mach-tui 0.8.0

//! Every screen is drawn once against an in-memory terminal.
//!
//! The drawing code does its own arithmetic on rects, widths and scroll
//! offsets, so a bad subtraction panics rather than misdraws. These
//! render each mode at a few sizes — including ones barely big enough —
//! and assert the frame comes out with something recognisable on it.

use chrono::{Datelike, Duration};
use ratatui::buffer::Buffer;
use ratatui::crossterm::event::{Event, KeyModifiers, MouseEvent, MouseEventKind};
use ratatui::style::Modifier;

use mach::app::{App, Focus, Mode};
use mach::form::CategoryForm;
use mach::input::handle_event;
use mach::model::{Block, Category, Label, LabelColor, Task};
use mach::store::Store;
use mach::ui;

#[path = "common/render.rs"]
mod render_common;
use render_common::{buffer_text, draw, find_cells, move_mouse};

/// The screen as text, one line per row.
fn render(app: &mut App, width: u16, height: u16) -> String {
    buffer_text(&draw(app, width, height))
}

/// Whether the cells spelling out `needle` are all bold — how the help
/// page marks a section heading. Panics if the text is not on screen.
fn is_bold(buffer: &Buffer, needle: &str) -> bool {
    let (x0, y) = find_cells(buffer, needle);
    (x0..x0 + needle.chars().count() as u16)
        .map(|x| &buffer[(x, y)])
        .filter(|cell| !cell.symbol().trim().is_empty())
        .all(|cell| cell.modifier.contains(Modifier::BOLD))
}

/// An app with two categories and a few tasks, backed by an independent
/// in-memory store for each test.
fn sample_app() -> App {
    let mut store = Store::open_in_memory_with_paths(
        std::env::temp_dir().join(format!("mach-render-test-{}", uuid::Uuid::new_v4())),
    )
    .unwrap();
    let categories = vec![
        Category {
            id: "c-work".into(),
            name: "Work".into(),
            description: "what pays".into(),
        },
        Category {
            id: "c-home".into(),
            name: "Home".into(),
            description: String::new(),
        },
    ];
    let mut flagged = Task::new(
        "ship the release",
        3,
        Some("c-work".into()),
        "2030-01-02 09:00",
    );
    flagged.description = vec![
        Block::text("with a note"),
        Block::todo("step one", true),
        Block::todo("step two", false),
        Block::link("https://example.com"),
        Block::bullet("a point"),
        Block::number("first"),
    ];
    let mut done = Task::new("已完成的任务", 0, Some("c-home".into()), "");
    done.done = true;
    let tasks = vec![flagged, done, Task::new("no category", 1, None, "09:00")];
    store
        .update(|data| {
            data.categories = categories;
            data.tasks = tasks;
            Ok(())
        })
        .unwrap();
    let mut app = App::with_store("test", store).unwrap();
    // A fresh store has no recorded version, so the welcome splash is up;
    // tests that want it set the mode themselves.
    app.mode = Mode::Normal;
    app
}

#[test]
fn draws_the_main_screen() {
    let mut app = sample_app();
    let screen = render(&mut app, 100, 30);
    assert!(screen.contains("Categories"), "{screen}");
    assert!(screen.contains("Tasks"), "{screen}");
    assert!(screen.contains("ship the release"), "{screen}");
    assert!(screen.contains("Work"), "{screen}");
    // Flags, tick marks and the due date all share the row.
    assert!(screen.contains("[✓]") && screen.contains("[ ]"), "{screen}");
    assert!(screen.contains("⚑"), "{screen}");
}

