// mind/ — Cognitive layer
//
// Mind state machine, DMN, identity, observation socket.
// Everything about how the mind operates, separate from the
// user interface (TUI, CLI) and the agent execution (tools, API).

pub mod dmn;
pub mod identity;
pub mod log;

// consciousness.rs — Mind state machine and event loop
//
// The core runtime for the consciousness binary. Mind manages turns,
// DMN state, compaction, scoring, and slash commands. The event loop
// bridges Mind (cognitive state) with App (TUI rendering).
//
// The event loop uses biased select! so priorities are deterministic:
// keyboard events > turn results > render ticks > DMN timer > UI messages.

use anyhow::Result;
use std::sync::Arc;
use std::time::Instant;
use tokio::sync::{mpsc, Mutex};

use crate::agent::{Agent, TurnResult};
use crate::agent::api::ApiClient;
use crate::config::{self, AppConfig, SessionConfig};
use crate::user::{self as tui};
use crate::user::ui_channel::{self, StatusInfo, StreamTarget, UiMessage};
use crate::subconscious::learn;

/// Compaction threshold — context is rebuilt when prompt tokens exceed this.
fn compaction_threshold(app: &AppConfig) -> u32 {
    (crate::agent::context::context_window() as u32) * app.compaction.hard_threshold_pct / 100
}


/// Shared state between Mind and UI.
#[derive(Clone)]
pub struct MindState {
    /// Pending user input — UI pushes, Mind consumes after turn completes.
    pub input: Vec<String>,
    /// True while a turn is in progress.
    pub turn_active: bool,
    /// DMN state
    pub dmn: dmn::State,
    pub dmn_turns: u32,
    pub max_dmn_turns: u32,
    /// Whether memory scoring is running.
    pub scoring_in_flight: bool,
    /// Whether compaction is running.
    pub compaction_in_flight: bool,
    /// Per-turn tracking
    pub last_user_input: Instant,
    pub consecutive_errors: u32,
    pub last_turn_had_tools: bool,
}

pub type SharedMindState = Arc<std::sync::Mutex<MindState>>;

/// What should happen after a state transition.
pub enum MindCommand {
    /// Start a turn with this input
    Turn(String, StreamTarget),
    /// Run compaction check
    Compact,
    /// Run memory scoring
    Score,
    /// Abort current turn, kill processes
    Interrupt,
    /// Reset session
    NewSession,
    /// Nothing to do
    None,
}

impl MindState {
    pub fn new(max_dmn_turns: u32) -> Self {
        Self {
            input: Vec::new(),
            turn_active: false,
            dmn: if dmn::is_off() { dmn::State::Off }
                 else { dmn::State::Resting { since: Instant::now() } },
            dmn_turns: 0,
            max_dmn_turns,
            scoring_in_flight: false,
            compaction_in_flight: false,
            last_user_input: Instant::now(),
            consecutive_errors: 0,
            last_turn_had_tools: false,
        }
    }

    /// Consume pending input, return a Turn command if ready.
    pub fn take_pending_input(&mut self) -> MindCommand {
        if self.turn_active || self.input.is_empty() {
            return MindCommand::None;
        }
        let text = self.input.join("\n");
        self.input.clear();
        self.dmn_turns = 0;
        self.consecutive_errors = 0;
        self.last_user_input = Instant::now();
        self.dmn = dmn::State::Engaged;
        MindCommand::Turn(text, StreamTarget::Conversation)
    }

    /// Process turn completion, return model switch name if requested.
    pub fn complete_turn(&mut self, result: &Result<TurnResult>, target: StreamTarget) -> Option<String> {
        self.turn_active = false;
        match result {
            Ok(turn_result) => {
                if turn_result.tool_errors > 0 {
                    self.consecutive_errors += turn_result.tool_errors;
                } else {
                    self.consecutive_errors = 0;
                }
                self.last_turn_had_tools = turn_result.had_tool_calls;
                self.dmn = dmn::transition(
                    &self.dmn,
                    turn_result.yield_requested,
                    turn_result.had_tool_calls,
                    target == StreamTarget::Conversation,
                );
                if turn_result.dmn_pause {
                    self.dmn = dmn::State::Paused;
                    self.dmn_turns = 0;
                }
                turn_result.model_switch.clone()
            }
            Err(_) => {
                self.consecutive_errors += 1;
                self.dmn = dmn::State::Resting { since: Instant::now() };
                None
            }
        }
    }

