//! Which focus records have a VARYING alpha — disc-wide, not export-wide?
//!
//! `rest()` returns an element's last hold keyframe. For a constant-alpha
//! element that is harmless. For one that pulses it returns the PEAK, which is
//! the `ui-settle-time.md` pathology: the plate's `ptbtn00f` ramps 0→80→0 and
//! `rest()` reports 80, its maximum.
//!
//! The port censused this over its own export (34 records, 2 varying) and
//! concluded there is nothing to fix. That conclusion is only as wide as the
//! export. This asks the same question of the whole disc.
use sylpheed_formats::{pak, ratc, ui_layout};

fn main() {
    let root =
        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
    let mut paks: Vec<_> = std::fs::read_dir(format!("{root}/dat"))
        .expect("dat/")
        .flatten()
        .map(|e| e.path())
        .filter(|p| p.extension().and_then(|s| s.to_str()) == Some("pak"))
        .collect();
    paks.sort();
    let (mut n_rec, mut n_elem, mut varying) = (0usize, 0usize, 0usize);
    let (mut at_peak, mut mid_ramp) = (0usize, 0usize);
    let mut by_pak: std::collections::BTreeMap<String, usize> = Default::default();
    let mut hits: Vec<String> = Vec::new();
    for p in &paks {
        let pn = p.file_name().unwrap().to_string_lossy().to_string();
        let Ok(ar) = pak::PakArchive::open(p) else {
            continue;
        };
        for (ei, e) in ar.entries().iter().enumerate() {
            let Ok(by) = ar.read(e) else { continue };
            if !ratc::is_ratc(&by) {
                continue;
            }
            let Some(b) = ui_layout::parse_build(&by) else {
                continue;
            };
            for (rn, &(o, s)) in &b.records {
                // A focus record is one whose name is another record's plus `f`.
                let Some(stem) = rn.strip_suffix("f.rat") else {
                    continue;
                };
                if !b.records.contains_key(&format!("{stem}.rat")) {
                    continue;
                }
                if o + s > by.len() {
                    continue;
                }
                let Some(lb) = ui_layout::parse_build(&by[o..o + s]) else {
                    continue;
                };
                n_rec += 1;
                for el in &lb.elements {
                    if el.keyframes.is_empty() {
                        continue;
                    }
                    n_elem += 1;
                    let a: Vec<u32> = el.keyframes.iter().map(|k| k.fade >> 24).collect();
                    let (lo, hi) = (*a.iter().min().unwrap(), *a.iter().max().unwrap());
                    if lo == hi {
                        continue;
                    }
                    varying += 1;
                    let rest = el.rest().map(|k| k.fade >> 24).unwrap_or(0);
                    if rest == hi {
                        at_peak += 1
                    } else {
                        mid_ramp += 1
                    }
                    *by_pak.entry(pn.clone()).or_default() += 1;
                    hits.push(format!(
                        "{pn} [{ei}] {rn}::{}  alpha {lo}..{hi}  rest()={rest}{}",
                        el.name,
                        if rest == hi { "  🔴 == PEAK" } else { "" }
                    ));
                }
            }
        }
    }
    println!("focus records disc-wide          : {n_rec}");
    println!("  their timed elements           : {n_elem}");
    println!("  with a VARYING alpha           : {varying}");
    println!("    of which rest() == the PEAK  : {at_peak}   <- burns bright forever");
    println!("    of which rest() is MID-RAMP  : {mid_ramp}   <- neither extreme; looks plausible");
    println!("\nby pak:");
    for (k, v) in &by_pak {
        println!("  {k:<34} {v}")
    }
    println!("\nevery varying one:");
    hits.sort();
    hits.dedup();
    for h in &hits {
        println!("  {h}")
    }
    println!("\n({} distinct)", hits.len());
}