// 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;
use crate::agent::{Agent, TurnResult};
use crate::agent::api::ApiClient;
use crate::agent::oneshot::{AutoAgent, AutoStep};
use crate::config::{AppConfig, SessionConfig};
use crate::subconscious::{defs, learn};

// ---------------------------------------------------------------------------
// Subconscious agents — forked from conscious agent, run on schedule
// ---------------------------------------------------------------------------

/// A subconscious agent managed by Mind.
struct SubconsciousAgent {
    name: String,
    def: defs::AgentDef,
    /// Conversation bytes at last trigger.
    last_trigger_bytes: u64,
    /// When the agent last ran.
    last_run: Option<Instant>,
    /// Running task handle + AutoAgent for status.
    handle: Option<tokio::task::JoinHandle<Result<String, String>>>,
}

/// Names and byte-interval triggers for the built-in subconscious agents.
const SUBCONSCIOUS_AGENTS: &[(&str, u64)] = &[
    ("subconscious-surface-observe", 0),      // every trigger
    ("subconscious-journal",         20_000), // every ~20KB of conversation
    ("subconscious-reflect",         100_000), // every ~100KB of conversation
];

impl SubconsciousAgent {
    fn new(name: &str, interval_bytes: u64) -> Option<Self> {
        let def = defs::get_def(name)?;
        Some(Self {
            name: name.to_string(),
            def,
            last_trigger_bytes: 0,
            last_run: None,
            handle: None,
        })
    }

    fn is_running(&self) -> bool {
        self.handle.as_ref().is_some_and(|h| !h.is_finished())
    }

    fn should_trigger(&self, conversation_bytes: u64, interval: u64) -> bool {
        if self.is_running() { return false; }
        if interval == 0 { return true; } // trigger every time
        conversation_bytes.saturating_sub(self.last_trigger_bytes) >= interval
    }
}
/// Which pane streaming text should go to.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum StreamTarget {
    /// User-initiated turn — text goes to conversation pane.
    Conversation,
    /// DMN-initiated turn — text goes to autonomous pane.
    Autonomous,
}

/// 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.
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,
    /// Handle to the currently running turn task.
    pub turn_handle: Option<tokio::task::JoinHandle<()>>,
}

impl Clone for MindState {
    fn clone(&self) -> Self {
        Self {
            input: self.input.clone(),
            turn_active: self.turn_active,
            dmn: self.dmn.clone(),
            dmn_turns: self.dmn_turns,
            max_dmn_turns: self.max_dmn_turns,
            scoring_in_flight: self.scoring_in_flight,
            compaction_in_flight: self.compaction_in_flight,
            last_user_input: self.last_user_input,
            consecutive_errors: self.consecutive_errors,
            last_turn_had_tools: self.last_turn_had_tools,
            turn_handle: None, // Not cloned — only Mind's loop uses this
        }
    }
}

/// What should happen after a state transition.
pub enum MindCommand {
    /// 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,
            turn_handle: None,
        }
    }

    /// Consume pending user input if no turn is active.
    /// Returns the text to send; caller is responsible for pushing it
    /// into the Agent's context and starting the turn.
    fn take_pending_input(&mut self) -> Option<String> {
        if self.turn_active || self.input.is_empty() {
            return 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;
        Some(text)
    }

    /// Process turn completion, return model switch name if requested.
    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 prompt and target if we should run a turn.
    fn dmn_tick(&mut self) -> Option<(String, StreamTarget)> {
        if matches!(self.dmn, dmn::State::Paused | dmn::State::Off) {
            return 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 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);
        Some((prompt, StreamTarget::Autonomous))
    }

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

/// Background task completion events.
enum BgEvent {
    ScoringDone,
}

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

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

pub struct Mind {
    pub agent: Arc<tokio::sync::Mutex<Agent>>,
    pub shared: Arc<SharedMindState>,
    pub config: SessionConfig,
    subconscious: tokio::sync::Mutex<Vec<SubconsciousAgent>>,
    turn_tx: mpsc::Sender<(Result<TurnResult>, StreamTarget)>,
    turn_watch: tokio::sync::watch::Sender<bool>,
    bg_tx: mpsc::UnboundedSender<BgEvent>,
    bg_rx: std::sync::Mutex<Option<mpsc::UnboundedReceiver<BgEvent>>>,
    _supervisor: crate::thalamus::supervisor::Supervisor,
}

impl Mind {
    pub fn new(
        config: SessionConfig,
        turn_tx: mpsc::Sender<(Result<TurnResult>, StreamTarget)>,
    ) -> Self {
        let shared_context = crate::agent::context::shared_context_state();
        let shared_active_tools = crate::agent::tools::shared_active_tools();

        let client = ApiClient::new(&config.api_base, &config.api_key, &config.model);
        let conversation_log = log::ConversationLog::new(
            config.session_dir.join("conversation.jsonl"),
        ).ok();

