mach/

input.rs

//! Keyboard and mouse handling.

use ratatui::crossterm::event::{
    Event, KeyCode, KeyEvent, KeyEventKind, KeyModifiers, MouseButton, MouseEvent, MouseEventKind,
};

use std::time::{Duration, Instant};

use crate::app::{App, Confirm, Focus, Mode};
use crate::form::Field;
use crate::text_input::TextInput;
use crate::undo::EditKind;

/// Two clicks on the same task within this long open it.
const DOUBLE_CLICK: Duration = Duration::from_millis(400);

/// Handle one terminal event and report whether the screen may have changed.
pub fn handle_event(app: &mut App, event: Event) -> bool {
    match event {
        Event::Key(key) if matches!(key.kind, KeyEventKind::Press | KeyEventKind::Repeat) => {
            handle_key(app, key);
            true
        }
        Event::Mouse(m)
            if app.pending.is_some()
                || matches!(
                    m.kind,
                    MouseEventKind::Down(MouseButton::Left)
                        | MouseEventKind::ScrollUp
                        | MouseEventKind::ScrollDown
                ) =>
        {
            handle_mouse(app, m);
            true
        }
        // The terminal's own paste (Cmd+V / middle click), delivered in
        // one piece because bracketed paste is on.
        Event::Paste(text) if !text.is_empty() => {
            paste_text(app, &text);
            true
        }
        // Crossterm has already resized the terminal; the next draw picks up
        // the new dimensions without any App mutation here.
        Event::Resize(_, _) => true,
        _ => false,
    }
}

/// Puts pasted text into whatever is being typed into. Bracketed paste
/// (the terminal's own Cmd/Ctrl+V) is enough — no separate key binding.
fn paste_text(app: &mut App, text: &str) {
    if text.is_empty() {
        return;
    }
    app.cancel_pending();
    match app.mode {
        Mode::TaskForm => {
            let Some(form) = &mut app.form else { return };
            match form.field {
                Field::Title => {
                    form.before_edit(EditKind::Atomic);
                    form.title.insert_str(text);
                }
                // Selectors are changed with arrows/clicks, not pasted text.
                Field::Category | Field::Due => {}
                Field::Body => {
                    form.before_edit(EditKind::Atomic);
                    form.body.insert_str(text);
                }
                Field::Importance => {}
            }
        }
        Mode::CategoryForm => {
            let Some(form) = &mut app.category_form else {
                return;
            };
            form.before_edit(EditKind::Atomic);
            if form.on_description {
                form.description.insert_str(text);
            } else {
                form.name.insert_str(text);
            }
        }
        Mode::Slash => {
            app.input.insert_str(text);
            app.slash_index = 0;
            app.clamp_slash_index();
        }
        Mode::Search => {
            app.input.insert_str(text);
            app.update_search();
        }
        _ => {}
    }
}

/// Ctrl+Z — undo (not Ctrl+Shift+Z).
fn is_undo_chord(key: KeyEvent) -> bool {
    matches!(key.code, KeyCode::Char('z') | KeyCode::Char('Z'))
        && key.modifiers.contains(KeyModifiers::CONTROL)
        && !key.modifiers.contains(KeyModifiers::SHIFT)
        && !key.modifiers.contains(KeyModifiers::ALT)
}

/// Ctrl+Shift+Z or Ctrl+Y — redo.
fn is_redo_chord(key: KeyEvent) -> bool {
    let ctrl = key.modifiers.contains(KeyModifiers::CONTROL);
    let shift = key.modifiers.contains(KeyModifiers::SHIFT);
    let alt = key.modifiers.contains(KeyModifiers::ALT);
    if !ctrl || alt {
        return false;
    }
    match key.code {
        KeyCode::Char('z') | KeyCode::Char('Z') if shift => true,
        KeyCode::Char('y') | KeyCode::Char('Y') if !shift => true,
        _ => false,
    }
}

/// Whether this key mutates editor content, and how to group it for undo.
fn content_edit_kind(key: KeyEvent) -> Option<EditKind> {
    let ctrl = key.modifiers.contains(KeyModifiers::CONTROL);
    let alt = key.modifiers.contains(KeyModifiers::ALT);
    let shift = key.modifiers.contains(KeyModifiers::SHIFT);
    let word = word_mod(key);
    match key.code {
        KeyCode::Char(c) if ctrl || alt => match c {
            // Deletes / kills — always their own step.
            'u' | 'k' | 'w' | 'W' if !shift => Some(EditKind::Atomic),
            // Ctrl+D toggles a body to-do (handled on body only).
            'd' | 'D' if ctrl && !alt && !shift => Some(EditKind::Atomic),
            _ => None,
        },
        KeyCode::Char(_) if !ctrl && !alt => Some(EditKind::Typing),
        KeyCode::Backspace if word => Some(EditKind::Atomic),
        KeyCode::Backspace | KeyCode::Delete => Some(EditKind::Typing),
        _ => None,
    }
}

fn handle_key(app: &mut App, key: KeyEvent) {
    // Cmd/Ctrl+C on a selection copies it. Copying always wins over
    // quitting, so the two can share the chord.
    if is_copy_chord(key) && copy_selected_body_image(app) {
        return;
    }
    // Auto-repeat comes from one physical hold, not a second affirmative
    // action. Keep navigation/edit repeats responsive, but never let one
    // complete an armed delete, purge, discard, or quit confirmation.
    if key.kind == KeyEventKind::Repeat
        && app
            .pending_confirmation()
            .is_some_and(|confirm| confirmation_key_matches(confirm, key, app.mode))
    {
        return;
    }
    // With nothing to copy, Ctrl+C twice leaves mach — but only from
    // the two panels. Inside a dialog or the `/` line it would be far too
    // easy to throw away what was typed, and Esc already backs out there.
    if is_ctrl_c(key) && app.mode == Mode::Normal {
        if app.awaiting(Confirm::Quit) {
            app.should_quit = true;
        } else {
            app.ask_confirm(Confirm::Quit, "Press Ctrl+C again to quit");
        }
        return;
    }

    // Confirmations are action-specific. Any key other than that action's
    // explicit second step cancels it before normal routing continues.
    let keeps_confirmation = app
        .pending_confirmation()
        .is_none_or(|confirm| confirmation_key_matches(confirm, key, app.mode));
    if !keeps_confirmation {
        app.cancel_pending();
    }

    if key.code == KeyCode::Enter
        && app.mode == Mode::Normal
        && let Some(Confirm::Purge(ids)) = app.pending_confirmation().cloned()
    {
        let count = app.purge_ids(&ids);
        if count > 0 {
            app.info(format!("Purged {count} done task(s)"));
        }
        return;
    }

    match app.mode {
        Mode::Welcome => {
            app.mode = Mode::Normal;
            if !matches!(key.code, KeyCode::Enter | KeyCode::Esc) {
                handle_key(app, key);
            }
        }
        Mode::Help => match key.code {
            KeyCode::Esc | KeyCode::Enter | KeyCode::Char('?') => app.mode = Mode::Normal,
            KeyCode::Up => app.help_scroll = app.help_scroll.saturating_sub(1),
            KeyCode::Down => app.help_scroll = app.help_scroll.saturating_add(1),
            KeyCode::PageUp => app.help_scroll = app.help_scroll.saturating_sub(10),
            KeyCode::PageDown => app.help_scroll = app.help_scroll.saturating_add(10),
            KeyCode::Home => app.help_scroll = 0,
            KeyCode::End => app.help_scroll = usize::MAX,
            _ => {}
        },
        Mode::Settings => handle_settings_key(app, key),
        Mode::TaskForm => handle_form_key(app, key),
        Mode::CategoryForm => handle_category_key(app, key),
        Mode::Slash => handle_slash_key(app, key),
        Mode::Search => handle_search_key(app, key),
        _ => handle_normal_key(app, key),
    }
}

fn confirmation_key_matches(confirm: &Confirm, key: KeyEvent, mode: Mode) -> bool {
    match confirm {
        Confirm::DeleteTask(_) | Confirm::DeleteCategory(_) => key.code == KeyCode::Backspace,
        Confirm::Purge(_) => key.code == KeyCode::Enter && mode == Mode::Normal,
        Confirm::DiscardTask(_) | Confirm::DiscardCategory(_) => key.code == KeyCode::Esc,
        Confirm::Quit => is_ctrl_c(key),
    }
}

