//! Conformance corpus of robustness evidence for soft bindings
//! (`live-conformance/robustness/`, extensions/robustness-evidence.md §13).
//!
//!   wai_robustness_vectors gen    <corpus-dir>   write the corpus from fixed seeds: the
//!                                                corpus documents, the conformance pictures,
//!                                                the records and vectors.json (this runs the
//!                                                harness over synthesis §7.5.8's measurement
//!                                                sets: build it in release)
//!   wai_robustness_vectors verify <corpus-dir>   every file regenerates byte for byte, no
//!                                                other file but README.md is there, and every
//!                                                case gets what it states
//!
//! The generator and this verifier are one implementation. The corpus's second
//! implementation is `live-conformance/robustness_verify.py`, written from the extension's
//! text and sharing no code with this binary.

use std::collections::BTreeMap;
use std::path::Path;
use wai::robustness::corpus;

fn main() {
    let a: Vec<String> = std::env::args().collect();
    match (a.get(1).map(String::as_str), a.get(2)) {
        (Some("gen"), Some(d)) => {
            for (name, body) in corpus::generate() {
                let p = Path::new(d).join(&name);
                if let Some(dir) = p.parent()
                    && let Err(e) = std::fs::create_dir_all(dir)
                {
                    eprintln!("create {}: {e}", dir.display());
                    std::process::exit(1);
                }
                if let Err(e) = std::fs::write(&p, body) {
                    eprintln!("write {}: {e}", p.display());
                    std::process::exit(1);
                }
            }
            println!("wrote {d}");
        }
        (Some("verify"), Some(d)) => std::process::exit(verify(Path::new(d))),
        _ => {
            eprintln!("usage: wai_robustness_vectors gen|verify <corpus-dir>");
            std::process::exit(2);
        }
    }
}

/// Every file under `dir`, by its path relative to `dir`, but the top-level README.md.
fn read_tree(dir: &Path) -> std::io::Result<BTreeMap<String, Vec<u8>>> {
    let mut out = BTreeMap::new();
    let mut stack = vec![dir.to_path_buf()];
    while let Some(d) = stack.pop() {
        for e in std::fs::read_dir(&d)? {
            let e = e?;
            let p = e.path();
            if p.is_dir() {
                stack.push(p);
                continue;
            }
            let rel = p.strip_prefix(dir).expect("under the directory").to_string_lossy().replace('\\', "/");
            if rel != "README.md" {
                out.insert(rel, std::fs::read(&p)?);
            }
        }
    }
    Ok(out)
}

fn verify(dir: &Path) -> i32 {
    let files = match read_tree(dir) {
        Ok(f) => f,
        Err(e) => {
            eprintln!("read {}: {e}", dir.display());
            return 1;
        }
    };
    let generated: BTreeMap<String, Vec<u8>> = corpus::generate().into_iter().collect();
    let same = files == generated;
    if !same {
        for k in generated.keys().filter(|k| files.get(*k) != generated.get(*k)) {
            println!("  differs or missing: {k}");
        }
        for k in files.keys().filter(|k| !generated.contains_key(*k)) {
            println!("  not generated: {k}");
        }
    }
    println!("{} every file regenerates byte for byte from its seeds, and no other file is there", if same { "PASS" } else { "FAIL" });
    let fails = corpus::verify(&files);
    for f in &fails {
        println!("FAIL {f}");
    }
    println!("{} every case gets what the corpus states", if fails.is_empty() { "PASS" } else { "FAIL" });
    (!same || !fails.is_empty()) as i32
}