#[test]
fn hover_adds_background_only_to_an_unselected_task_row() {
    let mut app = sample_app();
    let label = Label::new("tag", LabelColor::Orange);
    let label_id = label.id.clone();
    app.labels.push(label);
    app.tasks
        .iter_mut()
        .find(|task| task.title == "no category")
        .unwrap()
        .label_ids
        .push(label_id);
    let initial = draw(&mut app, 100, 30);
    let (selected_x, selected_y) = find_cells(&initial, "ship the release");
    let selected_style = initial[(selected_x, selected_y)].style();
    let (other_x, other_y) = find_cells(&initial, "no category");
    let other_style = initial[(other_x, other_y)].style();
    let (label_x, label_y) = find_cells(&initial, "tag");
    let label_style = initial[(label_x, label_y)].style();
    let selected = app.task_index;

    assert!(move_mouse(&mut app, selected_x, selected_y));
    let selected_hover = draw(&mut app, 100, 30);
    let hovered_style = selected_hover[(selected_x, selected_y)].style();
    assert_eq!(
        hovered_style, selected_style,
        "the selected row must keep its stronger active style"
    );

    assert!(move_mouse(&mut app, other_x, other_y));
    let other_hover = draw(&mut app, 100, 30);
    let hovered_style = other_hover[(other_x, other_y)].style();
    assert!(
        hovered_style.bg != other_style.bg
            || (hovered_style
                .add_modifier
                .contains(Modifier::DIM | Modifier::REVERSED)
                && !other_style
                    .add_modifier
                    .contains(Modifier::DIM | Modifier::REVERSED)),
        "an unselected task row should gain a background-style hover state"
    );
    assert!(
        !hovered_style.add_modifier.contains(Modifier::UNDERLINED),
        "hover is a background, not an underline"
    );
    assert_eq!(
        other_hover[(label_x, label_y)].style(),
        label_style,
        "task-row hover must preserve a label badge's identity color"
    );
    assert_eq!(
        other_hover[(selected_x, selected_y)].style(),
        selected_style,
        "the previous selected row must retain only its active style"
    );
    assert_eq!(
        app.task_index, selected,
        "drawing hover cannot select a task"
    );
}

#[test]
fn category_command_and_label_items_receive_background_hover() {
    let assert_hover_changed = |before: &Buffer, after: &Buffer, x, y, kind: &str| {
        let before = before[(x, y)].style();
        let after = after[(x, y)].style();
        assert_ne!(after, before, "{kind} should receive hover styling");
        assert!(
            !after.add_modifier.contains(Modifier::UNDERLINED),
            "{kind} hover must not add an underline"
        );
    };

    let mut categories = sample_app();
    let initial = draw(&mut categories, 100, 30);
    let (x, y) = find_cells(&initial, "Home");
    assert!(move_mouse(&mut categories, x, y));
    let hovered = draw(&mut categories, 100, 30);
    assert_hover_changed(&initial, &hovered, x, y, "category row");

    let mut commands = sample_app();
    commands.mode = Mode::Slash;
    let initial = draw(&mut commands, 100, 30);
    let (x, y) = find_cells(&initial, "/settings");
    assert!(move_mouse(&mut commands, x, y));
    let hovered = draw(&mut commands, 100, 30);
    assert_hover_changed(&initial, &hovered, x, y, "command row");

    let mut labels = sample_app();
    labels.create_label("bug").unwrap();
    labels.create_label("feat").unwrap();
    labels.open_labels();
    let initial = draw(&mut labels, 100, 30);
    let (selected_x, selected_y) = find_cells(&initial, "bug");
    let selected_style = initial[(selected_x, selected_y)].style();
    let (x, y) = find_cells(&initial, "feat");
    assert!(move_mouse(&mut labels, x, y));
    let hovered = draw(&mut labels, 100, 30);
    assert_hover_changed(&initial, &hovered, x, y, "label item");

    assert!(move_mouse(&mut labels, selected_x, selected_y));
    let selected_hover = draw(&mut labels, 100, 30);
    assert_eq!(
        selected_hover[(selected_x, selected_y)].style(),
        selected_style,
        "the selected label must keep its active style"
    );
}

