// main_screen.rs — F1 main view rendering
//
// The default four-pane layout: autonomous, conversation, tools, status bar.
// Contains draw_main (the App method), draw_conversation_pane, and draw_pane.

use ratatui::{
    layout::{Constraint, Direction, Layout, Rect},
    style::{Color, Modifier, Style},
    text::{Line, Span},
    widgets::{Block, Borders, Paragraph, Wrap},
    Frame,
};
use ratatui::crossterm::event::{KeyCode, KeyModifiers, MouseEvent, MouseEventKind, MouseButton};


use super::{App, ScreenView, screen_legend};
use crate::agent::context::{AstNode, NodeBody, Role, Ast};
use crate::mind::MindCommand;

// --- Slash command table ---

type CmdHandler = fn(&InteractScreen, &str);

struct SlashCommand {
    name: &'static str,
    help: &'static str,
    handler: CmdHandler,
}

fn commands() -> Vec<SlashCommand> { vec![
    SlashCommand { name: "/quit",  help: "Exit consciousness",
        handler: |_, _| {} },
    SlashCommand { name: "/new",   help: "Start fresh session (saves current)",
        handler: |s, _| { let _ = s.mind_tx.send(MindCommand::NewSession); } },
    SlashCommand { name: "/save",  help: "Save session to disk",
        handler: |s, _| {
            if let Ok(mut ag) = s.agent.state.try_lock() { ag.notify("saved"); }
        } },
    SlashCommand { name: "/model", help: "Show/switch model (/model <name>)",
        handler: |s, arg| {
            if arg.is_empty() {
                if let Ok(mut ag) = s.agent.state.try_lock() {
                    let names = s.agent.app_config.model_names();
                    let label = if names.is_empty() {
                        format!("model: {}", s.agent.model())
                    } else {
                        format!("model: {} ({})", s.agent.model(), names.join(", "))
                    };
                    ag.notify(label);
                }
            } else {
                let agent = s.agent.clone();
                let name = arg.to_string();
                tokio::spawn(async move {
                    let _act = crate::agent::start_activity(&agent, format!("switching to {}...", name)).await;
                    cmd_switch_model(&agent, &name).await;
                });
            }
        } },
    SlashCommand { name: "/score", help: "Score memory importance (full matrix)",
        handler: |s, _| { let _ = s.mind_tx.send(MindCommand::ScoreFull); } },
    SlashCommand { name: "/dmn",   help: "Show DMN state",
        handler: |s, _| {
            let st = s.shared_mind.lock().unwrap();
            if let Ok(mut ag) = s.agent.state.try_lock() {
                ag.notify(format!("DMN: {:?} ({}/{})", st.dmn, st.dmn_turns, st.max_dmn_turns));
            }
        } },
    SlashCommand { name: "/sleep", help: "Put DMN to sleep",
        handler: |s, _| {
            let mut st = s.shared_mind.lock().unwrap();
            st.dmn = crate::mind::subconscious::State::Resting { since: std::time::Instant::now() };
            st.dmn_turns = 0;
            if let Ok(mut ag) = s.agent.state.try_lock() { ag.notify("DMN sleeping"); }
        } },
    SlashCommand { name: "/wake",  help: "Wake DMN to foraging",
        handler: |s, _| {
            let mut st = s.shared_mind.lock().unwrap();
            if matches!(st.dmn, crate::mind::subconscious::State::Off) { crate::mind::subconscious::set_off(false); }
            st.dmn = crate::mind::subconscious::State::Foraging;
            st.dmn_turns = 0;
            if let Ok(mut ag) = s.agent.state.try_lock() { ag.notify("DMN foraging"); }
        } },
    SlashCommand { name: "/pause", help: "Full stop — no autonomous ticks (Ctrl+P)",
        handler: |s, _| {
            let mut st = s.shared_mind.lock().unwrap();
            st.dmn = crate::mind::subconscious::State::Paused;
            st.dmn_turns = 0;
            if let Ok(mut ag) = s.agent.state.try_lock() { ag.notify("DMN paused"); }
        } },
    SlashCommand { name: "/help",  help: "Show this help",
        handler: |s, _| { notify_help(&s.agent); } },
]}

fn dispatch_command(input: &str) -> Option<SlashCommand> {
    let cmd_name = input.split_whitespace().next()?;
    commands().into_iter().find(|c| c.name == cmd_name)
}

/// Switch model — used by both /model command and tool-initiated switches.
pub async fn cmd_switch_model(
    agent: &std::sync::Arc<crate::agent::Agent>,
    name: &str,
) {
    let resolved = match agent.app_config.resolve_model(name) {
        Ok(r) => r,
        Err(e) => {
            agent.state.lock().await.notify(format!("model error: {}", e));
            return;
        }
    };
    let _new_client = crate::agent::api::ApiClient::new(
        &resolved.api_base, &resolved.api_key, &resolved.model_id,
    );
    let prompt_changed = resolved.prompt_file != agent.prompt_file;
    if prompt_changed {
        agent.compact().await;
        agent.state.lock().await.notify(format!("switched to {} (recompacted)", resolved.model_id));
    } else {
        agent.state.lock().await.notify(format!("switched to {}", resolved.model_id));
    }
}

fn notify_help(agent: &std::sync::Arc<crate::agent::Agent>) {
    if let Ok(mut ag) = agent.state.try_lock() {
        let mut help = String::new();
        for cmd in &commands() {
            help.push_str(&format!("{:12} {}\n", cmd.name, cmd.help));
        }
        help.push_str("Keys: Tab ^Up/Down PgUp/Down Mouse Esc ^P ^R ^K");
        ag.notify(help);
    }
}