/// ⌘C / Ctrl+C — macOS terminals often send SUPER for Command.
fn is_copy_chord(key: KeyEvent) -> bool {
    matches!(key.code, KeyCode::Char('c') | KeyCode::Char('C'))
        && (key.modifiers.contains(KeyModifiers::SUPER)
            || key.modifiers.contains(KeyModifiers::CONTROL))
}

/// Ctrl+C alone. ⌘C is Copy on macOS and must never quit, so the quit
/// chord is narrower than [`is_copy_chord`].
fn is_ctrl_c(key: KeyEvent) -> bool {
    matches!(key.code, KeyCode::Char('c') | KeyCode::Char('C'))
        && key.modifiers == KeyModifiers::CONTROL
}

/// Copy the current selection (text, picture, or both) from a form field.
/// Returns true when the key was handled.
fn copy_selected_body_image(app: &mut App) -> bool {
    if app.mode == Mode::TaskForm
        && let Some(form) = &app.form
        && form.field == Field::Body
        && let Some(payload) = form.body.selected_payload()
    {
        finish_copy(app, payload);
        return true;
    }
    // Other fields: plain text selection only.
    if let Some(text) = selected_text_in_app(app) {
        finish_copy(app, crate::body::CopyPayload::Text(text));
        return true;
    }
    if app.mode != Mode::TaskForm {
        return false;
    }
    let Some(form) = &app.form else {
        return false;
    };
    // Full-size preview: copy that picture even with no body selection.
    if form.preview {
        let path = form
            .body
            .selected_image()
            .or_else(|| form.body.images().into_iter().next());
        if let Some(path) = path {
            finish_copy(app, crate::body::CopyPayload::Image(path));
            return true;
        }
    }
    false
}

fn selected_text_in_app(app: &App) -> Option<String> {
    match app.mode {
        Mode::TaskForm => {
            let form = app.form.as_ref()?;
            match form.field {
                Field::Title => form.title.selected_text(),
                Field::Body => form.body.selected_text(),
                Field::Category | Field::Due | Field::Importance => None,
            }
        }
        Mode::CategoryForm => {
            let form = app.category_form.as_ref()?;
            if form.on_description {
                form.description.selected_text()
            } else {
                form.name.selected_text()
            }
        }
        Mode::Slash | Mode::Search => app.input.selected_text(),
        _ => None,
    }
}

// ---------------------------------------------------------------- normal

fn handle_normal_key(app: &mut App, key: KeyEvent) {
    match key.code {
        KeyCode::Tab | KeyCode::BackTab => {
            if !app.searching {
                app.toggle_focus();
            }
        }
        // Esc backs out one step and never quits; use `/quit`.
        KeyCode::Esc => {
            if app.searching {
                app.end_search();
            }
        }
        // `/` opens the command palette (search, settings, …).
        KeyCode::Char('/') => app.open_slash(),
        KeyCode::Char('?') => {
            app.help_scroll = 0;
            app.mode = Mode::Help;
        }
        _ => match app.focus {
            Focus::Tasks => task_key(app, key),
            Focus::Sidebar => sidebar_key(app, key),
        },
    }
}

fn task_key(app: &mut App, key: KeyEvent) {
    let ctrl = key.modifiers.contains(KeyModifiers::CONTROL);
    let alt = key.modifiers.contains(KeyModifiers::ALT);
    let meta = key.modifiers.contains(KeyModifiers::SUPER);

    match key.code {
        KeyCode::Char('a') | KeyCode::Char('A') if ctrl && !alt => {
            if app.searching {
                app.info("Leave search (Esc) before adding a task");
                return;
            }
            app.open_new_task();
        }
        KeyCode::Char('f') | KeyCode::Char('F') if ctrl && !alt => {
            app.cycle_importance(app.task_index);
        }
        KeyCode::Enter => app.open_edit_task(),
        KeyCode::Char(' ') => app.toggle_done(app.task_index),
        KeyCode::Up if alt && !ctrl && !meta => {
            app.move_task_order(-1);
        }
        KeyCode::Down if alt && !ctrl && !meta => {
            app.move_task_order(1);
        }
        KeyCode::Up => app.navigate_vertical(-1),
        KeyCode::Down => app.navigate_vertical(1),
        KeyCode::PageUp => app.select_first_task(),
        KeyCode::PageDown => app.select_last_task(),
        // The panels sit side by side, so the arrows that point at them
        // are what moves between them.
        KeyCode::Left => {
            let _ = app.set_focus(Focus::Sidebar);
        }
        KeyCode::Backspace => {
            if let Some(id) = app.selected_task().map(|task| task.id.clone()) {
                let confirm = Confirm::DeleteTask(id.clone());
                if app.awaiting(confirm.clone()) {
                    if app.delete_task_by_id(&id) {
                        app.info("Task deleted");
                    }
                } else {
                    app.ask_confirm(confirm, "Press Backspace again to delete this task");
                }
            }
        }
        // Type-to-jump: plain characters fuzzy-select a row (no mode).
        KeyCode::Char(c) if !ctrl && !alt && !meta && !c.is_control() => {
            app.typeahead_jump(c);
        }
        _ => {}
    }
}

fn sidebar_key(app: &mut App, key: KeyEvent) {
    let ctrl = key.modifiers.contains(KeyModifiers::CONTROL);
    let alt = key.modifiers.contains(KeyModifiers::ALT);
    let meta = key.modifiers.contains(KeyModifiers::SUPER);

    match key.code {
        KeyCode::Char('a') | KeyCode::Char('A') if ctrl && !alt => app.open_new_category(),
        // Enter opens whatever is selected, and a category opens into
        // the same kind of dialog a task does.
        KeyCode::Enter => app.open_edit_category(),
        KeyCode::Right => {
            let _ = app.set_focus(Focus::Tasks);
        }
        KeyCode::Up if alt && !ctrl && !meta => {
            app.move_category_order(-1);
        }
        KeyCode::Down if alt && !ctrl && !meta => {
            app.move_category_order(1);
        }
        KeyCode::Up => app.navigate_vertical(-1),
        KeyCode::Down => app.navigate_vertical(1),
        KeyCode::PageUp => app.select_category(0),
        KeyCode::PageDown => app.select_last_category(),
        KeyCode::Backspace => {
            if app.is_all_view() {
                return;
            }
            let id = app.current_category_id().to_string();
            let confirm = Confirm::DeleteCategory(id.clone());
            if app.awaiting(confirm.clone()) {
                let count = app.category_progress(&id).1;
                if app.delete_category_by_id(&id) {
                    app.info(format!(
                        "Category deleted; {count} task(s) kept as Uncategorized"
                    ));
                }
            } else {
                let count = app.category_progress(app.current_category_id()).1;
                app.ask_confirm(
                    confirm,
                    format!(
                        "Press Backspace again to delete this category; {count} task(s) will be kept as Uncategorized"
                    ),
                );
            }
        }
        // Type-to-jump: plain characters fuzzy-select a category (no mode).
        KeyCode::Char(c) if !ctrl && !alt && !meta && !c.is_control() => {
            app.typeahead_jump(c);
        }
        _ => {}
    }
}

// ----------------------------------------------------------- text editing

/// macOS Option and Linux Alt both show up as [`KeyModifiers::ALT`].
/// Ctrl is the common non-Mac habit for the same motions.
fn word_mod(key: KeyEvent) -> bool {
    key.modifiers
        .intersects(KeyModifiers::ALT | KeyModifiers::CONTROL)
}

