// ui_channel.rs — Output routing for TUI panes
//
// All output from the agent (streaming text, tool calls, status updates)
// goes through a UiMessage enum sent over an mpsc channel. The TUI
// receives these messages and routes them to the appropriate pane.
//
// This replaces direct stdout/stderr printing throughout the codebase.
// The agent and API client never touch the terminal directly — they
// just send messages that the TUI renders where appropriate.
//
// The channel also fans out to a broadcast channel so the observation
// socket (observe.rs) can subscribe without touching the main path.

use std::sync::Arc;
use tokio::sync::{broadcast, mpsc};

// Re-export context types that moved to agent::context
pub use crate::agent::context::{ContextSection, SharedContextState, shared_context_state};

// ActiveToolCall lives in agent::tools — re-export for TUI access
pub use crate::agent::tools::ActiveToolCall;

/// Shared active tool calls — agent spawns, TUI reads metadata / aborts.
pub type SharedActiveTools = Arc<std::sync::Mutex<Vec<ActiveToolCall>>>;

pub fn shared_active_tools() -> SharedActiveTools {
    Arc::new(std::sync::Mutex::new(Vec::new()))
}

/// 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,
}

/// Status info for the bottom status bar.
#[derive(Debug, Clone)]
#[allow(dead_code)]
pub struct StatusInfo {
    pub dmn_state: String,
    pub dmn_turns: u32,
    pub dmn_max_turns: u32,
    pub prompt_tokens: u32,
    pub completion_tokens: u32,
    pub model: String,
    /// Number of tool calls dispatched in the current turn.
    pub turn_tools: u32,
    /// Context window budget breakdown (e.g. "id:8% mem:25% jnl:30% conv:37%").
    pub context_budget: String,
}

/// Context loading details for the debug screen.
#[derive(Debug, Clone)]
pub struct ContextInfo {
    pub model: String,
    pub available_models: Vec<String>,
    pub prompt_file: String,
    pub backend: String,
    #[allow(dead_code)]
    pub instruction_files: Vec<(String, usize)>,
    #[allow(dead_code)]
    pub memory_files: Vec<(String, usize)>,
    pub system_prompt_chars: usize,
    pub context_message_chars: usize,
}

/// Messages sent from agent/API to the TUI for rendering.
#[derive(Debug, Clone)]
#[allow(dead_code)]
pub enum UiMessage {
    /// Streaming text delta — routed to conversation or autonomous pane
    /// based on the current StreamTarget.
    TextDelta(String, StreamTarget),

    /// User's input echoed to conversation pane.
    UserInput(String),

    /// Tool call header: [tool_name] with args summary.
    ToolCall {
        name: String,
        args_summary: String,
    },

    /// Full tool result — goes to tools pane.
    ToolResult {
        name: String,
        result: String,
    },

    /// DMN state annotation: [dmn: foraging (3/20)].
    DmnAnnotation(String),

    /// Status bar update.
    StatusUpdate(StatusInfo),

    /// Live activity indicator for the status bar — shows what the
    /// agent is doing right now ("thinking...", "calling: bash", etc).
    /// Empty string clears the indicator.
    Activity(String),

    /// Reasoning/thinking tokens from the model (internal monologue).
    /// Routed to the autonomous pane so the user can peek at what
    /// the model is thinking about during long tool chains.
    Reasoning(String),

    /// A tool call started — shown as a live overlay above the status bar.
    ToolStarted { id: String, name: String, detail: String },

    /// A tool call finished — removes it from the live overlay.
    ToolFinished { id: String },

    /// Debug message (only shown when POC_DEBUG is set).
    Debug(String),

    /// Informational message — goes to conversation pane (command output, etc).
    Info(String),

    /// Context loading details — stored for the debug screen (Ctrl+D).
    ContextInfoUpdate(ContextInfo),

    /// Agent cycle state update — refreshes the F2 agents screen.
    AgentUpdate(Vec<crate::subconscious::subconscious::AgentSnapshot>),
}

