//! HTTP JSON-RPC integration tests against a real axum stack and a mock upstream API.
//!
//! Isolates config under a temp `HOME` so auth profiles and the OpenHuman provider resolve
//! the same state directory. Run with: `cargo test --test json_rpc_e2e`

use std::net::SocketAddr;
use std::path::Path;
use std::time::Duration;

use axum::routing::{get, post};
use axum::{Json, Router};
use futures_util::StreamExt;
use serde_json::{json, Value};
use tempfile::tempdir;

use openhuman_core::core::jsonrpc::build_core_http_router;

struct EnvVarGuard {
    key: &'static str,
    old: Option<String>,
}

impl EnvVarGuard {
    fn set_to_path(key: &'static str, path: &Path) -> Self {
        let old = std::env::var(key).ok();
        std::env::set_var(key, path.as_os_str());
        Self { key, old }
    }

    fn unset(key: &'static str) -> Self {
        let old = std::env::var(key).ok();
        std::env::remove_var(key);
        Self { key, old }
    }
}

impl Drop for EnvVarGuard {
    fn drop(&mut self) {
        match &self.old {
            Some(v) => std::env::set_var(self.key, v),
            None => std::env::remove_var(self.key),
        }
    }
}

fn mock_upstream_router() -> Router {
    // Matches `GET /settings` in `BackendOAuthClient::fetch_settings` (session store validation).
    async fn settings() -> Json<Value> {
        Json(json!({
            "success": true,
            "data": {
                "_id": "e2e-user-1",
                "username": "e2e"
            }
        }))
    }

    async fn chat_completions(Json(_body): Json<Value>) -> Json<Value> {
        Json(json!({
            "choices": [{
                "message": {
                    "role": "assistant",
                    "content": "Hello from e2e mock agent"
                }
            }]
        }))
    }

    Router::new()
        .route("/settings", get(settings))
        // `OpenHumanBackendProvider` uses `{api_url}/openai/v1` + `/chat/completions`.
        .route("/openai/v1/chat/completions", post(chat_completions))
}

async fn serve_on_ephemeral(
    app: Router,
) -> (
    SocketAddr,
    tokio::task::JoinHandle<Result<(), std::io::Error>>,
) {
    let listener = tokio::net::TcpListener::bind("127.0.0.1:0")
        .await
        .expect("bind");
    let addr = listener.local_addr().expect("addr");
    let handle = tokio::spawn(async move { axum::serve(listener, app).await });
    (addr, handle)
}

async fn post_json_rpc(rpc_base: &str, id: i64, method: &str, params: Value) -> Value {
    let client = reqwest::Client::builder()
        .timeout(Duration::from_secs(120))
        .build()
        .expect("client");
    let body = json!({
        "jsonrpc": "2.0",
        "id": id,
        "method": method,
        "params": params
    });
    let url = format!("{}/rpc", rpc_base.trim_end_matches('/'));
    let resp = client
        .post(&url)
        .json(&body)
        .send()
        .await
        .unwrap_or_else(|e| panic!("POST {url}: {e}"));
    assert!(
        resp.status().is_success(),
        "HTTP error {} for {}",
        resp.status(),
        method
    );
    resp.json::<Value>()
        .await
        .unwrap_or_else(|e| panic!("json for {method}: {e}"))
}

async fn read_first_sse_event(events_url: &str) -> Value {
    let client = reqwest::Client::builder()
        .timeout(Duration::from_secs(120))
        .build()
        .expect("client");
    let resp = client
        .get(events_url)
        .send()
        .await
        .unwrap_or_else(|e| panic!("GET {events_url}: {e}"));
    assert!(
        resp.status().is_success(),
        "SSE HTTP error {} for {}",
        resp.status(),
        events_url
    );

    let mut stream = resp.bytes_stream();
    let mut buffer = String::new();
    while let Some(item) = stream.next().await {
        let chunk = item.unwrap_or_else(|e| panic!("sse stream read failed: {e}"));
        let text = std::str::from_utf8(&chunk).unwrap_or("");
        buffer.push_str(text);
        while let Some(idx) = buffer.find("\n\n") {
            let block = buffer[..idx].to_string();
            buffer = buffer[idx + 2..].to_string();
            let mut data_lines = Vec::new();
            for line in block.lines() {
                if let Some(data) = line.strip_prefix("data:") {
                    data_lines.push(data.trim_start());
                }
            }
            if !data_lines.is_empty() {
                let payload = data_lines.join("\n");
                let value: Value = serde_json::from_str(&payload)
                    .unwrap_or_else(|e| panic!("invalid sse data json: {e}"));
                return value;
            }
        }
    }
    panic!("SSE stream ended before any event payload");
}

fn assert_no_jsonrpc_error<'a>(v: &'a Value, context: &str) -> &'a Value {
    if let Some(err) = v.get("error") {
        panic!("{context}: JSON-RPC error: {err}");
    }
    v.get("result")
        .unwrap_or_else(|| panic!("{context}: missing result: {v}"))
}

fn extract_string_outcome(result: &Value) -> String {
    if let Some(s) = result.as_str() {
        return s.to_string();
    }
    if let Some(inner) = result.get("result").and_then(Value::as_str) {
        return inner.to_string();
    }
    panic!("expected string or {{result: string}}, got {result}");
}

fn write_min_config(openhuman_dir: &Path, api_origin: &str) {
    let cfg = format!(
        r#"api_url = "{api_origin}"
default_model = "e2e-mock-model"
default_temperature = 0.7