/// Shared bindings for every one-line editor.
fn edit_line(input: &mut TextInput, key: KeyEvent) -> bool {
    let ctrl = key.modifiers.contains(KeyModifiers::CONTROL);
    let alt = key.modifiers.contains(KeyModifiers::ALT);
    let shift = key.modifiers.contains(KeyModifiers::SHIFT);
    let word = word_mod(key);
    match key.code {
        // Shift+Option+W — select the word under the caret (macOS Select Word).
        KeyCode::Char('w') | KeyCode::Char('W') if alt && shift => input.select_word(),
        // Option/Alt+b/f — emacs meta, what many Mac terminals send for
        // Option+←/→ when Option is wired as Meta.
        KeyCode::Char('b') | KeyCode::Char('B') if alt && shift => input.select_word_left(),
        KeyCode::Char('f') | KeyCode::Char('F') if alt && shift => input.select_word_right(),
        KeyCode::Char('b') | KeyCode::Char('B') if alt => input.word_left(),
        KeyCode::Char('f') | KeyCode::Char('F') if alt => input.word_right(),
        KeyCode::Char(c) if ctrl || alt => match c {
            'a' if shift => input.select_home(),
            'e' if shift => input.select_end(),
            'a' => input.home(),
            'e' => input.end(),
            'u' => input.delete_to_start(),
            'k' => input.delete_to_end(),
            // Option/Ctrl+W without Shift still deletes the previous word.
            'w' | 'W' => input.delete_word_left(),
            _ => return false,
        },
        KeyCode::Char(c) => input.insert(c),
        // Option+Delete (Backspace) deletes the word to the left, like macOS.
        KeyCode::Backspace if word => input.delete_word_left(),
        KeyCode::Backspace => input.backspace(),
        KeyCode::Delete => input.delete(),
        KeyCode::Left if word && shift => input.select_word_left(),
        KeyCode::Right if word && shift => input.select_word_right(),
        KeyCode::Left if shift => input.select_left(),
        KeyCode::Right if shift => input.select_right(),
        KeyCode::Left if word => input.word_left(),
        KeyCode::Right if word => input.word_right(),
        KeyCode::Left => input.left(),
        KeyCode::Right => input.right(),
        KeyCode::Home if shift => input.select_home(),
        KeyCode::End if shift => input.select_end(),
        KeyCode::Home => input.home(),
        KeyCode::End => input.end(),
        _ => return false,
    }
    true
}

/// The same bindings as [`edit_line`], for the multi-line block editors:
/// a task's body and a category's description. Adds ↑/↓ across blocks.
/// The `/` menu is handled by the caller before this runs.
fn edit_body(body: &mut crate::body::BodyEditor, key: KeyEvent) {
    let ctrl = key.modifiers.contains(KeyModifiers::CONTROL);
    let alt = key.modifiers.contains(KeyModifiers::ALT);
    let shift = key.modifiers.contains(KeyModifiers::SHIFT);
    let word = word_mod(key);
    match key.code {
        KeyCode::Char('w') | KeyCode::Char('W') if alt && shift => body.select_word(),
        KeyCode::Char('b') | KeyCode::Char('B') if alt && shift => body.select_word_left(),
        KeyCode::Char('f') | KeyCode::Char('F') if alt && shift => body.select_word_right(),
        KeyCode::Char('b') | KeyCode::Char('B') if alt => body.word_left(),
        KeyCode::Char('f') | KeyCode::Char('F') if alt => body.word_right(),
        KeyCode::Char(c) if ctrl || alt => match c {
            'a' if shift => body.select_home(),
            'e' if shift => body.select_end(),
            'a' => body.home(),
            'e' => body.end(),
            'u' => body.delete_to_start(),
            'k' => body.delete_to_end(),
            'w' | 'W' => body.delete_word_left(),
            _ => {}
        },
        KeyCode::Char(c) => body.insert(c),
        KeyCode::Backspace if word => body.delete_word_left(),
        KeyCode::Backspace => body.backspace(),
        KeyCode::Delete => body.delete(),
        KeyCode::Left if word && shift => body.select_word_left(),
        KeyCode::Right if word && shift => body.select_word_right(),
        KeyCode::Left if shift => body.select_left(),
        KeyCode::Right if shift => body.select_right(),
        KeyCode::Left if word => body.word_left(),
        KeyCode::Right if word => body.word_right(),
        KeyCode::Left => body.left(),
        KeyCode::Right => body.right(),
        KeyCode::Up => body.up(),
        KeyCode::Down => body.down(),
        KeyCode::Home if shift => body.select_home(),
        KeyCode::End if shift => body.select_end(),
        KeyCode::Home => body.home(),
        KeyCode::End => body.end(),
        _ => {}
    }
}

/// The category dialog: a name and a note (with `/` bullets).
fn handle_category_key(app: &mut App, key: KeyEvent) {
    if matches!(key.code, KeyCode::Char('s')) && key.modifiers.contains(KeyModifiers::CONTROL) {
        if app
            .category_form
            .as_ref()
            .is_some_and(|form| form.description.menu.is_some())
        {
            app.error("Choose or dismiss the description command before saving");
            return;
        }
        app.submit_category_form();
        return;
    }

    if is_undo_chord(key) {
        if let Some(form) = &mut app.category_form
            && form.undo()
        {
            app.info("Undo");
        }
        return;
    }
    if is_redo_chord(key) {
        if let Some(form) = &mut app.category_form
            && form.redo()
        {
            app.info("Redo");
        }
        return;
    }

    // Slash menu owns arrows / Enter while open on the description.
    if let Some(form) = app
        .category_form
        .as_mut()
        .filter(|form| form.on_description && form.description.menu.is_some())
    {
        let outcome = {
            // Structural apply (bullet etc.) needs a checkpoint first.
            if matches!(key.code, KeyCode::Enter | KeyCode::Tab) {
                form.before_edit(EditKind::Atomic);
            }
            body_menu_key(&mut form.description, key)
        };
        match outcome {
            MenuKey::Ignored => {}
            MenuKey::Handled => return,
            MenuKey::Copy(payload) => {
                finish_copy(app, payload);
                return;
            }
        }
    }

    match key.code {
        KeyCode::Esc => {
            let _ = request_close_category_form(app);
        }
        KeyCode::Tab | KeyCode::BackTab => {
            if let Some(form) = &mut app.category_form {
                form.description.close_menu();
                form.toggle_field();
            }
        }
        KeyCode::Enter => {
            let Some(form) = &mut app.category_form else {
                return;
            };
            if form.on_description {
                form.before_edit(EditKind::Atomic);
                let _ = form.description.newline();
            } else {
                form.toggle_field();
            }
        }
        _ => {
            let Some(form) = &mut app.category_form else {
                return;
            };
            if form.on_description {
                if let Some(mut kind) = content_edit_kind(key) {
                    if form.description.has_selection() {
                        kind = EditKind::Atomic;
                    }
                    form.before_edit(kind);
                } else {
                    form.break_coalesce();
                }
                edit_body(&mut form.description, key);
            } else if let Some(mut kind) = content_edit_kind(key) {
                if form.name.has_selection() {
                    kind = EditKind::Atomic;
                }
                form.before_edit(kind);
                edit_line(&mut form.name, key);
            } else {
                form.break_coalesce();
                edit_line(&mut form.name, key);
            }
        }
    }
}

/// The `/` command palette above the status bar.
fn handle_slash_key(app: &mut App, key: KeyEvent) {
    match key.code {
        KeyCode::Esc => close_slash(app),
        // Backspace on empty (or past the last char) drops the leading `/`.
        KeyCode::Backspace if app.input.is_empty() => close_slash(app),
        KeyCode::Up => {
            let n = crate::slash::matching(&app.input.value()).len();
            if n > 0 {
                app.slash_index = (app.slash_index + n - 1) % n;
            }
        }
        KeyCode::Down | KeyCode::Tab => {
            let n = crate::slash::matching(&app.input.value()).len();
            if n > 0 {
                app.slash_index = (app.slash_index + 1) % n;
            }
        }
        KeyCode::Enter => {
            let query = app.input.value();
            let matches = crate::slash::matching(&query);
            let cmd = matches.get(app.slash_index).copied();
            close_slash(app);
            if let Some(cmd) = cmd {
                run_slash(app, cmd, &query);
            }
        }
        _ => {
            if edit_line(&mut app.input, key) {
                app.slash_index = 0;
                app.clamp_slash_index();
            }
        }
    }
}

fn close_slash(app: &mut App) {
    app.mode = Mode::Normal;
    app.input = TextInput::default();
    app.slash_index = 0;
}

