pub mod context;
pub mod expression;
pub mod function;
pub mod operation;
pub mod string;

use std::collections::HashMap;

use expression::Expression;
use function::Function;
use operation::Operation;

use crate::context::Context;

fn add(a: f64, b: f64) -> f64 {
    a + b
}

fn mul(a: f64, b: f64) -> f64 {
    a * b
}

fn div(a: f64, b: f64) -> f64 {
    a / b
}

fn pow(a: f64, b: f64) -> f64 {
    a.powf(b)
}

fn sqrt(a: f64) -> f64 {
    a.sqrt()
}

impl<T> Function for T
where
    T: Fn(f64) -> f64,
{
    fn eval(&self, args: function::FunctionArgument) -> f64 {
        self(args.get(0))
    }
}

fn main() {
    let expr = "(2 + (3 + 10) * (3 + 10)) * 2";

    let mut funcs : HashMap<String, Box<dyn Function>> = HashMap::new();
    funcs.insert("sqrt".to_string(), Box::new(&sqrt));
    let ctx: Context = Context::new()
        .with_operations(opvec![('+', &add), ('*', &mul), ('/', &div), ('^', &pow)])
        .with_functions(funcs);
    let value = Expression::from_string(expr);

    match value.evaluate(&ctx) {
        Ok(res) => println!("{} = {}", expr, res),
        Err(err) => println!("Error: {}", err),
    }
}