use rust_decimal::{Decimal, dec};

use crate::math::types::{Expression, Operator};

#[test]
fn test_operator_display() {
    let cases = vec![
        (Operator::Add, "+"),
        (Operator::Subtract, "-"),
        (Operator::Multiply, "*"),
        (Operator::Divide, "/"),
        (Operator::Power, "^"),
        (Operator::Modulo, "%"),
    ];

    for (operation, expected) in cases {
        assert_eq!(operation.to_string(), expected);
    }
}

#[test]
fn test_expr_display_number() {
    let cases = vec![
        (Expression::Number(dec!(1)), "1"),
        (Expression::Number(dec!(0.5)), "0.5"),
        (
            Expression::Number(Decimal::PI),
            "3.1415926535897932384626433833",
        ),
    ];

    for (expr, expected) in cases {
        assert_eq!(expr.to_string(), expected);
    }
}

#[test]
fn test_expr_display_variable() {
    let expr = Expression::Variable("x".to_owned());
    assert_eq!(expr.to_string(), "x");
}

#[test]
fn test_expr_display_fraction() {
    let cases = vec![
        (
            Expression::Fraction(
                Box::new(Expression::Number(dec!(1))),
                Box::new(Expression::Number(dec!(2))),
            ),
            "(1 / 2)",
        ),
        (
            Expression::Fraction(
                Box::new(Expression::Number(dec!(5))),
                Box::new(Expression::Number(dec!(3))),
            ),
            "(5 / 3)",
        ),
    ];

    for (expr, expected) in cases {
        assert_eq!(expr.to_string(), expected);
    }
}

#[test]
fn test_expr_display_operation() {
    let cases = vec![
        (
            Expression::Operation(
                Operator::Multiply,
                Box::new(Expression::Number(dec!(1))),
                Box::new(Expression::Number(dec!(2))),
            ),
            "(1 * 2)",
        ),
        (
            Expression::Operation(
                Operator::Modulo,
                Box::new(Expression::Number(dec!(6))),
                Box::new(Expression::Number(dec!(3))),
            ),
            "(6 % 3)",
        ),
    ];

    for (expr, expected) in cases {
        assert_eq!(expr.to_string(), expected);
    }
}

#[test]
fn test_expr_display_function() {
    let expr = Expression::Function("sin".to_owned(), vec![Expression::Number(dec!(1))]);
    assert_eq!(expr.to_string(), "sin(1)");
}