extern crate modelthing;

use std::collections::HashSet;
use std::iter::FromIterator;
use modelthing::modelica_ast::*;

fn set_eq(a: Vec<String>, b: Vec<String>) -> bool {
    let set_a: HashSet<String> = HashSet::from_iter(a);
    let set_b: HashSet<String> = HashSet::from_iter(b);
    return set_a == set_b;
}

#[test]
fn test_expr_identifiers() {
    use modelthing::modelica_ast::Expr::*;

    assert!(set_eq(
        vec![],
        Integer(0).identifiers()));
    assert!(set_eq(
        vec!["x".to_string()],
        Ident("x".to_string()).identifiers()));
    assert!(set_eq(
        vec!["x".to_string(), "y".to_string(), "z".to_string()],
        BinExpr(BinOperator::Add,
            Box::new(Abs(Box::new(Ident("z".to_string())))),
            Box::new(BinExpr(BinOperator::Add,
                Box::new(Abs(Box::new(Ident("x".to_string())))),
                Box::new(Abs(Box::new(Ident("y".to_string()))))))).identifiers()));
    assert!(set_eq(
        vec!["z".to_string()],
        BinExpr(BinOperator::Add,
            Box::new(Ident("z".to_string())),
            Box::new(Ident("z".to_string()))).identifiers()));
}

#[test]
fn test_eqn_identifiers() {
    use modelthing::modelica_ast::Expr::*;

    assert!(set_eq(
        vec![],
        SimpleEquation{
            lhs: Integer(0),
            rhs: Integer(0),
        }.identifiers()));
    assert!(set_eq(
        vec!["z".to_string()],
        SimpleEquation{
            lhs: Ident("z".to_string()),
            rhs: BinExpr(BinOperator::Add,
                Box::new(Ident("z".to_string())),
                Box::new(Ident("z".to_string()))),
        }.identifiers()));
}

#[test]
fn test_rebalance_for() {
    use modelthing::modelica_ast::Expr::*;

    // z = a - 1.2345
    // a = z + 1.2345
    let done = SimpleEquation{
        lhs: Ident("z".to_string()),
        rhs: BinExpr(BinOperator::Subtract,
            Box::new(Ident("a".to_string())),
            Box::new(Float(1.2345)))};
    assert_eq!(done,
        done.rebalance_for("z".to_string()).unwrap());
    assert_eq!(SimpleEquation{
        lhs: Ident("a".to_string()),
        rhs: BinExpr(BinOperator::Add,
            Box::new(Ident("z".to_string())),
            Box::new(Float(1.2345)))},
        done.rebalance_for("a".to_string()).unwrap());

}