//! The collection, channel and struct nodes must emit Rust that actually compiles.
//!
//! Emitting *something* is not the bar — `node_coverage` measures that, and it passed for
//! these long before they worked. This compiles the whole emitted program, which is what
//! caught every bug in them: bare `map`/`tx`/`instance` identifiers where an input was not
//! connected (E0425), `HashMap::new()` with nothing to infer from (E0282), a struct type
//! nothing declared (E0422), and a `FieldSet` assigning through a non-`mut` binding
//! (E0594). Each of those emitted confidently and failed only at `rustc`.
use flowrs_core::graph::{Graph, WireMode};
use std::process::Command;

fn check(label: &str, g: &Graph) {
    let src = match g.to_rust() {
        Ok(s) => s,
        Err(e) => panic!("{label} should emit, but codegen refused: {e}"),
    };
    let dir = std::env::temp_dir().join("flowrs_probe_wired");
    std::fs::create_dir_all(dir.join("src")).unwrap();
    std::fs::write(
        dir.join("Cargo.toml"),
        "[workspace]\n[package]\nname=\"p\"\nversion=\"0.0.0\"\nedition=\"2021\"\n",
    )
    .unwrap();
    std::fs::write(dir.join("src/main.rs"), &src).unwrap();
    let out = Command::new("cargo")
        .args(["check", "--quiet", "--offline", "--message-format=short"])
        .current_dir(&dir)
        // `CARGO_TARGET_DIR` removed so this check does not depend on ambient config.
        //
        // `graph_build` in flowrs-mcp had a demonstrated false pass from an inherited
        // target dir: its scratch crates are all `flowrs_graph 0.0.0`, and one shared
        // target made them a single build unit, so cargo found a later program already
        // fresh and exited 0 without reading it. These harnesses use the same package
        // identity, so the same shape is possible here.
        //
        // Tested, and it did NOT reproduce: priming a shared target with a passing
        // harness and then running this one with its own codegen broken still failed
        // correctly. This is isolation against a hazard that has bitten once nearby,
        // not a fix for a bug demonstrated here.
        .env_remove("CARGO_TARGET_DIR")
        .output()
        .unwrap();
    if out.status.success() {
        return;
    }
    let e = String::from_utf8_lossy(&out.stderr);
    // A dependency that will not resolve offline is an environment limit, not a defect.
    if e.contains("failed to download") || e.contains("no matching package") {
        eprintln!("skipped {label}: dependencies unavailable offline");
        return;
    }
    let diags: Vec<&str> = e.lines().filter(|l| l.contains("error")).take(6).collect();
    panic!(
        "{label} emits Rust that does not compile:\n  {}\n--- source ---\n{src}",
        diags.join("\n  ")
    );
}

fn lit(g: &mut Graph, ty: &str, v: &str) -> flowrs_core::NodeId {
    let n = g.add_node(ty, 0.0, 0.0);
    g.nodes
        .get_mut(&n)
        .unwrap()
        .properties
        .insert("value".into(), v.into());
    n
}

#[test]
fn the_collection_channel_and_struct_nodes_compile_when_wired() {
    // HashMapNew -> HashMapInsert -> HashMapGet
    let mut g = Graph::new();
    let m = g.add_node("HashMapNew", 0.0, 0.0);
    let k = lit(&mut g, "StringLiteral", "alpha");
    let v = lit(&mut g, "IntLiteral", "7");
    let ins = g.add_node("HashMapInsert", 0.0, 0.0);
    g.add_wire(m, "map", ins, "map", WireMode::Move).unwrap();
    g.add_wire(k, "value", ins, "key", WireMode::Move).unwrap();
    g.add_wire(v, "value", ins, "value", WireMode::Move)
        .unwrap();
    check("HashMapInsert(wired)", &g);

    let k2 = lit(&mut g, "StringLiteral", "alpha");
    let get = g.add_node("HashMapGet", 0.0, 0.0);
    g.add_wire(ins, "map", get, "map", WireMode::Move).unwrap();
    g.add_wire(k2, "value", get, "key", WireMode::Move).unwrap();
    check("HashMapGet(wired)", &g);

    // ChannelNew -> Send / Recv
    let mut g = Graph::new();
    let ch = g.add_node("ChannelNew", 0.0, 0.0);
    let val = lit(&mut g, "IntLiteral", "3");
    let snd = g.add_node("Send", 0.0, 0.0);
    g.add_wire(ch, "sender", snd, "sender", WireMode::Move)
        .unwrap();
    g.add_wire(val, "value", snd, "value", WireMode::Move)
        .unwrap();
    let rcv = g.add_node("Recv", 0.0, 0.0);
    g.add_wire(ch, "receiver", rcv, "receiver", WireMode::Move)
        .unwrap();
    check("Send+Recv(wired)", &g);

    // StructNew -> FieldGet / FieldSet
    let mut g = Graph::new();
    let sn = g.add_node("StructNew", 0.0, 0.0);
    {
        let p = &mut g.nodes.get_mut(&sn).unwrap().properties;
        p.insert("type".into(), "Settings".into());
        p.insert("gain".into(), "3".into());
        p.insert("name".into(), "probe".into());
    }
    let fg = g.add_node("FieldGet", 0.0, 0.0);
    g.nodes
        .get_mut(&fg)
        .unwrap()
        .properties
        .insert("field".into(), "gain".into());
    g.add_wire(sn, "instance", fg, "instance", WireMode::Move)
        .unwrap();
    check("FieldGet(wired)", &g);

    let mut g2 = Graph::new();
    let sn2 = g2.add_node("StructNew", 0.0, 0.0);
    {
        let p = &mut g2.nodes.get_mut(&sn2).unwrap().properties;
        p.insert("type".into(), "Settings".into());
        p.insert("gain".into(), "3".into());
    }
    let nv = lit(&mut g2, "IntLiteral", "9");
    let fs = g2.add_node("FieldSet", 0.0, 0.0);
    g2.nodes
        .get_mut(&fs)
        .unwrap()
        .properties
        .insert("field".into(), "gain".into());
    g2.add_wire(sn2, "instance", fs, "instance", WireMode::Move)
        .unwrap();
    g2.add_wire(nv, "value", fs, "value", WireMode::Move)
        .unwrap();
    check("FieldSet(wired)", &g2);
}