mod client;
mod history;

pub use client::{
    ChatMessage, ConfigError, LlmBackend, LlmClient, LlmError,
    DEFAULT_BASE_URL, DEFAULT_MODEL, ENV_BASE_URL, ENV_MODEL, ENV_TOKEN,
    OLLAMA_DEFAULT_BASE_URL, OLLAMA_DEFAULT_MODEL,
};
pub use history::ConversationHistory;

use once_cell::sync::Lazy;
use parking_lot::RwLock;
use std::sync::Arc;

/// Shared mutable LLM client. Modules read via `current()`; the user can
/// hot-swap backends at runtime via `swap_to(LlmBackend::Ollama)` etc.
///
/// `None` means LLM is disabled (no GROQ_TOKEN and no Ollama reachable, or
/// `init_global()` was never called).
static GLOBAL: Lazy<RwLock<Option<Arc<LlmClient>>>> = Lazy::new(|| RwLock::new(None));

/// Initialise the global client from env vars (`JARVIS_LLM`, `GROQ_TOKEN`, ...).
/// Idempotent — replaces any previous global. Returns Ok even when the chosen
/// backend can't be probed: an Ollama server may not be running yet but we
/// stash the client anyway and let calls fail on first request.
pub fn init_global() -> Result<(), ConfigError> {
    let c = LlmClient::from_env()?;
    log::info!("LLM global initialised: backend={}, model={}", c.backend().name(), c.model());
    *GLOBAL.write() = Some(Arc::new(c));
    Ok(())
}

/// Return a clone of the active client. Cheap (Arc).
pub fn current() -> Option<Arc<LlmClient>> {
    GLOBAL.read().clone()
}

/// Name of the currently active backend, or "none" if not initialised.
pub fn current_backend_name() -> &'static str {
    match GLOBAL.read().as_ref().map(|c| c.backend()) {
        Some(LlmBackend::Groq) => "groq",
        Some(LlmBackend::Ollama) => "ollama",
        None => "none",
    }
}

/// Hot-swap to a different backend. Returns the new backend's name on success.
pub fn swap_to(backend: LlmBackend) -> Result<&'static str, ConfigError> {
    let c = match backend {
        LlmBackend::Groq => LlmClient::groq()?,
        LlmBackend::Ollama => LlmClient::ollama(),
    };
    let name = c.backend().name();
    log::info!("LLM swapped → backend={}, model={}", name, c.model());
    *GLOBAL.write() = Some(Arc::new(c));
    Ok(name)
}

/// Parse a backend name (case-insensitive) into the enum.
pub fn parse_backend(name: &str) -> Option<LlmBackend> {
    match name.trim().to_lowercase().as_str() {
        "groq" | "cloud" | "облако" | "клауд" => Some(LlmBackend::Groq),
        "ollama" | "local" | "локал" | "локальн" | "локальный" => Some(LlmBackend::Ollama),
        _ => None,
    }
}