//! `wai.live.coperformance` (extensions/co-performance.md): the committed corpus
//! `live-conformance/coperformance/` regenerates byte for byte from its fixed seeds, holds no
//! other file, every room in it gets the outcome it states, and the extension's §10 lists
//! exactly the reasons the reference reports. The generator itself asserts that the corpus
//! gives every one of them.
#![cfg(feature = "co_performance")]

use std::collections::BTreeMap;
use std::path::PathBuf;
use wai::co_performance::{corpus, Reason};

fn wai_dir() -> PathBuf {
    PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("..")
}

fn committed() -> BTreeMap<String, String> {
    let dir = wai_dir().join("live-conformance/coperformance");
    std::fs::read_dir(&dir)
        .expect("the committed corpus")
        .flatten()
        .map(|e| (e.file_name().to_string_lossy().into_owned(), e.path()))
        .filter(|(n, _)| n != "README.md")
        .map(|(n, p)| (n, std::fs::read_to_string(p).expect("a text file")))
        .collect()
}

#[test]
fn the_committed_corpus_regenerates_from_its_seeds() {
    let files = committed();
    let generated: BTreeMap<String, String> = corpus::generate().into_iter().collect();
    let extra: Vec<&String> = files.keys().filter(|k| !generated.contains_key(*k)).collect();
    let missing: Vec<&String> = generated.keys().filter(|k| !files.contains_key(*k)).collect();
    let differ: Vec<&String> = generated.iter().filter(|(k, v)| files.get(*k).is_some_and(|f| f != *v)).map(|(k, _)| k).collect();
    assert!(extra.is_empty() && missing.is_empty() && differ.is_empty(), "extra {extra:?}, missing {missing:?}, differ {differ:?}: run `wai_co_performance_vectors gen`");
}

#[test]
fn every_room_gets_its_stated_outcome() {
    let fails = corpus::verify(&committed());
    assert!(fails.is_empty(), "{}", fails.join("\n"));
}

/// §10 of the extension lists exactly the codes `Reason::ALL` has, each once, in order.
#[test]
fn the_extension_lists_the_reasons() {
    let text = std::fs::read_to_string(wai_dir().join("extensions/co-performance.md")).expect("the extension");
    let at = text.find("\n## 10. Reasons").expect("a §10");
    let end = text[at + 1..].find("\n## ").map_or(text.len(), |e| at + 1 + e);
    let listed: Vec<String> =
        text[at..end].lines().filter(|l| l.starts_with("| `")).filter_map(|l| l.split('`').nth(1).map(String::from)).collect();
    let want: Vec<String> = Reason::ALL.iter().map(|r| r.code().to_string()).collect();
    assert_eq!(listed, want, "§10's table and Reason::ALL differ");
}

fn unhex(s: &str) -> Vec<u8> {
    (0..s.len()).step_by(2).map(|i| u8::from_str_radix(&s[i..i + 2], 16).expect("hexadecimal")).collect()
}

fn d32(s: &str) -> [u8; 32] {
    unhex(s).try_into().expect("32 bytes")
}

/// A corpus room's inputs, read.
struct Room {
    descriptor: Vec<u8>,
    grants: Vec<Vec<u8>>,
    chains: Vec<Vec<Vec<u8>>>,
    policies: Vec<Vec<u8>>,
    objects: Vec<wai::co_performance::Object>,
    payloads: Vec<Vec<u8>>,
}

fn room(name: &str) -> Room {
    let files = committed();
    let doc: serde_json::Value = serde_json::from_str(&files["vectors.json"]).expect("JSON");
    let v = doc["vectors"].as_array().unwrap().iter().find(|v| v["name"] == name).expect("the room");
    let list = |v: &serde_json::Value| v.as_array().unwrap().iter().map(|h| unhex(h.as_str().unwrap())).collect::<Vec<_>>();
    Room {
        descriptor: unhex(v["descriptor"].as_str().unwrap()),
        grants: list(&v["grants"]),
        chains: v["chains"].as_array().unwrap().iter().map(list).collect(),
        policies: list(&v["policies"]),
        objects: v["objects"]
            .as_array()
            .unwrap()
            .iter()
            .map(|o| wai::co_performance::Object {
                principal: d32(o["principal"].as_str().unwrap()),
                track: d32(o["track"].as_str().unwrap()),
                group: o["group"].as_u64().unwrap(),
                object: o["object"].as_u64().unwrap(),
                digest: d32(o["digest"].as_str().unwrap()),
                arrival: o["arrival"].as_u64().unwrap(),
                due: o["due"].as_u64().unwrap(),
            })
            .collect(),
        payloads: list(&v["payloads"]),
    }
}

