//! Official single-instance transport, scoped to an explicitly selected profile.
use sha2::{Digest, Sha256};
use std::{ffi::OsString, io, path::PathBuf};
use tauri::{Emitter, Manager};

pub fn profile_identifier(base: &str, profile: Option<OsString>) -> io::Result<String> {
    let Some(profile) = profile else {
        return Ok(base.to_owned());
    };
    let path = crate::data_directory::resolve(PathBuf::new(), Some(profile))?;
    // Resolve the existing ancestor without creating a first-use profile.
    let canonical = crate::data_directory::canonical_exclusion(&path)?;
    let mut digest = Sha256::new();
    #[cfg(windows)]
    {
        use std::os::windows::ffi::OsStrExt;
        for unit in canonical.as_os_str().encode_wide() {
            digest.update(unit.to_le_bytes());
        }
    }
    #[cfg(not(windows))]
    {
        use std::os::unix::ffi::OsStrExt;
        digest.update(canonical.as_os_str().as_bytes());
    }
    Ok(format!("{base}.profile{:x}", digest.finalize()))
}

pub fn focus_search(app: &tauri::AppHandle) {
    if let Some(window) = app.get_webview_window("main") {
        let result = window
            .show()
            .and_then(|_| window.unminimize())
            .and_then(|_| window.set_focus());
        if let Err(error) = result {
            eprintln!("Could not focus searchi: {error}");
        }
        let _ = window.emit("focus-search", ());
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    #[test]
    fn default_identity_is_unchanged_and_invalid_profile_rejected() {
        assert_eq!(
            profile_identifier("dev.searchi.desktop", None).unwrap(),
            "dev.searchi.desktop"
        );
        assert!(profile_identifier("dev.searchi.desktop", Some("relative".into())).is_err());
    }
    #[test]
    fn canonical_profiles_are_stable_distinct_and_do_not_expose_paths() {
        let root = tempfile::tempdir().unwrap();
        let first = root.path().join("Gemäß_日本_😀");
        let second = root.path().join("other");
        let id = profile_identifier("dev.searchi.desktop", Some(first.clone().into_os_string()))
            .unwrap();
        assert!(!first.exists());
        std::fs::create_dir(&first).unwrap();
        assert_eq!(
            id,
            profile_identifier(
                "dev.searchi.desktop",
                Some(first.join(".").into_os_string())
            )
            .unwrap()
        );
        assert_ne!(
            id,
            profile_identifier("dev.searchi.desktop", Some(second.into_os_string())).unwrap()
        );
        assert!(!id.contains("Gemäß"));
        assert_eq!(id.len(), "dev.searchi.desktop.profile".len() + 64);
        assert!(!root.path().join("other").exists());
    }
}