//! Every record reachable from an element — leaf **and** `focus_link` — plus a
//! disc-wide census of how many elements have more than one.
//!
//! ⚠️ WHY. I claimed `ptbtn00f`'s peak alpha of 80 was undeclared, having read
//! `ptbtn00.rat` (the leaf, flat 255) and stopped. The pulse is in
//! `ptbtn00f.rat`, the focus record. `focus_link` was already parsed and
//! `ui_layout.rs` already documented it: the format was known and I did not
//! consult it. An absence claim is only as good as its enumeration, so this
//! enumerates rather than asking the reader to remember.
//!
//!     cargo run -p sylpheed-formats --example element_records -- GP_TITLE ptbtn00
//!     cargo run -p sylpheed-formats --example element_records -- --census
use std::path::PathBuf;
use sylpheed_formats::{pak::PakArchive, ui_layout};

fn main() {
    let root = PathBuf::from(std::env::var("SYLPHEED_DISC").expect("SYLPHEED_DISC"));
    let argv: Vec<String> = std::env::args().skip(1).collect();

    if argv.iter().any(|a| a == "--census") {
        let (mut els, mut linked, mut screens_with) = (0usize, 0usize, 0usize);
        let mut paks: Vec<_> = std::fs::read_dir(root.join("dat"))
            .expect("dat")
            .filter_map(|e| e.ok())
            .map(|e| e.path())
            .filter(|p| p.extension().map(|x| x == "pak").unwrap_or(false))
            .collect();
        paks.sort();
        for p in &paks {
            let Ok(ar) = PakArchive::open(p) else {
                continue;
            };
            for ent in ar.entries() {
                let Ok(by) = ar.read(ent) else { continue };
                let Some(b) = ui_layout::parse_build(&by) else {
                    continue;
                };
                let n = b.elements.iter().filter(|e| e.focus_link.is_some()).count();
                els += b.elements.len();
                linked += n;
                if n > 0 {
                    screens_with += 1
                }
            }
        }
        println!("elements disc-wide          : {els}");
        println!(
            "with a focus_link record    : {linked}  ({:.1}%)",
            100.0 * linked as f64 / els as f64
        );
        println!("builds containing at least 1: {screens_with}");
        println!("\nEach of those carries a SECOND record whose keyframes are invisible");
        println!("to anyone who looks up the leaf by name and stops.");
        return;
    }

    let pak = argv.first().cloned().unwrap_or_else(|| "GP_TITLE".into());
    let want = argv.get(1).cloned();
    let ar = PakArchive::open(root.join(format!("dat/{pak}.pak"))).expect("pak");
    for (i, ent) in ar.entries().iter().enumerate() {
        let Ok(by) = ar.read(ent) else { continue };
        let Some(b) = ui_layout::parse_build(&by) else {
            continue;
        };
        for el in &b.elements {
            if let Some(w) = &want {
                if !el.name.starts_with(w.as_str()) {
                    continue;
                }
            }
            if el.focus_link.is_none() && want.is_none() {
                continue;
            }
            println!("entry {i}: {}", el.name);
            let stem = el.name.trim_end_matches(".rat");
            for (tag, rec) in [
                ("leaf", format!("{stem}.rat")),
                ("focus", el.focus_link.clone().unwrap_or_default()),
            ] {
                if rec.is_empty() {
                    continue;
                }
                match b.records.get(rec.as_str()) {
                    Some(&(lo, ls)) => {
                        let bytes = &by[lo..(lo + ls).min(by.len())];
                        let loop_u = ui_layout::loop_length_units(bytes);
                        let kf: Vec<String> = ui_layout::parse_build(bytes)
                            .map(|lb| {
                                lb.elements
                                    .iter()
                                    .map(|e| {
                                        format!(
                                            "{} [{} keys, peak a{}]",
                                            e.name,
                                            e.keyframes.len(),
                                            e.keyframes
                                                .iter()
                                                .map(|k| k.fade >> 24)
                                                .max()
                                                .unwrap_or(0)
                                        )
                                    })
                                    .collect()
                            })
                            .unwrap_or_default();
                        println!("   {tag:<6} {rec:<20} loop {:?}  {}", loop_u, kf.join(", "));
                    }
                    None => println!("   {tag:<6} {rec:<20} (no such record)"),
                }
            }
        }
    }
}