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

        let subconscious = SUBCONSCIOUS_AGENTS.iter()
            .filter_map(|(name, interval)| SubconsciousAgent::new(name, *interval))
            .collect();

        let shared = Arc::new(std::sync::Mutex::new(MindState::new(config.app.dmn.max_turns)));
        let (turn_watch, _) = tokio::sync::watch::channel(false);
        let (bg_tx, bg_rx) = mpsc::unbounded_channel();

        let mut sup = crate::thalamus::supervisor::Supervisor::new();
        sup.load_config();
        sup.ensure_running();

        Self { agent, shared, config, subconscious: tokio::sync::Mutex::new(subconscious),
               turn_tx, turn_watch, bg_tx,
               bg_rx: std::sync::Mutex::new(Some(bg_rx)), _supervisor: sup }
    }

    /// Initialize — restore log, start daemons and background agents.
    pub async fn init(&self) {
        // Restore conversation
        let mut ag = self.agent.lock().await;
        ag.restore_from_log();
        ag.changed.notify_one();
        drop(ag);
    }

    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(&self, cmds: Vec<MindCommand>) {
        for cmd in cmds {
            match cmd {
                MindCommand::None => {}
                MindCommand::Compact => {
                    let threshold = compaction_threshold(&self.config.app) as usize;
                    let mut ag = self.agent.lock().await;
                    let sections = ag.shared_context.read().map(|s| s.clone()).unwrap_or_default();
                    if crate::agent::context::sections_used(&sections) > threshold {
                        ag.compact();
                        ag.notify("compacted");
                    }
                }
                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.shared.lock().unwrap().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,
                    );
                }
            }
        }
    }

    pub fn start_memory_scoring(&self) {
        let agent = self.agent.clone();
        let bg_tx = self.bg_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.memory_scoring_in_flight { return; }
                ag.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, &agent,
            ).await;
            {
                let mut ag = agent.lock().await;
                ag.memory_scoring_in_flight = false;
                if let Ok(ref scores) = result { ag.memory_scores = scores.clone(); }
            }
            let _ = bg_tx.send(BgEvent::ScoringDone);
        });
    }

    /// Push user/DMN message into the agent's context and spawn a turn.
    /// The text moves from pending_input to ContextState atomically —
    /// by the time this returns, the message is in context and the turn
    /// is running.
    /// Collect results from finished subconscious agents and inject
    /// their output into the conscious agent's context.
    async fn collect_subconscious_results(&self) {
        // Collect finished handles without holding the lock across await
        let finished: Vec<(String, tokio::task::JoinHandle<Result<String, String>>)> = {
            let mut subs = self.subconscious.lock().await;
            subs.iter_mut().filter_map(|sub| {
                if sub.handle.as_ref().is_some_and(|h| h.is_finished()) {
                    sub.last_run = Some(Instant::now());
                    Some((sub.name.clone(), sub.handle.take().unwrap()))
                } else {
                    None
                }
            }).collect()
        };

        for (name, handle) in finished {
            match handle.await {
                Ok(Ok(_output)) => {
                    let output_dir = crate::store::memory_dir()
                        .join("agent-output").join(&name);

                    // Surfaced memories
                    let surface_path = output_dir.join("surface");
                    if let Ok(content) = std::fs::read_to_string(&surface_path) {
                        let mut ag = self.agent.lock().await;
                        for key in content.lines().map(|l| l.trim()).filter(|l| !l.is_empty()) {
                            if let Some(rendered) = crate::cli::node::render_node(
                                &crate::store::Store::load().unwrap_or_default(), key,
                            ) {
                                let mut msg = crate::agent::api::types::Message::user(format!(
                                    "<system-reminder>\n--- {} (surfaced) ---\n{}\n</system-reminder>",
                                    key, rendered,
                                ));
                                msg.stamp();
                                ag.push_entry(crate::agent::context::ConversationEntry::Memory {
                                    key: key.to_string(), message: msg,
                                });
                            }
                        }
                        std::fs::remove_file(&surface_path).ok();
                    }

                    // Reflection
                    let reflect_path = output_dir.join("reflection");
                    if let Ok(content) = std::fs::read_to_string(&reflect_path) {
                        if !content.trim().is_empty() {
                            let mut ag = self.agent.lock().await;
                            ag.push_message(crate::agent::api::types::Message::user(format!(
                                "<system-reminder>\n--- subconscious reflection ---\n{}\n</system-reminder>",
                                content.trim(),
                            )));
                        }
                        std::fs::remove_file(&reflect_path).ok();
                    }

                    dbglog!("[mind] {} completed", name);
                }
                Ok(Err(e)) => dbglog!("[mind] {} failed: {}", name, e),
                Err(e) => dbglog!("[mind] {} panicked: {}", name, e),
            }
        }
    }

    /// Trigger subconscious agents that are due to run.
    async fn trigger_subconscious(&self) {
        if self.config.no_agents { return; }

        // Estimate conversation size from the conscious agent's entries
        let conversation_bytes = {
            let ag = self.agent.lock().await;
            ag.context.entries.iter()
                .filter(|e| !e.is_log() && !e.is_memory())
                .map(|e| e.message().content_text().len() as u64)
                .sum::<u64>()
        };

