extern crate rustijvm;

fn steps(machine: &mut rustijvm::Machine, num: usize) {
    for _ in 0..num {
        machine.step().unwrap();
    }
}

#[test]
fn task3_goto1() {
    let mut machine = rustijvm::Machine::new_from_file("files/task3/GOTO1.ijvm").unwrap();
    steps(&mut machine, 1);
    assert_eq!(machine.get_tos(), Ok(0x31));
    steps(&mut machine, 3);
    assert_eq!(machine.get_tos(), Ok(0x33));
    steps(&mut machine, 1);
}

#[test]
fn task3_goto2() {
    let mut machine = rustijvm::Machine::new_from_file("files/task3/GOTO2.ijvm").unwrap();
    steps(&mut machine, 1);
    assert_eq!(machine.get_tos(), Ok(0x31));
    steps(&mut machine, 3);
    assert_eq!(machine.get_tos(), Ok(0x33));
    steps(&mut machine, 3);
    assert_eq!(machine.get_tos(), Ok(0x32));
    steps(&mut machine, 1);
}

#[test]
fn task3_ifeq1() {
    let mut machine = rustijvm::Machine::new_from_file("files/task3/IFEQ1.ijvm").unwrap();

    steps(&mut machine, 1);
    assert_eq!(machine.get_tos(), Ok(0x5));

    // L2 iteration 1
    steps(&mut machine, 6);
    assert_eq!(machine.get_tos(), Ok(0x4));
    steps(&mut machine, 3);
    let pc = machine.get_program_counter();

    // L2 iteration 2
    steps(&mut machine, 6);
    assert_eq!(machine.get_tos(), Ok(0x3));
    steps(&mut machine, 3);
    assert_eq!(machine.get_program_counter(), pc);

    // L2 iteration 3
    steps(&mut machine, 6);
    assert_eq!(machine.get_tos(), Ok(0x2));
    steps(&mut machine, 3);
    assert_eq!(machine.get_program_counter(), pc);

    // L2 iteration 4
    steps(&mut machine, 6);
    assert_eq!(machine.get_tos(), Ok(0x1));
    steps(&mut machine, 3);
    assert_eq!(machine.get_program_counter(), pc);

    // L2 iteration 5
    steps(&mut machine, 6);
    assert_eq!(machine.get_tos(), Ok(0x0));
    steps(&mut machine, 2);
    assert_eq!(machine.get_program_counter(), pc + 15);
}

#[test]
fn task3_iflt1() {
    let mut machine = rustijvm::Machine::new_from_file("files/task3/IFLT1.ijvm").unwrap();
    let mut pc = 0;

    // L1
    steps(&mut machine, 2);
    assert_eq!(machine.get_program_counter(), pc + 5);
    pc = machine.get_program_counter();

    // L2
    steps(&mut machine, 2);
    assert_eq!(machine.get_program_counter(), pc + 5);
    pc = machine.get_program_counter();

    // L3
    steps(&mut machine, 2);
    assert_eq!(machine.get_program_counter(), pc + 5);
    pc = machine.get_program_counter();

    // L4
    steps(&mut machine, 4);
    assert_eq!(machine.get_program_counter(), pc + 19);
    steps(&mut machine, 1);
    assert_eq!(machine.get_tos(), Ok(0x37));
}

#[test]
fn task3_ificmpeq1() {
    let mut machine = rustijvm::Machine::new_from_file("files/task3/IFICMPEQ1.ijvm").unwrap();
    let mut pc = 0;

    // L1
    steps(&mut machine, 3);
    assert_eq!(machine.get_program_counter(), pc + 7);
    pc = machine.get_program_counter();

    // L2
    steps(&mut machine, 5);
    assert_eq!(machine.get_program_counter(), pc + 10);
    pc = machine.get_program_counter();

    // L3
    steps(&mut machine, 4);
    assert_eq!(machine.get_program_counter(), pc + 8);
    pc = machine.get_program_counter();

    // L4
    for _ in 0..3 {
        steps(&mut machine, 3);
        assert_eq!(machine.get_program_counter(), pc);
        pc = machine.get_program_counter()
    }

    // L6
    steps(&mut machine, 2);
    assert_eq!(machine.get_program_counter(), pc + 9);
    steps(&mut machine, 1);
    assert_eq!(machine.get_tos(), Ok(0x13));
}