/// Turn marker for the conversation pane gutter.
#[derive(Clone, Copy, PartialEq, Default)]
enum Marker {
    #[default]
    None,
    User,
    Assistant,
}

impl Marker {
    fn gutter_span(self) -> Option<Span<'static>> {
        match self {
            Marker::User => Some(Span::styled("● ", Style::default().fg(Color::Cyan))),
            Marker::Assistant => Some(Span::styled("● ", Style::default().fg(Color::Magenta))),
            Marker::None => None,
        }
    }
}

/// A line paired with a gutter marker, for use with ScrollPane.
struct MarkedLine {
    line: Line<'static>,
    marker: Marker,
}

impl super::scroll_pane::ScrollItem for MarkedLine {
    fn content(&self) -> ratatui::text::Text<'_> {
        ratatui::text::Text::from(self.line.clone())
    }

    fn gutter(&self) -> Option<Span<'_>> {
        self.marker.gutter_span()
    }
}

#[derive(PartialEq)]
enum PaneTarget {
    Conversation,
    ConversationAssistant,
    Tools,
    ToolResult,
}

const MAX_PANE_LINES: usize = 10_000;

/// Which pane receives scroll keys.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum ActivePane {
    Autonomous,
    Conversation,
    Tools,
}

/// Text selection within a pane. Anchor is where the click started,
/// cursor is where the mouse currently is. They may be in either order.
#[derive(Debug, Clone, PartialEq, Default)]
struct Selection {
    anchor_line: usize,
    anchor_col: usize,
    cursor_line: usize,
    cursor_col: usize,
}

impl Selection {
    fn new(line: usize, col: usize) -> Self {
        Self { anchor_line: line, anchor_col: col, cursor_line: line, cursor_col: col }
    }

    fn extend(&mut self, line: usize, col: usize) {
        self.cursor_line = line;
        self.cursor_col = col;
    }

    /// Normalized range: (start_line, start_col, end_line, end_col)
    fn range(&self) -> (usize, usize, usize, usize) {
        if (self.anchor_line, self.anchor_col) <= (self.cursor_line, self.cursor_col) {
            (self.anchor_line, self.anchor_col, self.cursor_line, self.cursor_col)
        } else {
            (self.cursor_line, self.cursor_col, self.anchor_line, self.anchor_col)
        }
    }

    fn text(&self, lines: &[Line<'static>]) -> String {
        let (start_line, start_col, end_line, end_col) = self.range();
        let mut result = String::new();
        for (i, line) in lines.iter().enumerate() {
            if i < start_line || i > end_line { continue; }
            let line_text: String = line.spans.iter().map(|s| s.content.as_ref()).collect();
            let sc = if i == start_line { start_col } else { 0 };
            let ec = if i == end_line { end_col } else { line_text.len() };
            if sc < line_text.len() {
                if let Some(selected) = line_text.get(sc..ec.min(line_text.len())) {
                    if !result.is_empty() {
                        result.push('\n');
                    }
                    result.push_str(selected);
                }
            }
        }
        result
    }
}

fn strip_ansi(text: &str) -> String {
    let mut out = String::with_capacity(text.len());
    let mut chars = text.chars().peekable();
    while let Some(ch) = chars.next() {
        if ch == '\x1b' {
            if chars.peek() == Some(&'[') {
                chars.next();
                while let Some(&c) = chars.peek() {
                    if c.is_ascii() && (0x20..=0x3F).contains(&(c as u8)) {
                        chars.next();
                    } else {
                        break;
                    }
                }
                if let Some(&c) = chars.peek() {
                    if c.is_ascii() && (0x40..=0x7E).contains(&(c as u8)) {
                        chars.next();
                    }
                }
            } else if let Some(&c) = chars.peek() {
                if c.is_ascii() && (0x40..=0x5F).contains(&(c as u8)) {
                    chars.next();
                }
            }
        } else {
            out.push(ch);
        }
    }
    out
}

fn new_textarea(lines: Vec<String>) -> tui_textarea::TextArea<'static> {
    let mut ta = tui_textarea::TextArea::new(lines);
    ta.set_cursor_line_style(Style::default());
    ta.set_wrap_mode(tui_textarea::WrapMode::Word);
    ta
}

fn parse_markdown(md: &str) -> Vec<Line<'static>> {
    tui_markdown::from_str(md)
        .lines
        .into_iter()
        .map(|line| {
            let spans: Vec<Span<'static>> = line.spans.into_iter()
                .map(|span| Span::styled(span.content.into_owned(), span.style))
                .collect();
            let mut result = Line::from(spans).style(line.style);
            result.alignment = line.alignment;
            result
        })
        .collect()
}

