//! Supplemental read-only bundle converter. Not part of the frozen product build.
use oa_core::{language, persistence, source_files, source_project, validate_candidate};
use std::{fs::OpenOptions, io::Write, path::Path};
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let args: Vec<_> = std::env::args_os().skip(1).collect();
    if args.len() != 2 { return Err("Expected snapshot bundle entry and NEW self-contained source path".into()); }
    let limits = source_project::ProjectLimits::default();
    let disk = source_files::load_project(Path::new(&args[0]), limits)?;
    if disk.diagnostics.iter().any(|d| d.diagnostic.severity == oa_core::validation::Severity::Error) { return Err(format!("Disk diagnostics: {:?}", disk.diagnostics).into()); }
    println!("Loader/lint warnings: {:?}", disk.diagnostics);
    let bundle = disk.reachable_bundle();
    if bundle.files != disk.bundle.files { return Err("Unreachable source buffers".into()); }
    for (name, text) in &bundle.files {
        match disk.expectations.get(name) {
            Some(source_files::DiskExpectation::Bytes(bytes)) if bytes.as_slice() == text.as_bytes() => {},
            _ => return Err(format!("Loader changed or omitted raw bytes: {name}").into()),
        }
    }
    let compiled = source_project::compile_bundle(&bundle, limits)
        .map_err(|e| format!("Compile diagnostics: {e:?}"))?;
    if compiled.bundle != bundle || compiled.decoded.migration.is_some() {
        return Err("Unexpected identity stabilization or migration".into());
    }
    let project = &compiled.decoded.project;
    validate_candidate(project)?;
    let source = language::format(project);
    let decoded = persistence::decode_with_report(source.as_bytes())?;
    if decoded.migration.is_some() || &decoded.project != project {
        return Err("Self-contained source roundtrip changed complete Project".into());
    }
    let mut output = OpenOptions::new().write(true).create_new(true).open(&args[1])?;
    output.write_all(source.as_bytes())?;
    output.sync_all()?;
    println!("Bundle files: {}; complete Project roundtrip exact", bundle.files.len());
    println!("Engineering warnings (not loader errors): {:?}", compiled.diagnostics);
    Ok(())
}