using System;
using System.Collections.Generic;
using UnityEngine;

class AndroidStatusBar
{
    // Enums
    public enum States
    {
        Unknown,
        Visible,
        VisibleOverContent,
        TranslucentOverContent,
        Hidden,
    }

    // Constants
    private const uint DEFAULT_BACKGROUND_COLOR = 0xff000000;

#if UNITY_ANDROID
    // Android flags for API 21+ (Android 5.0+) and newer
    private const int VIEW_SYSTEM_UI_FLAG_LOW_PROFILE = 1;          // Added in API 14 (Android 4.0.x)
    private const int VIEW_SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN = 1024; // Added in API 16 (Android 4.1.x)

    private static int WINDOW_FLAG_FULLSCREEN = 0x00000400;
    private static int WINDOW_FLAG_FORCE_NOT_FULLSCREEN = 0x00000800;
    private static int WINDOW_FLAG_LAYOUT_IN_SCREEN = 0x00000100;
    private static int WINDOW_FLAG_TRANSLUCENT_STATUS = 0x04000000;
    private static int WINDOW_FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS = -2147483648; // Added in API 21 (Android 5.0)

    // Current values
    private static int systemUiVisibilityValue;
    private static int flagsValue;
#endif

    // Properties
    private static States _statusBarState;
    private static uint _statusBarColor = DEFAULT_BACKGROUND_COLOR;
    private static bool _isStatusBarTranslucent;
    private static bool _dimmed;
    
    // ================================================================================================================
    // INTERNAL INTERFACE ---------------------------------------------------------------------------------------------

    static AndroidStatusBar()
    {
        ApplyUIStates();
        ApplyUIColors();
    }

    private static void ApplyUIStates()
    {
#if UNITY_ANDROID && !UNITY_EDITOR
        int newFlagsValue = 0;
        int newSystemUiVisibilityValue = 0;

        // Apply dim values
        if (_dimmed) newSystemUiVisibilityValue |= VIEW_SYSTEM_UI_FLAG_LOW_PROFILE;

        // Apply color values
        if (_statusBarColor != DEFAULT_BACKGROUND_COLOR) newFlagsValue |= WINDOW_FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS;

        // Apply status bar values
        switch (_statusBarState) {
            case States.Visible:
                _isStatusBarTranslucent = false;
                newFlagsValue |= WINDOW_FLAG_FORCE_NOT_FULLSCREEN;
                break;
            case States.VisibleOverContent:
                _isStatusBarTranslucent = false;
                newFlagsValue |= WINDOW_FLAG_FORCE_NOT_FULLSCREEN | WINDOW_FLAG_LAYOUT_IN_SCREEN;
                newSystemUiVisibilityValue |= VIEW_SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN;
                break;
            case States.TranslucentOverContent:
                _isStatusBarTranslucent = true;
                newFlagsValue |= WINDOW_FLAG_FORCE_NOT_FULLSCREEN | WINDOW_FLAG_LAYOUT_IN_SCREEN | WINDOW_FLAG_TRANSLUCENT_STATUS;
                newSystemUiVisibilityValue |= VIEW_SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN;
                break;
            case States.Hidden:
                newFlagsValue |= WINDOW_FLAG_FULLSCREEN | WINDOW_FLAG_LAYOUT_IN_SCREEN;
                if (_isStatusBarTranslucent) newFlagsValue |= WINDOW_FLAG_TRANSLUCENT_STATUS;
                break;
        }

        if (Screen.fullScreen) Screen.fullScreen = false;

        // Applies everything natively
        SetFlags(newFlagsValue);
        SetSystemUiVisibility(newSystemUiVisibilityValue);
#endif
    }

    private static void ApplyUIColors()
    {
#if UNITY_ANDROID && !UNITY_EDITOR
        RunOnAndroidUiThread(ApplyUIColorsAndroidInThread);
#endif
    }

#if UNITY_ANDROID
    private static void RunOnAndroidUiThread(Action target)
    {
        using (var unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
        {
            using (var activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
            {
                activity.Call("runOnUiThread", new AndroidJavaRunnable(target));
            }
        }
    }

    private static void SetSystemUiVisibility(int value)
    {
        if (systemUiVisibilityValue != value)
        {
            systemUiVisibilityValue = value;
            RunOnAndroidUiThread(SetSystemUiVisibilityInThread);
        }
    }

    private static void SetSystemUiVisibilityInThread()
    {
        using (var unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
        {
            using (var activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
            {
                using (var window = activity.Call<AndroidJavaObject>("getWindow"))
                {
                    using (var view = window.Call<AndroidJavaObject>("getDecorView"))
                    {
                        view.Call("setSystemUiVisibility", systemUiVisibilityValue);
                    }
                }
            }
        }
    }

    private static void SetFlags(int value)
    {
        if (flagsValue != value)
        {
            flagsValue = value;
            RunOnAndroidUiThread(SetFlagsInThread);
        }
    }

    private static void SetFlagsInThread()
    {
        using (var unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
        {
            using (var activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
            {
                using (var window = activity.Call<AndroidJavaObject>("getWindow"))
                {
                    window.Call("setFlags", flagsValue, -1); // (int)0x7FFFFFFF
                }
            }
        }
    }

    private static void ApplyUIColorsAndroidInThread()
    {
        using (var unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
        {
            using (var activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
            {
                using (var window = activity.Call<AndroidJavaObject>("getWindow"))
                {
                    window.Call("setStatusBarColor", unchecked((int)_statusBarColor));
                }
            }
        }
    }
#endif

    // ================================================================================================================
    // ACCESSOR INTERFACE ---------------------------------------------------------------------------------------------

    public static States statusBarState
    {
        get { return _statusBarState; }
        set
        {
            if (_statusBarState != value)
            {
                _statusBarState = value;
                ApplyUIStates();
            }
        }
    }

    public static bool dimmed
    {
        get { return _dimmed; }
        set
        {
            if (_dimmed != value)
            {
                _dimmed = value;
                ApplyUIStates();
            }
        }
    }

    public static uint statusBarColor
    {
        get { return _statusBarColor; }
        set
        {
            if (_statusBarColor != value)
            {
                _statusBarColor = value;
                ApplyUIColors();
                ApplyUIStates();
            }
        }
    }
}