#[test]
fn form_fields_do_not_receive_hover_styling() {
    let mut app = sample_app();
    app.open_edit_task();
    let initial = draw(&mut app, 100, 30);
    let title = app.form.as_ref().unwrap().areas.title;
    let category = app.form.as_ref().unwrap().areas.category;
    let (title_x, title_y) = find_cells(&initial, " Title ");
    let (category_x, category_y) = find_cells(&initial, " Category ");
    let title_style = initial[(title_x, title_y)].style();
    let category_style = initial[(category_x, category_y)].style();
    let field = app.form.as_ref().unwrap().field;

    assert!(handle_event(
        &mut app,
        Event::Mouse(MouseEvent {
            kind: MouseEventKind::Moved,
            column: title.x,
            row: title.y,
            modifiers: KeyModifiers::NONE,
        }),
    ));
    let title_hover = draw(&mut app, 100, 30);
    assert_eq!(
        title_hover[(title_x, title_y)].style(),
        title_style,
        "field chrome must not receive hover styling"
    );

    assert!(!handle_event(
        &mut app,
        Event::Mouse(MouseEvent {
            kind: MouseEventKind::Moved,
            column: category.x,
            row: category.y,
            modifiers: KeyModifiers::NONE,
        }),
    ));
    let category_hover = draw(&mut app, 100, 30);
    assert_eq!(
        category_hover[(category_x, category_y)].style(),
        category_style,
        "moving between form fields must not introduce hover styling"
    );
    assert_eq!(app.form.as_ref().unwrap().field, field);
}

#[test]
fn due_calendar_hover_marks_one_date_without_overriding_the_active_date() {
    let mut app = sample_app();
    app.open_edit_task();
    app.form.as_mut().unwrap().open_due_picker();
    let initial = draw(&mut app, 100, 40);
    let picker = app.form.as_ref().unwrap().picker.as_ref().unwrap();
    let days = picker.layout.days;
    let selected = picker.day;
    let first = selected.with_day(1).unwrap();
    let start = first
        .checked_sub_signed(Duration::days(
            first.weekday().num_days_from_sunday().into(),
        ))
        .unwrap();
    let cell_for = |date: chrono::NaiveDate| {
        let offset = date.signed_duration_since(start).num_days() as u16;
        (
            days.x.saturating_add((offset % 7).saturating_mul(3)),
            days.y.saturating_add(offset / 7),
        )
    };

    let (selected_x, selected_y) = cell_for(selected);
    let selected_text_x = selected_x.saturating_add(2);
    let selected_style = initial[(selected_text_x, selected_y)].style();
    assert!(move_mouse(&mut app, selected_x, selected_y));
    let active_hover = draw(&mut app, 100, 40);
    assert_eq!(
        active_hover[(selected_text_x, selected_y)].style(),
        selected_style,
        "the active date must keep its stronger selection style"
    );

    let next = selected.succ_opt().unwrap();
    let (next_x, next_y) = cell_for(next);
    let next_first_digit_x = next_x.saturating_add(1);
    let next_text_x = next_x.saturating_add(2);
    let gutter_style = initial[(next_x, next_y)].style();
    let first_digit_style = initial[(next_first_digit_x, next_y)].style();
    let before = initial[(next_text_x, next_y)].style();
    assert!(move_mouse(&mut app, next_x, next_y));
    let hovered = draw(&mut app, 100, 40);
    assert_eq!(
        hovered[(next_x, next_y)].style(),
        gutter_style,
        "the one-cell date gutter must remain unpainted"
    );
    assert_ne!(
        hovered[(next_first_digit_x, next_y)].style(),
        first_digit_style,
        "the two-character day field should include its leading digit cell"
    );
    let after = hovered[(next_text_x, next_y)].style();
    assert!(
        after.bg != before.bg
            || (after
                .add_modifier
                .contains(Modifier::DIM | Modifier::REVERSED)
                && !before
                    .add_modifier
                    .contains(Modifier::DIM | Modifier::REVERSED)),
        "an unselected calendar date should gain a background hover"
    );
    assert!(
        !after.add_modifier.contains(Modifier::UNDERLINED),
        "date hover is a background, not an underline"
    );
}

#[test]
fn draws_every_overlay() {
    for (mode, expect) in [
        (Mode::Help, "MOVING AROUND"),
        (Mode::Settings, "Sort"),
        (Mode::Welcome, "Welcome to mach"),
        (Mode::WhatsNew, "What's new in mach"),
        (Mode::Slash, "search tasks by text or label"),
    ] {
        let mut app = sample_app();
        app.mode = mode;
        let screen = render(&mut app, 100, 30);
        assert!(
            screen.contains(expect),
            "{mode:?} missing {expect:?}:\n{screen}"
        );
    }
}

