//! Sheet Right-to-Left: the grid is mirrored on screen and pointer/keyboard input follows it.

use egui::{Event, Key, Modifiers, PointerButton, Pos2};
use gridcraft_engine::Session;
use gridcraft_engine::core::{CellRef, RangeRef};
use gridcraft_ui_egui::{SheetApp, grid::Geo};
use serde_json::json;

type Harness = egui_kittest::Harness<'static, SheetApp>;

fn harness() -> Harness {
    let mut session = Session::new();
    session.new_workbook();
    session.execute("range.setValues", json!({"range": "A1", "values": [["first", 2], [3, "fourth"]]})).unwrap();
    session.execute("view.rightToLeft", json!({"on": true})).unwrap();
    session.execute("selection.set", json!({"cell": "B2"})).unwrap();
    let mut h = Harness::builder().with_size(egui::vec2(1200.0, 800.0)).build_ui_state(
        |ui, app: &mut SheetApp| {
            let ctx = ui.ctx().clone();
            app.logic(&ctx);
            app.ui(ui);
        },
        SheetApp::new(session, Default::default()),
    );
    h.run_steps(4);
    h
}

fn geo(h: &Harness) -> Geo {
    let app = h.state();
    let sheet = app.session.active().unwrap().wb.active().unwrap();
    Geo::new(sheet, app.grid.rect.unwrap(), app.view().scroll)
}

/// Where `a1` is drawn on screen.
fn point(h: &Harness, a1: &str) -> Pos2 {
    let app = h.state();
    let sheet = app.session.active().unwrap().wb.active().unwrap();
    geo(h).screen_cell_rect(sheet, CellRef::parse(a1).unwrap()).center()
}

fn frame(h: &mut Harness, event: Event) {
    h.input_mut().events.push(event);
    h.run_steps(1);
}

fn button(pos: Pos2, pressed: bool) -> Event {
    Event::PointerButton { pos, button: PointerButton::Primary, pressed, modifiers: Modifiers::NONE }
}

fn current(h: &Harness) -> RangeRef {
    h.state().session.active().unwrap().selection.current()
}

#[test]
fn column_a_is_drawn_on_the_right_and_clicks_hit_the_mirrored_cells() {
    let mut h = harness();
    let g = geo(&h);
    assert!(g.rtl);
    let (a1, b1) = (point(&h, "A1"), point(&h, "B1"));
    assert!(a1.x > b1.x, "A1 at {a1:?} should be right of B1 at {b1:?}");
    // Row headers sit on the right edge, so A1 ends where they begin.
    let sheet_a1 = {
        let app = h.state();
        let sheet = app.session.active().unwrap().wb.active().unwrap();
        g.screen_cell_rect(sheet, CellRef::parse("A1").unwrap())
    };
    assert!((sheet_a1.right() - (g.rect.right() - g.header_w)).abs() < 0.5);

    // Drag from C3 to F7 at their on-screen positions.
    let (from, to) = (point(&h, "C3"), point(&h, "F7"));
    frame(&mut h, Event::PointerMoved(from));
    frame(&mut h, button(from, true));
    frame(&mut h, Event::PointerMoved(to));
    frame(&mut h, button(to, false));
    h.run_steps(1);
    assert_eq!(current(&h), RangeRef::parse("C3:F7").unwrap());
}

#[test]
fn left_and_right_arrows_follow_the_screen() {
    let mut h = harness();
    h.key_press(Key::ArrowLeft);
    h.run_steps(1);
    assert_eq!(h.state().session.active().unwrap().selection.active, CellRef::parse("C2").unwrap());
    h.key_press(Key::ArrowRight);
    h.key_press(Key::ArrowRight);
    h.run_steps(1);
    assert_eq!(h.state().session.active().unwrap().selection.active, CellRef::parse("A2").unwrap());
}