//! Do adjacent `GP_DIALOG` entries differ in BUTTON COUNT?
//!
//! I offered an untested reading for why 63 of 65 adjacent pairs have different
//! element sets: dialog text baked into language-specific sprites, so EN/JP
//! entries differ by construction. `sylpheed-port` refuted it with a count — two
//! languages of one dialog cannot differ in how many buttons they have. This
//! re-derives that with my own reader before I record the refutation.
//!
//!     cargo run -p sylpheed-formats --example dialog_pair_button_counts
use std::path::PathBuf;
use sylpheed_formats::{pak::PakArchive, ui_layout};

fn btns(ar: &PakArchive, i: usize) -> Option<usize> {
    let by = ar.read(&ar.entries()[i]).ok()?;
    let b = ui_layout::parse_build(&by)?;
    Some(b.elements.iter().filter(|e| e.name.contains("btn")).count())
}

fn main() {
    let root = PathBuf::from(std::env::var("SYLPHEED_DISC").expect("SYLPHEED_DISC"));
    let ar = PakArchive::open(root.join("dat/GP_DIALOG.pak")).expect("GP_DIALOG");
    let n = ar.entries().len();
    let (mut diff, mut same, mut skip) = (0, 0, 0);
    let mut show = 0;
    for k in (0..n).step_by(2) {
        match (btns(&ar, k), btns(&ar, k + 1)) {
            (Some(a), Some(b)) => {
                if a != b {
                    diff += 1;
                    if show < 6 {
                        println!("   entries {k:3}/{:<3} button counts {a} vs {b}", k + 1);
                        show += 1;
                    }
                } else {
                    same += 1
                }
            }
            _ => skip += 1,
        }
    }
    println!("\nadjacent pairs differing in BUTTON COUNT: {diff}");
    println!("adjacent pairs with equal button counts  : {same}");
    println!("unreadable                               : {skip}");
    println!("\ntwo languages of one dialog cannot differ in button count.");
}