#[test]
fn whats_new_shows_complete_highlight_descriptions() {
    for (width, height) in [(60, 16), (100, 30)] {
        let mut app = sample_app();
        app.mode = Mode::WhatsNew;
        let screen = render(&mut app, width, height);

        for ending in ["assignments.", "editors.", "pickers."] {
            assert!(
                screen.contains(ending),
                "{ending:?} was clipped at {width}x{height}:\n{screen}"
            );
        }
    }
}

#[test]
fn help_marks_both_section_headings() {
    let mut app = sample_app();
    app.mode = Mode::Help;
    let buffer = draw(&mut app, 110, 40);
    // "COMMANDS  (press /)" has lowercase inside it, so a heading cannot
    // be recognised by its casing — it has to be marked as one.
    assert!(is_bold(&buffer, "MOVING AROUND"), "first heading not bold");
    assert!(
        is_bold(&buffer, "TASKS, CATEGORIES & LABELS"),
        "first heading not bold"
    );
    assert!(
        is_bold(&buffer, "COMMANDS  (press /)"),
        "second heading not bold"
    );
    assert!(is_bold(&buffer, "TASK PREVIEW"), "second heading not bold");
    // An ordinary row is plain, so the checks above mean something.
    assert!(
        !is_bold(&buffer, "/quit"),
        "description row should not be bold"
    );
}

#[test]
fn draws_the_task_dialog_with_a_description() {
    let mut app = sample_app();
    app.open_edit_task();
    // Tall enough that the docked preview shows the full description stack.
    let screen = render(&mut app, 100, 48);
    assert!(screen.contains("Edit task"), "{screen}");
    assert!(
        screen.contains("Title") && screen.contains("Due"),
        "{screen}"
    );
    assert!(screen.contains("ship the release"), "{screen}");
    // Description blocks keep their markers (docked under the task list).
    assert!(screen.contains("[✓] step one"), "{screen}");
    assert!(screen.contains("• a point"), "{screen}");
    assert!(screen.contains("1. first"), "{screen}");
    assert!(screen.contains("↗ https://example.com"), "{screen}");
    assert!(
        screen.contains("Task preview") || screen.contains("Esc list"),
        "{screen}"
    );
}

#[test]
fn preview_wraps_every_label_and_rows_compact_only_whole_label_tokens() {
    let mut app = sample_app();
    let labels = ["bug", "backend", "release", "customer-visible"]
        .into_iter()
        .map(|name| app.create_label(name).unwrap())
        .collect::<Vec<_>>();
    let task = app.selected_task().unwrap().id.clone();
    app.set_task_labels(&task, labels).unwrap();
    let labelled = app.tasks.iter_mut().find(|item| item.id == task).unwrap();
    labelled.due.clear();
    labelled.description.clear();
    app.invalidate_preview();
    app.rebuild_view();

    let wide_buffer = draw(&mut app, 100, 30);
    let wide = buffer_text(&wide_buffer);
    for label in ["bug", "backend", "release", "customer-visible"] {
        assert!(
            wide.contains(label),
            "missing {label:?} in preview:\n{wide}"
        );
    }
    assert!(!wide.contains("#bug"), "TUI labels no longer use #: {wide}");
    let (bug_x, bug_y) = find_cells(&wide_buffer, "bug");
    let (title_x, title_y) = find_cells(&wide_buffer, "ship the release");
    assert_eq!(
        bug_y, title_y,
        "first label match should be on the task row"
    );
    let expected_badge = app.theme().label_badge(app.labels[0].color, false);
    assert_eq!(
        wide_buffer[(bug_x, bug_y)].bg,
        expected_badge.bg.unwrap_or(ratatui::style::Color::Reset),
        "the focused task row must preserve the label badge background"
    );
    if expected_badge.bg.is_some() {
        assert_ne!(
            wide_buffer[(bug_x, bug_y)].bg,
            wide_buffer[(title_x, title_y)].bg,
            "the label color belongs to its badge, not its text"
        );
    }

    app.settings.preview_position = "right".into();
    let narrow = render(&mut app, 90, 30);
    let task_row = narrow
        .lines()
        .find(|line| line.contains("[ ]") && line.contains("ship the"))
        .expect("task row");
    assert!(task_row.contains("bug"), "{task_row}");
    assert!(
        task_row.contains("+"),
        "hidden labels need a count: {task_row}"
    );
    assert!(
        !task_row.contains("back…"),
        "label tokens must not truncate: {task_row}"
    );
}

