fn main() {
    let solver = Solver::new();
    let output = Output::new();

    let blue_transaction_len = 5;

    let blue_block = Block::builder().color(blue);
    let dark_gray_block = Block::builder().color(dark_gray);

    let log_layer = Layer::builder()
        .name("LogAPI")
        .push_entry(
            Entry::builder()
                .label("activeTxn: ")
                .content(
                    Blocks::builder()
                        .push(blue_transaction_len, blue_block.build())
                        .build(),
                )
                .build(),
        )
        .build();

    let other_transactions = [2, 7, 4];

    let group_commit_layer = Layer::builder()
        .name("GroupCommit")
        .push_entry(
            Entry::builder()
                .label("commitedTxn: ")
                .content(
                    BlockList::builder()
                        .append(
                            other_transactions
                                .iter()
                                // TODO: need collect?
                                .map(|len| Blocks::builder().push(len, dark_gray_block.build())),
                        )
                        .push(Blocks::builder().push(blue_transaction_len, blue_block.build()))
                        .build(),
                )
                .build(),
        )
        .build();

    let disk_log_layer = todo!();

    let applier_layer = todo!();

    let layers = &[
        &log_layer,
        &group_commit_layer,
        &disk_log_layer,
        &applier_layer,
    ];
    constraints::distribute_vertically(solver, layers);
    constraints::align_left(solver, layers);

    solver.solve();
    output.write_to_stdout(Output::Format::SVG);
}