// Copyright 2019-2022 Tauri Programme within The Commons Conservancy
// SPDX-License-Identifier: Apache-2.0
// SPDX-License-Identifier: MIT

// 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,
    #[deprecated(since = "macOS 10.14", note = "Use a semantic material instead.")]
    Light = 1,
    #[deprecated(since = "macOS 10.14", note = "Use a semantic material instead.")]
    Dark = 2,
    #[deprecated(since = "macOS 10.14", note = "Use a semantic material instead.")]
    MediumLight = 8,
    #[deprecated(since = "macOS 10.14", note = "Use a semantic material instead.")]
    UltraDark = 9,

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

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

    /// macOS 10.14+
    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,
}

/// <https://developer.apple.com/documentation/appkit/nsvisualeffectview/state>
#[allow(dead_code)]
#[repr(u64)]
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum NSVisualEffectState {
    /// Make window vibrancy state follow the window's active state
    FollowsWindowActiveState = 0,
    /// Make window vibrancy state always active
    Active = 1,
    /// Make window vibrancy state always inactive
    Inactive = 2,
}

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

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

    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,
        state: Option<NSVisualEffectState>,
        radius: Option<f64>,
    ) -> 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)
                || (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.setCornerRadius_(radius.unwrap_or(0.0));
            blurred_view.setBlendingMode_(NSVisualEffectBlendingMode::BehindWindow);
            blurred_view.setState_(state.unwrap_or(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,
    }

    // 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 setCornerRadius_(self, radius: f64);
        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 setCornerRadius_(self, radius: f64) {
            msg_send![self, setCornerRadius: radius]
        }

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

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