// The use of NSVisualEffectView comes from https://github.com/joboet/winit/tree/macos_blurred_background
// with a bit of rewrite by @youngsing to make it more like cocoa::appkit style.

/// <https://developer.apple.com/documentation/appkit/nsvisualeffectview/material>
#[repr(u64)]
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum NSVisualEffectMaterial {
  #[deprecated(
    since = "macOS 10.14",
    note = "A default material appropriate for the view's effectiveAppearance.  You should instead choose an appropriate semantic material."
  )]
  AppearanceBased = 0, // Default, Deprecated macOS 10.10–10.14
  #[deprecated(since = "macOS 10.14", note = "Use a semantic material instead.")]
  Light = 1, // Deprecated macOS 10.10–10.14
  #[deprecated(since = "macOS 10.14", note = "Use a semantic material instead.")]
  Dark = 2, // Deprecated macOS 10.10–10.14
  #[deprecated(since = "macOS 10.14", note = "Use a semantic material instead.")]
  MediumLight = 8, // Deprecated macOS 10.11–10.14
  #[deprecated(since = "macOS 10.14", note = "Use a semantic material instead.")]
  UltraDark = 9, // Deprecated macOS 10.11–10.14

  Titlebar = 3,  // macOS 10.10+
  Selection = 4, // macOS 10.10+

  Menu = 5,    // macOS 10.11+
  Popover = 6, // macOS 10.11+
  Sidebar = 7, // macOS 10.11+

  HeaderView = 10,            // macOS 10.14+
  Sheet = 11,                 // macOS 10.14+
  WindowBackground = 12,      // macOS 10.14+
  HudWindow = 13,             // macOS 10.14+
  FullScreenUI = 15,          // macOS 10.14+
  Tooltip = 17,               // macOS 10.14+
  ContentBackground = 18,     // macOS 10.14+
  UnderWindowBackground = 21, // macOS 10.14+
  UnderPageBackground = 22,   // macOS 10.14+
}

#[cfg(target_os = "macos")]
pub use internal::apply_vibrancy;

#[cfg(target_os = "macos")]
mod internal {
  use super::NSVisualEffectMaterial;

  use cocoa::{
    appkit::{
      NSAppKitVersionNumber, NSAppKitVersionNumber10_10, NSAppKitVersionNumber10_11,
      NSAutoresizingMaskOptions, NSView, NSViewHeightSizable, NSViewWidthSizable, NSWindow,
      NSWindowOrderingMode,
    },
    base::{id, nil, BOOL},
    foundation::{NSAutoreleasePool, NSPoint, NSRect, NSSize},
  };
  use objc::{class, msg_send, sel, sel_impl};

  use crate::Error;

  #[allow(deprecated)]
  pub fn apply_vibrancy(window: id, appearance: NSVisualEffectMaterial) -> Result<(), Error> {
    unsafe {
      if NSAppKitVersionNumber < NSAppKitVersionNumber10_10 {
        eprintln!("\"NSVisualEffectView\" is only available on macOS 10.10 or newer");
        return Err(Error::UnsupportedPlatformVersion(
          "\"apply_vibrancy()\" is only available on macOS 10.0 or newer.",
        ));
      }

      if !msg_send![class!(NSThread), isMainThread] {
        return Err(Error::NotMainThread(
          "\"apply_vibrancy()\" can only be used on the main thread.",
        ));
      }

      let mut m = appearance;
      if appearance as u32 > 9 && NSAppKitVersionNumber < NSAppKitVersionNumber10_14 {
        m = NSVisualEffectMaterial::AppearanceBased;
      } else if appearance as u32 > 4 && NSAppKitVersionNumber < NSAppKitVersionNumber10_11 {
        m = NSVisualEffectMaterial::AppearanceBased;
      }

      let ns_view: id = window.contentView();
      let bounds = NSView::bounds(ns_view);

      let blurred_view = NSVisualEffectView::initWithFrame_(NSVisualEffectView::alloc(nil), bounds);
      blurred_view.autorelease();

      blurred_view.setMaterial_(m);
      blurred_view.setBlendingMode_(NSVisualEffectBlendingMode::BehindWindow);
      blurred_view.setState_(NSVisualEffectState::FollowsWindowActiveState);
      NSVisualEffectView::setAutoresizingMask_(
        blurred_view,
        NSViewWidthSizable | NSViewHeightSizable,
      );

      let _: () = msg_send![ns_view, addSubview: blurred_view positioned: NSWindowOrderingMode::NSWindowBelow relativeTo: 0];
    }
    Ok(())
  }

