hh_cli/cli/tui/

app.rs

use std::cell::RefCell;
use std::path::Path;
use std::process::Command;
use std::time::Instant;

use crossterm::event::{KeyCode, KeyEvent, KeyModifiers};
use ratatui::text::Line;
use serde::Deserialize;
use tokio::sync::oneshot;

type QuestionResponder = std::sync::Arc<
    std::sync::Mutex<Option<oneshot::Sender<anyhow::Result<crate::core::QuestionAnswers>>>>,
>;

use super::commands::{SlashCommand, get_default_commands};
use super::event::{SubagentEventItem, TuiEvent};
use super::tool_render::render_tool_result;
use crate::core::MessageAttachment;

const SIDEBAR_WIDTH: u16 = 38;
const LEFT_COLUMN_RIGHT_MARGIN: u16 = 2;
const DEFAULT_CONTEXT_LIMIT: usize = 128_000;

#[derive(Debug, Clone, Copy)]
pub struct ScrollState {
    pub offset: usize,
    pub auto_follow: bool,
}

impl ScrollState {
    pub const fn new(auto_follow: bool) -> Self {
        Self {
            offset: 0,
            auto_follow,
        }
    }

    pub fn effective_offset(&self, total_lines: usize, visible_height: usize) -> usize {
        let max_offset = total_lines.saturating_sub(visible_height);
        if self.auto_follow {
            max_offset
        } else {
            self.offset.min(max_offset)
        }
    }

    pub fn scroll_up_steps(&mut self, total_lines: usize, visible_height: usize, steps: usize) {
        if steps == 0 {
            return;
        }

        if self.auto_follow {
            self.offset = total_lines.saturating_sub(visible_height);
            self.auto_follow = false;
        }

        self.offset = self.offset.saturating_sub(steps);
        self.auto_follow = false;
    }

    pub fn scroll_down_steps(&mut self, total_lines: usize, visible_height: usize, steps: usize) {
        if steps == 0 {
            return;
        }

        let max_offset = total_lines.saturating_sub(visible_height);
        self.offset = self.effective_offset(total_lines, visible_height);
        self.offset = self.offset.saturating_add(steps).min(max_offset);
        self.auto_follow = self.offset >= max_offset;
    }

    pub fn reset(&mut self, auto_follow: bool) {
        self.offset = 0;
        self.auto_follow = auto_follow;
    }
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct TodoItemView {
    pub content: String,
    pub status: TodoStatus,
    pub priority: TodoPriority,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum TodoStatus {
    Pending,
    InProgress,
    Completed,
    Cancelled,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum TodoPriority {
    High,
    Medium,
    Low,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum SubagentStatusView {
    Pending,
    Running,
    Completed,
    Failed,
    Cancelled,
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct SubagentItemView {
    pub task_id: String,
    pub name: String,
    pub parent_task_id: Option<String>,
    pub agent_name: String,
    pub prompt: String,
    pub summary: Option<String>,
    pub depth: usize,
    pub started_at: u64,
    pub finished_at: Option<u64>,
    pub status: SubagentStatusView,
}

#[derive(Debug, Clone)]
pub enum ChatMessage {
    User(String),
    Assistant(String),
    CompactionPending,
    Compaction(String),
    Thinking(String),
    ToolCall {
        name: String,
        args: String,
        output: Option<String>,
        is_error: Option<bool>,
    },
    Error(String),
    Footer {
        agent_display_name: String,
        provider_name: String,
        model_name: String,
        duration: String,
        interrupted: bool,
    },
}

#[derive(Debug, Clone)]
pub struct PendingQuestionView {
    pub header: String,
    pub question: String,
    pub options: Vec<QuestionOptionView>,
    pub selected_index: usize,
    pub custom_mode: bool,
    pub custom_value: String,
    pub question_index: usize,
    pub total_questions: usize,
    pub multiple: bool,
}

#[derive(Debug, Clone)]
pub struct QuestionOptionView {
    pub label: String,
    pub description: String,
    pub selected: bool,
    pub active: bool,
    pub custom: bool,
    pub submit: bool,
}

#[derive(Debug)]
struct PendingQuestionState {
    questions: Vec<crate::core::QuestionPrompt>,
    answers: crate::core::QuestionAnswers,
    custom_values: Vec<String>,
    question_index: usize,
    selected_index: usize,
    custom_mode: bool,
    responder: Option<QuestionResponder>,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum QuestionKeyResult {
    NotHandled,
    Handled,
    Submitted,
    Dismissed,
}

use crate::session::SessionMetadata;

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct SelectionPosition {
    pub line: usize,
    pub column: usize,
}

#[derive(Debug, Clone, Copy)]
pub struct ClipboardNotice {
    pub x: u16,
    pub y: u16,
    pub expires_at: Instant,
}

impl SelectionPosition {
    pub fn new(line: usize, column: usize) -> Self {
        Self { line, column }
    }
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub enum TextSelection {
    None,
    InProgress {
        start: SelectionPosition,
    },
    Active {
        start: SelectionPosition,
        end: SelectionPosition,
    },
}

impl TextSelection {
    pub fn is_none(&self) -> bool {
        matches!(self, TextSelection::None)
    }

    pub fn is_active(&self) -> bool {
        matches!(self, TextSelection::Active { .. })
    }

    pub fn get_range(&self) -> Option<(SelectionPosition, SelectionPosition)> {
        match self {
            TextSelection::Active { start, end } => {
                let (start_pos, end_pos) = if start.line < end.line
                    || (start.line == end.line && start.column <= end.column)
                {
                    (*start, *end)
                } else {
                    (*end, *start)
                };
                Some((start_pos, end_pos))
            }
            _ => None,
        }
    }