/// Live search after choosing Search from the palette.
fn handle_search_key(app: &mut App, key: KeyEvent) {
    match key.code {
        KeyCode::Esc => {
            app.input = TextInput::default();
            app.end_search();
        }
        KeyCode::Enter => {
            // Keep the current query; just leave the typing field.
            app.mode = Mode::Normal;
            app.input = TextInput::default();
            // Keep searching/search_query so the list stays narrowed until Esc.
            if app.search_query.is_empty() {
                app.end_search();
            }
        }
        _ => {
            if edit_line(&mut app.input, key) {
                app.update_search();
            }
        }
    }
}

fn run_slash(app: &mut App, cmd: crate::slash::SlashCommand, query: &str) {
    use crate::slash::{SlashCommand, args_for};
    match cmd {
        SlashCommand::Search => {
            let q = args_for(cmd, query);
            app.start_search(&q);
        }
        SlashCommand::Settings => {
            app.settings_index = 0;
            app.mode = Mode::Settings;
        }
        SlashCommand::Help => {
            app.help_scroll = 0;
            app.mode = Mode::Help;
        }
        SlashCommand::CopyTitle => match app.selected_task() {
            Some(task) => {
                finish_copy(app, crate::body::CopyPayload::Text(task.title.clone()));
            }
            None => app.info("No task selected"),
        },
        SlashCommand::CopyTask => match app.selected_task() {
            Some(task) => {
                let text = task_clipboard_text(task);
                finish_copy(app, crate::body::CopyPayload::Text(text));
            }
            None => app.info("No task selected"),
        },
        SlashCommand::Done => {
            if let Some(hidden) = app.toggle_hide_done() {
                if hidden {
                    app.info("Hiding completed tasks");
                } else {
                    app.info("Showing completed tasks");
                }
            }
        }
        SlashCommand::Purge => {
            let ids = app.purge_candidate_ids();
            if ids.is_empty() {
                app.info("No done tasks to purge");
            } else {
                let count = ids.len();
                app.ask_confirm(
                    Confirm::Purge(ids),
                    format!("Press Enter to purge {count} done task(s)"),
                );
            }
        }
        SlashCommand::Update => app.start_update_check(),
        SlashCommand::Quit => app.should_quit = true,
    }
}

// ------------------------------------------------------------ task dialog

/// Tab and the mouse move between fields; Enter saves, except in the
/// body where it starts a new block.
fn handle_form_key(app: &mut App, key: KeyEvent) {
    let ctrl = key.modifiers.contains(KeyModifiers::CONTROL);

    // Saving resolves the picker, but never guesses what an open body command
    // or full-screen preview was meant to do.
    if matches!(key.code, KeyCode::Char('s')) && ctrl {
        if app.form.as_ref().is_some_and(|form| form.preview) {
            app.error("Close the image preview before saving");
            return;
        }
        if app
            .form
            .as_ref()
            .is_some_and(|form| form.body.menu.is_some())
        {
            app.error("Choose or dismiss the body command before saving");
            return;
        }
        if let Some(form) = &mut app.form
            && form.picker.is_some()
        {
            form.take_due_picker();
        }
        app.submit_form();
        return;
    }

    // Esc peels one layer: preview → picker → slash menu → leave the form.
    // (Handled below in that order; bare Esc closes the dialog only when
    // none of those overlays are open.)

    // The image preview: Esc closes; Space / Enter toggles GIF pause.
    if app.form.as_ref().is_some_and(|f| f.preview) {
        match key.code {
            KeyCode::Esc => {
                // Drop frames/protocol first so the next draw cannot spend
                // another encode tick on this preview.
                if let Some(form) = &mut app.form {
                    form.close_image_preview();
                }
                app.images.clear_preview();
            }
            KeyCode::Enter | KeyCode::Char(' ') => {
                if let Some(form) = &mut app.form {
                    form.preview_click();
                }
            }
            _ => {}
        }
        return;
    }

    // Ctrl+Z / Ctrl+Shift+Z (Ctrl+Y) — form-wide undo/redo. The image
    // preview above owns its keys until explicitly closed.
    if is_undo_chord(key) {
        if let Some(form) = &mut app.form
            && form.undo()
        {
            app.info("Undo");
        }
        return;
    }
    if is_redo_chord(key) {
        if let Some(form) = &mut app.form
            && form.redo()
        {
            app.info("Redo");
        }
        return;
    }

    // The date/time picker owns Tab and the arrows while it is open.
    if app.form.as_ref().is_some_and(|f| f.picker.is_some()) {
        handle_picker_key(app, key);
        return;
    }

    // Slash menu: Esc closes the menu only (not the whole dialog).
    if app.form.as_ref().is_some_and(|f| f.body.menu.is_some()) && handle_menu_key(app, key) {
        return;
    }

    match key.code {
        KeyCode::Esc => {
            let _ = request_close_task_form(app);
        }
        KeyCode::Tab => {
            if let Some(form) = &mut app.form {
                form.focus_next();
            }
        }
        KeyCode::BackTab => {
            if let Some(form) = &mut app.form {
                form.focus_prev();
            }
        }
        // Enter never closes the dialog — it opens or adds whatever the
        // focused field holds. Ctrl+S is what saves.
        // ⌘Enter / Ctrl+Enter on a link opens it in the browser.
        KeyCode::Enter
            if key
                .modifiers
                .intersects(KeyModifiers::SUPER | KeyModifiers::CONTROL) =>
        {
            let url = app
                .form
                .as_ref()
                .filter(|f| f.field == Field::Body)
                .and_then(|f| f.body.link_url_at_cursor());
            if let Some(url) = url {
                match crate::open::open_url(&url) {
                    Ok(()) => app.info(format!("Opened {url}")),
                    Err(err) => app.error(err),
                }
            }
        }
        KeyCode::Enter => {
            let Some(form) = &mut app.form else { return };
            match form.field {
                Field::Title | Field::Category | Field::Importance => form.focus_next(),
                Field::Due => form.open_due_picker(),
                // On a picture there is nothing to type, so Enter is
                // what opens it.
                Field::Body if form.body.selected_image().is_some() => {
                    if let Some(err) = form.open_image_preview() {
                        app.error(err);
                    }
                }
                Field::Body => {
                    form.before_edit(EditKind::Atomic);
                    let _ = form.body.newline();
                }
            }
        }
        _ => {
            let Some(form) = &mut app.form else { return };
            match form.field {
                // Ctrl+D ticks a to-do off; everything else is ordinary
                // block editing.
                Field::Body
                    if ctrl && matches!(key.code, KeyCode::Char('d') | KeyCode::Char('D')) =>
                {
                    form.before_edit(EditKind::Atomic);
                    form.body.toggle();
                }
                Field::Body => {
                    if let Some(mut kind) = content_edit_kind(key) {
                        if form.body.has_selection() {
                            kind = EditKind::Atomic;
                        }
                        form.before_edit(kind);
                    } else {
                        form.break_coalesce();
                    }
                    edit_body(&mut form.body, key);
                }
                // Category is a bounded selector. All tasks is deliberately
                // absent; Backspace/Delete returns the task to Uncategorized.
                Field::Category => match key.code {
                    KeyCode::Left | KeyCode::Up => form.cycle_category(-1),
                    KeyCode::Right | KeyCode::Down | KeyCode::Char(' ') => form.cycle_category(1),
                    KeyCode::Backspace | KeyCode::Delete => form.clear_category(),
                    _ => form.break_coalesce(),
                },
                // Nothing to type here: the arrows and the digits set
                // how many flags the task carries.
                Field::Importance => match key.code {
                    KeyCode::Left | KeyCode::Down => {
                        form.set_importance(form.importance.saturating_sub(1))
                    }
                    KeyCode::Right | KeyCode::Up | KeyCode::Char(' ') => form.cycle_importance(),
                    KeyCode::Backspace | KeyCode::Delete => form.set_importance(0),
                    KeyCode::Char(c) if c.is_ascii_digit() => form.set_importance(c as u8 - b'0'),
                    _ => form.break_coalesce(),
                },
                // Due is picker-only — no free typing, so any character
                // opens the calendar instead of landing in the field.
                Field::Due => match key.code {
                    KeyCode::Char(_) => form.open_due_picker(),
                    KeyCode::Backspace | KeyCode::Delete => form.clear_due(),
                    _ => form.break_coalesce(),
                },
                // Arrow keys only ever move the cursor; Tab, Shift+Tab
                // and the mouse are what change fields.
                Field::Title => {
                    if let Some(mut kind) = content_edit_kind(key) {
                        if form.title.has_selection() {
                            kind = EditKind::Atomic;
                        }
                        form.before_edit(kind);
                    } else {
                        form.break_coalesce();
                    }
                    edit_line(&mut form.title, key);
                }
            }
        }
    }
}