  #[allow(non_upper_case_globals)]
  const NSAppKitVersionNumber10_14: f64 = 1671.0;

  // https://developer.apple.com/documentation/appkit/nsvisualeffectview/blendingmode
  #[allow(dead_code)]
  #[repr(u64)]
  #[derive(Clone, Copy, Debug, PartialEq)]
  enum NSVisualEffectBlendingMode {
    BehindWindow = 0,
    WithinWindow = 1,
  }

  // https://developer.apple.com/documentation/appkit/nsvisualeffectview/state
  #[allow(dead_code)]
  #[repr(u64)]
  #[derive(Clone, Copy, Debug, PartialEq)]
  enum NSVisualEffectState {
    FollowsWindowActiveState = 0,
    Active = 1,
    Inactive = 2,
  }

  // macos 10.10+
  // https://developer.apple.com/documentation/appkit/nsvisualeffectview
  #[allow(non_snake_case)]
  trait NSVisualEffectView: Sized {
    unsafe fn alloc(_: Self) -> id {
      msg_send![class!(NSVisualEffectView), alloc]
    }

    unsafe fn init(self) -> id;
    unsafe fn initWithFrame_(self, frameRect: NSRect) -> id;
    unsafe fn bounds(self) -> NSRect;
    unsafe fn frame(self) -> NSRect;
    unsafe fn setFrameSize(self, frameSize: NSSize);
    unsafe fn setFrameOrigin(self, frameOrigin: NSPoint);

    unsafe fn superview(self) -> id;
    unsafe fn removeFromSuperview(self);
    unsafe fn setAutoresizingMask_(self, autoresizingMask: NSAutoresizingMaskOptions);

    // API_AVAILABLE(macos(10.12));
    unsafe fn isEmphasized(self) -> BOOL;
    // API_AVAILABLE(macos(10.12));
    unsafe fn setEmphasized_(self, emphasized: BOOL);

    unsafe fn setMaterial_(self, material: NSVisualEffectMaterial);
    unsafe fn setState_(self, state: NSVisualEffectState);
    unsafe fn setBlendingMode_(self, mode: NSVisualEffectBlendingMode);
  }

  #[allow(non_snake_case)]
  impl NSVisualEffectView for id {
    unsafe fn init(self) -> id {
      msg_send![self, init]
    }

    unsafe fn initWithFrame_(self, frameRect: NSRect) -> id {
      msg_send![self, initWithFrame: frameRect]
    }

    unsafe fn bounds(self) -> NSRect {
      msg_send![self, bounds]
    }

    unsafe fn frame(self) -> NSRect {
      msg_send![self, frame]
    }

    unsafe fn setFrameSize(self, frameSize: NSSize) {
      msg_send![self, setFrameSize: frameSize]
    }

    unsafe fn setFrameOrigin(self, frameOrigin: NSPoint) {
      msg_send![self, setFrameOrigin: frameOrigin]
    }

    unsafe fn superview(self) -> id {
      msg_send![self, superview]
    }

    unsafe fn removeFromSuperview(self) {
      msg_send![self, removeFromSuperview]
    }

    unsafe fn setAutoresizingMask_(self, autoresizingMask: NSAutoresizingMaskOptions) {
      msg_send![self, setAutoresizingMask: autoresizingMask]
    }

    // API_AVAILABLE(macos(10.12));
    unsafe fn isEmphasized(self) -> BOOL {
      msg_send![self, isEmphasized]
    }

    // API_AVAILABLE(macos(10.12));
    unsafe fn setEmphasized_(self, emphasized: BOOL) {
      msg_send![self, setEmphasized: emphasized]
    }

    unsafe fn setMaterial_(self, material: NSVisualEffectMaterial) {
      msg_send![self, setMaterial: material]
    }

    unsafe fn setState_(self, state: NSVisualEffectState) {
      msg_send![self, setState: state]
    }

    unsafe fn setBlendingMode_(self, mode: NSVisualEffectBlendingMode) {
      msg_send![self, setBlendingMode: mode]
    }
  }
}