//! `just verdict`: the whole attempt pipeline in one command.
//! Gates on the candidate → interleaved A/B bench vs the baseline →
//! verdict by the CI-lower-bound rule → append-only ledger row.
//! Any gate failure is rejected-gate and the bench is skipped; the
//! --needs-human-review flag caps the verdict for FP/concurrency/
//! sanitizer-flagged attempts (SPEC §8) — it never upgrades one.

use anyhow::Result;
use bench_runner::{config::AcceptConfig, decide, exec, fingerprint::EnvFingerprint, stats};
use clap::Parser;
use diff_test::{
    all_passed, orchestrate::run_core_gates, target::TargetSpec, GateLayer, GateOutcome,
};
use ledger::{Attempt, BenchEvidence, GateResults, Ledger, Verdict};
use std::path::PathBuf;

#[derive(Parser)]
#[command(
    name = "verdict",
    about = "gates + bench + ledger row for one optimization attempt"
)]
struct Cli {
    /// Target name under targets/.
    target: String,
    /// Pristine baseline binary (repo-root-relative). Prefer
    /// --rebuild-baseline: workspace paths get silently rebuilt from the
    /// patched tree by test runs (observed: phase1-verdict-smoke-001).
    #[arg(long, conflicts_with = "rebuild_baseline")]
    baseline_bin: Option<String>,
    /// Rebuild the baseline from the pristine checkout (patch stashed,
    /// built to targets/<name>/baseline/, patch restored). SPEC §3.1.
    #[arg(long)]
    rebuild_baseline: bool,
    /// Candidate binary (repo-root-relative); also used in golden replay.
    #[arg(long)]
    candidate_bin: String,
    #[arg(long)]
    run_id: String,
    #[arg(long)]
    playbook_class: u8,
    #[arg(long)]
    hypothesis: String,
    #[arg(long)]
    hotspot: String,
    /// Unified-diff file recorded in the ledger (optional for build-config attempts).
    #[arg(long)]
    patch_file: Option<PathBuf>,
    /// Force the needs-human-review verdict tier (FP/concurrency/UB-adjacent).
    #[arg(long)]
    needs_human_review: bool,
    #[arg(long, default_value = "results/ledger.sqlite")]
    db: PathBuf,
    #[arg(long, default_value = "config/accept.toml")]
    config: PathBuf,
    #[arg(long, default_value = ".")]
    root: PathBuf,
}

/// Stash any workspace patch, build the baseline into the isolated
/// targets/<name>/baseline/ dir, restore the patch. Serialized within
/// this process — nothing else may touch the tree while this runs.
fn rebuild_pristine_baseline(
    root: &std::path::Path,
    target: &str,
    spec: &TargetSpec,
) -> Result<String> {
    let ws = format!("targets/{target}/workspace");
    let dirty = !std::process::Command::new("git")
        .args(["-C", &ws, "status", "--porcelain"])
        .output()?
        .stdout
        .is_empty();
    if dirty {
        anyhow::ensure!(
            std::process::Command::new("git")
                .args(["-C", &ws, "stash", "--include-untracked", "-q"])
                .status()?
                .success(),
            "git stash failed"
        );
    }
    let build = std::process::Command::new("sh")
        .arg("-c")
        .arg(&spec.build.baseline)
        .current_dir(root)
        .env(
            "CARGO_TARGET_DIR",
            root.join(format!("targets/{target}/baseline")),
        )
        .status();
    if dirty {
        anyhow::ensure!(
            std::process::Command::new("git")
                .args(["-C", &ws, "stash", "pop", "-q"])
                .status()?
                .success(),
            "git stash pop failed — workspace patch may be stranded in stash"
        );
    }
    anyhow::ensure!(build?.success(), "baseline build failed");
    let bin_name = std::path::Path::new(&spec.build.binary)
        .file_name()
        .and_then(|n| n.to_str())
        .ok_or_else(|| anyhow::anyhow!("bad build.binary path"))?;
    let baseline = format!("targets/{target}/baseline/release/{bin_name}");
    anyhow::ensure!(
        root.join(&baseline).exists(),
        "baseline binary missing: {baseline}"
    );
    println!("baseline rebuilt from pristine checkout: {baseline}");
    Ok(baseline)
}

fn now_utc() -> String {
    let out = std::process::Command::new("date")
        .args(["-u", "+%Y-%m-%dT%H:%M:%SZ"])
        .output();
    match out {
        Ok(o) if o.status.success() => String::from_utf8_lossy(&o.stdout).trim().to_string(),
        _ => "unknown".to_string(),
    }
}

fn main() -> Result<()> {
    let cli = Cli::parse();
    let root = cli.root.canonicalize()?;
    std::env::set_current_dir(&root)?;
    let spec = TargetSpec::load(&root, &cli.target)?;
    let cfg = AcceptConfig::load(&root.join(&cli.config))?;
    let started = std::time::Instant::now();

    let baseline_bin = if cli.rebuild_baseline {
        rebuild_pristine_baseline(&root, &cli.target, &spec)?
    } else {
        cli.baseline_bin.clone().ok_or_else(|| {
            anyhow::anyhow!("pass --rebuild-baseline (preferred) or --baseline-bin")
        })?
    };