    pub fn get_active_start(&self) -> Option<SelectionPosition> {
        match self {
            TextSelection::Active { start, .. } | TextSelection::InProgress { start } => {
                Some(*start)
            }
            TextSelection::None => None,
        }
    }
}

pub struct ChatApp {
    pub messages: Vec<ChatMessage>,
    pub input: String,
    pub cursor: usize,
    pub message_scroll: ScrollState,
    pub sidebar_scroll: ScrollState,
    pub should_quit: bool,
    pub is_processing: bool,
    pub session_id: Option<String>,
    pub session_name: String,
    session_epoch: u64,
    run_epoch: u64,
    pub working_directory: String,
    pub git_branch: Option<String>,
    pub context_budget: usize,
    processing_started_at: Option<Instant>,
    pub todo_items: Vec<TodoItemView>,
    pub subagent_items: Vec<SubagentItemView>,
    // Cached rendered lines (rebuilt only when messages change)
    pub cached_lines: RefCell<Vec<Line<'static>>>,
    pub cached_width: RefCell<usize>,
    pub needs_rebuild: RefCell<bool>,
    pub available_sessions: Vec<SessionMetadata>,
    pub is_picking_session: bool,
    pub commands: Vec<SlashCommand>,
    pub filtered_commands: Vec<SlashCommand>,
    pub selected_command_index: usize,
    pub pending_attachments: Vec<MessageAttachment>,
    pub current_model_ref: String,
    pub available_models: Vec<ModelOptionView>,
    pub last_context_tokens: Option<usize>,
    preferred_column: Option<usize>,
    // Text selection state
    pub text_selection: TextSelection,
    pub clipboard_notice: Option<ClipboardNotice>,
    pending_question: Option<PendingQuestionState>,
    // Agent state
    pub current_agent_name: Option<String>,
    pub available_agents: Vec<AgentOptionView>,
    // Running agent task handle (for cancellation)
    agent_task: Option<tokio::task::JoinHandle<()>>,
    esc_interrupt_pending: bool,
    // Footer state for completed agent runs
    last_run_duration: Option<String>,
    last_run_interrupted: bool,
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct AgentOptionView {
    pub name: String,
    pub display_name: String,
    pub color: Option<String>,
    pub mode: String,
}

pub struct SubmittedInput {
    pub text: String,
    pub attachments: Vec<MessageAttachment>,
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ModelOptionView {
    pub full_id: String,
    pub provider_name: String,
    pub model_name: String,
    pub modality: String,
    pub max_context_size: usize,
}

impl ChatApp {
    pub fn new(session_name: String, cwd: &Path) -> Self {
        let commands = get_default_commands();
        Self {
            messages: Vec::new(),
            input: String::new(),
            cursor: 0,
            message_scroll: ScrollState::new(true),
            sidebar_scroll: ScrollState::new(false),
            should_quit: false,
            is_processing: false,
            session_id: None,
            session_name,
            session_epoch: 0,
            run_epoch: 0,
            working_directory: cwd.display().to_string(),
            git_branch: detect_git_branch(cwd),
            context_budget: DEFAULT_CONTEXT_LIMIT,
            processing_started_at: None,
            todo_items: Vec::new(),
            subagent_items: Vec::new(),
            cached_lines: RefCell::new(Vec::new()),
            cached_width: RefCell::new(0),
            needs_rebuild: RefCell::new(true),
            available_sessions: Vec::new(),
            is_picking_session: false,
            commands,
            filtered_commands: Vec::new(),
            selected_command_index: 0,
            pending_attachments: Vec::new(),
            current_model_ref: String::new(),
            available_models: Vec::new(),
            last_context_tokens: None,
            preferred_column: None,
            text_selection: TextSelection::None,
            clipboard_notice: None,
            pending_question: None,
            current_agent_name: None,
            available_agents: Vec::new(),
            agent_task: None,
            esc_interrupt_pending: false,
            last_run_duration: None,
            last_run_interrupted: false,
        }
    }

    pub fn set_agents(&mut self, agents: Vec<AgentOptionView>, selected: Option<String>) {
        self.available_agents = agents;
        self.current_agent_name = selected;
    }

    pub fn cycle_agent(&mut self) {
        if self.available_agents.is_empty() {
            return;
        }

        // Only cycle through primary agents
        let primary_agents: Vec<_> = self
            .available_agents
            .iter()
            .filter(|a| a.mode == "primary")
            .collect();

        if primary_agents.is_empty() {
            return;
        }

        let current = self.current_agent_name.as_deref();

        if let Some(current_name) = current {
            // Find current agent index among primary agents
            if let Some(pos) = primary_agents.iter().position(|a| a.name == current_name) {
                // Move to next primary agent
                let next_pos = (pos + 1) % primary_agents.len();
                self.current_agent_name = Some(primary_agents[next_pos].name.clone());
                return;
            }
        }

        // If no current agent or not found, select first primary agent
        self.current_agent_name = Some(primary_agents[0].name.clone());
    }

    pub fn selected_agent(&self) -> Option<&AgentOptionView> {
        self.current_agent_name
            .as_ref()
            .and_then(|name| self.available_agents.iter().find(|a| a.name == *name))
    }