struct PaneState {
    lines: Vec<Line<'static>>,
    markers: Vec<Marker>,
    current_line: String,
    current_color: Color,
    md_buffer: String,
    use_markdown: bool,
    pending_marker: Marker,
    scroll: super::scroll_pane::ScrollPaneState,
    selection: Option<Selection>,
}

impl PaneState {
    fn new(use_markdown: bool) -> Self {
        Self {
            lines: Vec::new(), markers: Vec::new(),
            current_line: String::new(), current_color: Color::Reset,
            md_buffer: String::new(), use_markdown,
            pending_marker: Marker::None,
            scroll: super::scroll_pane::ScrollPaneState::new(),
            selection: None,
        }
    }

    fn evict(&mut self) {
        if self.lines.len() > MAX_PANE_LINES {
            let excess = self.lines.len() - MAX_PANE_LINES;
            self.lines.drain(..excess);
            self.markers.drain(..excess);
            self.scroll.invalidate();
        }
    }

    fn flush_pending(&mut self) {
        if self.use_markdown && !self.md_buffer.is_empty() {
            let parsed = parse_markdown(&self.md_buffer);
            for (i, line) in parsed.into_iter().enumerate() {
                let marker = if i == 0 { std::mem::take(&mut self.pending_marker) } else { Marker::None };
                self.lines.push(line);
                self.markers.push(marker);
            }
            self.md_buffer.clear();
        }
        if !self.current_line.is_empty() {
            let line = std::mem::take(&mut self.current_line);
            self.lines.push(Line::styled(line, Style::default().fg(self.current_color)));
            self.markers.push(std::mem::take(&mut self.pending_marker));
        }
    }

    fn push_line(&mut self, line: String, color: Color) {
        self.push_line_with_marker(line, color, Marker::None);
    }

    fn append_text(&mut self, text: &str) {
        let clean = strip_ansi(text);
        if self.use_markdown {
            self.md_buffer.push_str(&clean);
        } else {
            for ch in clean.chars() {
                if ch == '\n' {
                    let line = std::mem::take(&mut self.current_line);
                    self.lines.push(Line::styled(line, Style::default().fg(self.current_color)));
                    self.markers.push(Marker::None);
                    self.evict();
                } else {
                    self.current_line.push(ch);
                }
            }
        }
    }

    fn push_line_with_marker(&mut self, line: String, color: Color, marker: Marker) {
        self.flush_pending();
        self.lines.push(Line::styled(strip_ansi(&line), Style::default().fg(color)));
        self.markers.push(marker);
        self.evict();
    }

    fn pop_line(&mut self) {
        self.lines.pop();
        self.markers.pop();
        self.scroll.invalidate_from(self.lines.len());
    }

    fn scroll_up(&mut self, n: u16) {
        self.scroll.scroll_up(n);
    }

    fn scroll_down(&mut self, n: u16) {
        self.scroll.scroll_down(n);
    }

    fn all_lines(&self) -> Vec<Line<'static>> {
        let (lines, _) = self.all_lines_with_markers();
        lines
    }

    fn all_lines_with_markers(&self) -> (Vec<Line<'static>>, Vec<Marker>) {
        let mut lines: Vec<Line<'static>> = self.lines.clone();
        let mut markers: Vec<Marker> = self.markers.clone();
        if self.use_markdown && !self.md_buffer.is_empty() {
            let parsed = parse_markdown(&self.md_buffer);
            let count = parsed.len();
            lines.extend(parsed);
            if count > 0 {
                markers.push(self.pending_marker);
                markers.extend(std::iter::repeat(Marker::None).take(count - 1));
            }
        } else if !self.current_line.is_empty() {
            lines.push(Line::styled(self.current_line.clone(), Style::default().fg(self.current_color)));
            markers.push(self.pending_marker);
        }
        (lines, markers)
    }

    /// Convert mouse coordinates (relative to pane) to line/column position.
    fn mouse_to_position(&self, mouse_x: u16, mouse_y: u16) -> Option<(usize, usize)> {
        let (lines, _) = self.all_lines_with_markers();
        self.scroll.screen_to_item(mouse_x, mouse_y, &lines)
    }

    /// Set the selection start position.
    fn start_selection(&mut self, line: usize, col: usize) {
        self.selection = Some(Selection::new(line, col));
    }

    /// Update the selection end position.
    fn extend_selection(&mut self, line: usize, col: usize) {
        if let Some(ref mut sel) = self.selection {
            sel.extend(line, col);
        }
    }