    // Gates run on the candidate binary.
    let gates = run_core_gates(&root, &spec, &cli.candidate_bin)?;
    for (layer, outcome) in &gates {
        match outcome {
            GateOutcome::Passed => println!("{layer:?}: PASS"),
            GateOutcome::Failed { detail } => println!("{layer:?}: FAIL — {detail}"),
            GateOutcome::Skipped { reason } => println!("{layer:?}: skipped — {reason}"),
        }
    }
    let gate_results = GateResults {
        upstream_tests: matches!(gates[0].1, GateOutcome::Passed),
        golden_replay: matches!(gates[1].1, GateOutcome::Passed),
        fuzz_iters: 0,
        fuzz_divergence: false,
        sanitizers_clean: false,
    };
    debug_assert!(matches!(gates[0].0, GateLayer::UpstreamTests));

    let pin = &cfg.pin_prefix;
    let wrap = |bin: &str| {
        let cmd = spec.bench.command.replace("{binary}", bin);
        if pin.is_empty() {
            format!("sh -c \"{cmd}\"")
        } else {
            format!("{pin} sh -c \"{cmd}\"")
        }
    };

    let (verdict, bench) =
        if !all_passed(&gates) {
            println!("verdict: rejected-gate (bench skipped)");
            (Verdict::RejectedGate, None)
        } else {
            println!(
                "bench: {} measured + {} warm-up runs/side, interleaved, pin='{}'",
                cfg.runs_per_side, cfg.warmup_runs, pin
            );
            let samples = exec::run_interleaved(
                &wrap(&baseline_bin),
                &wrap(&cli.candidate_bin),
                cfg.runs_per_side,
                cfg.warmup_runs,
                0.0,
            )?;
            let ratio = stats::bootstrap_ratio_ci(
                &samples.baseline_s,
                &samples.candidate_s,
                cfg.bootstrap_iters,
                cfg.confidence,
                cfg.bootstrap_seed,
            );
            let (bm, blo, bhi) = stats::bootstrap_median_ci(
                &samples.baseline_s,
                cfg.bootstrap_iters,
                cfg.confidence,
                cfg.bootstrap_seed,
            );
            let (cm, clo, chi) = stats::bootstrap_median_ci(
                &samples.candidate_s,
                cfg.bootstrap_iters,
                cfg.confidence,
                cfg.bootstrap_seed,
            );
            println!(
            "speedup (baseline/candidate): median {:.4}, {:.0}% CI [{:.4}, {:.4}] | workload: {}",
            ratio.median, cfg.confidence * 100.0, ratio.lo, ratio.hi, spec.bench.workload
        );
            let mut v = decide(ratio, cfg.threshold);
            if cli.needs_human_review && v == Verdict::Accepted {
                v = Verdict::NeedsHumanReview;
            }
            let fp = EnvFingerprint::collect(pin, "system-default");
            (
                v,
                Some(BenchEvidence {
                    baseline_median: bm,
                    baseline_ci: (blo, bhi),
                    candidate_median: cm,
                    candidate_ci: (clo, chi),
                    speedup_median: ratio.median,
                    speedup_ci: (ratio.lo, ratio.hi),
                    env_fingerprint: serde_json::json!({
                        "fingerprint": fp,
                        "workload": spec.bench.workload,
                        "target_commit": spec.source.commit,
                        "gates_detail": "fuzz/sanitizers per-attempt manual in Phase 1",
                    }),
                }),
            )
        };

    let patch = match &cli.patch_file {
        Some(p) => std::fs::read_to_string(p)?,
        None => "(no source patch)".into(),
    };
    let attempt = Attempt {
        run_id: cli.run_id.clone(),
        timestamp: now_utc(),
        target: cli.target.clone(),
        target_commit: spec.source.commit.clone(),
        phase: 1,
        hotspot: cli.hotspot,
        playbook_class: cli.playbook_class,
        hypothesis: cli.hypothesis,
        patch,
        gates: gate_results,
        bench,
        verdict,
        tokens_spent: 0,
        wall_time_s: started.elapsed().as_secs_f64(),
    };
    Ledger::open(&root.join(&cli.db))?.record(&attempt)?;
    println!(
        "verdict: {} (ledger row {})",
        attempt.verdict.as_str(),
        attempt.run_id
    );
    Ok(())
}