    pub fn handle_event(&mut self, event: &TuiEvent) {
        match event {
            TuiEvent::Thinking(text) => {
                self.append_thinking_delta(text);
                self.mark_dirty();
            }
            TuiEvent::ToolStart { name, args } => {
                if !self.is_duplicate_pending_tool_call(name, args) {
                    self.messages.push(ChatMessage::ToolCall {
                        name: name.clone(),
                        args: args.to_string(),
                        output: None,
                        is_error: None,
                    });
                }
                self.mark_dirty();
            }
            TuiEvent::ToolEnd { name, result } => {
                self.complete_tool_call(name, result);
                if name == "question" {
                    self.pending_question = None;
                }
                self.mark_dirty();
            }
            TuiEvent::TodoItemsChanged(items) => {
                self.todo_items = items
                    .iter()
                    .map(|item| TodoItemView {
                        content: item.content.clone(),
                        status: TodoStatus::from_core(item.status.clone()),
                        priority: TodoPriority::from_core(item.priority.clone()),
                    })
                    .collect();
                self.mark_dirty();
            }
            TuiEvent::AssistantDelta(delta) => {
                if let Some(ChatMessage::Assistant(existing)) = self.messages.last_mut() {
                    existing.push_str(delta);
                    self.mark_dirty();
                    return;
                }
                self.messages.push(ChatMessage::Assistant(delta.clone()));
                self.mark_dirty();
            }
            TuiEvent::ContextUsage(tokens) => {
                self.last_context_tokens = Some(*tokens);
            }
            TuiEvent::AssistantDone => {
                self.set_processing(false);

                // Append footer if we have duration info
                if let (Some(duration), Some(agent)) = (
                    self.last_run_duration.take(),
                    self.selected_agent().cloned(),
                ) {
                    // Get provider and model names
                    let provider_name = self
                        .available_models
                        .iter()
                        .find(|model| model.full_id == self.selected_model_ref())
                        .map(|model| model.provider_name.clone())
                        .unwrap_or_default();
                    let model_name = self
                        .available_models
                        .iter()
                        .find(|model| model.full_id == self.selected_model_ref())
                        .map(|model| model.model_name.clone())
                        .unwrap_or_default();

                    self.messages.push(ChatMessage::Footer {
                        agent_display_name: agent.display_name.clone(),
                        provider_name,
                        model_name,
                        duration: duration.clone(),
                        interrupted: self.last_run_interrupted,
                    });
                    self.mark_dirty();

                    // Reset interrupted flag
                    self.last_run_interrupted = false;
                }
            }
            TuiEvent::SessionTitle(title) => {
                self.session_name = title.clone();
                self.mark_dirty();
            }
            TuiEvent::CompactionStart => {
                self.messages.push(ChatMessage::CompactionPending);
                self.mark_dirty();
            }
            TuiEvent::CompactionDone(summary) => {
                let mut replaced_pending = false;
                for message in self.messages.iter_mut().rev() {
                    if matches!(message, ChatMessage::CompactionPending) {
                        *message = ChatMessage::Compaction(summary.clone());
                        replaced_pending = true;
                        break;
                    }
                }
                if !replaced_pending {
                    self.messages.push(ChatMessage::Compaction(summary.clone()));
                }
                self.set_processing(false);
                self.mark_dirty();
            }
            TuiEvent::QuestionPrompt {
                questions,
                responder,
            } => {
                self.pending_question = Some(PendingQuestionState {
                    answers: vec![Vec::new(); questions.len()],
                    custom_values: vec![String::new(); questions.len()],
                    questions: questions.clone(),
                    question_index: 0,
                    selected_index: 0,
                    custom_mode: false,
                    responder: Some(responder.clone()),
                });
                self.mark_dirty();
            }
            TuiEvent::SubagentsChanged(items) => {
                self.subagent_items = items.iter().filter_map(to_subagent_item_view).collect();
                self.mark_dirty();
            }
            TuiEvent::Error(msg) => {
                self.messages.push(ChatMessage::Error(msg.clone()));
                self.set_processing(false);
                self.mark_dirty();
            }
            TuiEvent::Tick => {}
            TuiEvent::Key(_) => {}
        }
    }

    pub fn has_pending_question(&self) -> bool {
        self.pending_question.is_some()
    }

    pub fn pending_question_view(&self) -> Option<PendingQuestionView> {
        let state = self.pending_question.as_ref()?;
        let question = state.questions.get(state.question_index)?;
        let mut options = Vec::new();
        let selected = state.answers[state.question_index].clone();

        for (idx, option) in question.options.iter().enumerate() {
            options.push(QuestionOptionView {
                label: option.label.clone(),
                description: option.description.clone(),
                selected: selected.contains(&option.label),
                active: idx == state.selected_index,
                custom: false,
                submit: false,
            });
        }

        if question.custom {
            options.push(QuestionOptionView {
                label: "Type your own answer".to_string(),
                description: String::new(),
                selected: !state.custom_values[state.question_index].trim().is_empty()
                    && selected.contains(&state.custom_values[state.question_index]),
                active: options.len() == state.selected_index,
                custom: true,
                submit: false,
            });
        }

        if question.multiple {
            options.push(QuestionOptionView {
                label: "Submit answers".to_string(),
                description: "Continue to the next question".to_string(),
                selected: false,
                active: options.len() == state.selected_index,
                custom: false,
                submit: true,
            });
        }

        Some(PendingQuestionView {
            header: question.header.clone(),
            question: question.question.clone(),
            options,
            selected_index: state.selected_index,
            custom_mode: state.custom_mode,
            custom_value: state.custom_values[state.question_index].clone(),
            question_index: state.question_index,
            total_questions: state.questions.len(),
            multiple: question.multiple,
        })
    }

    pub fn handle_question_key(&mut self, key_event: KeyEvent) -> QuestionKeyResult {
        let Some(state) = self.pending_question.as_mut() else {
            return QuestionKeyResult::NotHandled;
        };

        let Some(question) = state.questions.get(state.question_index).cloned() else {
            self.pending_question = None;
            return QuestionKeyResult::Dismissed;
        };

