//! `app` 的单测：主题切换、窗口尺寸、截图闸门、gallery 能构图，以及**presenter 接线的闭环**。
//!
//! 闭环测试用的是 `MockBackend`（presenter 自带的假后端）：它走的是与真 host 完全相同的
//! `dispatch → drain_events → AppState::apply → 视图模型` 通道，所以「点 Play → 状态真的变」
//! 这件事在这里就能判死，不必等图形环境。

use unlucky_design::color::SchemeFlavor;
use unlucky_presenter::mock::MockBackend;
use unlucky_presenter::router::Route;
use unlucky_presenter::settings_bridge::SettingsBridge;

use super::message::Message;
use super::state::App;
use super::{APP_TITLE, WINDOW_SIZE};
use crate::cli::{Options, Screen};
use crate::pages;
use crate::theme::Families;

const FAMILIES: Families = Families {
    text: "Segoe UI",
    display: "Segoe UI",
    mono: "Consolas",
};

/// 不碰磁盘的 App（mock 后端 + 内存设置桥）。
fn headless(options: Options, flavor: SchemeFlavor) -> App {
    App::with_presenter(
        options,
        FAMILIES,
        flavor,
        Box::new(MockBackend::new()),
        SettingsBridge::memory_only(),
    )
}

fn screenshot_options() -> Options {
    Options {
        screenshot: Some(std::path::PathBuf::from("x.png")),
        ..Options::default()
    }
}

#[test]
fn switching_flavor_rebuilds_styles_but_keeps_ui_state() {
    let mut app = headless(Options::default(), SchemeFlavor::Light);
    app.state.navigate(Route::Logs);
    app.refresh_view();
    assert_eq!(app.ui().name(), "ull-m3-light");

    app.set_flavor(SchemeFlavor::Dark);

    assert_eq!(app.ui().name(), "ull-m3-dark", "切主题要换主题名");
    assert_eq!(app.state.route(), &Route::Logs, "切主题不许重置 UI 状态");
    assert_eq!(app.view.screen, pages::Screen::Logs, "视图模型跟着路由");
    assert!(app.options.screenshot.is_none(), "切主题不许改启动参数");
}

#[test]
fn window_size_is_the_acceptance_size() {
    assert_eq!((WINDOW_SIZE.width, WINDOW_SIZE.height), (1180.0, 760.0));
    assert_eq!(APP_TITLE, "Unlucky Launcher");
}

#[test]
fn screenshot_mode_never_waits_for_the_system_theme() {
    // 门禁依赖：CI 的 runtime-smoke 不带主题，xvfb 里也没有主题会话。
    let options = screenshot_options();
    assert!(!options.wants_system_theme(), "截图模式不许等系统主题");
    assert_eq!(options.capture_flavor(), Some(SchemeFlavor::Light));

    let app = headless(options, SchemeFlavor::Light);
    assert!(app.has_screenshot() && app.ui().name() == "ull-m3-light");
}

#[test]
fn gallery_screen_builds_a_tree() {
    assert_eq!(Options::default().screen, Screen::Shell, "默认仍是产品骨架");
    let options = Options {
        screen: Screen::Gallery,
        ..Options::default()
    };
    let app = headless(options, SchemeFlavor::Light);
    // 真实像素由 `--screen=gallery --screenshot` 出图 + `gallery::probe` 量
    let _ = app.view();
}

#[test]
fn frames_are_only_requested_in_screenshot_mode() {
    let mut app = headless(Options::default(), SchemeFlavor::Light);
    assert!(!app.wants_frames(), "普通运行不订阅帧，避免每帧重绘");

    app.options.screenshot = Some(std::path::PathBuf::from("x.png"));
    assert!(
        app.wants_frames(),
        "截图模式必须订阅帧事件才能在第 3 帧出图"
    );
}

// --------------------------------------------------------------- presenter 闭环

/// **首屏快照在 Boot 就到位**（截图在第 3 帧落盘，等 30 fps 的 tick 会拍进空页面）。
#[test]
fn boot_drains_the_first_snapshot_before_the_first_frame() {
    let mut app = headless(screenshot_options(), SchemeFlavor::Light);
    assert!(app.view.instances.rows.is_empty(), "还没 Boot");

    let _ = app.update(Message::Boot);

    assert_eq!(
        app.view.instances.rows.len(),
        4,
        "mock 的四个实例已进视图模型"
    );
    assert_eq!(app.view.screen, pages::Screen::Instances);
}

/// 首屏自动选中第一行（右栏不该开局空白），且**只做一次**：返回列表后再刷新不弹回详情。
#[test]
fn the_first_snapshot_selects_the_first_instance_once() {
    let mut app = headless(screenshot_options(), SchemeFlavor::Light);
    let _ = app.update(Message::Boot);
    assert_eq!(
        app.state.route(),
        &Route::Detail("survival".to_string()),
        "首屏快照到位后自动选中第一行"
    );

    let _ = app.update(Message::Page(pages::Message::Navigate(Route::Instances)));
    assert_eq!(app.state.route(), &Route::Instances);

    // 再推进一拍（会 drain_events + auto_select）：不该把他弹回详情页
    app.advance(super::state::TICK);
    assert_eq!(app.state.route(), &Route::Instances, "自动选中只做一次");
}

