation = st.selectbox("Choose operation", ["Add (+)", "Subtract (-)", "Multiply (*)", "Divide (/)"], key="basic_op")

    if st.button("Calculate", key="basic_calc"):
        if operation == "Add (+)":
            result = num1 + num2
        elif operation == "Subtract (-)":
            result = num1 - num2
        elif operation == "Multiply (*)":
            result = num1 * num2
        elif operation == "Divide (/)":
            if num2 != 0:
                result = num1 / num2
            else:
                st.error("Cannot divide by zero.")
                result = None
        if result is not None:
            st.success(f"Result: {result}")

with tab2:
    st.header("Scientific Functions")
    num = st.number_input("Enter a number", key="sci_num")
    function = st.selectbox("Choose function", ["Power (x^y)", "Square Root", "Log10", "Natural Log", "Factorial"], key="sci_func")

    if function == "Power (x^y)":
        exponent = st.number_input("Enter exponent", key="sci_exponent")

    if st.button("Calculate", key="sci_calc"):
        try:
            if function == "Power (x^y)":
                result = math.pow(num, exponent)
            elif function == "Square Root":
                if num < 0:
                    st.error("Square root of negative number is not supported.")
                    result = None
                else:
                    result = math.sqrt(num)
            elif function == "Log10":
                if num <= 0:
                    st.error("Logarithm undefined for zero or negative numbers.")
                    result = None
                else:
                    result = math.log10(num)
            elif function == "Natural Log":
                if num <= 0:
                    st.error("Natural log undefined for zero or negative numbers.")
                    result = None
                else:
                    result = math.log(num)
            elif function == "Factorial":
                if num < 0 or int(num) != num:
                    st.error("Factorial only defined for non-negative integers.")
                    result = None
                else:
                    result = math.factorial(int(num))
            if result is not None:
                st.success(f"Result: {result}")
        except Exception as e:
            st.error(f"Error: {e}")

with tab3:
    st.header("Trigonometric Functions")
    angle = st.number_input("Enter angle in degrees", key="trig_angle")
    trig_func = st.selectbox("Choose function", ["sin", "cos", "tan"], key="trig_func")

    if st.button("Calculate", key="trig_calc"):
        rad = math.radians(angle)
        if trig_func == "sin":
            result = math.sin(rad)
        elif trig_func == "cos":
            result = math.cos(rad)
        elif trig_func == "tan":
            if math.isclose(math.cos(rad), 0, abs_tol=1e-10):
                st.error("tan is undefined for this angle.")
                result = None
            else:
                result = math.tan(rad)
        if result is not None:
            st.success(f"{trig_func}({angle}°) = {result}")