        if state.custom_mode {
            match key_event.code {
                KeyCode::Char(c) if !key_event.modifiers.contains(KeyModifiers::CONTROL) => {
                    state.custom_values[state.question_index].push(c);
                    self.mark_dirty();
                    return QuestionKeyResult::Handled;
                }
                KeyCode::Backspace => {
                    state.custom_values[state.question_index].pop();
                    self.mark_dirty();
                    return QuestionKeyResult::Handled;
                }
                KeyCode::Esc => {
                    let existing_custom = state.custom_values[state.question_index].clone();
                    if !existing_custom.is_empty() {
                        let normalized = normalize_custom_input(&existing_custom);
                        state.answers[state.question_index].retain(|item| item != &normalized);
                        state.custom_values[state.question_index].clear();
                    }
                    state.custom_mode = false;
                    self.mark_dirty();
                    return QuestionKeyResult::Handled;
                }
                KeyCode::Enter => {
                    if key_event.modifiers.contains(KeyModifiers::SHIFT) {
                        state.custom_values[state.question_index].push('\n');
                        self.mark_dirty();
                        return QuestionKeyResult::Handled;
                    }

                    let custom = normalize_custom_input(&state.custom_values[state.question_index]);
                    state.custom_mode = false;
                    if custom.trim().is_empty() {
                        self.mark_dirty();
                        return QuestionKeyResult::Handled;
                    }
                    if question.multiple {
                        if !state.answers[state.question_index].contains(&custom) {
                            state.answers[state.question_index].push(custom);
                        }
                        self.mark_dirty();
                        return QuestionKeyResult::Handled;
                    }

                    state.answers[state.question_index] = vec![custom];
                    return self.advance_or_submit_question();
                }
                _ => return QuestionKeyResult::Handled,
            }
        }

        let option_count =
            question.options.len() + usize::from(question.custom) + usize::from(question.multiple);

        match key_event.code {
            KeyCode::Char(_) if !key_event.modifiers.contains(KeyModifiers::CONTROL) => {
                QuestionKeyResult::Handled
            }
            KeyCode::Up => {
                state.selected_index = if state.selected_index == 0 {
                    option_count.saturating_sub(1)
                } else {
                    state.selected_index.saturating_sub(1)
                };
                self.mark_dirty();
                QuestionKeyResult::Handled
            }
            KeyCode::Down => {
                state.selected_index = (state.selected_index + 1) % option_count.max(1);
                self.mark_dirty();
                QuestionKeyResult::Handled
            }
            KeyCode::Esc => {
                let existing_custom = state.custom_values[state.question_index].clone();
                if !existing_custom.is_empty() {
                    let normalized = normalize_custom_input(&existing_custom);
                    state.answers[state.question_index].retain(|item| item != &normalized);
                    state.custom_values[state.question_index].clear();
                    state.custom_mode = false;
                    self.mark_dirty();
                    return QuestionKeyResult::Handled;
                }

                self.finish_question_with_error(anyhow::anyhow!("question dismissed by user"));
                QuestionKeyResult::Dismissed
            }
            KeyCode::Char(digit) if digit.is_ascii_digit() => {
                let index = digit.to_digit(10).unwrap_or(0) as usize;
                if index == 0 {
                    return QuestionKeyResult::Handled;
                }
                let choice = index - 1;
                if choice < option_count {
                    state.selected_index = choice;
                    return self.apply_question_selection(question);
                }
                QuestionKeyResult::Handled
            }
            KeyCode::Enter => self.apply_question_selection(question),
            _ => QuestionKeyResult::Handled,
        }
    }

    fn apply_question_selection(
        &mut self,
        question: crate::core::QuestionPrompt,
    ) -> QuestionKeyResult {
        let Some(state) = self.pending_question.as_mut() else {
            return QuestionKeyResult::Dismissed;
        };

        let choice = state.selected_index;
        let custom_index = if question.custom {
            Some(question.options.len())
        } else {
            None
        };
        let submit_index = if question.multiple {
            question.options.len() + usize::from(question.custom)
        } else {
            usize::MAX
        };

        if choice < question.options.len() {
            let label = question.options[choice].label.clone();
            if question.multiple {
                if state.answers[state.question_index].contains(&label) {
                    state.answers[state.question_index].retain(|item| item != &label);
                } else {
                    state.answers[state.question_index].push(label);
                }
                self.mark_dirty();
                return QuestionKeyResult::Handled;
            }

            state.answers[state.question_index] = vec![label];
            return self.advance_or_submit_question();
        }

        if custom_index.is_some() && custom_index == Some(choice) {
            state.custom_mode = true;
            self.mark_dirty();
            return QuestionKeyResult::Handled;
        }

        if choice == submit_index {
            return self.advance_or_submit_question();
        }

        QuestionKeyResult::Handled
    }

    fn advance_or_submit_question(&mut self) -> QuestionKeyResult {
        let Some(state) = self.pending_question.as_mut() else {
            return QuestionKeyResult::Dismissed;
        };

        if state.question_index + 1 < state.questions.len() {
            state.question_index += 1;
            state.selected_index = 0;
            state.custom_mode = false;
            self.mark_dirty();
            return QuestionKeyResult::Handled;
        }

        let answers = state.answers.clone();
        self.finish_question_with_answers(answers);
        QuestionKeyResult::Submitted
    }

    fn finish_question_with_answers(&mut self, answers: crate::core::QuestionAnswers) {
        if let Some(mut pending) = self.pending_question.take()
            && let Some(guarded) = pending.responder.take()
            && let Ok(mut lock) = guarded.lock()
            && let Some(sender) = lock.take()
        {
            let _ = sender.send(Ok(answers));
        }
        self.mark_dirty();
    }

    fn finish_question_with_error(&mut self, error: anyhow::Error) {
        if let Some(mut pending) = self.pending_question.take()
            && let Some(guarded) = pending.responder.take()
            && let Ok(mut lock) = guarded.lock()
            && let Some(sender) = lock.take()
        {
            let _ = sender.send(Err(error));
        }
        self.mark_dirty();
    }

    pub fn submit_input(&mut self) -> SubmittedInput {
        let input = std::mem::take(&mut self.input);
        let attachments = std::mem::take(&mut self.pending_attachments);
        self.cursor = 0;
        self.preferred_column = None;
        if !input.is_empty() || !attachments.is_empty() {
            self.messages.push(ChatMessage::User(input.clone()));
            self.set_processing(true);
            self.message_scroll.auto_follow = true; // Follow the new response
            self.mark_dirty();
        }
        SubmittedInput {
            text: input,
            attachments,
        }
    }