    /// Get the selected text, or None if nothing is selected.
    fn get_selection(&self) -> Option<String> {
        let (lines, _) = self.all_lines_with_markers();
        self.selection.as_ref().map(|sel| sel.text(&lines))
    }
}

pub(crate) struct InteractScreen {
    autonomous: PaneState,
    conversation: PaneState,
    tools: PaneState,
    textarea: tui_textarea::TextArea<'static>,
    input_history: Vec<String>,
    history_index: Option<usize>,
    active_pane: ActivePane,
    pane_areas: [Rect; 3],
    // State sync with agent — double buffer
    last_generation: u64,
    last_entries: Vec<AstNode>,
    pending_display_count: usize,
    /// Reference to agent for state sync
    agent: std::sync::Arc<crate::agent::Agent>,
    shared_mind: std::sync::Arc<crate::mind::SharedMindState>,
    mind_tx: tokio::sync::mpsc::UnboundedSender<crate::mind::MindCommand>,
}

impl InteractScreen {
    pub fn new(
        agent: std::sync::Arc<crate::agent::Agent>,
        shared_mind: std::sync::Arc<crate::mind::SharedMindState>,
        mind_tx: tokio::sync::mpsc::UnboundedSender<crate::mind::MindCommand>,
    ) -> Self {
        Self {
            autonomous: PaneState::new(true),
            conversation: PaneState::new(true),
            tools: PaneState::new(false),
            textarea: new_textarea(vec![String::new()]),
            input_history: Vec::new(),
            history_index: None,
            active_pane: ActivePane::Conversation,
            pane_areas: [Rect::default(); 3],
            last_generation: 0,
            last_entries: Vec::new(),
            pending_display_count: 0,
            agent,
            shared_mind,
            mind_tx,
        }
    }

    fn route_node(node: &AstNode) -> Vec<(PaneTarget, String, Marker)> {
        match node {
            AstNode::Leaf(leaf) => {
                let text = leaf.body().text().to_string();
                match leaf.body() {
                    NodeBody::Memory { .. } | NodeBody::Thinking(_)
                        | NodeBody::Log(_) | NodeBody::Dmn(_) => vec![],
                    NodeBody::Content(_) => {
                        if text.is_empty() || text.starts_with("<system-reminder>") { vec![] }
                        else { vec![(PaneTarget::Conversation, text, Marker::User)] }
                    }
                    NodeBody::ToolCall { name, arguments } => {
                        let line = format!("[{}] {}", name, arguments.chars().take(80).collect::<String>());
                        vec![(PaneTarget::Tools, line, Marker::None)]
                    }
                    NodeBody::ToolResult(t) => {
                        if t.is_empty() { vec![] }
                        else { vec![(PaneTarget::ToolResult, text, Marker::None)] }
                    }
                }
            }
            AstNode::Branch { role, children, .. } => {
                match role {
                    Role::User => {
                        let text: String = children.iter()
                            .filter_map(|c| c.leaf())
                            .filter(|l| matches!(l.body(), NodeBody::Content(_)))
                            .map(|l| l.body().text())
                            .collect::<Vec<_>>()
                            .join("");
                        if text.is_empty() || text.starts_with("<system-reminder>") { vec![] }
                        else { vec![(PaneTarget::Conversation, text, Marker::User)] }
                    }
                    Role::Assistant => {
                        let mut items = Vec::new();
                        for child in children {
                            items.extend(Self::route_node(child));
                        }
                        // Re-tag content as assistant
                        for item in &mut items {
                            if item.0 == PaneTarget::Conversation {
                                item.0 = PaneTarget::ConversationAssistant;
                                item.2 = Marker::Assistant;
                            }
                        }
                        items
                    }
                    Role::System => vec![],
                }
            }
        }
    }

    fn push_routed(&mut self, node: &AstNode) {
        for (target, text, marker) in Self::route_node(node) {
            match target {
                PaneTarget::Conversation => {
                    self.conversation.current_color = Color::Cyan;
                    self.conversation.append_text(&text);
                    self.conversation.pending_marker = marker;
                    self.conversation.flush_pending();
                },
                PaneTarget::ConversationAssistant => {
                    self.conversation.current_color = Color::Reset;
                    self.conversation.append_text(&text);
                    self.conversation.pending_marker = marker;
                    self.conversation.flush_pending();
                },
                PaneTarget::Tools =>
                    self.tools.push_line(text, Color::Yellow),
                PaneTarget::ToolResult => {
                    for line in text.lines().take(20) {
                        self.tools.push_line(format!("  {}", line), Color::DarkGray);
                    }
                }
            }
        }
    }

    fn pop_routed(&mut self, node: &AstNode) {
        for (target, _, _) in Self::route_node(node) {
            match target {
                PaneTarget::Conversation | PaneTarget::ConversationAssistant
                    => self.conversation.pop_line(),
                PaneTarget::Tools | PaneTarget::ToolResult
                    => self.tools.pop_line(),
            }
        }
    }

    fn sync_from_agent(&mut self) {
        for _ in 0..self.pending_display_count {
            self.conversation.pop_line();
        }
        self.pending_display_count = 0;

        let (generation, entries) = {
            let st = match self.agent.state.try_lock() {
                Ok(st) => st,
                Err(_) => return,
            };
            let generation = st.generation;
            drop(st);
            let ctx = match self.agent.context.try_lock() {
                Ok(ctx) => ctx,
                Err(_) => return,
            };
            (generation, ctx.conversation().to_vec())
        };

        // Full reset on generation change
        if generation != self.last_generation {
            self.conversation = PaneState::new(true);
            self.autonomous = PaneState::new(true);
            self.tools = PaneState::new(false);
            self.last_entries.clear();
        }

