use std::rc::Rc;

use talc_lang::{compiler::compile, optimize, parser, value::Value, Vm};

fn assert_eval(src: &str, value: Value) {
	let mut ex = parser::parse(src).expect(&format!("failed to parse expression"));
	optimize(&mut ex);
	let f = compile(&ex, None).expect("failed to compile expression");
	let f = Rc::new(f);
	let mut vm = Vm::new(16, Vec::new());
	let res = vm
		.run_function(f.clone(), vec![f.into()])
		.expect("vm produced an exception");

	assert_eq!(
		res.get_type().name(),
		value.get_type().name(),
		"result and target types differ"
	);
	assert_eq!(res, value, "result and target differ");
}

#[test]
fn scope() {
	assert_eval(
		"
            var x = 7
            var y = 10
            do
                var x = 200
                y = 100
            end
            x + y
        ",
		Value::Int(7 + 100),
	);
	assert_eval(
		"
            var cond = true
            var z = 2
            if cond then var z = 5 else var z = 6 end
            z
        ",
		Value::Int(2),
	);
	assert_eval(
		"
            var i = 55
            var j = 66
            for i in 0..10 do
                j = i
            end
            i + j
        ",
		Value::Int(55 + 9),
	);
}

#[test]
fn forloop() {
	assert_eval(
		"
            sum = 0
            for i in 0..5 do
                for j in 0..10 do
                    sum += i*j
                end
            end
            sum
        ",
		Value::Int(45 * 10),
	);
	assert_eval(
		"
            map = {a=3, b=2, c=4, d=7}
            prod = 1
            for k in map do
                prod *= map[k]
            end
            prod
        ",
		Value::Int(3 * 2 * 4 * 7),
	);
}

#[test]
fn closures() {
	assert_eval(
		"
            var x = 2
            next = \\-> do x = x * 2 + 1 end
            next() + next() + next()
        ",
		Value::Int(5 + 11 + 23),
	);
	assert_eval(
		"
            var x = 0
            fn outer(n) do
                fn inner() do
                    x += n
                    n += 1
                    x
                end
            end

            var f = outer(2)
            var g = outer(6)
            f() + f() + g() + g() + f()
        ",
		Value::Int(2 + 5 + 11 + 18 + 22),
	);
}

#[test]
fn tailcall() {
	assert_eval(
		"
            fn test(n, a) do
                if n <= 0 then
                    a
                else
                    self(n-1, n+a)
                end
            end
            test(24, 0)
        ",
		Value::Int(300),
	) // = 24 + 23 + ... + 1
}