use ai_app::ui::fixture::{PHONE_FRAME_MS, PHONE_SCALE, phone_size};
use iris::harness::{Harness, TouchAction, TouchScript};
use iris::prelude::*;

fn opened() -> (Harness, ai_app::ui::TranscriptScreen) {
    let mut h = Harness::new(phone_size(), PHONE_SCALE);
    let opened = ai_app::ui::fixture::open(&mut h.rsc, &mut h.state).expect("the fixture folds");
    h.frame(0);
    h.frame(PHONE_FRAME_MS);
    (h, opened.screen)
}

fn script(name: &str, text: &str) -> TouchScript {
    TouchScript::parse(text).unwrap_or_else(|e| panic!("{name}: {e}"))
}

fn tracked_row(h: &mut Harness, screen: &ai_app::ui::TranscriptScreen) -> (RowKey, f32) {
    let middle = phone_size().y / 2.0;
    let list = (screen.list)(&mut h.rsc);
    let key = list.key_at(middle).expect("a row under the viewport");
    let (top, _) = list.extent(key).expect("that row has an extent");
    (key, top)
}

fn row_top(h: &mut Harness, screen: &ai_app::ui::TranscriptScreen, key: RowKey) -> f32 {
    (screen.list)(&mut h.rsc)
        .extent(key)
        .expect("the tracked row is still loaded")
        .0
}

#[test]
fn a_cancelled_flick_does_not_fling() {
    let (mut h, screen) = opened();
    let flick = script(
        "flick-cancelled",
        include_str!("../touch/flick-cancelled.touch"),
    );
    h.replay(&flick);

    assert_eq!(
        (screen.list)(&mut h.rsc).fling_velocity(),
        None,
        "a gesture the platform took away must not fling"
    );

    let (key, settled) = tracked_row(&mut h, &screen);
    let end = flick.end_ms() + 1_000;
    let mut t = flick.end_ms();
    while t <= end {
        h.frame(t);
        t += PHONE_FRAME_MS;
    }
    let now = row_top(&mut h, &screen, key);
    assert!(
        (now - settled).abs() < 0.5,
        "the list kept moving after a cancelled gesture: {settled} -> {now}"
    );
}

#[test]
fn a_press_ended_by_a_cancel_leaves_no_origin_for_the_next_one() {
    let (mut h, screen) = opened();

    h.touch(TouchAction::Down, Vec2::new(540.0, 700.0), 0);
    h.touch(TouchAction::Cancel, Vec2::new(540.0, 700.0), 8);

    let (key, before) = tracked_row(&mut h, &screen);

    h.touch(TouchAction::Down, Vec2::new(540.0, 1900.0), 200);
    h.touch(TouchAction::Up, Vec2::new(540.0, 1900.0), 250);

    let after = row_top(&mut h, &screen, key);
    assert!(
        (after - before).abs() < 0.5,
        "a tap after a cancelled press panned the list by {}px, the distance between them",
        after - before
    );
    assert_eq!(
        (screen.list)(&mut h.rsc).fling_velocity(),
        None,
        "and it must not have flung either"
    );
}

#[test]
fn panning_a_code_fence_then_tapping_elsewhere_moves_nothing() {
    use ai_app::client::transcript_fold::{TranscriptItem, TranscriptRow};

    let (mut h, mut screen) = opened();
    let fence = TranscriptRow::Single(TranscriptItem::AssistantMsg {
        seq: 9_000_000,
        text: "```\none two three four five six seven eight nine ten eleven twelve\n\
               thirteen fourteen fifteen sixteen seventeen eighteen nineteen\n```"
            .to_string(),
        settled: true,
    });
    let para = TranscriptRow::Single(TranscriptItem::AssistantMsg {
        seq: 9_000_001,
        text: "A plain paragraph with nothing to tap in it, only words, so that a \
               press here is a press on ordinary text and nothing else."
            .to_string(),
        settled: true,
    });
    screen.push_row(&mut h.rsc, &fence);
    screen.push_row(&mut h.rsc, &para);
    (screen.list)(&mut h.rsc).jump_to_end();
    h.frame(100);
    h.frame(108);

    let key = ai_app::ui::row::row_key(&fence.key());
    let (top, bottom) = (screen.list)(&mut h.rsc)
        .extent(key)
        .expect("the fence row is on screen");
    let y = (top + bottom) / 2.0;
    assert!(
        y > 0.0 && y < phone_size().y,
        "the fence row has to be on screen to be pressed: {top}..{bottom}"
    );

    h.touch(TouchAction::Down, Vec2::new(800.0, y), 200);
    for (i, x) in [760.0, 700.0, 620.0, 540.0].into_iter().enumerate() {
        h.touch(TouchAction::Move, Vec2::new(x, y), 208 + 8 * i as u64);
    }
    h.touch(TouchAction::Up, Vec2::new(540.0, y), 248);

    let (tracked, before) = tracked_row(&mut h, &screen);

    let para_key = ai_app::ui::row::row_key(&para.key());
    let (ptop, pbottom) = (screen.list)(&mut h.rsc)
        .extent(para_key)
        .expect("the paragraph row is on screen");
    h.touch(
        TouchAction::Down,
        Vec2::new(540.0, (ptop + pbottom) / 2.0),
        400,
    );
    h.touch(
        TouchAction::Up,
        Vec2::new(540.0, (ptop + pbottom) / 2.0),
        450,
    );

    let after = row_top(&mut h, &screen, tracked);
    assert!(
        (after - before).abs() < 0.5,
        "a tap after panning a code fence moved the transcript by {}px",
        after - before
    );
}