//! cb-sim — scenario runner binary (GameKernel K17; precursor of `cb sim`).
//! Parses scenario files, dispatches each to its game by the `<game>/`
//! prefix of its `scenario` field, and executes it. Exit codes: 0 all
//! passed, 1 any failure — including a scenario whose game prefix is not
//! registered, and a run in which nothing executed. There is deliberately
//! no "tolerable" non-zero exit: a silent skip is the failure mode this
//! binary exists to catch.

use cb_game_runtime::{scenario, RunOutcome, ScenarioFile};
use games_ground::GroundState;

fn main() {
    let args: Vec<String> = std::env::args().skip(1).collect();
    if args.is_empty() {
        eprintln!("usage: cb-sim <scenario.yaml>...");
        std::process::exit(64);
    }

    let mut failed = false;
    let mut passed = 0usize;
    let mut covered: Vec<String> = Vec::new();

    for path in &args {
        let text = match std::fs::read_to_string(path) {
            Ok(t) => t,
            Err(e) => {
                eprintln!("{path}: read error: {e}");
                failed = true;
                continue;
            }
        };
        let sc = match ScenarioFile::from_yaml(&text) {
            Err(e) => {
                eprintln!("{path}: parse error: {e}");
                failed = true;
                continue;
            }
            Ok(sc) => sc,
        };

        let outcome = match sc.scenario.split('/').next() {
            Some("ground") => scenario::run::<GroundState>(&sc),
            _ => {
                // A renamed or typo'd prefix would otherwise skip every
                // scenario while the run still looked clean.
                eprintln!(
                    "FAIL {} — no game registered for prefix {:?}",
                    sc.scenario,
                    sc.scenario.split('/').next().unwrap_or("")
                );
                failed = true;
                continue;
            }
        };

        match outcome {
            RunOutcome::Passed { covers } => {
                println!(
                    "PASS {} covers={}{}",
                    sc.scenario,
                    covers.join(","),
                    if sc.provisional { " provisional" } else { "" }
                );
                covered.extend(covers);
                passed += 1;
            }
            RunOutcome::Failed { reason } => {
                println!("FAIL {} — {reason}", sc.scenario);
                failed = true;
            }
        }
    }

    covered.sort();
    covered.dedup();
    println!("{passed} passed, {} rules covered", covered.len());

    // Positive control: a run that executed nothing must not pass. This
    // is the same class of error as a benchmark timing rejected work.
    if passed == 0 {
        eprintln!("FAIL — no scenario executed; refusing to report success");
        failed = true;
    }

    if failed {
        std::process::exit(1);
    }
}