/// Date + time picker: Tab moves Calendar → Hour → Minute; arrows adjust
/// the focused part; Enter writes the value back into Due.
fn handle_picker_key(app: &mut App, key: KeyEvent) {
    use crate::duepicker::PickerFocus;

    let Some(form) = &mut app.form else { return };
    match key.code {
        KeyCode::Esc => {
            form.picker = None;
            return;
        }
        KeyCode::Char('x') | KeyCode::Delete => {
            form.clear_due();
            return;
        }
        KeyCode::Enter => {
            form.take_due_picker();
            return;
        }
        _ => {}
    }

    let Some(picker) = &mut form.picker else {
        return;
    };
    match key.code {
        KeyCode::Tab => picker.focus_next(),
        KeyCode::BackTab => picker.focus_prev(),
        KeyCode::Char('t') => {
            picker.today();
            picker.now_time();
        }
        KeyCode::Left => match picker.focus {
            PickerFocus::Calendar => picker.move_days(-1),
            PickerFocus::Hour => picker.bump_hour(-1),
            PickerFocus::Minute => picker.bump_minute(-5),
        },
        KeyCode::Right => match picker.focus {
            PickerFocus::Calendar => picker.move_days(1),
            PickerFocus::Hour => picker.bump_hour(1),
            PickerFocus::Minute => picker.bump_minute(5),
        },
        KeyCode::Up => match picker.focus {
            PickerFocus::Calendar => picker.move_days(-7),
            PickerFocus::Hour => picker.bump_hour(1),
            PickerFocus::Minute => picker.bump_minute(5),
        },
        KeyCode::Down => match picker.focus {
            PickerFocus::Calendar => picker.move_days(7),
            PickerFocus::Hour => picker.bump_hour(-1),
            PickerFocus::Minute => picker.bump_minute(-5),
        },
        KeyCode::PageUp => match picker.focus {
            PickerFocus::Calendar => picker.move_months(-1),
            PickerFocus::Hour => picker.bump_hour(1),
            PickerFocus::Minute => picker.bump_minute(15),
        },
        KeyCode::PageDown => match picker.focus {
            PickerFocus::Calendar => picker.move_months(1),
            PickerFocus::Hour => picker.bump_hour(-1),
            PickerFocus::Minute => picker.bump_minute(-15),
        },
        // Space on the clock → now; digits type hour/minute directly.
        KeyCode::Char(' ') if picker.focus != PickerFocus::Calendar => picker.now_time(),
        KeyCode::Char(c) if c.is_ascii_digit() => picker.type_digit(c as u8 - b'0'),
        _ => {}
    }
}

/// Returns true when the key belonged to the open slash menu.
fn handle_menu_key(app: &mut App, key: KeyEvent) -> bool {
    let Some(form) = app.form.as_mut().filter(|form| form.body.menu.is_some()) else {
        return false;
    };
    // Split the borrow: menu keys only need the body, copy needs App.
    let outcome = {
        // Applying a command (Enter/Tab) mutates structure — checkpoint first.
        if matches!(key.code, KeyCode::Enter | KeyCode::Tab) {
            form.before_edit(EditKind::Atomic);
        }
        body_menu_key(&mut form.body, key)
    };
    match outcome {
        MenuKey::Ignored => false,
        MenuKey::Handled => true,
        MenuKey::Copy(payload) => {
            finish_copy(app, payload);
            true
        }
    }
}

enum MenuKey {
    Ignored,
    Handled,
    Copy(crate::body::CopyPayload),
}

fn body_menu_key(body: &mut crate::body::BodyEditor, key: KeyEvent) -> MenuKey {
    match key.code {
        KeyCode::Up => {
            body.menu_prev();
            MenuKey::Handled
        }
        KeyCode::Down => {
            body.menu_next();
            MenuKey::Handled
        }
        KeyCode::Esc => {
            body.close_menu();
            MenuKey::Handled
        }
        KeyCode::Tab | KeyCode::Enter => match body.menu_selected() {
            Some(command) => match body.apply(command) {
                Some(payload) => MenuKey::Copy(payload),
                None => MenuKey::Handled,
            },
            None => {
                body.close_menu();
                MenuKey::Handled
            }
        },
        _ => MenuKey::Ignored,
    }
}

/// Title, then body as plain text (same export as body `/copy`).
fn task_clipboard_text(task: &crate::model::Task) -> String {
    let body = crate::body::BodyEditor::new(&task.body).text_for_copy();
    if body.is_empty() {
        task.title.clone()
    } else {
        format!("{}\n\n{body}", task.title)
    }
}

fn finish_copy(app: &mut App, payload: crate::body::CopyPayload) {
    match payload {
        crate::body::CopyPayload::Text(text) => {
            if text.is_empty() {
                app.info("Nothing to copy");
                return;
            }
            match copy_text(&text) {
                Ok(ClipboardTarget::System) => app.info("Copied text to clipboard"),
                Ok(ClipboardTarget::Terminal) => app.info("Copied text through the terminal"),
                Err(err) => app.error(format!("Could not copy: {err}")),
            }
        }
        crate::body::CopyPayload::Image(path) => match copy_image_file(&path) {
            Ok(()) => app.info("Copied image to clipboard"),
            Err(err) => app.error(format!("Could not copy image: {err}")),
        },
        crate::body::CopyPayload::All(lines) => {
            if lines.is_empty() {
                app.info("Nothing to copy");
                return;
            }
            match copy_all(&lines) {
                Ok(ClipboardTarget::System) => app.info("Copied text and pictures"),
                Ok(ClipboardTarget::Terminal) => app.info("Copied plain text through the terminal"),
                Err(err) => app.error(format!("Could not copy: {err}")),
            }
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum ClipboardTarget {
    System,
    Terminal,
}

const MAX_OSC52_RAW_BYTES: usize = 64 * 1024;
const MAX_OSC52_ENCODED_BYTES: usize = 80 * 1024;
const MAX_RICH_CLIPBOARD_BYTES: usize = 8 * 1024 * 1024;

fn copy_text(text: &str) -> Result<ClipboardTarget, String> {
    match arboard::Clipboard::new().and_then(|mut clipboard| clipboard.set_text(text)) {
        Ok(()) => Ok(ClipboardTarget::System),
        Err(system_error) => osc52_copy(text).map_err(|terminal_error| {
            format!("system clipboard: {system_error}; terminal clipboard: {terminal_error}")
        }),
    }
}

fn osc52_copy(text: &str) -> Result<ClipboardTarget, String> {
    use std::io::Write;

    let sequence = osc52_sequence(text)?;
    let mut stdout = std::io::stdout().lock();
    stdout
        .write_all(sequence.as_bytes())
        .and_then(|()| stdout.flush())
        .map_err(|error| error.to_string())?;
    Ok(ClipboardTarget::Terminal)
}

fn osc52_sequence(text: &str) -> Result<String, String> {
    use base64::Engine;

    if text.len() > MAX_OSC52_RAW_BYTES {
        return Err(format!(
            "OSC 52 text is {} bytes; raw limit is {MAX_OSC52_RAW_BYTES} bytes",
            text.len()
        ));
    }
    let encoded = base64::engine::general_purpose::STANDARD.encode(text.as_bytes());
    if encoded.len() > MAX_OSC52_ENCODED_BYTES {
        return Err(format!(
            "OSC 52 payload is {} bytes; encoded limit is {MAX_OSC52_ENCODED_BYTES} bytes",
            encoded.len()
        ));
    }
    Ok(format!("\x1b]52;c;{encoded}\x07"))
}