    /// Get or rebuild cached lines for the given width (interior mutability)
    pub fn get_lines(&self, width: usize) -> std::cell::Ref<'_, Vec<Line<'static>>> {
        let needs_rebuild = *self.needs_rebuild.borrow();
        let cached_width = *self.cached_width.borrow();

        if needs_rebuild || cached_width != width {
            let lines = super::ui::build_message_lines(self, width);
            *self.cached_lines.borrow_mut() = lines;
            *self.cached_width.borrow_mut() = width;
            *self.needs_rebuild.borrow_mut() = false;
        }
        self.cached_lines.borrow()
    }

    pub fn progress_panel_height(&self) -> u16 {
        0
    }

    pub fn message_viewport_height(&self, total_height: u16) -> usize {
        total_height.saturating_sub(self.progress_panel_height() + 3 + 1 + 1 + 1 + 2) as usize
    }

    pub fn message_wrap_width(&self, total_width: u16) -> usize {
        let main_width = if total_width > SIDEBAR_WIDTH {
            total_width.saturating_sub(SIDEBAR_WIDTH + LEFT_COLUMN_RIGHT_MARGIN)
        } else {
            total_width
        };
        main_width.saturating_sub(2) as usize
    }

    pub fn context_usage(&self) -> (usize, usize) {
        if let Some(tokens) = self.last_context_tokens {
            return (tokens, self.context_budget);
        }

        let boundary = self
            .messages
            .iter()
            .rposition(|message| matches!(message, ChatMessage::Compaction(_)))
            .unwrap_or(0);
        let mut chars = self.input.len();
        for message in self.messages.iter().skip(boundary) {
            chars += match message {
                ChatMessage::User(text)
                | ChatMessage::Assistant(text)
                | ChatMessage::Compaction(text)
                | ChatMessage::Thinking(text) => text.len(),
                ChatMessage::CompactionPending => 0,
                ChatMessage::ToolCall {
                    name, args, output, ..
                } => name.len() + args.len() + output.as_ref().map(|s| s.len()).unwrap_or(0),
                ChatMessage::Error(text) => text.len(),
                ChatMessage::Footer { .. } => 0,
            };
        }
        let estimated_tokens = chars / 4;
        (estimated_tokens, self.context_budget)
    }

    pub fn processing_step(&self, interval_ms: u128) -> usize {
        if !self.is_processing {
            return 0;
        }

        let elapsed_ms = self
            .processing_started_at
            .map(|started| started.elapsed().as_millis())
            .unwrap_or_default();
        let interval = interval_ms.max(1);
        (elapsed_ms / interval) as usize
    }

    pub fn processing_duration(&self) -> String {
        if !self.is_processing {
            return String::new();
        }

        let elapsed_secs = self
            .processing_started_at
            .map(|started| started.elapsed().as_secs())
            .unwrap_or_default();

        let minutes = elapsed_secs / 60;
        let seconds = elapsed_secs % 60;

        if minutes == 0 {
            format!("{}s", seconds)
        } else {
            format!("{}m {}s", minutes, seconds)
        }
    }

    fn append_thinking_delta(&mut self, delta: &str) {
        if delta.is_empty() {
            return;
        }

        if let Some(ChatMessage::Thinking(existing)) = self.messages.last_mut() {
            existing.push_str(delta);
            return;
        }

        self.messages.push(ChatMessage::Thinking(delta.to_string()));
    }

    fn is_duplicate_pending_tool_call(&self, name: &str, args: &serde_json::Value) -> bool {
        let Some(ChatMessage::ToolCall {
            name: last_name,
            args: last_args,
            is_error,
            ..
        }) = self.messages.last()
        else {
            return false;
        };

        is_error.is_none() && last_name == name && last_args == &args.to_string()
    }

    fn complete_tool_call(&mut self, name: &str, result: &crate::tool::ToolResult) {
        let rendered = render_tool_result(name, result);
        if let Some(todos) = rendered.todos {
            self.todo_items = todos;
        }
        if name == "task" && !result.is_error {
            self.update_subagent_items_from_task_result(result);
        }

        // Find the matching ToolCall
        for message in self.messages.iter_mut().rev() {
            if let ChatMessage::ToolCall {
                name: tool_name,
                is_error: status,
                output: out,
                ..
            } = message
                && tool_name == name
                && status.is_none()
            {
                *status = Some(result.is_error);
                *out = Some(rendered.text);
                return;
            }
        }
    }

    fn update_subagent_items_from_task_result(&mut self, result: &crate::tool::ToolResult) {
        let parsed = parse_task_tool_output(&result.payload)
            .or_else(|| serde_json::from_str::<TaskToolWireOutput>(&result.output).ok());
        let Some(parsed) = parsed else {
            return;
        };

        let Some(status) = SubagentStatusView::from_wire(&parsed.status) else {
            return;
        };

        let item = SubagentItemView {
            task_id: parsed.task_id,
            name: parsed.name,
            parent_task_id: parsed.parent_task_id,
            agent_name: parsed.agent_name,
            prompt: parsed.prompt,
            summary: parsed.summary.or(parsed.error),
            depth: parsed.depth,
            started_at: parsed.started_at,
            finished_at: parsed.finished_at,
            status,
        };

        if let Some(existing) = self
            .subagent_items
            .iter_mut()
            .find(|existing| existing.task_id == item.task_id)
        {
            *existing = item;
        } else {
            self.subagent_items.push(item);
        }
    }