#[test]
fn draws_labels_manager_and_task_label_picker_at_supported_sizes() {
    for (width, height) in [(60, 16), (100, 30)] {
        let mut app = sample_app();
        app.create_label("bug").unwrap();
        app.create_label("backend").unwrap();
        if height == 16 {
            for name in ["frontend", "design", "docs", "release", "blocked", "later"] {
                app.create_label(name).unwrap();
            }
        }
        app.mode = Mode::Labels;
        let manager_buffer = draw(&mut app, width, height);
        let manager = buffer_text(&manager_buffer);
        assert!(manager.contains("Labels"), "{manager}");
        assert!(manager.contains("bug"), "{manager}");
        let (_, bug_y) = find_cells(&manager_buffer, "bug");
        let (_, backend_y) = find_cells(&manager_buffer, "backend");
        assert_eq!(bug_y, backend_y, "labels should flow across the row");

        app.begin_rename_label();
        let editor = render(&mut app, width, height);
        for field in ["Edit label", "Name", "Color"] {
            assert!(editor.contains(field), "missing {field:?}:\n{editor}");
        }

        app.close_labels();
        app.open_edit_task();
        app.form
            .as_mut()
            .unwrap()
            .set_field(mach::form::Field::Labels);
        app.form.as_mut().unwrap().open_label_picker();
        let picker_buffer = draw(&mut app, width, height);
        let picker = buffer_text(&picker_buffer);
        let form = app.form.as_ref().unwrap();
        let picker_area = form.label_picker_area().unwrap();
        if height == 16 {
            assert!(
                picker_area.y >= form.areas.labels.bottom(),
                "short label picker must shrink below its field:\n{picker}"
            );
        }
        let title_area = form.areas.title;
        let overlaps_title = picker_area.x < title_area.right()
            && picker_area.right() > title_area.x
            && picker_area.y < title_area.bottom()
            && picker_area.bottom() > title_area.y;
        assert!(
            !overlaps_title,
            "label picker must shrink instead of covering Title:\n{picker}"
        );
        if width >= 100 {
            assert!(picker.contains("bug"), "{picker}");
        }
    }
}

#[test]
fn task_label_picker_shows_manage_when_choices_fit_the_color_palette() {
    let mut app = sample_app();
    let choice_count = LabelColor::ALL.len().saturating_sub(2);
    for index in 0..choice_count {
        app.create_label(&format!("label-{index:02}")).unwrap();
    }
    app.open_edit_task();
    app.form
        .as_mut()
        .unwrap()
        .set_field(mach::form::Field::Labels);
    app.form.as_mut().unwrap().open_label_picker();

    let picker = render(&mut app, 100, 44);

    assert!(picker.contains("label-09"), "{picker}");
    assert!(picker.contains("Manage"), "{picker}");
}

#[test]
fn task_form_overlays_replace_overlapped_description_images_with_a_marker() {
    for field in [mach::form::Field::Labels, mach::form::Field::Due] {
        let mut app = sample_app();
        app.create_label("bug").unwrap();
        app.tasks[0].description = vec![
            Block::text("one"),
            Block::text("two"),
            Block::image("missing.png"),
        ];
        app.rebuild_view();
        app.open_edit_task();

        let form = app.form.as_mut().unwrap();
        match field {
            mach::form::Field::Labels => form.open_label_picker(),
            mach::form::Field::Due => form.open_due_picker(),
            _ => unreachable!(),
        }

        let screen = render(&mut app, 140, 50);
        assert!(
            screen.contains("[image]"),
            "{field:?} overlay must hide the image protocol it covers:\n{screen}"
        );
    }
}

