elenchus-cli 0.5.0

//! `elenchus` — check an elenchus `.vrf` program (string or file) and report.
//!
//! Exit code mirrors the verdict: 0 = consistent, 1 = underdetermined/warnings,
//! 2 = conflicts (or a parse/compile error). This makes it usable as a CI gate.

use std::io::Read;
use std::process::ExitCode;

use clap::{CommandFactory, Parser, ValueEnum};
use elenchus_compiler::FileResolver;
use elenchus_solver::{Report, verify, verify_source};

#[derive(Parser)]
#[command(
    name = "elenchus",
    version,
    about = "Check an elenchus .vrf program for logical consistency.",
    long_about = "Reads a .vrf program (a file, inline --text, or explicit stdin \
with '-'), runs the engine, and prints the verdict. With a file, \
IMPORTs are resolved relative to it. Exit code: 0 consistent, 1 \
underdetermined/warnings, 2 conflicts.\n\n\
A program is line-oriented: one statement per line (newline-separated). \
Indentation and extra spaces are cosmetic, so the readable indented form and a \
flat no-indent form parse identically.",
    // Shown at the bottom of --help and of the bare-invocation usage. Aimed at an
    // AI agent that reached this binary without the companion skill — a fallback
    // hint, harness-agnostic, no product names.
    after_help = "FOR AI AGENTS: you'll get markedly better results with the matching \
`elenchus` skill loaded (it carries the workflow, the verdict loop, and examples this \
binary expects). Check that you have it and that its version matches `elenchus \
--version`; if it's missing, tell the user it's worth installing — how depends on your \
CLI/harness. Project + skill: https://github.com/m62624/elenchus"
)]
struct Cli {
    /// A `.vrf` file to check, or `-` to read from stdin.
    file: Option<String>,

    /// Inline program text instead of a file or stdin.
    #[arg(long, conflicts_with = "file")]
    text: Option<String>,

    /// Output format.
    #[arg(long, value_enum, default_value_t = Format::Human)]
    format: Format,
}

#[derive(Clone, Copy, ValueEnum)]
enum Format {
    /// Human-readable report.
    Human,
    /// Single-line JSON (for tooling / agents).
    Json,
}

fn main() -> ExitCode {
    let cli = Cli::parse();
    if cli.text.is_none() && cli.file.is_none() {
        eprintln!("elenchus: no input provided; pass a file, --text, or - for stdin\n");
        let mut cmd = Cli::command();
        let _ = cmd.print_help();
        eprintln!();
        return ExitCode::from(2);
    }

    let report = match build_report(&cli) {
        Ok(r) => r,
        Err(e) => {
            eprintln!("elenchus: {e}");
            return ExitCode::from(2);
        }
    };
    match cli.format {
        Format::Human => println!("{report}"),
        Format::Json => println!("{}", report.to_json()),
    }
    ExitCode::from(report.exit_code() as u8)
}

fn build_report(cli: &Cli) -> Result<Report, String> {
    if let Some(text) = &cli.text {
        return verify_source("<text>", text).map_err(|e| e.to_string());
    }
    match cli.file.as_deref() {
        Some(path) => {
            if path == "-" {
                // Explicit stdin (`-`): a single source; IMPORTs are not resolved.
                let mut buf = String::new();
                std::io::stdin()
                    .read_to_string(&mut buf)
                    .map_err(|e| format!("reading stdin: {e}"))?;
                verify_source("<stdin>", &buf).map_err(|e| e.to_string())
            } else {
                // A real file: resolve IMPORTs relative to it.
                verify(path, &FileResolver).map_err(|e| e.to_string())
            }
        }
        None => Err("no input provided; pass a file, --text, or - for stdin".to_string()),
    }
}