        // Detect changed entries (streaming updates mutate the last entry)
        // Walk backwards from the end, pop any that differ
        let mut pop_from = self.last_entries.len();
        for i in (0..self.last_entries.len()).rev() {
            if i >= entries.len() {
                pop_from = i;
                continue;
            }
            // Compare token count as a cheap change detector
            if self.last_entries[i].tokens() != entries[i].tokens() {
                pop_from = i;
            } else {
                break; // entries before this haven't changed
            }
        }
        while self.last_entries.len() > pop_from {
            let popped = self.last_entries.pop().unwrap();
            self.pop_routed(&popped);
        }

        // Push new/changed entries
        for node in entries.iter().skip(self.last_entries.len()) {
            self.push_routed(node);
            self.last_entries.push(node.clone());
        }

        self.last_generation = generation;

        // Display pending input (queued in Mind, not yet accepted)
        let mind = self.shared_mind.lock().unwrap();
        for input in &mind.input {
            self.conversation.push_line_with_marker(
                input.clone(), Color::DarkGray, Marker::User,
            );
            self.pending_display_count += 1;
        }
    }

    /// Dispatch user input — slash commands or conversation.
    fn dispatch_input(&self, input: &str, app: &mut App) {
        let input = input.trim();
        if input.is_empty() { return; }

        if input == "/quit" || input == "/exit" {
            app.should_quit = true;
            return;
        }

        if input.starts_with('/') {
            if let Some(cmd) = dispatch_command(input) {
                (cmd.handler)(self, &input[cmd.name.len()..].trim_start());
            } else {
                if let Ok(mut ag) = self.agent.state.try_lock() {
                    ag.notify(format!("unknown: {}", input.split_whitespace().next().unwrap_or(input)));
                }
            }
            return;
        }

        // Regular input → queue to Mind, then wake it
        self.shared_mind.lock().unwrap().input.push(input.to_string());
        let _ = self.mind_tx.send(MindCommand::None);
    }

    fn scroll_active_up(&mut self, n: u16) {
        match self.active_pane {
            ActivePane::Autonomous => self.autonomous.scroll_up(n),
            ActivePane::Conversation => self.conversation.scroll_up(n),
            ActivePane::Tools => self.tools.scroll_up(n),
        }
    }

    fn scroll_active_down(&mut self, n: u16) {
        match self.active_pane {
            ActivePane::Autonomous => self.autonomous.scroll_down(n),
            ActivePane::Conversation => self.conversation.scroll_down(n),
            ActivePane::Tools => self.tools.scroll_down(n),
        }
    }

    fn handle_mouse(&mut self, mouse: MouseEvent) {
        match mouse.kind {
            MouseEventKind::ScrollUp => self.scroll_active_up(3),
            MouseEventKind::ScrollDown => self.scroll_active_down(3),
            MouseEventKind::Down(MouseButton::Left) => {
                let (x, y) = (mouse.column, mouse.row);
                for (i, area) in self.pane_areas.iter().enumerate() {
                    if x >= area.x && x < area.x + area.width && y >= area.y && y < area.y + area.height {
                        self.active_pane = match i { 0 => ActivePane::Autonomous, 1 => ActivePane::Conversation, _ => ActivePane::Tools };
                        let rel_x = x.saturating_sub(area.x);
                        let rel_y = y.saturating_sub(area.y);
                        self.selection_event(i, rel_x, rel_y, true);
                        break;
                    }
                }
            }
            MouseEventKind::Drag(MouseButton::Left) => {
                let (x, y) = (mouse.column, mouse.row);
                let i = match self.active_pane { ActivePane::Autonomous => 0, ActivePane::Conversation => 1, ActivePane::Tools => 2 };
                let area = self.pane_areas[i];
                if x >= area.x && x < area.x + area.width && y >= area.y && y < area.y + area.height {
                    let rel_x = x.saturating_sub(area.x);
                    let rel_y = y.saturating_sub(area.y);
                    self.selection_event(i, rel_x, rel_y, false);
                }
            }
            MouseEventKind::Up(MouseButton::Left) => {
                self.copy_selection_to_clipboard();
            }
            MouseEventKind::Down(MouseButton::Middle) => {
                self.paste_from_selection();
            }
            _ => {}
        }
    }

    /// Copy the current selection to the clipboard via OSC 52.
    fn copy_selection_to_clipboard(&self) {
        let text = match self.active_pane {
            ActivePane::Autonomous => self.autonomous.get_selection(),
            ActivePane::Conversation => self.conversation.get_selection(),
            ActivePane::Tools => self.tools.get_selection(),
        };
        if let Some(ref selected_text) = text {
            if selected_text.is_empty() { return; }
            // OSC 52 clipboard copy
            use std::io::Write;
            use base64::Engine;
            let encoded = base64::engine::general_purpose::STANDARD.encode(selected_text);
            let mut stdout = std::io::stdout().lock();
            let _ = write!(stdout, "\x1b]52;c;{}\x07", encoded);
            let _ = stdout.flush();
        }
    }

