use std::fs;
use std::io::{Read, Seek, SeekFrom};
use std::process::Command;
use sylpheed_formats::slb;
fn rg(disc: &str, g: u64, n: usize) -> Vec<u8> {
    let mut segs = vec![];
    let mut cum = 0u64;
    for i in 0..5 {
        let p = format!("{disc}/dat/sound.p{i:02}");
        if let Ok(m) = fs::metadata(&p) {
            segs.push((cum, m.len(), p));
            cum += m.len();
        }
    }
    let mut out = vec![];
    let (mut need, mut pos) = (n, g);
    for (base, len, path) in &segs {
        if need == 0 || pos >= base + len || pos < *base {
            continue;
        }
        let local = pos - base;
        let take = need.min((len - local) as usize);
        let mut f = fs::File::open(path).unwrap();
        f.seek(SeekFrom::Start(local)).unwrap();
        let mut b = vec![0u8; take];
        f.read_exact(&mut b).unwrap();
        out.extend_from_slice(&b);
        need -= take;
        pos += take as u64;
    }
    out
}
fn dur(w: &str) -> String {
    let o = Command::new("ffprobe")
        .args([
            "-v",
            "error",
            "-show_entries",
            "format=duration:stream=channels",
            "-of",
            "default=nw=1:nk=1",
            w,
        ])
        .output()
        .unwrap();
    String::from_utf8_lossy(&o.stdout).replace('\n', " ")
}
fn movdur(disc: &str, m: &str) -> String {
    dur(&format!("{disc}/dat/movie/{m}"))
}
fn main() {
    let disc = std::env::var("SYLPHEED_DISC").unwrap();
    // descriptor trailer global offsets (from scan) => cue N data = [desc(N-1)..desc(N)]
    // (id, end_off, movie)
    let cues = [
        (1600u32, 437044592u64, "ADV.wmv"),
        (1601, 437345648, "RT01A.wmv"),
        (1602, 437712240, "RT01B.wmv"),
        (1603, 438080880, "RT01C_1.wmv"),
        (1604, 438451568, "RT01C_2.wmv"),
        (1605, 438789488, "RT02A.wmv"),
    ];
    for k in 1..cues.len() {
        let (id, end, mov) = cues[k];
        let start = cues[k - 1].1;
        let region = rg(&disc, start, (end - start) as usize + 12000); // +tail to include full data before next trailer
        let riffs = slb::to_xma_riffs(&region);
        let mut total = 0.0f32;
        let mut parts = vec![];
        for (j, r) in riffs.iter().enumerate() {
            let xp = format!("/tmp/cue{id}_{j}.xma.wav");
            let wp = format!("/tmp/cue{id}_{j}.wav");
            fs::write(&xp, r).unwrap();
            let _ = Command::new("ffmpeg")
                .args(["-hide_banner", "-v", "error", "-y", "-i", &xp, &wp])
                .status();
            let d = dur(&wp);
            parts.push(d.clone());
            total += d
                .split_whitespace()
                .next()
                .unwrap_or("0")
                .parse::<f32>()
                .unwrap_or(0.0);
        }
        // spanning?
        let span_adv_end = 437547264u64;
        let _spans = start < span_adv_end && end > span_adv_end || (start / 1_000 != end / 1_000);
        println!("cue {id} ({mov}): region[{start}..{end}] {} bytes, {} riff(s), Σ={:.1}s  | movie={}  parts={:?}",
            end-start, riffs.len(), total, movdur(&disc,mov), parts);
    }
    println!("\nWAVs at /tmp/cue16XX_*.wav  (listen: RT01B=1602, RT01C_1=1603, RT01C_2=1604)");
}