//! Integration test: drive the built `aura` binary as a downstream user would,
//! asserting the `run` subcommand's stdout/exit contract and the bad-args path.

use std::process::Command;

/// Path to the freshly-built `aura` binary (Cargo sets this env var for the test
/// crate; the binary is named `aura` in `Cargo.toml`).
const BIN: &str = env!("CARGO_BIN_EXE_aura");

#[test]
fn run_prints_json_and_exits_zero() {
    let out = Command::new(BIN).arg("run").output().expect("spawn aura run");
    assert!(out.status.success(), "exit status: {:?}", out.status);

    let stdout = String::from_utf8(out.stdout).expect("utf-8 stdout");
    // exactly one line (the JSON object + a trailing newline from println!).
    assert_eq!(stdout.lines().count(), 1, "stdout was: {stdout:?}");
    let line = stdout.trim_end();

    // canonical cycle-0009 JSON shape: nested manifest + metrics, stable keys.
    assert!(line.starts_with("{\"manifest\":{\"commit\":\"unknown\","), "got: {line}");
    assert!(line.contains("\"broker\":\"sim-optimal(pip_size=0.0001)\""), "got: {line}");
    assert!(line.contains("\"window\":[1,7]"), "got: {line}");
    assert!(line.contains("\"metrics\":{\"total_pips\":"), "got: {line}");
    // the integer sign-flip count is stable across float renderings.
    assert!(line.ends_with("\"exposure_sign_flips\":1}}"), "got: {line}");
}

#[test]
fn no_args_prints_usage_and_exits_two() {
    let out = Command::new(BIN).output().expect("spawn aura");
    assert_eq!(out.status.code(), Some(2), "exit status: {:?}", out.status);
    assert!(out.stdout.is_empty(), "stdout should be empty on the usage path");
    let stderr = String::from_utf8(out.stderr).expect("utf-8 stderr");
    assert!(stderr.contains("usage"), "stderr was: {stderr:?}");
}

/// Property: `--help`/`-h` is the success-path help affordance, not the error
/// path. A newcomer's reflex first command (C22 first-contact ergonomics, #20)
/// prints the usage to stdout and exits 0; the conventional `-h` alias behaves
/// identically. An *unknown* subcommand keeps the error path (exit 2) so the
/// help fix does not regress bad-args handling.
#[test]
fn help_flag_prints_usage_to_stdout_and_exits_zero() {
    for flag in ["--help", "-h"] {
        let out = Command::new(BIN).arg(flag).output().expect("spawn aura --help");
        assert_eq!(out.status.code(), Some(0), "`aura {flag}` exit: {:?}", out.status);
        let stdout = String::from_utf8(out.stdout).expect("utf-8 stdout");
        assert!(
            !stdout.trim().is_empty(),
            "`aura {flag}` should print help to stdout, got: {stdout:?}"
        );
        // The usage names the only subcommand a newcomer can run.
        assert!(
            stdout.contains("run"),
            "`aura {flag}` help should mention the `run` subcommand, got: {stdout:?}"
        );
    }

    // Negative-preservation: an unknown subcommand is still the error path.
    let out = Command::new(BIN).arg("frobnicate").output().expect("spawn aura frobnicate");
    assert_eq!(
        out.status.code(),
        Some(2),
        "unknown subcommand must stay exit 2: {:?}",
        out.status
    );
}