    pub fn set_processing(&mut self, processing: bool) {
        // Capture final duration and interrupted status when ending processing
        if !processing && self.is_processing {
            if let Some(started) = self.processing_started_at {
                let elapsed_secs = started.elapsed().as_secs();
                let minutes = elapsed_secs / 60;
                let seconds = elapsed_secs % 60;
                self.last_run_duration = if minutes == 0 {
                    Some(format!("{}s", seconds))
                } else {
                    Some(format!("{}m {}s", minutes, seconds))
                };
            }
            self.last_run_interrupted = self.esc_interrupt_pending;
        }

        self.is_processing = processing;
        if !processing {
            self.clear_pending_esc_interrupt();
        }
        self.processing_started_at = if processing {
            Some(Instant::now())
        } else {
            None
        };
    }

    pub fn session_epoch(&self) -> u64 {
        self.session_epoch
    }

    pub fn run_epoch(&self) -> u64 {
        self.run_epoch
    }

    pub fn bump_session_epoch(&mut self) {
        self.session_epoch = self.session_epoch.wrapping_add(1);
    }

    pub fn bump_run_epoch(&mut self) {
        self.run_epoch = self.run_epoch.wrapping_add(1);
    }

    pub fn start_new_session(&mut self, session_name: String) {
        self.bump_session_epoch();
        self.messages.clear();
        self.todo_items.clear();
        self.subagent_items.clear();
        self.last_context_tokens = None;
        self.session_id = None;
        self.session_name = session_name;
        self.available_sessions.clear();
        self.is_picking_session = false;
        self.message_scroll.reset(true);
        self.sidebar_scroll.reset(false);
        self.set_processing(false);
        self.pending_question = None;
        self.cancel_agent_task();
        self.mark_dirty();
    }

    /// Cancel any running agent task
    pub fn cancel_agent_task(&mut self) {
        if let Some(handle) = self.agent_task.take() {
            self.bump_run_epoch();
            handle.abort();
        }
        self.clear_pending_esc_interrupt();
    }

    /// Set the agent task handle
    pub fn set_agent_task(&mut self, handle: tokio::task::JoinHandle<()>) {
        // Cancel any existing task first
        self.cancel_agent_task();
        self.agent_task = Some(handle);
    }

    pub fn arm_esc_interrupt(&mut self) {
        self.esc_interrupt_pending = true;
    }

    pub fn clear_pending_esc_interrupt(&mut self) {
        self.esc_interrupt_pending = false;
    }

    pub fn should_interrupt_on_esc(&self) -> bool {
        self.esc_interrupt_pending
    }

    pub fn processing_interrupt_hint(&self) -> &'static str {
        if self.esc_interrupt_pending {
            "esc again to interrupt"
        } else {
            "esc interrupt"
        }
    }

    pub fn update_command_filtering(&mut self) {
        if self.input.starts_with('/') {
            let query = self.input.trim();
            self.filtered_commands = self
                .commands
                .iter()
                .filter(|cmd| cmd.name.starts_with(query))
                .cloned()
                .collect();
        } else {
            self.filtered_commands.clear();
        }

        if self.selected_command_index >= self.filtered_commands.len() {
            self.selected_command_index = 0;
        }
    }

    pub fn mark_dirty(&self) {
        *self.needs_rebuild.borrow_mut() = true;
    }

    pub fn configure_models(
        &mut self,
        current_model_ref: String,
        available_models: Vec<ModelOptionView>,
    ) {
        self.current_model_ref = current_model_ref;
        self.available_models = available_models;
        self.context_budget = self
            .available_models
            .iter()
            .find(|model| model.full_id == self.current_model_ref)
            .map(|model| model.max_context_size)
            .unwrap_or(DEFAULT_CONTEXT_LIMIT);
        self.last_context_tokens = None;
    }

    pub fn selected_model_ref(&self) -> &str {
        self.current_model_ref.as_str()
    }

    pub fn set_selected_model(&mut self, model_ref: &str) {
        self.current_model_ref = model_ref.to_string();
        self.context_budget = self
            .available_models
            .iter()
            .find(|model| model.full_id == self.current_model_ref)
            .map(|model| model.max_context_size)
            .unwrap_or(DEFAULT_CONTEXT_LIMIT);
        self.last_context_tokens = None;
    }

    pub fn insert_char(&mut self, ch: char) {
        self.input.insert(self.cursor, ch);
        self.cursor += ch.len_utf8();
        self.preferred_column = None;
    }

    pub fn insert_str(&mut self, text: &str) {
        if text.is_empty() {
            return;
        }
        self.input.insert_str(self.cursor, text);
        self.cursor += text.len();
        self.preferred_column = None;
    }

    pub fn backspace(&mut self) {
        if self.cursor == 0 {
            return;
        }
        if let Some((idx, _)) = self.input[..self.cursor].char_indices().next_back() {
            self.input.drain(idx..self.cursor);
            self.cursor = idx;
            self.preferred_column = None;
        }
    }

    pub fn clear_input(&mut self) {
        self.input.clear();
        self.pending_attachments.clear();
        self.cursor = 0;
        self.preferred_column = None;
    }

    pub fn set_input(&mut self, value: String) {
        self.input = value;
        self.pending_attachments.clear();
        self.cursor = self.input.len();
        self.preferred_column = None;
    }

    pub fn add_pending_attachment(&mut self, attachment: MessageAttachment) {
        self.pending_attachments.push(attachment);
    }

    pub fn move_to_line_start(&mut self) {
        let (start, _) = current_line_bounds(&self.input, self.cursor);
        if self.cursor == start {
            let (line_index, _) = cursor_line_col(&self.input, self.cursor);
            if line_index > 0
                && let Some((prev_start, _)) = line_bounds_by_index(&self.input, line_index - 1)
            {
                self.cursor = prev_start;
            }
        } else {
            self.cursor = start;
        }
        self.preferred_column = None;
    }

