//! Is `BGM_103` the ONLY bank with those two wave sizes?
//!
//! `authored/audio.json` says *"Static code, disc census and runtime all agree"*
//! — three legs. Reading the sentence beneath it, legs two and three are **one**
//! comparison: the disc's declared wave sizes matched byte-for-byte against what
//! the XMA probe saw at the menu. That is a disc-to-runtime match, not two
//! independent confirmations.
//!
//! It is a third leg only if the census independently EXCLUDES alternatives — if
//! some other bank carried the same two sizes, the byte match would not
//! distinguish it. So the sizes are counted across every `BGM_*` bank on the
//! disc.
//!
//! Prompted by the Decoder's point that a decorative second support is worse
//! than none: **a conclusion with two supports reads as better evidenced than
//! one with a single support, so apparent redundancy is itself the
//! misinformation.**
use sylpheed_formats::media;

fn main() {
    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
    let src = media::DirectorySource::new(&root);
    const WANT: [usize; 2] = [3_876_864, 3_930_112];
    let (mut found, mut matches) = (0usize, Vec::new());
    for n in 0..=199u32 {
        let name = format!("BGM_{n:03}.slb");
        let Ok(riffs) = media::sound_bank_riffs(&src, &name) else { continue };
        if riffs.is_empty() { continue }
        found += 1;
        let sizes: Vec<usize> = riffs.iter().map(|r| r.len()).collect();
        // Compare on the DATA payload the port sums, not on the RIFF wrapper:
        // a wrapper differs by header bytes and would hide a real collision.
        let near = sizes.iter().any(|s| WANT.iter().any(|w| s.abs_diff(*w) < 4096));
        if near {
            matches.push((name.clone(), sizes.clone()));
        }
    }
    println!("  {found} BGM_* bank(s) readable on this disc");
    for (n, s) in &matches {
        println!("    {n:<14} wave sizes {s:?}");
    }
    println!("\n  {} bank(s) carry a wave within 4 KiB of {WANT:?}", matches.len());
    println!("  Exactly 1 means the census EXCLUDES alternatives and is a real third");
    println!("  leg. More than 1 means the byte match does not distinguish BGM_103,");
    println!("  and \"three legs\" is two. Zero means this reader cannot see the");
    println!("  incumbent and its answer means nothing.");
}