//! `wai.media.upscale` (extensions/exact-upscale.md): the committed corpus
//! `live-conformance/upscale/` regenerates byte for byte from its fixed seeds and its two
//! pinned trained priors, holds no other file, every case in it gets the outcome it states,
//! and the extension's §8 lists exactly the reasons the reference reports. The generator
//! itself asserts that the corpus gives every one of them.
#![cfg(feature = "exact_upscale")]

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

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

fn committed() -> BTreeMap<String, Vec<u8>> {
    let dir = wai_dir().join("live-conformance/upscale");
    let mut files = BTreeMap::new();
    for sub in ["", "priors"] {
        for e in std::fs::read_dir(dir.join(sub)).expect("the committed corpus").flatten() {
            let name = e.file_name().to_string_lossy().into_owned();
            if e.path().is_dir() || (sub.is_empty() && name == "README.md") {
                continue;
            }
            let key = if sub.is_empty() { name } else { format!("{sub}/{name}") };
            files.insert(key, std::fs::read(e.path()).expect("a file"));
        }
    }
    files
}

fn inputs(files: &BTreeMap<String, Vec<u8>>) -> BTreeMap<String, Vec<u8>> {
    corpus::INPUT_PRIORS.iter().filter_map(|(n, _)| files.get(&format!("priors/{n}")).map(|b| (n.to_string(), b.clone()))).collect()
}

#[test]
fn the_trained_priors_are_the_pinned_ones() {
    assert_eq!(corpus::check_input_priors(&inputs(&committed())), Vec::<String>::new());
}

#[test]
fn the_committed_corpus_regenerates_from_its_seeds() {
    let files = committed();
    let mut generated: BTreeMap<String, Vec<u8>> = corpus::generate(&inputs(&files)).into_iter().collect();
    for (n, _) in corpus::INPUT_PRIORS {
        let k = format!("priors/{n}");
        generated.insert(k.clone(), files[&k].clone());
    }
    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_upscale_vectors gen`");
}

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

/// §8 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/exact-upscale.md")).expect("the extension");
    let at = text.find("\n## 8. Reasons").expect("a §8");
    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, "§8's table and Reason::ALL differ");
}

/// Every derivation output the corpus states is in `sha256.json`, and each digest there is
/// an output of the corpus's accepted upscale records.
#[test]
fn the_sidecar_names_every_accepted_output() {
    let files = committed();
    let side: serde_json::Value = serde_json::from_slice(&files["sha256.json"]).expect("sha256.json");
    let doc: serde_json::Value = serde_json::from_slice(&files["vectors.json"]).expect("vectors.json");
    let mut want = 0;
    for v in doc["vectors"].as_array().unwrap().iter().filter(|v| v["outcome"] == "accept") {
        for (i, t) in v["upscales"].as_array().unwrap().iter().enumerate() {
            let u = wai::exact_upscale::read_upscale(t.as_str().unwrap()).unwrap();
            let k = format!("{}/upscale/{i}/output", v["name"].as_str().unwrap());
            assert_eq!(side[&k]["sha256"].as_str(), Some(wai::exact_upscale::hex(&u.output).as_str()), "{k}");
            want += 1;
        }
    }
    assert_eq!(side.as_object().unwrap().len(), want);
}