//! Integration coverage for server process startup behavior.
//!
//! Scope: launch the real `lesavka-server` binary and assert startup stays
//! resilient in this non-gadget test environment.
//! Targets: `server/src/main.rs`.
//! Why: missing gadget endpoints should not crash the relay; the server keeps
//! running and opens HID lazily when the device nodes appear.

use serial_test::serial;
use std::fs;
use std::path::PathBuf;
use std::process::Command;
use std::time::{Duration, Instant};

fn cargo_binary(name: &str) -> Option<PathBuf> {
    let key = format!("CARGO_BIN_EXE_{name}");
    option_env!("CARGO_BIN_EXE_lesavka-server")
        .filter(|_| name == "lesavka-server")
        .map(PathBuf::from)
        .or_else(|| std::env::var_os(key).map(PathBuf::from))
        .filter(|path| path.exists() && path.is_file())
}

fn candidate_dirs() -> Vec<PathBuf> {
    let exe = std::env::current_exe().expect("current exe path");
    let mut dirs = Vec::new();
    if let Some(parent) = exe.parent() {
        dirs.push(parent.to_path_buf());
        if let Some(grand) = parent.parent() {
            dirs.push(grand.to_path_buf());
        }
    }
    dirs.push(PathBuf::from("target/debug"));
    dirs.push(PathBuf::from("target/llvm-cov-target/debug"));
    dirs
}

fn find_binary(name: &str) -> Option<PathBuf> {
    cargo_binary(name).or_else(|| {
        candidate_dirs()
            .into_iter()
            .map(|dir| dir.join(name))
            .find(|path| path.exists() && path.is_file())
    })
}

fn server_package_version() -> Option<String> {
    let manifest = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
        .parent()?
        .join("server/Cargo.toml");
    fs::read_to_string(manifest).ok()?.lines().find_map(|line| {
        let trimmed = line.trim();
        trimmed
            .strip_prefix("version")
            .and_then(|value| value.split('=').nth(1))
            .map(str::trim)
            .and_then(|value| value.strip_prefix('"')?.strip_suffix('"'))
            .map(str::to_string)
    })
}

fn wait_for_log(path: &PathBuf, needle: &str, deadline: Instant) -> String {
    loop {
        let log = fs::read_to_string(path).unwrap_or_default();
        if log.contains(needle) {
            return log;
        }
        assert!(
            Instant::now() < deadline,
            "timed out waiting for log line {needle:?}; log was:\n{log}"
        );
        std::thread::sleep(Duration::from_millis(50));
    }
}

#[test]
#[serial]
fn server_binary_stays_up_with_missing_hid_nodes_and_current_version() {
    let Some(bin) = find_binary("lesavka-server") else {
        return;
    };
    let log_path = PathBuf::from("/tmp/lesavka-server.log");
    let _ = fs::remove_file(&log_path);

    let mut child = Command::new(bin)
        .env("LESAVKA_DISABLE_UVC", "1")
        .spawn()
        .expect("spawn lesavka-server");

    let deadline = Instant::now() + Duration::from_secs(3);
    if let Some(version) = server_package_version() {
        let _ = wait_for_log(
            &log_path,
            &format!("lesavka_server v{version} starting up"),
            deadline,
        );
    }
    let log = wait_for_log(
        &log_path,
        "HID endpoints are not ready; relay will keep running and open them lazily",
        deadline,
    );
    assert!(
        child.try_wait().expect("poll child").is_none(),
        "server should stay alive with lazy HID recovery; log was:\n{log}"
    );
    let _ = child.kill();
    let _ = child.wait();
}