    pub fn move_to_line_end(&mut self) {
        let (_, end) = current_line_bounds(&self.input, self.cursor);
        if self.cursor == end {
            let (line_index, _) = cursor_line_col(&self.input, self.cursor);
            if let Some((_, next_end)) = line_bounds_by_index(&self.input, line_index + 1) {
                self.cursor = next_end;
            }
        } else {
            self.cursor = end;
        }
        self.preferred_column = None;
    }

    pub fn move_cursor_up(&mut self) {
        self.move_cursor_vertical(-1);
    }

    pub fn move_cursor_down(&mut self) {
        self.move_cursor_vertical(1);
    }

    pub fn move_cursor_left(&mut self) {
        if self.cursor == 0 {
            return;
        }
        if let Some((idx, _)) = self.input[..self.cursor].char_indices().next_back() {
            self.cursor = idx;
            self.preferred_column = None;
        }
    }

    pub fn move_cursor_right(&mut self) {
        if self.cursor >= self.input.len() {
            return;
        }
        if let Some(ch) = self.input[self.cursor..].chars().next() {
            self.cursor += ch.len_utf8();
            self.preferred_column = None;
        }
    }

    fn move_cursor_vertical(&mut self, direction: isize) {
        if self.input.is_empty() {
            return;
        }

        let (line_index, column) = cursor_line_col(&self.input, self.cursor);
        let target_column = self.preferred_column.unwrap_or(column);
        let target_line = if direction < 0 {
            line_index.saturating_sub(1)
        } else {
            line_index + 1
        };

        if direction < 0 && line_index == 0 {
            return;
        }

        let total_lines = self.input.split('\n').count();
        if target_line >= total_lines {
            return;
        }

        self.cursor = line_col_to_cursor(&self.input, target_line, target_column);
        self.preferred_column = Some(target_column);
    }

    // Text selection methods
    pub fn start_selection(&mut self, line: usize, column: usize) {
        self.text_selection = TextSelection::InProgress {
            start: SelectionPosition::new(line, column),
        };
    }

    pub fn update_selection(&mut self, line: usize, column: usize) {
        match &self.text_selection {
            TextSelection::InProgress { start } => {
                self.text_selection = TextSelection::Active {
                    start: *start,
                    end: SelectionPosition::new(line, column),
                };
            }
            TextSelection::Active { start, .. } => {
                self.text_selection = TextSelection::Active {
                    start: *start,
                    end: SelectionPosition::new(line, column),
                };
            }
            TextSelection::None => {
                self.start_selection(line, column);
            }
        }
    }

    pub fn end_selection(&mut self) {
        if let TextSelection::InProgress { .. } = self.text_selection {
            self.text_selection = TextSelection::None;
        }
    }

    pub fn clear_selection(&mut self) {
        self.text_selection = TextSelection::None;
    }

    pub fn show_clipboard_notice(&mut self, x: u16, y: u16) {
        self.clipboard_notice = Some(ClipboardNotice {
            x,
            y,
            expires_at: Instant::now() + std::time::Duration::from_secs(1),
        });
    }

    pub fn active_clipboard_notice(&self) -> Option<ClipboardNotice> {
        self.clipboard_notice
            .filter(|notice| Instant::now() <= notice.expires_at)
    }

    /// Get selected text from the lines
    pub fn get_selected_text(&self, lines: &[Line<'static>]) -> String {
        if !self.text_selection.is_active() {
            return String::new();
        }

        let (start, end) = match self.text_selection.get_range() {
            Some(range) => range,
            None => return String::new(),
        };

        if start.line >= lines.len() || end.line >= lines.len() {
            return String::new();
        }

        let mut selected_text = String::new();
        let start_idx = start.line;
        let end_idx = end.line;

        for (offset, line) in lines[start_idx..=end_idx].iter().enumerate() {
            let line_idx = start_idx + offset;
            let line_text = line
                .spans
                .iter()
                .map(|s| s.content.as_ref())
                .collect::<String>();

            let (start_col, end_col) = if line_idx == start_idx && line_idx == end_idx {
                (start.column, end.column)
            } else if line_idx == start_idx {
                (start.column, line_text.chars().count())
            } else if line_idx == end_idx {
                (0, end.column)
            } else {
                (0, line_text.chars().count())
            };

            let chars: Vec<char> = line_text.chars().collect();
            let clamped_start = start_col.min(chars.len());
            let clamped_end = end_col.min(chars.len());
            if clamped_start >= clamped_end {
                continue;
            }
            let selected_line = chars[clamped_start..clamped_end].iter().collect::<String>();

            selected_text.push_str(&selected_line);
            if line_idx < end_idx {
                selected_text.push('\n');
            }
        }

        selected_text
    }

    /// Check if a point (line, column) is within the selection
    pub fn is_point_selected(&self, line: usize, column: usize) -> bool {
        let (start, end) = match self.text_selection.get_range() {
            Some(range) => range,
            None => return false,
        };

        if line > end.line || (line == end.line && column > end.column) {
            return false;
        }

        if line < start.line || (line == start.line && column < start.column) {
            return false;
        }

        true
    }
}

#[derive(Debug, Deserialize)]
struct TaskToolWireOutput {
    task_id: String,
    status: String,
    name: String,
    agent_name: String,
    prompt: String,
    depth: usize,
    #[serde(default)]
    parent_task_id: Option<String>,
    started_at: u64,
    #[serde(default)]
    finished_at: Option<u64>,
    #[serde(default)]
    summary: Option<String>,
    #[serde(default)]
    error: Option<String>,
}

