//! `flowrsc firmware explain`. Without the `firmexplain` feature it says what is missing; with it,
//! it runs. `flowrsc firmware <graph>` keeps working beside the new subcommand either way.

use clap::Parser;
use flowrs_cli::{Cli, run};

fn flowrsc(args: &[&str]) -> (i32, String, String) {
    let cli = Cli::try_parse_from(std::iter::once("flowrsc").chain(args.iter().copied()))
        .unwrap_or_else(|e| panic!("{args:?}: {e}"));
    let (mut out, mut err) = (Vec::new(), Vec::new());
    let code = run(&cli, &mut out, &mut err);
    (
        code,
        String::from_utf8_lossy(&out).into_owned(),
        String::from_utf8_lossy(&err).into_owned(),
    )
}

const BLINK: &str = concat!(
    env!("CARGO_MANIFEST_DIR"),
    "/../flowrs-sim/firmware/stm32/blink_pc13.bin"
);

#[test]
fn the_graph_form_still_parses_beside_the_subcommand() {
    assert!(
        Cli::try_parse_from(["flowrsc", "firmware", "g.fdsl", "-o", "x", "--board", "b"]).is_ok()
    );
    // All three of them are still required.
    assert!(Cli::try_parse_from(["flowrsc", "firmware", "g.fdsl"]).is_err());
    assert!(Cli::try_parse_from(["flowrsc", "firmware"]).is_err());
    assert!(Cli::try_parse_from(["flowrsc", "firmware", "explain", "image.bin"]).is_ok());
}

#[cfg(not(feature = "firmexplain"))]
#[test]
fn a_build_with_no_twins_says_where_to_find_one() {
    let (code, out, err) = flowrsc(&["firmware", "explain", BLINK, "--board", "stm32f103"]);
    assert_eq!(code, 2);
    assert!(out.is_empty());
    assert!(err.contains("--features firmexplain"), "{err}");
    assert!(err.contains("stays in your browser"), "{err}");
}

#[cfg(feature = "firmexplain")]
mod with_twins {
    use super::*;

    /// One twin CPU per process, and the tests here run on threads.
    static CPU: std::sync::Mutex<()> = std::sync::Mutex::new(());

    fn one_at_a_time() -> std::sync::MutexGuard<'static, ()> {
        CPU.lock()
            .unwrap_or_else(std::sync::PoisonError::into_inner)
    }

    #[test]
    fn it_reports_the_three_parts_for_a_board() {
        let _cpu = one_at_a_time();
        let (code, out, err) = flowrsc(&[
            "firmware",
            "explain",
            BLINK,
            "--board",
            "bluepill_f103c8",
            "--cycles",
            "3000000",
        ]);
        assert_eq!(code, 0, "{err}");
        assert!(out.contains("OBSERVATIONS"), "{out}");
        assert!(out.contains("EVIDENCE"), "{out}");
        assert!(out.contains("UNKNOWNS"), "{out}");
        assert!(out.contains("PC13 (output) toggled at 50.00 Hz"), "{out}");
        assert!(out.contains("authorised to examine"), "{out}");
        assert!(
            out.contains("flowrsc firmware explain") && out.contains("--board bluepill_f103c8"),
            "the command that runs it again: {out}"
        );
    }

    #[test]
    fn it_answers_in_json_on_request_and_finds_the_board_when_not_told() {
        let _cpu = one_at_a_time();
        let (code, out, err) = flowrsc(&[
            "firmware", "explain", BLINK, "--json", "--cycles", "2000000",
        ]);
        assert_eq!(code, 0, "{err}");
        let v: serde_json::Value = serde_json::from_str(&out).unwrap();
        assert_eq!(v["ranking"]["schema"], "flowrs.firmexplain.ranking/1");
        assert!(v["ranking"]["candidates"].as_array().unwrap().len() > 1);
        assert_eq!(v["explanation"]["schema"], "flowrs.firmexplain/1");
    }

    #[test]
    fn what_changed_is_said() {
        let _cpu = one_at_a_time();
        let (code, out, err) = flowrsc(&[
            "firmware",
            "explain",
            &format!(
                "{}/../flowrs-renode/tests/firmware/embassy_f103.bin",
                env!("CARGO_MANIFEST_DIR")
            ),
            "--board",
            "stm32f103",
            "--cycles",
            "7200000",
            "--compare-with",
            "PA0=1@50ms",
        ]);
        assert_eq!(code, 0, "{err}");
        assert!(out.contains("WHAT CHANGED"), "{out}");
        assert!(out.contains("usb ready"), "{out}");
    }

    #[test]
    fn what_cannot_run_is_a_usage_error() {
        let _cpu = one_at_a_time();
        for (args, says) in [
            (
                vec!["firmware", "explain", "no-such-file", "--board", "stm32f4"],
                "no-such-file",
            ),
            (
                vec!["firmware", "explain", BLINK, "--board", "no-such"],
                "no board or twin platform",
            ),
            (
                vec!["firmware", "explain", BLINK, "--board", "uno"],
                "runs in the browser",
            ),
            (
                vec![
                    "firmware",
                    "explain",
                    BLINK,
                    "--board",
                    "stm32f4",
                    "--stimulus",
                    "PA0",
                ],
                "PA0=1",
            ),
        ] {
            let (code, _, err) = flowrsc(&args);
            assert_eq!(code, 2, "{args:?}: {err}");
            assert!(err.contains(says), "{args:?}: {err}");
        }
    }
}