// Module 8: Push chains. Each test matches a heading in scenarios.md.
use engine::harness::*;

/// An empty level `width` wide and `height` high.
fn empty_level(width: i32, height: i32) -> LevelDef {
    LevelDef {
        width,
        height,
        ..Default::default()
    }
}

/// Place one text object per word: `(word, x, y)`.
fn write(b: &mut Baba, words: &[(&str, i32, i32)]) {
    for &(word, x, y) in words {
        b.place(&format!("text:{word}"), x, y);
    }
}

#[test]
fn test_08_chain_moves_together() {
    let mut b = new_baba(empty_level(6, 4));
    write(&mut b, &[("BABA", 0, 0), ("IS", 1, 0), ("YOU", 2, 0)]);
    write(&mut b, &[("ROCK", 0, 1), ("IS", 1, 1), ("PUSH", 2, 1)]);
    let baba = b.place("baba", 0, 3);
    let rocks = [
        b.place("rock", 1, 3),
        b.place("rock", 2, 3),
        b.place("rock", 3, 3),
    ];

    b.move_dir(Dir::Right);

    assert_eq!(b.pos_of(baba), Some((1, 3)));
    assert_eq!(b.pos_of(rocks[0]), Some((2, 3)));
    assert_eq!(b.pos_of(rocks[1]), Some((3, 3)));
    assert_eq!(b.pos_of(rocks[2]), Some((4, 3)));
    assert_eq!(b.kinds_at(0, 3), Vec::<String>::new());
    assert_eq!(b.kinds_at(4, 3), vec!["rock"]);
}

#[test]
fn test_08_chain_into_stop_nothing_moves() {
    let mut b = new_baba(empty_level(6, 5));
    write(&mut b, &[("BABA", 0, 0), ("IS", 1, 0), ("YOU", 2, 0)]);
    write(&mut b, &[("ROCK", 0, 1), ("IS", 1, 1), ("PUSH", 2, 1)]);
    write(&mut b, &[("WALL", 0, 2), ("IS", 1, 2), ("STOP", 2, 2)]);
    let baba = b.place("baba", 0, 4);
    let rocks = [
        b.place("rock", 1, 4),
        b.place("rock", 2, 4),
        b.place("rock", 3, 4),
    ];
    let wall = b.place("wall", 4, 4);

    b.move_dir(Dir::Right);

    assert_eq!(b.pos_of(baba), Some((0, 4)));
    assert_eq!(b.pos_of(rocks[0]), Some((1, 4)));
    assert_eq!(b.pos_of(rocks[1]), Some((2, 4)));
    assert_eq!(b.pos_of(rocks[2]), Some((3, 4)));
    assert_eq!(b.pos_of(wall), Some((4, 4)));
}

#[test]
fn test_08_open_shut_during_push() {
    let mut b = new_baba(empty_level(5, 5));
    write(&mut b, &[("BABA", 0, 0), ("IS", 1, 0), ("YOU", 2, 0)]);
    write(
        &mut b,
        &[
            ("KEY", 0, 1),
            ("IS", 1, 1),
            ("PUSH", 2, 1),
            ("AND", 3, 1),
            ("OPEN", 4, 1),
        ],
    );
    write(
        &mut b,
        &[
            ("DOOR", 0, 2),
            ("IS", 1, 2),
            ("STOP", 2, 2),
            ("AND", 3, 2),
            ("SHUT", 4, 2),
        ],
    );
    let baba = b.place("baba", 0, 4);
    let key = b.place("key", 1, 4);
    let door = b.place("door", 2, 4);

    b.move_dir(Dir::Right);

    assert_eq!(b.pos_of(key), None);
    assert_eq!(b.pos_of(door), None);
    // Inferred, not stated by a source: Baba lands on the key's former tile.
    assert_eq!(b.pos_of(baba), Some((1, 4)));
    assert_eq!(b.kinds_at(2, 4), Vec::<String>::new());
    assert_eq!(b.kinds_at(1, 4), vec!["baba"]);
}

#[test]
fn test_08_text_pushed() {
    let mut b = new_baba(empty_level(4, 5));
    write(&mut b, &[("BABA", 0, 0), ("IS", 1, 0), ("YOU", 2, 0)]);
    let baba = b.place("baba", 0, 2);
    let rock_text = b.place("text:ROCK", 1, 2);
    write(&mut b, &[("IS", 2, 3), ("PUSH", 2, 4)]);

    assert_eq!(b.rules(), vec!["BABA IS YOU", "TEXT IS PUSH"]);

    b.move_dir(Dir::Right);

    assert_eq!(b.pos_of(baba), Some((1, 2)));
    assert_eq!(b.pos_of(rock_text), Some((2, 2)));
    assert_eq!(
        b.rules(),
        vec!["BABA IS YOU", "ROCK IS PUSH", "TEXT IS PUSH"]
    );
}

#[test]
fn test_08_level_edge_is_stop() {
    let mut b = new_baba(empty_level(3, 3));
    write(&mut b, &[("BABA", 0, 0), ("IS", 1, 0), ("YOU", 2, 0)]);
    let baba = b.place("baba", 1, 2);
    let flag_text = b.place("text:FLAG", 2, 2);

    b.move_dir(Dir::Right);

    assert_eq!(b.pos_of(baba), Some((1, 2)));
    assert_eq!(b.pos_of(flag_text), Some((2, 2)));

    b.move_dir(Dir::Down);

    assert_eq!(b.pos_of(baba), Some((1, 2)));
    assert_eq!(b.pos_of(flag_text), Some((2, 2)));
}