/// Decode a body image file and put its pixels on the system clipboard.
fn copy_image_file(path: &std::path::Path) -> Result<(), String> {
    let rgba = crate::image::load_dynamic(path)?.into_rgba8();
    let (width, height) = rgba.dimensions();
    let data = arboard::ImageData {
        width: width as usize,
        height: height as usize,
        bytes: rgba.into_raw().into(),
    };
    arboard::Clipboard::new()
        .and_then(|mut c| c.set_image(data))
        .map_err(|e| e.to_string())
}

/// Put the whole body on the clipboard as HTML (with embedded images)
/// plus a plain-text fallback. Notes, browsers, and mail clients can
/// paste the rich form; terminals get the text.
fn copy_all(lines: &[crate::body::CopyLine]) -> Result<ClipboardTarget, String> {
    let (plain, html) = build_clipboard_payload(lines, MAX_RICH_CLIPBOARD_BYTES);

    match arboard::Clipboard::new()
        .and_then(|mut clipboard| clipboard.set_html(html.as_str(), Some(plain.as_str())))
    {
        Ok(()) => Ok(ClipboardTarget::System),
        Err(system_error) => osc52_copy(&plain).map_err(|terminal_error| {
            format!("system clipboard: {system_error}; terminal clipboard: {terminal_error}")
        }),
    }
}

fn build_clipboard_payload(
    lines: &[crate::body::CopyLine],
    rich_budget: usize,
) -> (String, String) {
    build_clipboard_payload_with(lines, rich_budget, image_data_url)
}

fn build_clipboard_payload_with(
    lines: &[crate::body::CopyLine],
    rich_budget: usize,
    mut load_image: impl FnMut(&std::path::Path, usize) -> Result<String, String>,
) -> (String, String) {
    use crate::body::CopyLine;

    const IMAGE_PREFIX: &str = r#"<div><img src=""#;
    const IMAGE_SUFFIX: &str = r#"" /></div>"#;
    let mut html = String::new();
    let mut plain = String::new();
    for (i, line) in lines.iter().enumerate() {
        if i > 0 {
            plain.push('\n');
        }
        match line {
            CopyLine::Text(text) => {
                plain.push_str(text);
                push_rich_fragment(
                    &mut html,
                    &format!("<div>{}</div>", escape_html(text)),
                    rich_budget,
                );
            }
            CopyLine::Link(url) => {
                plain.push_str(url);
                let label = escape_html(url);
                let fragment = match crate::open::normalize_url(url) {
                    Some(url) => {
                        let href = escape_html(&url);
                        format!("<div><a href=\"{href}\">{label}</a></div>")
                    }
                    None => format!("<div>{label}</div>"),
                };
                push_rich_fragment(&mut html, &fragment, rich_budget);
            }
            CopyLine::Image(path) => {
                let label = format!("[image: {}]", path.display());
                plain.push_str(&label);
                let url_budget = rich_budget
                    .saturating_sub(html.len())
                    .saturating_sub(IMAGE_PREFIX.len() + IMAGE_SUFFIX.len());
                let image = load_image(path, url_budget)
                    .ok()
                    .filter(|url| url.len() <= url_budget)
                    .map(|url| format!("{IMAGE_PREFIX}{url}{IMAGE_SUFFIX}"));
                let fragment = image.unwrap_or_else(|| {
                    // Keep layout order without letting data URLs consume an
                    // unbounded clipboard string.
                    format!("<div>{}</div>", escape_html(&label))
                });
                push_rich_fragment(&mut html, &fragment, rich_budget);
            }
        }
    }
    (plain, html)
}

fn push_rich_fragment(html: &mut String, fragment: &str, budget: usize) {
    if html.len().saturating_add(fragment.len()) <= budget {
        html.push_str(fragment);
    }
}

fn image_data_url(path: &std::path::Path, url_budget: usize) -> Result<String, String> {
    use base64::Engine;
    use image::ImageEncoder;
    use std::io::Write;

    const PREFIX: &str = "data:image/png;base64,";
    let encoded_budget = url_budget
        .checked_sub(PREFIX.len())
        .ok_or_else(|| "rich clipboard image budget is exhausted".to_string())?;
    // Base64 expands three bytes into four. Keep the encoded URL inside the
    // caller's remaining rich-payload budget before allocating its String.
    let png_budget = (encoded_budget / 4) * 3;
    if png_budget == 0 {
        return Err("rich clipboard image budget is exhausted".to_string());
    }

    struct BoundedPng {
        bytes: Vec<u8>,
        limit: usize,
    }

    impl Write for BoundedPng {
        fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
            if self.bytes.len().saturating_add(buf.len()) > self.limit {
                return Err(std::io::Error::other(
                    "encoded image exceeds rich clipboard budget",
                ));
            }
            self.bytes.extend_from_slice(buf);
            Ok(buf.len())
        }

        fn flush(&mut self) -> std::io::Result<()> {
            Ok(())
        }
    }

    let rgba = crate::image::load_dynamic(path)?.into_rgba8();
    let (width, height) = rgba.dimensions();
    let mut png = BoundedPng {
        bytes: Vec::new(),
        limit: png_budget,
    };
    image::codecs::png::PngEncoder::new(&mut png)
        .write_image(
            rgba.as_raw(),
            width,
            height,
            image::ExtendedColorType::Rgba8,
        )
        .map_err(|e| format!("{}: {e}", path.display()))?;
    let b64 = base64::engine::general_purpose::STANDARD.encode(png.bytes);
    let url = format!("{PREFIX}{b64}");
    if url.len() > url_budget {
        return Err("encoded image exceeds rich clipboard budget".to_string());
    }
    Ok(url)
}

fn escape_html(s: &str) -> String {
    let mut out = String::with_capacity(s.len());
    for c in s.chars() {
        match c {
            '&' => out.push_str("&amp;"),
            '<' => out.push_str("&lt;"),
            '>' => out.push_str("&gt;"),
            '"' => out.push_str("&quot;"),
            _ => out.push(c),
        }
    }
    out
}

// -------------------------------------------------------------- settings

fn handle_settings_key(app: &mut App, key: KeyEvent) {
    match key.code {
        KeyCode::Esc => app.mode = Mode::Normal,
        KeyCode::Up => {
            app.settings_index = app.settings_index.saturating_sub(1);
        }
        KeyCode::Down => {
            app.settings_index = (app.settings_index + 1).min(crate::app::SETTINGS_ITEMS.len() - 1);
        }
        KeyCode::Right | KeyCode::Tab => app.cycle_setting(app.settings_index, 1),
        KeyCode::Left | KeyCode::BackTab => app.cycle_setting(app.settings_index, -1),
        _ => {}
    }
}

/// Close a form only when there is no content to lose, or after the same
/// entity-bound discard action is explicitly confirmed with Esc again.
fn request_close_task_form(app: &mut App) -> bool {
    let Some(form) = app.form.as_ref() else {
        return true;
    };
    if !form.is_dirty() {
        app.close_form();
        return true;
    }
    let confirm = Confirm::DiscardTask(form.editing.clone());
    if app.awaiting(confirm.clone()) {
        app.close_form();
        true
    } else {
        app.ask_confirm(confirm, "Unsaved changes · press Esc again to discard");
        false
    }
}

fn request_close_category_form(app: &mut App) -> bool {
    let Some(form) = app.category_form.as_ref() else {
        return true;
    };
    if !form.is_dirty() {
        app.close_category_form();
        return true;
    }
    let confirm = Confirm::DiscardCategory(form.editing.clone());
    if app.awaiting(confirm.clone()) {
        app.close_category_form();
        true
    } else {
        app.ask_confirm(confirm, "Unsaved changes · press Esc again to discard");
        false
    }
}