#[test]
fn labels_manager_occludes_underlying_task_preview_images() {
    let mut app = sample_app();
    app.settings.preview_position = "right".into();
    app.tasks[0].description = (0..14)
        .map(|_| Block::text("line"))
        .chain(std::iter::once(Block::image("missing.png")))
        .collect();
    app.rebuild_view();
    app.open_labels();
    app.begin_new_label();

    let screen = render(&mut app, 140, 50);
    assert!(
        screen.contains("[image]"),
        "the labels manager must hide the preview image protocol it covers:\n{screen}"
    );
}

#[test]
fn narrow_side_preview_uses_a_stacked_in_place_editor() {
    let mut app = sample_app();
    app.settings.preview_position = "right".into();
    app.open_edit_task();

    let buffer = draw(&mut app, 90, 30);
    let preview = app.areas.preview;
    let (edit_x, _) = find_cells(&buffer, " Edit task ");
    assert!(
        edit_x >= preview.x && edit_x < preview.right(),
        "editor should stay inside the task preview: preview={preview:?}\n{}",
        buffer_text(&buffer)
    );

    let (_, title_y) = find_cells(&buffer, " Title ");
    let (_, category_y) = find_cells(&buffer, " Category ");
    let (_, labels_y) = find_cells(&buffer, " Labels ");
    let (_, due_y) = find_cells(&buffer, " Due ");
    let (_, flags_y) = find_cells(&buffer, " Flags ");
    assert!(
        title_y < category_y && category_y < labels_y && labels_y < due_y && due_y < flags_y,
        "compact metadata fields should stack vertically\n{}",
        buffer_text(&buffer)
    );
}

#[test]
fn modal_task_editor_keeps_the_task_preview_visible_behind_it() {
    let mut app = sample_app();
    app.settings.preview_position = "right".into();
    app.tasks[0].title = format!("{}UNDERLAY", " ".repeat(32));
    app.invalidate_preview();
    app.rebuild_view();
    app.open_edit_task();

    let buffer = draw(&mut app, 120, 16);
    let preview = app.areas.preview;
    let (edit_x, _) = find_cells(&buffer, " Edit task ");
    assert!(edit_x < preview.x, "fixture should use the modal fallback");

    // The modal ends before the right edge. A marker placed at the far end
    // of the underlying preview title must remain visible beside it.
    let edge_start = buffer.area.width.saturating_sub(14);
    let mut right_edge = String::new();
    for y in 0..buffer.area.height {
        for x in edge_start..buffer.area.width {
            right_edge.push_str(buffer[(x, y)].symbol());
        }
        right_edge.push('\n');
    }
    assert!(
        right_edge.contains("UNDERLAY"),
        "modal fallback should preserve the task preview\n{}",
        buffer_text(&buffer)
    );
}

#[test]
fn draws_the_new_task_dialog_and_its_calendar() {
    let mut app = sample_app();
    app.select_category(1);
    app.open_new_task();
    let screen = render(&mut app, 100, 30);
    assert!(screen.contains("New task"), "{screen}");
    assert!(
        screen.contains("Category") && screen.contains("Work"),
        "{screen}"
    );

    app.form.as_mut().unwrap().open_due_picker();
    let screen = render(&mut app, 100, 30);
    assert!(
        screen.contains("Su") && screen.contains("Sa"),
        "weekday header:\n{screen}"
    );
    assert!(screen.contains("clear(x)"), "{screen}");
}

#[test]
fn draws_the_category_dialog() {
    let mut app = sample_app();
    app.focus = Focus::Sidebar;
    app.select_category(1);
    app.open_edit_category();
    let screen = render(&mut app, 100, 30);
    assert!(screen.contains("Edit category"), "{screen}");
    assert!(
        screen.contains("Work") && screen.contains("what pays"),
        "{screen}"
    );

    app.category_form = Some(CategoryForm::new());
    assert!(render(&mut app, 100, 30).contains("New category"));
}

#[test]
fn draws_search_and_its_empty_result() {
    let mut app = sample_app();
    app.start_search("ship");
    let screen = render(&mut app, 100, 30);
    assert!(screen.contains("ship the release"), "{screen}");
    assert!(
        !screen.contains("no category"),
        "other tasks filtered out:\n{screen}"
    );

    app.start_search("nothing matches this");
    let screen = render(&mut app, 100, 30);
    assert!(screen.contains("No tasks found"), "{screen}");
}

