//! Media identification (extensions/media-identify.md): the committed corpus `identify-conformance/`
//! regenerates byte for byte with every result, the extension's tables are the reference's, and
//! `wai identify` gives what the library gives.
#![cfg(feature = "identify")]

use std::collections::BTreeMap;
use std::path::PathBuf;
use std::process::Command;
use wai::identify::{corpus, embedded_table, identify_bytes, signature_table};

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

fn committed() -> BTreeMap<String, Vec<u8>> {
    let root = wai_dir().join("identify-conformance");
    let mut out = BTreeMap::new();
    for sub in ["ext", "gen"] {
        for e in std::fs::read_dir(root.join(sub)).expect("a corpus directory").flatten() {
            let name = e.file_name().to_string_lossy().to_string();
            out.insert(format!("{sub}/{name}"), std::fs::read(e.path()).unwrap());
        }
    }
    out.insert("vectors.json".into(), std::fs::read(root.join("vectors.json")).expect("vectors.json"));
    out
}

#[test]
fn the_corpus_regenerates_and_every_result_holds() {
    let files = committed();
    assert!(files.keys().filter(|k| k.starts_with("ext/")).count() >= 40, "the external vectors");
    let fails = corpus::verify(&files);
    assert!(fails.is_empty(), "{}: run `wai_identify_vectors gen`", fails.join("\n"));
}

fn spec() -> String {
    std::fs::read_to_string(wai_dir().join("extensions/media-identify.md")).expect("the extension")
}

fn section(text: &str, heading: &str) -> String {
    let at = text.find(&format!("\n{heading}")).unwrap_or_else(|| panic!("{heading}"));
    let end = text[at + 1..].find("\n## ").map_or(text.len(), |e| at + 1 + e);
    text[at..end].to_string()
}

/// The table rows of `text`, their cells without their backticks.
fn rows(text: &str) -> Vec<Vec<String>> {
    text.lines()
        .filter(|l| l.starts_with("| ") && !l.starts_with("| id ") && !l.starts_with("|-"))
        .map(|l| l.trim_matches('|').split('|').map(|c| c.trim().trim_matches('`').to_string()).collect())
        .collect()
}

#[test]
fn section_6_lists_the_references_signatures() {
    let text = spec();
    let listed = rows(&section(&text, "## 6."));
    let table = signature_table();
    assert_eq!(listed.len(), table.len());
    for (row, (id, kind, parts, caps)) in listed.iter().zip(table) {
        assert_eq!(row[0], id);
        assert_eq!(row[1], kind);
        let bytes: Vec<String> = parts.iter().map(|(at, b)| format!("{at}:{}", b.iter().map(|x| format!("{x:02x}")).collect::<String>())).collect();
        assert_eq!(row[2], bytes.join(" "), "{id}");
        assert_eq!(row[3], caps.join(" "), "{id}");
    }
}

#[test]
fn section_7_lists_the_references_embedded_signatures() {
    let text = spec();
    let listed = rows(&section(&text, "## 7."));
    let table = embedded_table();
    assert_eq!(listed.len(), table.len());
    for (row, (id, bytes, back)) in listed.iter().zip(table) {
        assert_eq!(row[0], id);
        assert_eq!(row[1], bytes.iter().map(|x| format!("{x:02x}")).collect::<String>());
        assert_eq!(row[2], back.to_string());
        assert!(bytes.len() >= 8, "{id}: §7's floor");
    }
}

#[test]
fn every_reason_and_verdict_is_stated_and_reached() {
    let text = spec();
    let doc: serde_json::Value = serde_json::from_slice(&committed()["vectors.json"]).unwrap();
    let results: Vec<&serde_json::Value> = doc["vectors"].as_array().unwrap().iter().map(|v| &v["result"]).collect();
    for why in ["overrun", "invalid", "crc", "limit", "unknown_size"] {
        assert!(section(&text, "## 3.").contains(&format!("| `{why}` |")), "{why}");
        assert!(
            results.iter().any(|r| r["candidates"].as_array().unwrap().iter().any(|c| c["stopped"]["why"] == why)),
            "no vector reaches {why}"
        );
    }
    for verdict in ["identified", "ambiguous", "signature_only", "unknown"] {
        assert!(section(&text, "## 4.").contains(&format!("`{verdict}`")), "{verdict}");
        assert!(results.iter().any(|r| r["verdict"] == verdict), "no vector reaches {verdict}");
    }
    for strength in ["signature", "structure", "parameters"] {
        assert!(results.iter().any(|r| r["candidates"].as_array().unwrap().iter().any(|c| c["strength"] == strength)), "{strength}");
    }
}

fn wai() -> Command {
    Command::new(env!("CARGO_BIN_EXE_wai"))
}

#[test]
fn wai_identify_gives_what_the_library_gives() {
    let p = wai_dir().join("identify-conformance/ext/avc-aac.mp4");
    let o = wai().args(["identify", p.to_str().unwrap(), "--json"]).output().unwrap();
    assert!(o.status.success(), "{}", String::from_utf8_lossy(&o.stderr));
    let v: serde_json::Value = serde_json::from_slice(&o.stdout).unwrap();
    assert_eq!(v["op"], "media.inspect");
    assert_eq!(v["data"], identify_bytes(&std::fs::read(&p).unwrap()));
    let o = wai().args(["identify", p.to_str().unwrap()]).output().unwrap();
    let text = String::from_utf8_lossy(&o.stdout);
    assert!(text.contains("isobmff (container, structure)"), "{text}");
    assert!(text.contains("video avc1 (avc) 32x32"), "{text}");
    assert!(text.contains("wai.video.avc"), "{text}");
}

#[test]
fn a_directory_and_a_missing_file_are_errors_not_results() {
    let d = wai_dir();
    let o = wai().args(["identify", d.to_str().unwrap()]).output().unwrap();
    assert!(!o.status.success());
    assert!(String::from_utf8_lossy(&o.stderr).contains("a directory"));
    let o = wai().args(["identify", "/no/such/file"]).output().unwrap();
    assert!(!o.status.success());
    let o = wai().args(["identify"]).output().unwrap();
    assert_eq!(o.status.code(), Some(2));
}