    /// Paste from tmux buffer via middle-click.
    fn paste_from_selection(&mut self) {
        let result = std::process::Command::new("tmux")
            .args(["save-buffer", "-"]).output();
        if let Ok(output) = result {
            if output.status.success() {
                let text = String::from_utf8_lossy(&output.stdout).into_owned();
                if !text.is_empty() {
                    self.textarea.insert_str(&text);
                }
            }
        }
    }

    fn pane_mut(&mut self, idx: usize) -> &mut PaneState {
        match idx { 0 => &mut self.autonomous, 1 => &mut self.conversation, _ => &mut self.tools }
    }

    fn selection_event(&mut self, pane_idx: usize, rel_x: u16, rel_y: u16, start: bool) {
        let pane = self.pane_mut(pane_idx);
        if let Some((line, col)) = pane.mouse_to_position(rel_x, rel_y) {
            if start {
                pane.start_selection(line, col);
            } else {
                pane.extend_selection(line, col);
            }
        }
        self.copy_selection_to_clipboard();
    }

    /// Draw the main (F1) screen — four-pane layout with status bar.
    fn draw_main(&mut self, frame: &mut Frame, size: Rect, app: &App) {
        // Main layout: content area + active tools overlay + status bar
        let st_guard = app.agent.state.try_lock().ok();
        let tool_lines = st_guard.as_ref()
            .map(|st| st.active_tools.len() as u16).unwrap_or(0);
        let main_chunks = Layout::default()
            .direction(Direction::Vertical)
            .constraints([
                Constraint::Min(3),              // content area
                Constraint::Length(tool_lines),   // active tools (0 when empty)
                Constraint::Length(1),            // status bar
            ])
            .split(size);

        let content_area = main_chunks[0];
        let tools_overlay_area = main_chunks[1];
        let status_area = main_chunks[2];

        // Content: left column (55%) + right column (45%)
        let columns = Layout::default()
            .direction(Direction::Horizontal)
            .constraints([
                Constraint::Percentage(55),
                Constraint::Percentage(45),
            ])
            .split(content_area);

        let left_col = columns[0];
        let right_col = columns[1];

        // Left column: autonomous (35%) + conversation (65%)
        let left_panes = Layout::default()
            .direction(Direction::Vertical)
            .constraints([
                Constraint::Percentage(35),
                Constraint::Percentage(65),
            ])
            .split(left_col);

        let auto_area = left_panes[0];
        let conv_area = left_panes[1];

        // Store pane areas for mouse click detection
        self.pane_areas = [auto_area, conv_area, right_col];

        // Draw autonomous pane
        let auto_active = self.active_pane == ActivePane::Autonomous;
        draw_pane(frame, auto_area, "autonomous", &mut self.autonomous, auto_active,
            Some(&screen_legend()));

        // Draw tools pane
        let tools_active = self.active_pane == ActivePane::Tools;
        draw_pane(frame, right_col, "tools", &mut self.tools, tools_active, None);

        // Draw conversation pane (with input line)
        let conv_active = self.active_pane == ActivePane::Conversation;

        // Input area: compute visual height, split, render gutter + textarea
        let input_text = self.textarea.lines().join("\n");
        let input_para_measure = Paragraph::new(input_text).wrap(Wrap { trim: false });
        let input_line_count = (input_para_measure.line_count(conv_area.width.saturating_sub(5)) as u16)
            .max(1)
            .min(5);

        let conv_chunks = Layout::default()
            .direction(Direction::Vertical)
            .constraints([
                Constraint::Min(1),                 // conversation text
                Constraint::Length(input_line_count), // input area
            ])
            .split(conv_area);

        let text_area_rect = conv_chunks[0];
        let input_area = conv_chunks[1];

        draw_conversation_pane(frame, text_area_rect, &mut self.conversation, conv_active);

        // " > " gutter + textarea, aligned with conversation messages
        let input_chunks = Layout::default()
            .direction(Direction::Horizontal)
            .constraints([
                Constraint::Length(3),  // " > " gutter
                Constraint::Min(1),    // textarea
            ])
            .split(input_area);

        let gutter = Paragraph::new(Line::styled(
            " > ",
            Style::default().fg(Color::Cyan).add_modifier(Modifier::BOLD),
        ));
        frame.render_widget(gutter, input_chunks[0]);
        frame.render_widget(&self.textarea, input_chunks[1]);

        if let Some(ref st) = st_guard {
            if !st.active_tools.is_empty() {
            let tool_style = Style::default().fg(Color::Yellow).add_modifier(Modifier::DIM);
            let tool_text: Vec<Line> = st.active_tools.iter().map(|t| {
                let elapsed = t.started.elapsed().as_secs();
                let line = if t.detail.is_empty() {
                    format!("  [{}] ({}s)", t.name, elapsed)
                } else {
                    format!("  [{}] {} ({}s)", t.name, t.detail, elapsed)
                };
                Line::styled(line, tool_style)
            }).collect();
            let tool_para = Paragraph::new(tool_text);
            frame.render_widget(tool_para, tools_overlay_area);
        }}