[secrets]
encrypt = false
"#
    );
    std::fs::create_dir_all(openhuman_dir).expect("mkdir openhuman");
    let path = openhuman_dir.join("config.toml");
    std::fs::write(&path, &cfg).expect("write config");
    let _: openhuman_core::openhuman::config::Config =
        toml::from_str(&cfg).expect("config toml must match Config schema");
}

#[tokio::test]
async fn json_rpc_protocol_auth_and_agent_hello() {
    let tmp = tempdir().expect("tempdir");
    let home = tmp.path();
    let openhuman_home = home.join(".openhuman");

    let _home_guard = EnvVarGuard::set_to_path("HOME", home);
    let _workspace_guard = EnvVarGuard::unset("OPENHUMAN_WORKSPACE");

    let external_backend = std::env::var("BACKEND_URL")
        .ok()
        .or_else(|| std::env::var("VITE_BACKEND_URL").ok())
        .filter(|s| !s.trim().is_empty());
    let (mock_origin, mock_join) = if let Some(origin) = external_backend {
        (origin, None)
    } else {
        let (mock_addr, join) = serve_on_ephemeral(mock_upstream_router()).await;
        (format!("http://{}", mock_addr), Some(join))
    };

    write_min_config(&openhuman_home, &mock_origin);

    let (rpc_addr, rpc_join) = serve_on_ephemeral(build_core_http_router(false)).await;
    let rpc_base = format!("http://{}", rpc_addr);

    tokio::time::sleep(Duration::from_millis(100)).await;

    // --- core.ping (baseline protocol) ---
    let ping = post_json_rpc(&rpc_base, 1, "core.ping", json!({})).await;
    let ping_result = assert_no_jsonrpc_error(&ping, "core.ping");
    assert_eq!(ping_result.get("ok"), Some(&json!(true)));

    // --- unknown method ---
    let unknown = post_json_rpc(&rpc_base, 2, "core.not_a_real_method", json!({})).await;
    assert!(
        unknown.get("error").is_some(),
        "expected error for unknown method: {unknown}"
    );

    // --- auth: session state (no JWT yet) ---
    let state_before = post_json_rpc(&rpc_base, 3, "openhuman.auth_get_state", json!({})).await;
    let state_outer = assert_no_jsonrpc_error(&state_before, "get_state");
    let state_body = state_outer.get("result").unwrap_or(state_outer);
    assert!(
        state_body.get("isAuthenticated").is_some() || state_body.get("is_authenticated").is_some(),
        "unexpected auth state shape: {state_body}"
    );

    // --- auth: store session (validates JWT against mock GET /auth/integrations) ---
    let store = post_json_rpc(
        &rpc_base,
        4,
        "openhuman.auth_store_session",
        json!({
            "token": "e2e-test-jwt",
            "user_id": "e2e-user"
        }),
    )
    .await;
    assert_no_jsonrpc_error(&store, "store_session");

    // --- agent: single chat turn (mock chat completions) ---
    let chat = post_json_rpc(
        &rpc_base,
        5,
        "openhuman.local_ai_agent_chat",
        json!({
            "message": "Hello",
        }),
    )
    .await;
    let chat_result = assert_no_jsonrpc_error(&chat, "agent_chat");
    let reply = extract_string_outcome(chat_result);
    assert!(
        reply.contains("e2e mock") || reply.contains("Hello"),
        "unexpected agent reply: {reply:?}"
    );

    // --- web channel RPC + SSE loop ---
    let client_id = "e2e-client-1";
    let thread_id = "thread-1";
    let events_url = format!("{}/events?client_id={}", rpc_base, client_id);
    let sse_task = tokio::spawn(async move { read_first_sse_event(&events_url).await });

    let web_chat = post_json_rpc(
        &rpc_base,
        6,
        "openhuman.channel_web_chat",
        json!({
            "client_id": client_id,
            "thread_id": thread_id,
            "message": "Hello from web channel",
            "model_override": "e2e-mock-model",
        }),
    )
    .await;
    let web_chat_result = assert_no_jsonrpc_error(&web_chat, "channel_web_chat");
    assert_eq!(
        web_chat_result
            .get("result")
            .and_then(|v| v.get("accepted")),
        Some(&json!(true))
    );

    let sse_event = sse_task.await.expect("sse task join should succeed");
    assert_eq!(
        sse_event.get("event").and_then(Value::as_str),
        Some("chat_done")
    );
    assert_eq!(
        sse_event.get("thread_id").and_then(Value::as_str),
        Some(thread_id)
    );
    assert!(
        sse_event
            .get("full_response")
            .and_then(Value::as_str)
            .unwrap_or_default()
            .len()
            > 0,
        "expected non-empty chat_done response payload: {sse_event}"
    );

    if let Some(join) = mock_join {
        join.abort();
    }
    rpc_join.abort();
}