    /// DMN tick — returns a Turn action with the DMN prompt, or None.
    pub fn dmn_tick(&mut self) -> MindCommand {
        if matches!(self.dmn, dmn::State::Paused | dmn::State::Off) {
            return MindCommand::None;
        }

        self.dmn_turns += 1;
        if self.dmn_turns > self.max_dmn_turns {
            self.dmn = dmn::State::Resting { since: Instant::now() };
            self.dmn_turns = 0;
            return MindCommand::None;
        }

        let dmn_ctx = dmn::DmnContext {
            user_idle: self.last_user_input.elapsed(),
            consecutive_errors: self.consecutive_errors,
            last_turn_had_tools: self.last_turn_had_tools,
        };
        let prompt = self.dmn.prompt(&dmn_ctx);
        MindCommand::Turn(prompt, StreamTarget::Autonomous)
    }

    pub fn interrupt(&mut self) {
        self.input.clear();
        self.dmn = dmn::State::Resting { since: Instant::now() };
    }
}

pub fn shared_mind_state(max_dmn_turns: u32) -> SharedMindState {
    Arc::new(std::sync::Mutex::new(MindState::new(max_dmn_turns)))
}

// --- Mind: cognitive state machine ---

pub struct Mind {
    pub agent: Arc<Mutex<Agent>>,
    pub shared: SharedMindState,
    pub config: SessionConfig,
    ui_tx: ui_channel::UiSender,
    turn_tx: mpsc::Sender<(Result<TurnResult>, StreamTarget)>,
    turn_handle: Option<tokio::task::JoinHandle<()>>,
    turn_watch: tokio::sync::watch::Sender<bool>,
}

impl Mind {
    pub fn new(
        agent: Arc<Mutex<Agent>>,
        shared: SharedMindState,
        config: SessionConfig,
        ui_tx: ui_channel::UiSender,
        turn_tx: mpsc::Sender<(Result<TurnResult>, StreamTarget)>,
    ) -> Self {
        let (turn_watch, _) = tokio::sync::watch::channel(false);
        Self { agent, shared, config, ui_tx, turn_tx, turn_handle: None, turn_watch }
    }

    pub fn turn_watch(&self) -> tokio::sync::watch::Receiver<bool> {
        self.turn_watch.subscribe()
    }

    /// Execute an Action from a MindState method.
    async fn run_commands(&mut self, cmds: Vec<MindCommand>) {
        for cmd in cmds {
            match cmd {
                MindCommand::None => {}
                MindCommand::Compact => {
                    let threshold = compaction_threshold(&self.config.app);
                    let mut ag = self.agent.lock().await;
                    if ag.last_prompt_tokens() > threshold {
                        ag.compact();
                    }
                }
                MindCommand::Score => {
                    let mut s = self.shared.lock().unwrap();
                    if !s.scoring_in_flight {
                        s.scoring_in_flight = true;
                        drop(s);
                        self.start_memory_scoring();
                    }
                }
                MindCommand::Interrupt => {
                    self.shared.lock().unwrap().interrupt();
                    let ag = self.agent.lock().await;
                    let mut tools = ag.active_tools.lock().unwrap();
                    for entry in tools.drain(..) { entry.handle.abort(); }
                    drop(tools); drop(ag);
                    if let Some(h) = self.turn_handle.take() { h.abort(); }
                    self.shared.lock().unwrap().turn_active = false;
                    let _ = self.turn_watch.send(false);
                }
                MindCommand::NewSession => {
                    {
                        let mut s = self.shared.lock().unwrap();
                        s.dmn = dmn::State::Resting { since: Instant::now() };
                        s.dmn_turns = 0;
                    }
                    let new_log = log::ConversationLog::new(
                        self.config.session_dir.join("conversation.jsonl"),
                    ).ok();
                    let mut ag = self.agent.lock().await;
                    let shared_ctx = ag.shared_context.clone();
                    let shared_tools = ag.active_tools.clone();
                    *ag = Agent::new(
                        ApiClient::new(&self.config.api_base, &self.config.api_key, &self.config.model),
                        self.config.system_prompt.clone(), self.config.context_parts.clone(),
                        self.config.app.clone(), self.config.prompt_file.clone(),
                        new_log, shared_ctx, shared_tools,
                    );
                }
                MindCommand::Turn(input, target) => {
                    if target == StreamTarget::Conversation {
                        let _ = self.ui_tx.send(UiMessage::UserInput(input.clone()));
                    }
                    self.shared.lock().unwrap().turn_active = true;
                    let _ = self.turn_watch.send(true);
                    let agent = self.agent.clone();
                    let ui_tx = self.ui_tx.clone();
                    let result_tx = self.turn_tx.clone();
                    self.turn_handle = Some(tokio::spawn(async move {
                        let result = Agent::turn(agent, &input, &ui_tx, target).await;
                        let _ = result_tx.send((result, target)).await;
                    }));
                }
            }
        }
    }