        // Collect which agents to trigger (can't hold lock across await)
        let to_trigger: Vec<(usize, Vec<AutoStep>, Vec<crate::agent::tools::Tool>, String, i32)> = {
            let mut subs = self.subconscious.lock().await;
            let mut result = Vec::new();
            for (i, &(_name, interval)) in SUBCONSCIOUS_AGENTS.iter().enumerate() {
                if i >= subs.len() { continue; }
                if !subs[i].should_trigger(conversation_bytes, interval) { continue; }

                let sub = &mut subs[i];
                sub.last_trigger_bytes = conversation_bytes;

                let steps: Vec<AutoStep> = sub.def.steps.iter().map(|s| {
                    // TODO: resolve remaining placeholders (seen_current, input:walked, etc.)
                    AutoStep { prompt: s.prompt.clone(), phase: s.phase.clone() }
                }).collect();

                let all_tools = crate::agent::tools::memory_and_journal_tools();
                let tools: Vec<crate::agent::tools::Tool> = if sub.def.tools.is_empty() {
                    all_tools.to_vec()
                } else {
                    all_tools.into_iter()
                        .filter(|t| sub.def.tools.iter().any(|w| w == t.name))
                        .collect()
                };

                result.push((i, steps, tools, sub.name.clone(), sub.def.priority));
            }
            result
        };

        if to_trigger.is_empty() { return; }

        // Fork from conscious agent (one lock acquisition for all)
        let conscious = self.agent.lock().await;
        let mut spawns = Vec::new();
        for (idx, steps, tools, name, priority) in to_trigger {
            let output_dir = crate::store::memory_dir()
                .join("agent-output").join(&name);
            std::fs::create_dir_all(&output_dir).ok();

            let mut auto = AutoAgent::from_agent(
                name.clone(), &conscious, tools, steps, priority);
            dbglog!("[mind] triggering {}", name);

            let handle = tokio::spawn(async move {
                unsafe { std::env::set_var("POC_AGENT_OUTPUT_DIR", &output_dir); }
                auto.run(None).await
            });
            spawns.push((idx, handle));
        }
        drop(conscious);

        // Store handles
        let mut subs = self.subconscious.lock().await;
        for (idx, handle) in spawns {
            if idx < subs.len() {
                subs[idx].handle = Some(handle);
            }
        }
    }

    async fn start_turn(&self, text: &str, target: StreamTarget) {
        {
            let mut ag = self.agent.lock().await;
            match target {
                StreamTarget::Conversation => {
                    ag.push_message(crate::agent::api::types::Message::user(text));
                }
                StreamTarget::Autonomous => {
                    let mut msg = crate::agent::api::types::Message::user(text);
                    msg.stamp();
                    ag.push_entry(crate::agent::context::ConversationEntry::Dmn(msg));
                }
            }

            // Compact if over budget before sending
            let threshold = compaction_threshold(&self.config.app) as usize;
            ag.publish_context_state();
            let used = {
                let sections = ag.shared_context.read().map(|s| s.clone()).unwrap_or_default();
                crate::agent::context::sections_used(&sections)
            };
            if used > threshold {
                ag.compact();
                ag.notify("compacted");
            }
        }
        self.shared.lock().unwrap().turn_active = true;
        let _ = self.turn_watch.send(true);
        let agent = self.agent.clone();
        let result_tx = self.turn_tx.clone();
        self.shared.lock().unwrap().turn_handle = Some(tokio::spawn(async move {
            let result = Agent::turn(agent).await;
            let _ = result_tx.send((result, target)).await;
        }));
    }

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

    /// Mind event loop — locks MindState, calls state methods, executes actions.
    pub async fn run(
        &self,
        mut input_rx: tokio::sync::mpsc::UnboundedReceiver<MindCommand>,
        mut turn_rx: mpsc::Receiver<(Result<TurnResult>, StreamTarget)>,
    ) {
        let mut bg_rx = self.bg_rx.lock().unwrap().take()
            .expect("Mind::run() called twice");
        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;

                cmd = input_rx.recv() => {
                    match cmd {
                        Some(cmd) => cmds.push(cmd),
                        None => break, // UI shut down
                    }
                }

                Some(bg) = bg_rx.recv() => {
                    match bg {
                        BgEvent::ScoringDone => {
                            self.shared.lock().unwrap().scoring_in_flight = false;
                        }
                    }
                }

                Some((result, target)) = turn_rx.recv() => {
                    self.shared.lock().unwrap().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::chat::cmd_switch_model(&self.agent, &name).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);
                    }

                    // Trigger subconscious agents after conscious turn completes
                    self.collect_subconscious_results().await;
                    self.trigger_subconscious().await;
                }

                _ = tokio::time::sleep(timeout), if !turn_active => {
                    let tick = self.shared.lock().unwrap().dmn_tick();
                    if let Some((prompt, target)) = tick {
                        self.start_turn(&prompt, target).await;
                    }
                }
            }

            // Check for pending user input → push to agent context and start turn
            let pending = self.shared.lock().unwrap().take_pending_input();
            if let Some(text) = pending {
                self.start_turn(&text, StreamTarget::Conversation).await;
            }

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