/// **点 Play → 命令真的派发出去 → 事件回流 → 页面真的变**（不做乐观回显）。
#[test]
fn launching_goes_through_the_backend_and_comes_back_as_events() {
    let mut app = headless(screenshot_options(), SchemeFlavor::Light);
    let _ = app.update(Message::Boot);
    let _ = app.update(Message::Page(pages::Message::Navigate(Route::Detail(
        "survival".to_string(),
    ))));

    let detail = app.view.instances.detail.as_ref().expect("有选中项");
    assert!(
        detail.can_launch && !detail.can_stop,
        "空闲：可启动不可停止"
    );

    let _ = app.update(Message::Page(pages::Message::Launch(
        "survival".to_string(),
    )));

    let detail = app.view.instances.detail.as_ref().expect("有选中项");
    assert!(
        !detail.can_launch && detail.can_stop,
        "派发 LaunchInstance 后后端发回了 Busy 事件：按钮组合必须已经翻转"
    );
    assert_eq!(
        detail.status.as_deref(),
        Some("Downloading · 0%"),
        "状态行来自事件里的进度，不是本地假造"
    );
}

/// 时间推进真的把状态往前推（后端的脚本按 tick 的累计时长走）。
#[test]
fn ticks_advance_the_backend_script() {
    let mut app = headless(screenshot_options(), SchemeFlavor::Light);
    let _ = app.update(Message::Boot);
    let _ = app.update(Message::Page(pages::Message::Navigate(Route::Detail(
        "survival".to_string(),
    ))));
    let _ = app.update(Message::Page(pages::Message::Launch(
        "survival".to_string(),
    )));

    // 33 ms × 50 ≈ 1.65 s：mock 的脚本在 1.5 s 从 Download 切到 Verify
    for _ in 0..50 {
        app.advance(super::state::TICK);
    }

    let detail = app.view.instances.detail.as_ref().expect("有选中项");
    let status = detail.status.as_deref().unwrap_or_default();
    assert!(
        status.starts_with("Verifying") || status.starts_with("Starting"),
        "50 拍之后应已过下载阶段，实际 {status:?}"
    );
}

/// 停止也是真命令：`StopInstance` 让 mock 直接回一条 Idle 事件。
#[test]
fn stopping_returns_to_idle_through_an_event() {
    let mut app = headless(screenshot_options(), SchemeFlavor::Light);
    let _ = app.update(Message::Boot);
    let _ = app.update(Message::Page(pages::Message::Navigate(Route::Detail(
        "survival".to_string(),
    ))));
    let _ = app.update(Message::Page(pages::Message::Launch(
        "survival".to_string(),
    )));
    let _ = app.update(Message::Page(pages::Message::Stop("survival".to_string())));

    let detail = app.view.instances.detail.as_ref().expect("有选中项");
    assert!(detail.can_launch && !detail.can_stop, "停下来回到空闲");
    assert!(detail.status.is_none(), "空闲没有状态行");
}

/// 导航：一级页替换、详情压栈、返回出栈——页面换的是 `Route`，不是页面自己的选中项。
#[test]
fn navigation_follows_the_presenter_router() {
    let mut app = headless(screenshot_options(), SchemeFlavor::Light);
    let _ = app.update(Message::Boot);

    let _ = app.update(Message::Page(pages::Message::Navigate(Route::Detail(
        "survival".to_string(),
    ))));
    assert_eq!(app.view.screen, pages::Screen::Instances, "详情仍是实例页");
    assert!(app.state.router.can_go_back());

    let _ = app.update(Message::Page(pages::Message::Navigate(Route::Settings)));
    assert_eq!(app.view.screen, pages::Screen::Settings);
    assert_eq!(
        app.view.active,
        Some(pages::Screen::Settings.nav()),
        "导航轨高亮跟着路由走"
    );
    assert!(
        !app.state.router.can_go_back(),
        "一级页互相替换，不进栈（presenter::router 的语义）"
    );

    let _ = app.update(Message::Page(pages::Message::Navigate(Route::Instances)));
    assert_eq!(app.view.screen, pages::Screen::Instances);
}

/// 视图模型跟着窗口宽度走（交互模式下 600 / 840 两条断点靠 resize 事件生效）。
#[test]
fn resizing_the_window_rebuilds_the_view_model() {
    let mut app = headless(Options::default(), SchemeFlavor::Light);
    let _ = app.update(Message::Boot);

    let _ = app.update(Message::Window(iced::window::Event::Resized(
        iced::Size::new(1180.0, 760.0),
    )));
    assert!((app.view.window_width - 1180.0).abs() < f32::EPSILON);

    let _ = app.update(Message::Window(iced::window::Event::Resized(
        iced::Size::new(700.0, 600.0),
    )));
    assert!((app.view.window_width - 700.0).abs() < f32::EPSILON);
    // 页面照旧能构图（窄窗退化到单列，不 panic）
    let _ = app.view();
}

/// 截图模式不读设置文件里的主题（D30 可复现：两台机器出同一张图）。
#[test]
fn screenshot_mode_ignores_the_settings_file_theme() {
    let mut app = headless(screenshot_options(), SchemeFlavor::Light);
    app.apply_config_theme();
    assert_eq!(app.ui().name(), "ull-m3-light", "截图模式的主题只认命令行");
}