    pub fn start_memory_scoring(&self) {
        let agent = self.agent.clone();
        let shared = self.shared.clone();
        let ui_tx = self.ui_tx.clone();
        let cfg = crate::config::get();
        let max_age = cfg.scoring_interval_secs;
        let response_window = cfg.scoring_response_window;
        tokio::spawn(async move {
            let (context, client) = {
                let mut ag = agent.lock().await;
                if ag.agent_cycles.memory_scoring_in_flight { return; }
                ag.agent_cycles.memory_scoring_in_flight = true;
                (ag.context.clone(), ag.client_clone())
            };
            let result = learn::score_memories_incremental(
                &context, max_age as i64, response_window, &client, &ui_tx,
            ).await;
            {
                let mut ag = agent.lock().await;
                ag.agent_cycles.memory_scoring_in_flight = false;
                if let Ok(ref scores) = result { ag.agent_cycles.memory_scores = scores.clone(); }
            }
            shared.lock().unwrap().scoring_in_flight = false;
        });
    }

    pub async fn shutdown(&mut self) {
        if let Some(handle) = self.turn_handle.take() { handle.abort(); }
    }

    /// Mind event loop — locks MindState, calls state methods, executes actions.
    pub async fn run(
        &mut self,
        mut input_rx: tokio::sync::mpsc::UnboundedReceiver<MindCommand>,
        mut turn_rx: mpsc::Receiver<(Result<TurnResult>, StreamTarget)>,
    ) {
        loop {
            let timeout = self.shared.lock().unwrap().dmn.interval();
            let turn_active = self.shared.lock().unwrap().turn_active;

            let mut cmds = Vec::new();

            tokio::select! {
                biased;

                Some(cmd) = input_rx.recv() => {
                    cmds.push(cmd);
                }

                Some((result, target)) = turn_rx.recv() => {
                    self.turn_handle = None;
                    let model_switch = self.shared.lock().unwrap().complete_turn(&result, target);
                    let _ = self.turn_watch.send(false);

                    if let Some(name) = model_switch {
                        crate::user::event_loop::cmd_switch_model(&self.agent, &name, &self.ui_tx).await;
                    }

                    // Post-turn maintenance
                    {
                        let mut ag = self.agent.lock().await;
                        ag.age_out_images();
                        ag.publish_context_state();
                    }

                    cmds.push(MindCommand::Compact);
                    if !self.config.no_agents {
                        cmds.push(MindCommand::Score);
                    }
                }

                _ = tokio::time::sleep(timeout), if !turn_active => {
                    let tick = self.shared.lock().unwrap().dmn_tick();
                    cmds.push(tick);
                }
            }

            // Always check for pending input
            cmds.push(self.shared.lock().unwrap().take_pending_input());

            self.run_commands(cmds).await;
        }
    }
}

// --- Startup ---

pub async fn run(cli: crate::user::CliArgs) -> Result<()> {
    let (config, _figment) = config::load_session(&cli)?;

    if config.app.debug {
        unsafe { std::env::set_var("POC_DEBUG", "1") };
    }

    // Start channel daemons
    let mut channel_supervisor = crate::thalamus::supervisor::Supervisor::new();
    channel_supervisor.load_config();
    channel_supervisor.ensure_running();

    // Initialize idle state machine
    let mut idle_state = crate::thalamus::idle::State::new();
    idle_state.load();