        // Draw status bar with live activity indicator
        let timer = if !app.activity.is_empty() {
            let elapsed = app.activity_started.map(|t| t.elapsed().as_secs()).unwrap_or(0);
            format!(" {}s", elapsed)
        } else {
            String::new()
        };
        let tools_info = if app.status.turn_tools > 0 {
            format!(" ({}t)", app.status.turn_tools)
        } else {
            String::new()
        };
        let activity_part = if app.activity.is_empty() {
            String::new()
        } else {
            format!(" | {}{}{}", app.activity, tools_info, timer)
        };

        let budget_part = if app.status.context_budget.is_empty() {
            String::new()
        } else {
            format!(" [{}]", app.status.context_budget)
        };

        let left_status = format!(
            " {} | {}/{} dmn | {}K tok in{}{}",
            app.status.dmn_state,
            app.status.dmn_turns,
            app.status.dmn_max_turns,
            app.status.prompt_tokens / 1000,
            budget_part,
            activity_part,
        );

        let proc_indicator = if app.running_processes > 0 {
            format!(" {}proc", app.running_processes)
        } else {
            String::new()
        };
        let reason_indicator = if app.reasoning_effort != "none" {
            format!(" reason:{}", app.reasoning_effort)
        } else {
            String::new()
        };
        let right_legend = format!(
            "{}{} ^P:pause ^R:reason ^K:kill | {} ",
            reason_indicator,
            proc_indicator,
            app.status.model,
        );

        // Pad the middle to fill the status bar
        let total_width = status_area.width as usize;
        let used = left_status.len() + right_legend.len();
        let padding = if total_width > used {
            " ".repeat(total_width - used)
        } else {
            " ".to_string()
        };

        let status = Paragraph::new(Line::from(vec![
            Span::styled(&left_status, Style::default().fg(Color::White).bg(Color::DarkGray)),
            Span::styled(padding, Style::default().bg(Color::DarkGray)),
            Span::styled(
                right_legend,
                Style::default().fg(Color::DarkGray).bg(Color::Gray),
            ),
        ]));

        frame.render_widget(status, status_area);
    }
}

impl ScreenView for InteractScreen {
    fn label(&self) -> &'static str { "interact" }

    fn tick(&mut self, frame: &mut Frame, area: Rect,
            events: &[ratatui::crossterm::event::Event], app: &mut App) {
        use ratatui::crossterm::event::Event;
        // Handle events
        for event in events {
            match event {
                Event::Key(key) if key.kind == ratatui::crossterm::event::KeyEventKind::Press => {
            match key.code {
                KeyCode::Esc => { let _ = self.mind_tx.send(crate::mind::MindCommand::Interrupt); }
                KeyCode::Enter if !key.modifiers.contains(KeyModifiers::ALT) && !key.modifiers.contains(KeyModifiers::SHIFT) => {
                    let input: String = self.textarea.lines().join("\n");
                    if !input.is_empty() {
                        if self.input_history.last().map_or(true, |h| h != &input) {
                            self.input_history.push(input.clone());
                        }
                        self.history_index = None;
                        self.dispatch_input(&input, app);
                        self.textarea = new_textarea(vec![String::new()]);
                    }
                }
                KeyCode::Char('c') if key.modifiers.contains(KeyModifiers::CONTROL) && key.modifiers.contains(KeyModifiers::SHIFT) => {
                    // Ctrl+Shift+C: copy selection
                    self.copy_selection_to_clipboard();
                }
                // Paste: terminal handles Ctrl+Shift+V natively via bracketed paste
                KeyCode::Up if key.modifiers.contains(KeyModifiers::CONTROL) => self.scroll_active_up(3),
                KeyCode::Down if key.modifiers.contains(KeyModifiers::CONTROL) => self.scroll_active_down(3),
                KeyCode::Up => {
                    if !self.input_history.is_empty() {
                        let idx = match self.history_index { None => self.input_history.len() - 1, Some(i) => i.saturating_sub(1) };
                        self.history_index = Some(idx);
                        let mut ta = new_textarea(self.input_history[idx].lines().map(String::from).collect());
                        ta.move_cursor(tui_textarea::CursorMove::End);
                        self.textarea = ta;
                    }
                }
                KeyCode::Down => {
                    if let Some(idx) = self.history_index {
                        if idx + 1 < self.input_history.len() {
                            self.history_index = Some(idx + 1);
                            let mut ta = new_textarea(self.input_history[idx + 1].lines().map(String::from).collect());
                            ta.move_cursor(tui_textarea::CursorMove::End);
                            self.textarea = ta;
                        } else {
                            self.history_index = None;
                            self.textarea = new_textarea(vec![String::new()]);
                        }
                    }
                }
                KeyCode::PageUp => self.scroll_active_up(10),
                KeyCode::PageDown => self.scroll_active_down(10),
                KeyCode::Tab => {
                    self.active_pane = match self.active_pane {
                        ActivePane::Autonomous => ActivePane::Tools,
                        ActivePane::Tools => ActivePane::Conversation,
                        ActivePane::Conversation => ActivePane::Autonomous,
                    };
                }
                _ => { self.textarea.input(*key); }
            }
                }
                Event::Mouse(mouse) => { self.handle_mouse(*mouse); }
                Event::Paste(text) => {
                    self.textarea.insert_str(text);
                }
                _ => {}
            }
        }

        // Sync state from agent
        self.sync_from_agent();