// ------------------------------------------------------------------ mouse

fn handle_mouse(app: &mut App, m: MouseEvent) {
    app.cancel_pending();
    if app.mode == Mode::Slash {
        handle_slash_mouse(app, m);
        return;
    }
    if app.mode == Mode::TaskForm {
        // The full-size image is modal over the panels. Route it before
        // hit-testing the list beneath, or a preview click can close the form.
        if app.form.as_ref().is_some_and(|form| form.preview) {
            handle_form_mouse(app, m);
            return;
        }
        // A clean editor may yield to the underlying panels. Dirty content
        // stays modal; Esc is the explicit discard path.
        if click_on_panels(app, m) {
            if !request_close_task_form(app) {
                return;
            }
        } else {
            handle_form_mouse(app, m);
            return;
        }
    }
    if app.mode == Mode::CategoryForm {
        if click_on_panels(app, m) {
            if !request_close_category_form(app) {
                return;
            }
        } else {
            if let (MouseEventKind::Down(MouseButton::Left), Some(form)) =
                (m.kind, &mut app.category_form)
            {
                if contains(form.name_area, m.column, m.row) {
                    form.set_description_focus(false);
                    form.name
                        .set_cursor_from_col((m.column - form.name_area.x) as usize);
                } else if contains(form.description_area, m.column, m.row) {
                    form.set_description_focus(true);
                    form.description.click(
                        m.row - form.description_area.y,
                        (m.column - form.description_area.x) as usize,
                    );
                }
            }
            return;
        }
    }
    if app.mode.is_overlay() {
        return;
    }
    match m.kind {
        // The wheel works on the list under the pointer, not on whichever
        // panel holds the keyboard focus — so you can spin through
        // categories without first clicking into them. Focus stays put.
        MouseEventKind::ScrollUp | MouseEventKind::ScrollDown => {
            let delta = if m.kind == MouseEventKind::ScrollUp {
                -1
            } else {
                1
            };
            if contains(app.areas.tasks, m.column, m.row) {
                app.move_task_selection(delta);
            } else if contains(app.areas.sidebar, m.column, m.row) && !app.searching {
                // Same reason clicking a category is blocked mid-search:
                // picking one would silently drop the query.
                app.move_category_selection(delta);
            }
        }
        MouseEventKind::Down(MouseButton::Left) => {
            let (x, y) = (m.column, m.row);
            let sidebar = app.areas.sidebar;
            let tasks = app.areas.tasks;
            if contains(sidebar, x, y) {
                if app.searching {
                    return;
                }
                let _ = app.set_focus(Focus::Sidebar);
                let row = app.cat_state.offset() + (y - sidebar.y) as usize;
                if row >= app.categories.len() {
                    return;
                }
                app.select_category(row);
                if clicked_again(app, Focus::Sidebar, row) {
                    app.open_edit_category();
                }
            } else if contains(tasks, x, y) {
                let _ = app.set_focus(Focus::Tasks);
                let visual = app.task_state.offset() + (y - tasks.y) as usize;
                let Some(row) = app.task_at_visual_row(visual) else {
                    // Separator / empty — no task under the pointer.
                    return;
                };
                // The checkbox and the flags toggle when clicked
                // directly; the flags are the last column, so everything
                // from their first cell rightwards counts as them.
                let on_flags = app.areas.flag_x.is_some_and(|at| x >= at);
                let on_done = app
                    .areas
                    .done_x
                    .is_some_and(|at| x >= at && x < at + crate::ui::DONE_MARK_WIDTH);
                if on_flags {
                    app.cycle_importance(row);
                } else if on_done {
                    app.toggle_done(row);
                } else {
                    // Anywhere else selects, and selecting twice in
                    // quick succession opens the task.
                    app.select_task(row);
                    if clicked_again(app, Focus::Tasks, row) {
                        app.open_edit_task();
                    }
                }
            } else if contains(app.areas.preview, x, y) && app.selected_task().is_some() {
                // Click the permanent preview to edit the selected task.
                let _ = app.set_focus(Focus::Tasks);
                app.open_edit_task();
            }
        }
        _ => {}
    }
}

fn handle_slash_mouse(app: &mut App, mouse: MouseEvent) {
    let rect = app.areas.slash_menu;
    match mouse.kind {
        MouseEventKind::ScrollUp | MouseEventKind::ScrollDown
            if contains(rect, mouse.column, mouse.row) =>
        {
            let count = crate::slash::matching(&app.input.value()).len();
            if count == 0 {
                return;
            }
            if mouse.kind == MouseEventKind::ScrollUp {
                app.slash_index = (app.slash_index + count - 1) % count;
            } else {
                app.slash_index = (app.slash_index + 1) % count;
            }
        }
        MouseEventKind::Down(MouseButton::Left) => {
            if contains(rect, mouse.column, mouse.row)
                && mouse.row > rect.y
                && mouse.row + 1 < rect.bottom()
            {
                let row = (mouse.row - rect.y - 1) as usize;
                let query = app.input.value();
                let commands = crate::slash::matching(&query);
                if let Some(command) = commands.get(row).copied() {
                    app.slash_index = row;
                    close_slash(app);
                    run_slash(app, command, &query);
                }
            } else {
                close_slash(app);
            }
        }
        _ => {}
    }
}

/// True when a left-click lands on the sidebar or task list (and not on
/// an open form control that happens to sit in those coordinates).
fn click_on_panels(app: &App, m: MouseEvent) -> bool {
    if m.kind != MouseEventKind::Down(MouseButton::Left) {
        return false;
    }
    let (x, y) = (m.column, m.row);
    if !contains(app.areas.sidebar, x, y) && !contains(app.areas.tasks, x, y) {
        return false;
    }
    // Prefer form chrome when it overlaps the panels (modal / picker).
    if let Some(form) = &app.form {
        if form.areas.field_at(x, y).is_some() {
            return false;
        }
        if form.picker.as_ref().is_some_and(|p| p.contains(x, y)) {
            return false;
        }
        if form.body_menu_area.is_some_and(|r| contains(r, x, y)) {
            return false;
        }
    }
    if let Some(form) = &app.category_form
        && (contains(form.name_area, x, y) || contains(form.description_area, x, y))
    {
        return false;
    }
    true
}

/// Clicking a field focuses it and puts the cursor where the pointer
/// landed. Clicks on the task list or sidebar leave the dialog (see
/// [`handle_mouse`]); other outside clicks are ignored. Double-click on
/// a picture opens it, same as Enter. The due picker also takes clicks
/// and scroll.
fn handle_form_mouse(app: &mut App, m: MouseEvent) {
    // Scroll over the open date/time picker.
    if matches!(
        m.kind,
        MouseEventKind::ScrollUp | MouseEventKind::ScrollDown
    ) && app.form.as_ref().is_some_and(|f| f.picker.is_some())
    {
        let up = matches!(m.kind, MouseEventKind::ScrollUp);
        if let Some(form) = &mut app.form
            && let Some(picker) = &mut form.picker
        {
            let _ = picker.scroll(m.column, m.row, up);
        }
        return;
    }

    // Scroll over the open body `/` menu moves the selection.
    if matches!(
        m.kind,
        MouseEventKind::ScrollUp | MouseEventKind::ScrollDown
    ) && app.form.as_ref().is_some_and(|f| f.body.menu.is_some())
    {
        let up = matches!(m.kind, MouseEventKind::ScrollUp);
        if let Some(form) = &mut app.form {
            if up {
                form.body.menu_prev();
            } else {
                form.body.menu_next();
            }
        }
        return;
    }

    if m.kind != MouseEventKind::Down(MouseButton::Left) {
        return;
    }
    // Click in the image preview: pause/resume GIF (does not close).
    if app.form.as_ref().is_some_and(|f| f.preview) {
        if let Some(form) = &mut app.form {
            form.preview_click();
        }
        return;
    }

    // Clicks on the date/time picker (days, hour, minute).
    if app.form.as_ref().is_some_and(|f| f.picker.is_some()) {
        let Some(form) = &mut app.form else { return };
        let handled = form
            .picker
            .as_mut()
            .is_some_and(|p| p.click(m.column, m.row));
        if handled {
            return;
        }
        // Click outside the picker closes it (unless reopening Due).
        if !form.areas.due.contains(ratatui::layout::Position {
            x: m.column,
            y: m.row,
        }) {
            form.picker = None;
        }
    }

