use std::{
    path::{Path, PathBuf},
    process::Command,
};

// ── Cert installation ─────────────────────────────────────────────────────────

/// Find the bridge cert in the given captures dir.
pub fn find_bridge_cert(captures_dir: &str) -> Option<PathBuf> {
    let p = Path::new(captures_dir).join("bridge_cert.pem");
    p.exists().then_some(p)
}

/// Install the bridge cert into the Wine/Proton prefix cert store so the game
/// trusts TLS connections to the bridge. Falls back to the system CA store.
pub fn install_cert(cert_src: &Path) -> anyhow::Result<()> {
    // Try certutil inside the Proton prefix first (Wine cert store)
    let wine_result = try_wine_certutil(cert_src);
    if wine_result.is_ok() {
        return wine_result;
    }

    // Fallback: Linux system CA store via pkexec/sudo
    let dest = Path::new("/usr/local/share/ca-certificates/openfut-bridge.crt");
    let script = format!(
        "cp '{}' '{}' && update-ca-certificates",
        cert_src.display(),
        dest.display()
    );
    run_elevated(&script)
}

fn try_wine_certutil(cert_src: &Path) -> anyhow::Result<()> {
    // certutil is available inside a Wine prefix via winetricks or natively
    let status = Command::new("wine")
        .args([
            "certutil",
            "-addstore",
            "-user",
            "Root",
            &cert_src.to_string_lossy(),
        ])
        .status();

    match status {
        Ok(s) if s.success() => Ok(()),
        Ok(s) => anyhow::bail!("wine certutil exited {s}"),
        Err(e) => anyhow::bail!("wine certutil not available: {e}"),
    }
}

pub(crate) fn run_elevated(script: &str) -> anyhow::Result<()> {
    let status = Command::new("pkexec").args(["sh", "-c", script]).status();

    match status {
        Ok(s) if s.success() => Ok(()),
        _ => {
            let s = Command::new("sudo").args(["sh", "-c", script]).status()?;
            if s.success() {
                Ok(())
            } else {
                anyhow::bail!("elevated command failed")
            }
        }
    }
}

// ── DLL hook deployment ───────────────────────────────────────────────────────

/// Deploy openfut_hook.dll into the FIFA 23 game directory and write
/// openfut.cfg with the structured server configuration the hook reads.
/// `cfg_contents` must be the full `openfut.cfg` body (see
/// `LauncherConfig::hook_cfg_contents`) — this function does not invent any
/// address itself, so a missing server can never silently become loopback.
/// Uses `version.dll` as the hijack name — FIFA 23 loads it but defers to
/// the system copy, so Proton picks up our local one first.
pub fn deploy_hook_dll(dll_src: &Path, game_dir: &Path, cfg_contents: &str) -> anyhow::Result<()> {
    if !dll_src.exists() {
        anyhow::bail!(
            "Hook DLL not found at {}. Build it first with:\n\
             cargo build --release --target x86_64-pc-windows-gnu\n\
             (inside openfut-hook/)",
            dll_src.display()
        );
    }
    std::fs::create_dir_all(game_dir)?;
    std::fs::copy(dll_src, game_dir.join("version.dll"))?;
    std::fs::write(game_dir.join("openfut.cfg"), cfg_contents)?;
    Ok(())
}

/// Update only openfut.cfg without redeploying the DLL. `cfg_contents` is the
/// full structured `openfut.cfg` body.
pub fn update_hook_config(game_dir: &Path, cfg_contents: &str) -> anyhow::Result<()> {
    let cfg = game_dir.join("openfut.cfg");
    if !cfg.exists() {
        anyhow::bail!("Hook DLL not deployed yet — deploy first.");
    }
    std::fs::write(cfg, cfg_contents)?;
    Ok(())
}

/// Remove the deployed hook DLL from the FIFA game directory.
pub fn remove_hook_dll(game_dir: &Path) -> anyhow::Result<()> {
    let dest = game_dir.join("version.dll");
    if dest.exists() {
        std::fs::remove_file(&dest)?;
    }
    Ok(())
}

/// Check whether our hook DLL is deployed in the game directory.
pub fn hook_dll_deployed(game_dir: &Path) -> bool {
    game_dir.join("version.dll").exists()
}

/// The Steam launch options the user needs to paste in to enable the override.
/// Proton loads local DLLs named in WINEDLLOVERRIDES ahead of system ones.
pub const STEAM_LAUNCH_OPTIONS: &str = "WINEDLLOVERRIDES=\"version=n,b\" %command%";

// ── Game launch ───────────────────────────────────────────────────────────────

/// Launch the game via the user-provided shell command. Runs `sh -c <command>`
/// (optionally from `workdir`), streaming stdout+stderr into `log_buf` on a
/// background thread. The launcher does not assume Steam vs umu-run vs a custom
/// script — whatever the user configured is what runs.
pub fn launch_game(
    command: &str,
    workdir: &str,
    log_buf: std::sync::Arc<std::sync::Mutex<crate::logs::LogBuffer>>,
) -> anyhow::Result<()> {
    use std::io::{BufRead, BufReader};
    use std::process::{Command, Stdio};

    if command.trim().is_empty() {
        anyhow::bail!("No game launch command configured (set it in the Config tab).");
    }

    let mut cmd = Command::new("sh");
    cmd.arg("-c").arg(command);
    if !workdir.trim().is_empty() {
        cmd.current_dir(workdir);
    }
    cmd.stdout(Stdio::piped()).stderr(Stdio::piped());

    log_buf
        .lock()
        .unwrap()
        .push(format!("[launcher] launching game: {command}"));

    let mut child = cmd.spawn()?;

    if let Some(out) = child.stdout.take() {
        let buf = std::sync::Arc::clone(&log_buf);
        std::thread::spawn(move || {
            for line in BufReader::new(out).lines().map_while(Result::ok) {
                buf.lock().unwrap().push(line);
            }
        });
    }
    if let Some(err) = child.stderr.take() {
        let buf = std::sync::Arc::clone(&log_buf);
        std::thread::spawn(move || {
            for line in BufReader::new(err).lines().map_while(Result::ok) {
                buf.lock().unwrap().push(line);
            }
        });
    }
    // Reap the child in the background so a finished game doesn't linger as a
    // zombie; we don't block the UI on it.
    std::thread::spawn(move || {
        let _ = child.wait();
        log_buf
            .lock()
            .unwrap()
            .push("[launcher] game process exited.".to_string());
    });

    Ok(())
}