#[test]
fn draws_an_empty_store() {
    let mut app = sample_app();
    app.tasks.clear();
    app.rebuild_view();
    assert!(render(&mut app, 100, 30).contains("No active tasks"));
}

#[test]
fn survives_sizes_from_tiny_to_wide() {
    // Below the floor the UI says so instead of laying anything out.
    let mut app = sample_app();
    assert!(render(&mut app, 20, 5).contains("too small"));
    assert!(render(&mut app, 30, 8).contains("60×16"));

    // At and above the honest floor every mode remains operable.
    for (width, height) in [(60, 16), (80, 24), (200, 60)] {
        for mode in [
            Mode::Normal,
            Mode::Help,
            Mode::Settings,
            Mode::Labels,
            Mode::Welcome,
            Mode::WhatsNew,
            Mode::Slash,
            Mode::TaskForm,
            Mode::CategoryForm,
        ] {
            let mut app = sample_app();
            match mode {
                Mode::TaskForm => app.open_edit_task(),
                Mode::CategoryForm => {
                    app.select_category(1);
                    app.open_edit_category();
                }
                _ => app.mode = mode,
            }
            render(&mut app, width, height);
        }
    }
}

#[test]
fn minimum_size_keeps_both_primary_panels_visible() {
    let mut app = sample_app();
    let screen = render(&mut app, 60, 16);
    assert!(screen.contains("Categories"), "{screen}");
    assert!(screen.contains("Tasks"), "{screen}");
    assert!(screen.contains("ship the re"), "{screen}");
}

#[test]
fn wide_help_uses_paired_columns_and_content_height() {
    let mut app = sample_app();
    app.mode = Mode::Help;
    let buffer = draw(&mut app, 120, 40);

    let (_, title_y) = find_cells(&buffer, " mach ");
    let (_, moving_y) = find_cells(&buffer, "MOVING AROUND");
    let (_, tasks_y) = find_cells(&buffer, "TASKS, CATEGORIES & LABELS");

    assert_eq!(moving_y, tasks_y, "wide help sections must share a row");
    assert!(title_y > 0, "wide help must not fill the terminal height");
}

#[test]
fn narrow_help_scrolls_to_every_section() {
    let mut app = sample_app();
    app.mode = Mode::Help;
    let top = render(&mut app, 80, 24);
    assert!(top.contains("MOVING AROUND"), "{top}");

    app.help_scroll = usize::MAX;
    let bottom = render(&mut app, 80, 24);
    assert!(bottom.contains("PREVIEW"), "{bottom}");
    assert!(bottom.contains("github.com/Q1CHENL/mach"), "{bottom}");
}

#[test]
fn hidden_geometry_is_cleared_on_an_undersized_frame() {
    let mut app = sample_app();
    let _ = render(&mut app, 100, 30);
    assert!(!app.areas.tasks.is_empty());
    assert!(!app.areas.command_bar.is_empty());

    let _ = render(&mut app, 20, 5);
    assert!(app.areas.tasks.is_empty());
    assert!(app.areas.sidebar.is_empty());
    assert!(app.areas.command_bar.is_empty());
    assert!(app.areas.slash_menu.is_empty());
}

#[test]
fn a_clipped_read_only_preview_says_that_more_content_exists() {
    let mut app = sample_app();
    app.tasks[0].description = (0..40)
        .map(|index| Block::text(&format!("preview line {index}")))
        .collect();
    app.invalidate_preview();
    app.rebuild_view();

    let screen = render(&mut app, 80, 24);
    assert!(screen.contains("↓ more · Enter to edit"), "{screen}");
}

#[test]
fn survives_every_sort_order() {
    for sort in mach::settings::SORTS {
        let mut app = sample_app();
        app.settings.sort = sort.to_string();
        app.rebuild_view();
        assert!(
            render(&mut app, 100, 30).contains("ship the release"),
            "sort {sort}"
        );
    }
}