    // Channel status
    let (channel_tx, channel_rx) = tokio::sync::mpsc::channel::<Vec<(String, bool, u32)>>(4);
    {
        let tx = channel_tx.clone();
        tokio::spawn(async move {
            let result = crate::thalamus::channels::fetch_all_channels().await;
            let _ = tx.send(result).await;
        });
    }
    let notify_rx = crate::thalamus::channels::subscribe_all();

    // Create UI channel
    let (ui_tx, ui_rx) = ui_channel::channel();

    // Shared state
    let shared_context = ui_channel::shared_context_state();
    let shared_active_tools = ui_channel::shared_active_tools();

    // Startup info
    let _ = ui_tx.send(UiMessage::Info("consciousness v0.3 (tui)".into()));
    let _ = ui_tx.send(UiMessage::Info(format!(
        "  model: {} (available: {})", config.model, config.app.model_names().join(", "),
    )));
    let client = ApiClient::new(&config.api_base, &config.api_key, &config.model);
    let _ = ui_tx.send(UiMessage::Info(format!("  api:   {} ({})", config.api_base, client.backend_label())));
    let _ = ui_tx.send(UiMessage::Info(format!(
        "  context: {}K chars ({} config, {} memory files)",
        config.context_parts.iter().map(|(_, c)| c.len()).sum::<usize>() / 1024,
        config.config_file_count, config.memory_file_count,
    )));

    let conversation_log_path = config.session_dir.join("conversation.jsonl");
    let conversation_log = log::ConversationLog::new(conversation_log_path.clone())
        .expect("failed to create conversation log");
    let _ = ui_tx.send(UiMessage::Info(format!("  log:   {}", conversation_log.path().display())));

    let agent = Arc::new(Mutex::new(Agent::new(
        client,
        config.system_prompt.clone(),
        config.context_parts.clone(),
        config.app.clone(),
        config.prompt_file.clone(),
        Some(conversation_log),
        shared_context.clone(),
        shared_active_tools.clone(),
    )));

    // Restore conversation from log
    {
        let mut agent_guard = agent.lock().await;
        if agent_guard.restore_from_log() {
            ui_channel::replay_session_to_ui(agent_guard.entries(), &ui_tx);
            let _ = ui_tx.send(UiMessage::Info("--- restored from conversation log ---".into()));
        }
    }

    // Send initial budget to status bar
    {
        let agent_guard = agent.lock().await;
        let _ = ui_tx.send(UiMessage::StatusUpdate(StatusInfo {
            dmn_state: "resting".to_string(),
            dmn_turns: 0, dmn_max_turns: 0,
            prompt_tokens: 0, completion_tokens: 0,
            model: agent_guard.model().to_string(),
            turn_tools: 0,
            context_budget: agent_guard.budget().status_string(),
        }));
    }

    let (turn_tx, turn_rx) = mpsc::channel::<(Result<TurnResult>, StreamTarget)>(1);

    let no_agents = config.no_agents;
    let shared_mind = shared_mind_state(config.app.dmn.max_turns);
    crate::user::event_loop::send_context_info(&config, &ui_tx);
    let mut mind = Mind::new(agent, shared_mind.clone(), config, ui_tx.clone(), turn_tx);
    if !no_agents {
        mind.start_memory_scoring();
    }

    // Start observation socket
    let socket_path = mind.config.session_dir.join("agent.sock");
    let (observe_input_tx, observe_input_rx) = log::input_channel();
    if !no_agents {
        log::start(socket_path, ui_tx.subscribe(), observe_input_tx);
    }

    // Mind ↔ UI channel
    let (mind_tx, mind_rx) = tokio::sync::mpsc::unbounded_channel();

    // App for TUI
    let app = tui::App::new(mind.config.model.clone(), shared_context, shared_active_tools);
    let ui_agent = mind.agent.clone();
    let turn_watch = mind.turn_watch();

    // Spawn Mind event loop
    tokio::spawn(async move {
        mind.run(mind_rx, turn_rx).await;
    });
    crate::user::event_loop::run(
        app, ui_agent, shared_mind, turn_watch, mind_tx, ui_tx, ui_rx, observe_input_rx,
        channel_tx, channel_rx, notify_rx, idle_state,
    ).await
}