fn parse_task_tool_output(value: &serde_json::Value) -> Option<TaskToolWireOutput> {
    serde_json::from_value(value.clone()).ok()
}

fn normalize_custom_input(value: &str) -> String {
    value.trim_end_matches('\n').to_string()
}
impl TodoStatus {
    pub fn from_core(status: crate::core::TodoStatus) -> Self {
        match status {
            crate::core::TodoStatus::Pending => Self::Pending,
            crate::core::TodoStatus::InProgress => Self::InProgress,
            crate::core::TodoStatus::Completed => Self::Completed,
            crate::core::TodoStatus::Cancelled => Self::Cancelled,
        }
    }

    pub fn from_wire(status: &str) -> Option<Self> {
        match status {
            "pending" => Some(Self::Pending),
            "in_progress" => Some(Self::InProgress),
            "completed" => Some(Self::Completed),
            "cancelled" => Some(Self::Cancelled),
            _ => None,
        }
    }
}

impl TodoPriority {
    pub fn from_core(priority: crate::core::TodoPriority) -> Self {
        match priority {
            crate::core::TodoPriority::High => Self::High,
            crate::core::TodoPriority::Medium => Self::Medium,
            crate::core::TodoPriority::Low => Self::Low,
        }
    }

    pub fn from_wire(priority: &str) -> Option<Self> {
        match priority {
            "high" => Some(Self::High),
            "medium" => Some(Self::Medium),
            "low" => Some(Self::Low),
            _ => None,
        }
    }
}

impl SubagentStatusView {
    pub fn is_terminal(self) -> bool {
        matches!(self, Self::Completed | Self::Failed | Self::Cancelled)
    }

    pub fn is_active(self) -> bool {
        matches!(self, Self::Pending | Self::Running)
    }

    pub fn from_wire(status: &str) -> Option<Self> {
        match status {
            "pending" | "queued" => Some(Self::Pending),
            "running" => Some(Self::Running),
            "completed" | "done" => Some(Self::Completed),
            "failed" | "error" => Some(Self::Failed),
            "cancelled" => Some(Self::Cancelled),
            _ => None,
        }
    }

    pub fn from_lifecycle(status: crate::session::types::SubAgentLifecycleStatus) -> Self {
        match status {
            crate::session::types::SubAgentLifecycleStatus::Pending => Self::Pending,
            crate::session::types::SubAgentLifecycleStatus::Running => Self::Running,
            crate::session::types::SubAgentLifecycleStatus::Completed => Self::Completed,
            crate::session::types::SubAgentLifecycleStatus::Failed => Self::Failed,
            crate::session::types::SubAgentLifecycleStatus::Cancelled => Self::Cancelled,
        }
    }
}

fn to_subagent_item_view(item: &SubagentEventItem) -> Option<SubagentItemView> {
    let status = SubagentStatusView::from_wire(&item.status)?;
    Some(SubagentItemView {
        task_id: item.task_id.clone(),
        name: item.name.clone(),
        parent_task_id: item.parent_task_id.clone(),
        agent_name: item.agent_name.clone(),
        prompt: item.prompt.clone(),
        summary: item.summary.clone().or(item.error.clone()),
        depth: item.depth,
        started_at: item.started_at,
        finished_at: item.finished_at,
        status,
    })
}

impl Default for ChatApp {
    fn default() -> Self {
        Self::new("Session".to_string(), Path::new("."))
    }
}

fn detect_git_branch(cwd: &Path) -> Option<String> {
    let branch = run_git_command(cwd, &["rev-parse", "--abbrev-ref", "HEAD"])?;
    if branch == "HEAD" {
        return run_git_command(cwd, &["rev-parse", "--short", "HEAD"])
            .map(|hash| format!("detached@{hash}"));
    }
    Some(branch)
}

fn run_git_command(cwd: &Path, args: &[&str]) -> Option<String> {
    let output = Command::new("git")
        .arg("-C")
        .arg(cwd)
        .args(args)
        .output()
        .ok()?;

    if !output.status.success() {
        return None;
    }

    let text = String::from_utf8(output.stdout).ok()?;
    let trimmed = text.trim();
    if trimmed.is_empty() {
        return None;
    }

    Some(trimmed.to_string())
}

fn current_line_bounds(input: &str, cursor: usize) -> (usize, usize) {
    let cursor = cursor.min(input.len());
    let start = input[..cursor].rfind('\n').map_or(0, |idx| idx + 1);
    let end = input[cursor..]
        .find('\n')
        .map_or(input.len(), |idx| cursor + idx);
    (start, end)
}

fn cursor_line_col(input: &str, cursor: usize) -> (usize, usize) {
    let cursor = cursor.min(input.len());
    let mut line = 0usize;
    let mut line_start = 0usize;

    for (idx, ch) in input.char_indices() {
        if idx >= cursor {
            break;
        }
        if ch == '\n' {
            line += 1;
            line_start = idx + 1;
        }
    }

    let col = input[line_start..cursor].chars().count();
    (line, col)
}

fn line_col_to_cursor(input: &str, target_line: usize, target_col: usize) -> usize {
    let mut line_start = 0usize;

    for (line_idx, line) in input.split('\n').enumerate() {
        let line_end = line_start + line.len();
        if line_idx == target_line {
            let rel = line
                .char_indices()
                .nth(target_col)
                .map_or(line.len(), |(idx, _)| idx);
            return line_start + rel;
        }
        line_start = line_end + 1;
    }

    input.len()
}

fn line_bounds_by_index(input: &str, target_line: usize) -> Option<(usize, usize)> {
    let mut line_start = 0usize;

    for (line_idx, line) in input.split('\n').enumerate() {
        let line_end = line_start + line.len();
        if line_idx == target_line {
            return Some((line_start, line_end));
        }
        line_start = line_end + 1;
    }

    None
}