// ------------------------------------------------------- picture geometry

/// A picture is letterboxed into its box, never cropped.
///
/// The size is worked out in cells and the terminal is then told to draw
/// `cells × cell_size` pixels there, so this has to come out to a rect that
/// fits — anything larger is clipped by the terminal, which reads as the
/// right and bottom of the picture being cut off.
#[test]
fn a_picture_is_letterboxed_into_its_box_never_cropped() {
    use image::DynamicImage;
    use ratatui::layout::{Rect, Size};
    use ratatui_image::picker::Picker;
    use ratatui_image::{FontSize, Resize};

    let cell = FontSize::new(8, 16);
    // Wider than any box below, so a crop would be obvious.
    let (iw, ih) = (1873u32, 1050u32);
    #[allow(deprecated, reason = "the only way to pin a cell size for a test")]
    let picker = Picker::from_fontsize(cell);
    let protocol = picker.new_resize_protocol(DynamicImage::new_rgba8(iw, ih));

    for box_size in [
        Size::new(128, 55),
        Size::new(120, 50),
        Size::new(200, 60),
        Size::new(60, 40),
        Size::new(10, 4),
    ] {
        let fitted = protocol.size_for(Resize::Scale(None), box_size);
        let area = Rect {
            x: 0,
            y: 0,
            width: box_size.width,
            height: box_size.height,
        };
        let picture = ui::centered(
            area,
            fitted.width.min(area.width),
            fitted.height.min(area.height),
        );

        assert!(
            picture.width <= area.width && picture.height <= area.height,
            "{box_size:?}: picture {picture:?} spills out of its box"
        );
        assert!(
            picture.right() <= area.right() && picture.bottom() <= area.bottom(),
            "{box_size:?}: picture {picture:?} would be clipped"
        );

        // Aspect ratio survives, to within the cell the size is rounded up to.
        let want_h = (box_size.width as f32 * cell.width as f32 * ih as f32)
            / (iw as f32 * cell.height as f32);
        let capped = want_h.min(box_size.height as f32);
        assert!(
            (picture.height as f32 - capped).abs() <= 1.5,
            "{box_size:?}: {} rows, expected about {capped:.1}",
            picture.height
        );
    }
}

#[test]
fn categories_scrollbar_track_uses_accent_when_focused() {
    let mut app = sample_app();
    app.focus = Focus::Sidebar;
    for i in 0..40 {
        app.categories.push(Category {
            id: format!("c-{i}"),
            name: format!("Cat{i}"),
            description: String::new(),
        });
    }
    app.rebuild_view();
    let buffer = draw(&mut app, 100, 20);
    let accent = app.theme().accent;
    // Right border column of the Categories panel (SIDEBAR_WIDTH = 26).
    let x = mach::ui::SIDEBAR_WIDTH - 1;
    let mut found_track = false;
    for y in 2..18 {
        let cell = &buffer[(x, y)];
        let sym = cell.symbol();
        if matches!(sym, "│" | "┃" | "║") {
            found_track = true;
            assert_eq!(
                cell.style().fg,
                Some(accent),
                "track at ({x},{y}) should be accent, got {:?} sym={sym:?}",
                cell.style().fg
            );
        }
        if sym == "█" || sym == "▐" {
            assert_eq!(cell.style().fg, Some(accent), "thumb should be accent");
        }
    }
    assert!(
        found_track,
        "expected a scrollbar track on the categories border"
    );
}

#[test]
fn preview_can_sit_on_the_right() {
    let mut app = sample_app();
    app.settings.preview_position = "right".into();
    // Wide + tall enough for a side preview.
    let screen = render(&mut app, 120, 30);
    assert!(screen.contains("Task preview"), "{screen}");
    assert!(screen.contains("ship the release"), "{screen}");
    // Tasks and Task preview titles should appear on the same band (top),
    // not only with Task preview under a short task list.
    let lines: Vec<&str> = screen.lines().collect();
    let tasks_y = lines
        .iter()
        .position(|l| l.contains("Tasks"))
        .expect("Tasks");
    let preview_y = lines
        .iter()
        .position(|l| l.contains("Task preview"))
        .expect("Task preview");
    assert!(
        preview_y.abs_diff(tasks_y) <= 2,
        "preview should be beside tasks, not far below: tasks={tasks_y} preview={preview_y}\n{screen}"
    );
}