//! macOS 原生标题栏适配。定位系统窗口按钮并沿用用户的标题栏双击设置。
//! 仅在 macOS 编译；Objective-C 交互局限在原生窗口层，不参与 Endor 布局与事件分发。
//!
//! Keep AppKit's real window buttons aligned with the custom tab strip.
use objc2_app_kit::{NSApplication, NSView, NSWindowButton, NSWindowStyleMask};
use objc2_foundation::{MainThreadMarker, NSPoint, NSString, NSUserDefaults};
use winit::{
    raw_window_handle::{HasWindowHandle, RawWindowHandle},
    window::Window,
};

/// The custom draggable row does not receive AppKit's titlebar double-click
/// action automatically. Use the native click count and native window actions.
/// 读取系统偏好的标题栏双击行为，委托原生窗口执行相应动作。
pub fn titlebar_double_click(window: &Window) -> bool {
    // AppKit 必须在主线程调用；不在主线程、无有效句柄或句柄非 AppKit 时返回未处理。
    let Some(main_thread) = MainThreadMarker::new() else {
        return false;
    };
    let Ok(handle) = window.window_handle() else {
        return false;
    };
    let RawWindowHandle::AppKit(handle) = handle.as_raw() else {
        return false;
    };
    // SAFETY: called on the event-loop thread during a left-button press, with
    // a live winit-owned NSView. No native object outlives the Window borrow.
    unsafe {
        let Some(event) = NSApplication::sharedApplication(main_thread).currentEvent() else {
            return false;
        };
        // 依赖系统原生连击计数，不自行推算两次输入时间，保持用户设置与系统行为一致。
        if event.clickCount() != 2 {
            return false;
        }
        let view = &*handle.ns_view.as_ptr().cast::<NSView>();
        let Some(native) = view.window() else {
            return false;
        };
        // 全屏时把双击视作已处理，但不执行缩放/最小化，避免自绘标题行改变全屏状态。
        if native.styleMask().contains(NSWindowStyleMask::FullScreen) {
            return true;
        }
        let action = NSUserDefaults::standardUserDefaults()
            .stringForKey(&NSString::from_str("AppleActionOnDoubleClick"))
            .map(|value| value.to_string());
        // 按系统偏好执行动作；缺省采用 Zoom，禁用或未知选项不动作，但仍返回已处理。
        match action.as_deref() {
            Some("Minimize") => native.performMiniaturize(None),
            None | Some("Maximize" | "Fill") => native.performZoom(None),
            // Respect disabled/unrecognized system actions without moving it.
            _ => {}
        }
    }
    true
}

/// Called only on winit's main thread, after native creation and before drawing.
/// AppKit can restore its default button positions when laying out the title bar.
/// 调整真实 macOS 窗口三键的位置，与全尺寸内容和侧栏控制区对齐。
pub fn align_controls(window: &Window) {
    let Ok(handle) = window.window_handle() else {
        return;
    };
    let RawWindowHandle::AppKit(handle) = handle.as_raw() else {
        return;
    };
    // SAFETY: winit owns this NSView for the lifetime of the borrowed Window.
    // All AppKit access is on the event-loop thread; no native pointers escape.
    unsafe {
        let view = &*handle.ns_view.as_ptr().cast::<NSView>();
        let Some(native) = view.window() else {
            return;
        };
        // Fullscreen traffic lights belong to AppKit's separate floating toolbar.
        if native.styleMask().contains(NSWindowStyleMask::FullScreen) {
            return;
        }
        let bounds = view.bounds();
        let center = f64::from(crate::sidebar::HEADER) / 2.0;
        // AppKit 视图可能以左下或左上为原点；先在内容视图内算标题行中心，再转到按钮父视图。
        let content_y = if view.isFlipped() {
            bounds.origin.y + center
        } else {
            bounds.origin.y + bounds.size.height - center
        };
        for kind in [
            NSWindowButton::NSWindowCloseButton,
            NSWindowButton::NSWindowMiniaturizeButton,
            NSWindowButton::NSWindowZoomButton,
        ] {
            let Some(button) = native.standardWindowButton(kind) else {
                continue;
            };
            let Some(parent) = button.superview() else {
                continue;
            };
            // 按钮可能位于不同 AppKit 容器，必须使用 convertPoint 而不能直接赋内容视图坐标。
            let target = parent.convertPoint_fromView(NSPoint::new(0.0, content_y), Some(view));
            let frame = button.frame();
            let y = target.y - frame.size.height / 2.0;
            // Preserve native button size, horizontal spacing and behavior.
            // 只改变足够明显的纵向偏差，保留系统按钮横向间距、尺寸与原生动作，避免反复微调布局。
            if (frame.origin.y - y).abs() > 0.01 {
                button.setFrameOrigin(NSPoint::new(frame.origin.x, y));
            }
        }
    }
}