        // Read status from agent + mind state
        if let Ok(mut st) = self.agent.state.try_lock() {
            st.expire_activities();
            app.status.prompt_tokens = st.last_prompt_tokens;
            app.status.model = self.agent.model().to_string();
            app.activity = st.activities.last()
                .map(|a| a.label.clone())
                .unwrap_or_default();
            app.activity_started = st.activities.last()
                .map(|a| a.started);
        }
        if let Ok(ctx) = self.agent.context.try_lock() {
            let window = crate::agent::context::context_window();
            if window > 0 {
                let sys = ctx.system().iter().map(|n| n.tokens()).sum::<usize>();
                let id = ctx.identity().iter().map(|n| n.tokens()).sum::<usize>();
                let jnl = ctx.journal().iter().map(|n| n.tokens()).sum::<usize>();
                let mut mem = 0usize;
                let mut conv = 0usize;
                for n in ctx.conversation() {
                    let t = n.tokens();
                    if matches!(n, AstNode::Leaf(l) if matches!(l.body(), NodeBody::Memory { .. })) {
                        mem += t;
                    } else {
                        conv += t;
                    }
                }
                let used = sys + id + jnl + mem + conv;
                let free = window.saturating_sub(used);
                let pct = |n: usize| if n == 0 { 0 } else { ((n * 100) / window).max(1) };
                app.status.context_budget = format!(
                    "sys:{}% id:{}% jnl:{}% mem:{}% conv:{}% free:{}%",
                    pct(sys), pct(id), pct(jnl), pct(mem), pct(conv), pct(free),
                );
            }
        }
        {
            let mind = self.shared_mind.lock().unwrap();
            app.status.dmn_state = mind.dmn.label().to_string();
            app.status.dmn_turns = mind.dmn_turns;
            app.status.dmn_max_turns = mind.max_dmn_turns;
        }

        // Draw
        self.draw_main(frame, area, app);
    }

}

/// Draw the conversation pane with a two-column layout: marker gutter + text.
/// The gutter shows a marker at turn boundaries, aligned with the input gutter.
fn draw_conversation_pane(
    frame: &mut Frame,
    area: Rect,
    pane: &mut PaneState,
    is_active: bool,
) {
    use super::scroll_pane::ScrollPane;

    let border_style = if is_active {
        Style::default().fg(Color::Cyan)
    } else {
        Style::default().fg(Color::DarkGray)
    };

    let block = Block::default()
        .title(" conversation ")
        .borders(Borders::ALL)
        .border_style(border_style);

    let (lines, markers) = pane.all_lines_with_markers();

    // Apply selection highlighting
    let items: Vec<MarkedLine> = if let Some(ref sel) = pane.selection {
        let (sl, sc, el, ec) = sel.range();
        lines.into_iter().zip(markers).enumerate().map(|(i, (line, marker))| {
            let line = if i >= sl && i <= el {
                let line_text: String = line.spans.iter().map(|s| s.content.as_ref()).collect();
                let start_col = if i == sl { sc } else { 0 };
                let end_col = if i == el { ec } else { line_text.len() };
                if start_col < end_col {
                    let before = if start_col > 0 { &line_text[..start_col] } else { "" };
                    let selected = &line_text[start_col..end_col];
                    let after = if end_col < line_text.len() { &line_text[end_col..] } else { "" };
                    let mut spans = Vec::new();
                    if !before.is_empty() { spans.push(Span::raw(before.to_string())); }
                    spans.push(Span::styled(selected.to_string(), Style::default().bg(Color::DarkGray).fg(Color::White)));
                    if !after.is_empty() { spans.push(Span::raw(after.to_string())); }
                    Line::from(spans).style(line.style).alignment(line.alignment.unwrap_or(ratatui::layout::Alignment::Left))
                } else {
                    line
                }
            } else {
                line
            };
            MarkedLine { line, marker }
        }).collect()
    } else {
        lines.into_iter().zip(markers).map(|(line, marker)| MarkedLine { line, marker }).collect()
    };

    let widget = ScrollPane::new(&items)
        .block(block)
        .gutter_width(2)
        .pin_to_bottom(true);
    frame.render_stateful_widget(widget, area, &mut pane.scroll);
}

/// Draw a scrollable text pane (free function to avoid borrow issues).
fn draw_pane(
    frame: &mut Frame,
    area: Rect,
    title: &str,
    pane: &mut PaneState,
    is_active: bool,
    left_title: Option<&str>,
) {
    use super::scroll_pane::ScrollPane;

    let border_style = if is_active {
        Style::default().fg(Color::Cyan)
    } else {
        Style::default().fg(Color::DarkGray)
    };

    let mut block = Block::default()
        .borders(Borders::ALL)
        .border_style(border_style);
    if let Some(left) = left_title {
        block = block
            .title_top(Line::from(left).left_aligned())
            .title_top(Line::from(format!(" {} ", title)).right_aligned());
    } else {
        block = block.title(format!(" {} ", title));
    }

    let lines = pane.all_lines();
    let widget = ScrollPane::new(&lines)
        .block(block)
        .pin_to_bottom(true);
    frame.render_stateful_widget(widget, area, &mut pane.scroll);
}