/// What a room clock signs, read from the room replayed up to each statement only a room key
/// signs (co-performance §8), is that statement byte for byte: every commitment, selection and
/// fidelity statement of the corpus's accepted rooms, recomputed from the room as it stood just
/// before it; and every object's marks are the flags the replay gives it.
#[test]
fn the_clock_signs_what_the_verifier_recomputes() {
    use wai::co_performance::{magic, replay, Input, Statement};
    use wai::live_events::{kind, Event};
    let mut checked = BTreeMap::<String, usize>::new();
    for name in ["jam", "audience"] {
        let r = room(name);
        let d = wai::live_room::Descriptor::parse(&r.descriptor).unwrap();
        for (c, chain) in r.chains.iter().enumerate() {
            for (i, rec) in chain.iter().enumerate() {
                let ev = Event::parse(rec).unwrap();
                if ev.kind != kind::META || !d.is_room_key(&ev.principal) || ev.payload.len() < 4 {
                    continue;
                }
                let m: [u8; 4] = ev.payload[..4].try_into().unwrap();
                if ![magic::COMMIT, magic::SELECTION, magic::FIDELITY].contains(&m) {
                    continue;
                }
                let mut before = r.chains.clone();
                before[c].truncate(i);
                let inp = Input { descriptor: &r.descriptor, grants: &r.grants, head: None, chains: &before, policies: &r.policies, objects: &r.objects, payloads: &r.payloads };
                let rp = replay(&inp).unwrap_or_else(|e| panic!("{name}: the room before record {i} of chain {c} replays: {e:?}"));
                let signed = Statement::parse(&ev.payload).unwrap();
                let made = match &signed {
                    Statement::Commit(x) => Statement::Commit(rp.commitment(&x.window, ev.t).expect("a commitment")),
                    Statement::Selection(x) => Statement::Selection(rp.selection(&x.window, x.seed).expect("a selection")),
                    Statement::Fidelity(x) => Statement::Fidelity(rp.fidelity(x.through, ev.t).expect("a fidelity statement")),
                    _ => unreachable!("filtered above"),
                };
                assert_eq!(made.encode(), ev.payload, "{name}: chain {c} record {i}");
                *checked.entry(String::from_utf8(m.to_vec()).unwrap()).or_default() += 1;
                // Once signed, the clock does not sign it again.
                if let Statement::Commit(x) = &signed {
                    let rp = replay(&Input { chains: &r.chains, ..inp }).unwrap();
                    assert!(rp.commitment(&x.window, ev.t).is_none(), "{name}: a window committed is not committed again");
                    assert!(rp.windows().iter().any(|w| w.digest == x.window && w.commit.is_some() && w.selected));
                }
            }
        }
        // Every object's marks are the flags the whole room's replay gives it.
        let inp = Input { descriptor: &r.descriptor, grants: &r.grants, head: None, chains: &r.chains, policies: &r.policies, objects: &r.objects, payloads: &r.payloads };
        let rp = replay(&inp).unwrap();
        let mut marked = BTreeMap::<([u8; 32], u64, u64), u8>::new();
        for rec in r.chains.iter().flatten() {
            let ev = Event::parse(rec).unwrap();
            if ev.kind == kind::META && ev.payload.starts_with(&magic::MARK) {
                let Statement::Mark(x) = Statement::parse(&ev.payload).unwrap() else { unreachable!() };
                *marked.entry((x.track, x.group, x.object)).or_default() |= x.flags;
            }
        }
        for o in &r.objects {
            assert_eq!(rp.marks_for(o), marked.get(&(o.track, o.group, o.object)).copied().unwrap_or(0), "{name}: the marks of object {}/{}", o.group, o.object);
        }
        *checked.entry("objects".into()).or_default() += r.objects.len();
    }
    assert!(checked.get("WPK1").copied().unwrap_or(0) >= 3 && checked.get("WPS1").copied().unwrap_or(0) >= 3 && checked.get("WPF1").copied().unwrap_or(0) >= 1, "{checked:?}");
    assert!(room("jam").objects.iter().any(|o| {
        let r = room("jam");
        let inp = Input { descriptor: &r.descriptor, grants: &r.grants, head: None, chains: &r.chains, policies: &r.policies, objects: &r.objects, payloads: &r.payloads };
        replay(&inp).unwrap().marks_for(o) != 0
    }), "the jam room has an object to mark");
}

/// A draw's selection is refused a seed that is not the one committed to, and a commitment is
/// not made before its window closes.
#[test]
fn the_clock_keeps_to_the_commitment_and_the_seed() {
    use wai::co_performance::{replay, rule, Input};
    let r = room("audience");
    let inp = Input { descriptor: &r.descriptor, grants: &r.grants, head: None, chains: &r.chains, policies: &r.policies, objects: &r.objects, payloads: &r.payloads };
    let rp = replay(&inp).unwrap();
    let ws = rp.windows();
    let draw = ws.iter().find(|w| w.window.rule == rule::DRAW).expect("a draw");
    assert!(rp.selection(&draw.digest, [0xee; 32]).is_none(), "a seed not committed to");
    // The room without its clock's statements after the draw opened: no commitment before close.
    let mut cut = r.chains.clone();
    let d = wai::live_room::Descriptor::parse(&r.descriptor).unwrap();
    for c in cut.iter_mut() {
        if c.first().is_some_and(|x| d.is_room_key(&wai::live_events::Event::parse(x).unwrap().principal)) {
            c.retain(|x| wai::live_events::Event::parse(x).unwrap().t <= draw.opened);
        }
    }
    let rp = replay(&Input { chains: &cut, ..inp }).unwrap();
    assert!(rp.commitment(&draw.digest, draw.window.close - 1).is_none(), "commit_early");
    assert!(rp.commitment(&draw.digest, draw.window.close).is_some());
    assert!(rp.selection(&draw.digest, [0; 32]).is_none(), "no selection before a commitment");
}