/// Sender that fans out to both the TUI (mpsc) and observers (broadcast).
#[derive(Clone)]
pub struct UiSender {
    tui: mpsc::UnboundedSender<UiMessage>,
    observe: broadcast::Sender<UiMessage>,
}

impl UiSender {
    pub fn send(&self, msg: UiMessage) -> Result<(), mpsc::error::SendError<UiMessage>> {
        // Broadcast to observers (ignore errors — no subscribers is fine)
        let _ = self.observe.send(msg.clone());
        self.tui.send(msg)
    }

    /// Subscribe to the broadcast side (for the observation socket).
    pub fn subscribe(&self) -> broadcast::Receiver<UiMessage> {
        self.observe.subscribe()
    }
}

/// Convenience type for the receiving half.
pub type UiReceiver = mpsc::UnboundedReceiver<UiMessage>;

/// Create a new UI channel pair.
pub fn channel() -> (UiSender, UiReceiver) {
    let (tui_tx, tui_rx) = mpsc::unbounded_channel();
    let (observe_tx, _) = broadcast::channel(1024);
    (UiSender { tui: tui_tx, observe: observe_tx }, tui_rx)
}

/// Replay a restored session into the TUI panes so the user can see
/// conversation history immediately on restart. Shows user input,
/// assistant responses, and brief tool call summaries. Skips the system
/// prompt, context message, DMN plumbing, and image injection messages.
pub fn replay_session_to_ui(entries: &[crate::agent::context::ConversationEntry], ui_tx: &UiSender) {
    use crate::agent::api::types::Role;

    crate::dbglog!("[replay] replaying {} entries to UI", entries.len());
    for (i, e) in entries.iter().enumerate() {
        let m = e.message();
        let preview: String = m.content_text().chars().take(60).collect();
        crate::dbglog!("[replay]   [{}] {:?} mem={} tc={} tcid={:?} {:?}",
            i, m.role, e.is_memory(), m.tool_calls.as_ref().map_or(0, |t| t.len()),
            m.tool_call_id.as_deref(), preview);
    }

    let mut seen_first_user = false;
    let mut target = StreamTarget::Conversation;

    for entry in entries {
        if entry.is_memory() { continue; }
        let msg = entry.message();
        match msg.role {
            Role::System => {}
            Role::User => {
                if !seen_first_user {
                    seen_first_user = true;
                    continue;
                }
                let text = msg.content_text();
                if text.starts_with("Your context was just compacted")
                    || text.starts_with("Your context was just rebuilt")
                    || text.starts_with("[Earlier in this conversation")
                    || text.starts_with("Here is the image")
                    || text.contains("[image aged out")
                {
                    continue;
                }
                if text.starts_with("[dmn]") {
                    target = StreamTarget::Autonomous;
                    let first_line = text.lines().next().unwrap_or("[dmn]");
                    let _ = ui_tx.send(UiMessage::DmnAnnotation(first_line.to_string()));
                } else {
                    target = StreamTarget::Conversation;
                    let _ = ui_tx.send(UiMessage::UserInput(text.to_string()));
                }
            }
            Role::Assistant => {
                if let Some(ref calls) = msg.tool_calls {
                    for call in calls {
                        let _ = ui_tx.send(UiMessage::ToolCall {
                            name: call.function.name.clone(),
                            args_summary: String::new(),
                        });
                    }
                }
                let text = msg.content_text();
                if !text.is_empty() {
                    let _ = ui_tx.send(UiMessage::TextDelta(format!("{}\n", text), target));
                }
            }
            Role::Tool => {
                let text = msg.content_text();
                let preview: String = text.lines().take(3).collect::<Vec<_>>().join("\n");
                let truncated = if text.lines().count() > 3 {
                    format!("{}...", preview)
                } else {
                    preview
                };
                let _ = ui_tx.send(UiMessage::ToolResult {
                    name: String::new(),
                    result: truncated,
                });
            }
        }
    }
}