//! Are `GP_DIALOG`'s 140 entries adjacent EN/JP pairs, one per dialog record?
//!
//! The dialog table has 70 records and the archive has 140 entries. If the
//! pairing is adjacent — (0,1), (2,3), … — then dialog index = entry / 2, and the
//! unbound id-to-entry join becomes an ordering question rather than a search.
//!
//! Test: for each pair, compare the SET of element names. GP_TITLE's EN/JP pairs
//! share their sprite sets exactly except for the title art (4/7), so identical
//! sets are the signature of a language pair.
//!
//!     cargo run -p sylpheed-formats --example dialog_pairing
use std::collections::BTreeSet;
use std::path::PathBuf;
use sylpheed_formats::{pak::PakArchive, ui_layout};

fn names(ar: &PakArchive, i: usize) -> Option<BTreeSet<String>> {
    let by = ar.read(&ar.entries()[i]).ok()?;
    let b = ui_layout::parse_build(&by)?;
    Some(b.elements.iter().map(|e| e.name.clone()).collect())
}

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 adj_same, mut adj_diff, mut skipped) = (0, 0, 0);
    for k in (0..n).step_by(2) {
        match (names(&ar, k), names(&ar, k + 1)) {
            (Some(a), Some(b)) => {
                if a == b {
                    adj_same += 1;
                    println!("   identical pair: entries {k}/{}", k + 1)
                } else {
                    adj_diff += 1
                }
            }
            _ => skipped += 1,
        }
    }
    println!("ADJACENT pairing (2k, 2k+1):  identical {adj_same}  differing {adj_diff}  unreadable {skipped}");
    // rival hypothesis: halves, (i, i+70)
    let (mut h_same, mut h_diff, mut h_skip) = (0, 0, 0);
    for k in 0..n / 2 {
        match (names(&ar, k), names(&ar, k + n / 2)) {
            (Some(a), Some(b)) => {
                if a == b {
                    h_same += 1
                } else {
                    h_diff += 1
                }
            }
            _ => h_skip += 1,
        }
    }
    println!(
        "HALVES pairing   (i, i+70):   identical {h_same}  differing {h_diff}  unreadable {h_skip}"
    );
}