    // Body `/` menu: click a row to run it; click elsewhere closes the
    // menu only (dialog stays open). Handled before body.click, which
    // would otherwise dismiss the menu without selecting anything.
    if app.form.as_ref().is_some_and(|f| f.body.menu.is_some()) {
        match click_body_slash_menu(app, m.column, m.row) {
            MenuClick::Handled | MenuClick::CopyDone => return,
            MenuClick::Miss => {
                // Fall through: place the cursor / change field, menu
                // closes via body.click or set_field.
            }
        }
    }

    enum AfterClick {
        None,
        OpenUrl(String),
        PreviewErr(String),
    }
    let after = {
        let Some(form) = &mut app.form else { return };
        let Some(field) = form.areas.field_at(m.column, m.row) else {
            // Click outside the dialog fields — do not keep a pending
            // double-click that could open a picture on the next hit.
            form.last_body_click = None;
            return;
        };
        // Leaving Due dismisses the calendar so keys go to the new field.
        form.set_field(field);

        let area = form.areas.rect(field);
        let col = (m.column - area.x) as usize;
        let row = (m.row - area.y) as usize;
        match field {
            Field::Title => {
                form.title.set_cursor_from_col(col);
                form.last_body_click = None;
                AfterClick::None
            }
            Field::Due => {
                form.open_due_picker();
                form.last_body_click = None;
                AfterClick::None
            }
            Field::Category => {
                form.cycle_category(1);
                form.last_body_click = None;
                AfterClick::None
            }
            Field::Body => {
                // Resolve the link against the painted glyphs before click()
                // moves the cursor; blank row padding is not a hit target.
                let clicked_link = form.body.link_url_at_position(row as u16, col);
                let hit = form.body.click(row as u16, col);
                if !hit {
                    form.last_body_click = None;
                    AfterClick::None
                } else if let Some(url) = clicked_link {
                    form.last_body_click = None;
                    AfterClick::OpenUrl(url)
                } else if form.body.selected_image().is_some() {
                    // Pictures are letterboxed — only the drawn box counts.
                    // Gutter clicks must not select the picture or insert a
                    // blank line (←/→ are what create a caret next to it).
                    let line = form.body.cursor_line();
                    if !form.image_hit_at(line, m.column, m.row) {
                        form.body.abandon_image_selection();
                        form.last_body_click = None;
                        AfterClick::None
                    } else {
                        let now = Instant::now();
                        let again = form.last_body_click.is_some_and(|(at, last)| {
                            last == line && now.duration_since(at) < DOUBLE_CLICK
                        });
                        if again {
                            form.last_body_click = None;
                            match form.open_image_preview() {
                                Some(err) => AfterClick::PreviewErr(err),
                                None => AfterClick::None,
                            }
                        } else {
                            form.last_body_click = Some((now, line));
                            AfterClick::None
                        }
                    }
                } else {
                    form.last_body_click = None;
                    AfterClick::None
                }
            }
            Field::Importance => {
                form.cycle_importance();
                form.last_body_click = None;
                AfterClick::None
            }
        }
    };
    match after {
        AfterClick::None => {}
        AfterClick::OpenUrl(url) => match crate::open::open_url(&url) {
            Ok(()) => app.info(format!("Opened {url}")),
            Err(err) => app.error(err),
        },
        AfterClick::PreviewErr(err) => app.error(err),
    }
}

enum MenuClick {
    /// Click was on the menu (selected a row or the chrome).
    Handled,
    /// Copy command finished (clipboard side effects applied).
    CopyDone,
    /// Click missed the menu rect entirely.
    Miss,
}

/// Hit-test the open body `/` dropdown. Clicking a command row runs it.
fn click_body_slash_menu(app: &mut App, x: u16, y: u16) -> MenuClick {
    let Some(form) = app.form.as_ref() else {
        return MenuClick::Miss;
    };
    let Some(rect) = form.body_menu_area else {
        return MenuClick::Miss;
    };
    if !contains(rect, x, y) {
        return MenuClick::Miss;
    }

    // Rows sit inside the border: top border at rect.y, first command at y+1.
    let commands = form.body.menu_commands();
    if commands.is_empty() {
        return MenuClick::Handled;
    }
    if y <= rect.y || y >= rect.bottom().saturating_sub(1) {
        // Title / bottom border — keep the menu open, select nothing.
        return MenuClick::Handled;
    }
    let idx = (y - rect.y - 1) as usize;
    if idx >= commands.len() {
        return MenuClick::Handled;
    }

    let command = commands[idx];
    let Some(form) = app.form.as_mut() else {
        return MenuClick::Miss;
    };
    if let Some(menu) = &mut form.body.menu {
        menu.index = idx;
    }
    form.before_edit(EditKind::Atomic);
    match form.body.apply(command) {
        Some(payload) => {
            finish_copy(app, payload);
            MenuClick::CopyDone
        }
        None => MenuClick::Handled,
    }
}

/// Whether this click lands on the row the last one did, soon enough to
/// count as a double click. Records the click either way.
fn clicked_again(app: &mut App, panel: Focus, row: usize) -> bool {
    let now = Instant::now();
    let again = app.last_click.is_some_and(|(at, last_panel, last_row)| {
        last_panel == panel && last_row == row && now.duration_since(at) < DOUBLE_CLICK
    });
    app.last_click = (!again).then_some((now, panel, row));
    again
}

fn contains(area: ratatui::layout::Rect, x: u16, y: u16) -> bool {
    area.contains(ratatui::layout::Position { x, y })
}

#[cfg(test)]
mod tests {
    use std::path::PathBuf;

    use crate::body::CopyLine;

    use super::{
        MAX_OSC52_ENCODED_BYTES, MAX_OSC52_RAW_BYTES, build_clipboard_payload_with, osc52_sequence,
    };

    #[test]
    fn terminal_clipboard_fallback_preserves_utf8_text() {
        assert_eq!(osc52_sequence("买菜").unwrap(), "\u{1b}]52;c;5Lmw6I+c\u{7}");
    }

    #[test]
    fn terminal_clipboard_rejects_oversized_raw_and_encoded_payloads() {
        let raw = osc52_sequence(&"x".repeat(MAX_OSC52_RAW_BYTES + 1)).unwrap_err();
        assert!(raw.contains("raw limit"), "{raw}");

        let encoded_input = "x".repeat(62 * 1024);
        assert!(encoded_input.len() <= MAX_OSC52_RAW_BYTES);
        let encoded = osc52_sequence(&encoded_input).unwrap_err();
        assert!(encoded.contains("encoded limit"), "{encoded}");
        assert!(MAX_OSC52_ENCODED_BYTES < encoded_input.len() * 4 / 3 + 4);
    }

    #[test]
    fn rich_clipboard_budget_replaces_an_oversized_image_but_keeps_plain_text() {
        let lines = vec![
            CopyLine::Text("before".into()),
            CopyLine::Image(PathBuf::from("huge.png")),
            CopyLine::Text("after".into()),
        ];
        let budget = 128;
        let (plain, html) = build_clipboard_payload_with(&lines, budget, |_, _| {
            Ok(format!("data:image/png;base64,{}", "A".repeat(256)))
        });

        assert_eq!(plain, "before\n[image: huge.png]\nafter");
        assert!(html.contains("[image: huge.png]"), "{html}");
        assert!(!html.contains("<img"), "{html}");
        assert!(html.len() <= budget);
    }

    #[test]
    fn rich_clipboard_only_links_to_approved_url_schemes() {
        let lines = vec![
            CopyLine::Link("example.com/?a=1&b=2".into()),
            CopyLine::Link("javascript:alert(1)".into()),
        ];

        let (plain, html) = build_clipboard_payload_with(&lines, 1024, |_, _| unreachable!());

        assert_eq!(plain, "example.com/?a=1&b=2\njavascript:alert(1)");
        assert!(
            html.contains("href=\"https://example.com/?a=1&amp;b=2\""),
            "{html}"
        );
        assert_eq!(html.matches("<a ").count(), 1, "{html}");
        assert!(html.contains("<div>javascript:alert(1)</div>"), "{html}");
    }
}