trnovel 0.16.0

//! 阅读设置浮层:把阅读行为偏好(`ReaderDisplayConfig`)搬到 TUI 里可视化调整,
//! 用户不必手改 `~/.novel/reader-display.json`。
//!
//! 只改 `READER_DISPLAY` atom,落盘由 `ReadNovel` 的防抖 effect 统一负责——面板与
//! `v` 键(切换标题)走同一条写盘路径,不会出现两套时序。

use crossterm::event::{Event, KeyCode, KeyEventKind};
use ratatui::{
    layout::{Constraint, Margin},
    style::Style,
    text::Line,
};
use ratatui_kit::prelude::*;

use crate::{
    components::AdjustableSettingItem,
    keymap::{ReaderAction, display_first_key},
    pages::read_novel::visible_lines,
    theme::AppChromeTheme,
};

/// 面板条目数(索引上界)。新增条目时同步改这里与下方渲染的索引判断。
const ITEM_COUNT: usize = 2;

#[derive(Props, Default)]
pub struct ReaderSettingsModalProps {
    pub open: bool,
    pub is_editing: bool,
}

#[component]
pub fn ReaderSettingsModal(
    props: &ReaderSettingsModalProps,
    mut hooks: Hooks,
) -> impl Into<AnyElement<'static>> {
    let theme = hooks.use_component_theme::<AppChromeTheme>();
    let reader_keymap = hooks.use_atom(&crate::state::KEYMAP).read().reader.clone();
    let reader_display = hooks.use_atom(&crate::state::READER_DISPLAY);
    // 正文可见行数与 ReadContent 同源(同一个终端高度),用于把重叠行数换算成实际步长展示。
    let (_, height) = hooks.use_terminal_size();

    let mut index = hooks.use_state(|| 0usize);
    let is_open = props.open;
    let is_editing = props.is_editing;

    hooks.use_event_handler(EventScope::Current, EventPriority::Normal, move |event| {
        let Event::Key(key) = event else {
            return EventResult::Ignored;
        };
        if key.kind != KeyEventKind::Press {
            return EventResult::Ignored;
        }
        if !is_open || !is_editing {
            return EventResult::Ignored;
        }
        match key.code {
            KeyCode::Char('j') | KeyCode::Down => {
                index.set((index.get() + 1).min(ITEM_COUNT - 1));
                EventResult::Consumed
            }
            KeyCode::Char('k') | KeyCode::Up => {
                index.set(index.get().saturating_sub(1));
                EventResult::Consumed
            }
            _ => EventResult::Ignored,
        }
    });

    // hooks 全部注册完再提前返回:关闭时不构建面板内容(提示行的 describe + format!
    // 与整棵子树每帧都会被求值一次,而它绝大多数时间不可见)。
    if !is_open {
        return element!(View).into_any();
    }

    let hint = Line::from(format!(
        "↑/↓ 选择 · ←/→ 调整 · {} 关闭",
        display_first_key(&reader_keymap, ReaderAction::ToggleReaderSettings)
    ))
    .centered()
    .style(theme.muted);

    let config = *reader_display.read();
    // 同屏展示派生步长:用户无法凭「2」想象效果,但看到「每页滚动 28 行」就懂了;
    // 终端极矮把步长压到 1 时也能一眼看见。
    let overlap_value = format!(
        "{} 行(每页滚动 {} 行)",
        config.page_overlap,
        config.page_step(visible_lines(height))
    );
    let title_value = if config.show_title { "开" } else { "关" };

    element!(Modal(
        width:Constraint::Percentage(60),
        height: Constraint::Length(10),
        open: is_open,
        // 非阻塞浮层:关闭键(o)与 Tab/i 都在父级 root handler 上,默认 blocks_lower=true
        // 会截断 root → 面板一开就关不掉。背景正文已用 is_scroll 门控,不会重复响应。
        blocks_lower: false,
        margin: Margin::new(1, 1),
        style: Style::default().dim(),
    ) {
        View(margin: Margin::new(1, 1)) {
            Border(
                border_style: theme.border.not_dim(),
                top_title: Line::from("阅读设置").centered().style(theme.title),
                bottom_title: hint,
            ) {
                View(height: Constraint::Length(3)) {
                    AdjustableSettingItem(
                        is_editing: index.get() == 0 && is_editing,
                        label: "翻页重叠:".to_string(),
                        value: overlap_value,
                        on_decrease: move |_| reader_display.write().decrease_page_overlap(),
                        on_increase: move |_| reader_display.write().increase_page_overlap(),
                    )
                }
                View(height: Constraint::Length(3)) {
                    AdjustableSettingItem(
                        is_editing: index.get() == 1 && is_editing,
                        // 此前只有 v 键盲切、没有可视入口,与翻页重叠同属 ReaderDisplayConfig,
                        // 一并收进面板。
                        label: "显示标题:".to_string(),
                        value: title_value.to_string(),
                        on_decrease: move |_| reader_display.write().show_title = false,
                        on_increase: move |_| reader_display.write().show_title = true,
                    )
                }
            }
        }
    })
    .into_any()
}