use cortex_core::discovery::{DeviceInfo, DiscoveryResponse};
use neuron::api::{self, NeuronState};
use neuron::harness::HarnessRegistry;
use neuron::health::HealthCache;
use serde_json::json;
use std::sync::Arc;
use tokio::sync::RwLock;

async fn spawn_neuron(discovery: DiscoveryResponse) -> String {
    let health_cache = Arc::new(HealthCache::new());
    let registry = HarnessRegistry::new();

    let state = Arc::new(NeuronState {
        discovery,
        health_cache,
        registry: RwLock::new(registry),
    });

    let app = api::neuron_routes().with_state(state);
    let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
    let addr = listener.local_addr().unwrap();
    tokio::spawn(async move {
        axum::serve(listener, app).await.unwrap();
    });
    format!("http://{addr}")
}

fn fake_discovery() -> DiscoveryResponse {
    DiscoveryResponse {
        hostname: "test-node".into(),
        os: "Linux".into(),
        kernel: "6.19.0".into(),
        cuda_version: Some("12.8".into()),
        driver_version: Some("570.86.16".into()),
        devices: vec![
            DeviceInfo {
                index: 0,
                name: "NVIDIA GeForce RTX 5090".into(),
                vram_total_mb: 32614,
                compute_capability: "12.0".into(),
            },
            DeviceInfo {
                index: 1,
                name: "NVIDIA GeForce RTX 5090".into(),
                vram_total_mb: 32614,
                compute_capability: "12.0".into(),
            },
        ],
        harnesses: vec![],
    }
}

#[tokio::test]
async fn test_discovery_endpoint() {
    let url = spawn_neuron(fake_discovery()).await;

    let client = reqwest::Client::new();
    let resp = client
        .get(format!("{url}/discovery"))
        .send()
        .await
        .expect("request should succeed");

    assert_eq!(resp.status(), 200);

    let body: serde_json::Value = resp.json().await.unwrap();
    assert_eq!(body["hostname"], "test-node");
    assert_eq!(body["cuda_version"], "12.8");

    let devices = body["devices"].as_array().unwrap();
    assert_eq!(devices.len(), 2);
    assert_eq!(devices[0]["name"], "NVIDIA GeForce RTX 5090");
    assert_eq!(devices[0]["vram_total_mb"], 32614);
}

#[tokio::test]
async fn test_health_endpoint() {
    let url = spawn_neuron(fake_discovery()).await;

    let client = reqwest::Client::new();
    let resp = client
        .get(format!("{url}/health"))
        .send()
        .await
        .expect("request should succeed");

    assert_eq!(resp.status(), 200);

    let body: serde_json::Value = resp.json().await.unwrap();
    assert_eq!(body["uptime_secs"], 0);
}

#[tokio::test]
async fn test_discovery_no_gpus() {
    let disc = DiscoveryResponse {
        hostname: "cpu-only".into(),
        os: "Linux".into(),
        kernel: "6.19.0".into(),
        cuda_version: None,
        driver_version: None,
        devices: vec![],
        harnesses: vec![],
    };
    let url = spawn_neuron(disc).await;

    let client = reqwest::Client::new();
    let resp = client
        .get(format!("{url}/discovery"))
        .send()
        .await
        .expect("request should succeed");

    assert_eq!(resp.status(), 200);

    let body: serde_json::Value = resp.json().await.unwrap();
    assert_eq!(body["hostname"], "cpu-only");
    assert!(body["cuda_version"].is_null());
    assert!(body["devices"].as_array().unwrap().is_empty());
}

#[tokio::test]
async fn test_models_empty_registry() {
    let url = spawn_neuron(fake_discovery()).await;

    let client = reqwest::Client::new();
    let resp = client
        .get(format!("{url}/models"))
        .send()
        .await
        .expect("request should succeed");

    assert_eq!(resp.status(), 200);

    let body: serde_json::Value = resp.json().await.unwrap();
    assert!(body.as_array().unwrap().is_empty());
}

/// Verify the candle harness registers, list is empty by default, and a
/// load attempt for an obviously-bogus model id returns a 4xx error
/// without crashing the daemon. Real load/unload exercising actual GGUF
/// download is covered by `tests/candle_lifecycle.rs` (cuda-integration).
#[tokio::test]
async fn test_candle_harness_registers_and_rejects_bogus_model() {
    use cortex_core::harness::HarnessConfig;
    use neuron::config::HarnessSettings;

    let registry = HarnessRegistry::from_configs(
        &[HarnessConfig {
            name: "candle".into(),
        }],
        "http://localhost:13131",
        &HarnessSettings::default(),
    );

    let health_cache = Arc::new(HealthCache::new());
    let state = Arc::new(NeuronState {
        discovery: fake_discovery(),
        health_cache,
        registry: RwLock::new(registry),
    });

    let app = api::neuron_routes().with_state(state);
    let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
    let neuron_addr = listener.local_addr().unwrap();
    tokio::spawn(async move {
        axum::serve(listener, app).await.unwrap();
    });
    let neuron_url = format!("http://{neuron_addr}");

    let client = reqwest::Client::new();

    let resp = client
        .get(format!("{neuron_url}/models"))
        .send()
        .await
        .unwrap();
    assert_eq!(resp.status(), 200);
    let models: Vec<serde_json::Value> = resp.json().await.unwrap();
    assert!(models.is_empty());

    // Sending a wrong-harness spec should be rejected synchronously
    // without touching the network or the model registry.
    let resp = client
        .post(format!("{neuron_url}/models/load"))
        .json(&json!({"model_id": "definitely/not-real", "harness": "not-candle"}))
        .send()
        .await
        .unwrap();
    assert_eq!(resp.status(), 400);

    // Registry still empty.
    let resp = client
        .get(format!("{neuron_url}/models"))
        .send()
        .await
        .unwrap();
    let models: Vec<serde_json::Value> = resp.json().await.unwrap();
    assert!(models.is_empty());
}