using System;
using System.Collections.Generic;
using System.Linq;
using Unity.UIWidgets.foundation;

namespace Unity.UIWidgets.services 
{
    public abstract class KeyboardKey : Diagnosticable
    {
        protected KeyboardKey() { }
    }
    
    public class LogicalKeyboardKey : KeyboardKey, IEquatable<LogicalKeyboardKey> 
    {
        public bool Equals(LogicalKeyboardKey other)
        {
            if (ReferenceEquals(null, other)) {
                return false;
            }

            if (ReferenceEquals(this, other)) {
                return true;
            }

            return keyId == other.keyId;
        }

        public override bool Equals(object obj)
        {
            if (ReferenceEquals(null, obj)) {
                return false;
            }

            if (ReferenceEquals(this, obj)) {
                return true;
            }

            if (obj.GetType() != GetType()) {
                return false;
            }

            return Equals((LogicalKeyboardKey) obj);
        }

        public override int GetHashCode()
        {
            unchecked
            {
                int hashCode = (int)keyId;
                hashCode = (hashCode * 397) ^ (debugName != null ? debugName.GetHashCode() : 0);
                hashCode = (hashCode * 397) ^ (keyLabel != null ? keyLabel.GetHashCode() : 0);
                return hashCode;
            }
        }

        protected LogicalKeyboardKey(long keyId, string debugName = null, string keyLabel = null) : base()
        {
            D.assert(keyId != null);
            this.keyId = keyId;
            this.debugName = debugName;
            this.keyLabel = keyLabel;
        }
        
        public readonly long keyId;
          
        public readonly string debugName;

        public readonly string keyLabel;

        public static LogicalKeyboardKey findKeyByKeyId(int keyId) => _knownLogicalKeys[keyId];

        public static bool isControlCharacter(string label) 
        {
            if (label.Length > 1) 
            {
              return false;
            }
            int codeUnit = label[0];
            return (codeUnit <= 0x1f && codeUnit >= 0x00) || (codeUnit >= 0x7f && codeUnit <= 0x9f);
        }
          
        public bool  isAutogenerated 
        {
            get 
            {
                return (keyId & autogeneratedMask) != 0;
            }
        }

        public HashSet<LogicalKeyboardKey> synonyms 
        {
            get {
                HashSet<LogicalKeyboardKey> result = new HashSet<LogicalKeyboardKey>();
                LogicalKeyboardKey item = _synonyms[this];
                if (item == null) {
                    return result;
                }
                result.Add(item: item);
                return result;
            }
        }
        
        public static HashSet<LogicalKeyboardKey> collapseSynonyms(HashSet<LogicalKeyboardKey> input) 
        { 
            HashSet<LogicalKeyboardKey> result = new HashSet<LogicalKeyboardKey>();
            foreach (LogicalKeyboardKey key in input) 
            {
                LogicalKeyboardKey synonym = _synonyms[key];
                result.Add(synonym ?? key);
            }
            return result;
        }

      
      public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
        base.debugFillProperties(properties);
        properties.add(new StringProperty("keyId", keyId.ToString().PadLeft(8,'\0'), showName: true));
        properties.add(new StringProperty("keyLabel", keyLabel, showName: true));
        properties.add(new StringProperty("debugName", debugName, showName: true, defaultValue: null));
      }
      
      /// Mask for the 32-bit value portion of the key code.
      ///
      /// This is used by platform-specific code to generate Flutter key codes.
      public static readonly long valueMask = 0x000FFFFFFFF;
      
      /// Mask for the platform prefix portion of the key code.
      ///
      /// This is used by platform-specific code to generate Flutter key codes.
      public static readonly long platformMask = 0x0FF00000000;

      /// Mask for the auto-generated bit portion of the key code.
      ///
      /// This is used by platform-specific code to generate new Flutter key codes
      /// for keys which are not recognized.
      public static readonly long autogeneratedMask = 0x10000000000;
      
      /// Mask for the synonym pseudo-keys generated for keys which appear in more
      /// than one place on the keyboard.
      ///
      /// IDs in this range are used to represent keys which appear in multiple
      /// places on the keyboard, such as the SHIFT, ALT, CTRL, and numeric keypad
      /// keys. These key codes will never be generated by the key event system, but
      /// may be used in key maps to represent the union of all the keys of each
      /// type in order to match them.
      ///
      /// To look up the synonyms that are defined, look in the [synonyms] map.
      public static readonly long synonymMask = 0x20000000000;

      /// The code prefix for keys which have a Unicode representation.
      ///
      /// This is used by platform-specific code to generate Flutter key codes.
      public static readonly long unicodePlane = 0x00000000000;

      /// The code prefix for keys which do not have a Unicode representation.
      ///
      /// This is used by platform-specific code to generate Flutter key codes using
      /// HID Usage codes.
      public static readonly long hidPlane = 0x00100000000;

      /// Represents the logical "None" key on the keyboard.
      ///
      /// See the function [RawKeyEvent.logicalKey] for more information.
      public static readonly LogicalKeyboardKey none = new LogicalKeyboardKey(0x00100000000, debugName: foundation_.kReleaseMode ? null : "None");

        /// Represents the logical "Control Left" key on the keyboard.
      ///
      /// See the function [RawKeyEvent.logicalKey] for more information.
      public static readonly LogicalKeyboardKey controlLeft = new LogicalKeyboardKey(0x001000700e0, debugName: foundation_.kReleaseMode ? null : "Control Left");

      /// Represents the logical "Shift Left" key on the keyboard.
      ///
      /// See the function [RawKeyEvent.logicalKey] for more information.
      public static readonly LogicalKeyboardKey shiftLeft = new LogicalKeyboardKey(0x001000700e1, debugName: foundation_.kReleaseMode ? null : "Shift Left");

      /// Represents the logical "Alt Left" key on the keyboard.
      ///
      /// See the function [RawKeyEvent.logicalKey] for more information.
      public static readonly LogicalKeyboardKey altLeft = new LogicalKeyboardKey(0x001000700e2, debugName: foundation_.kReleaseMode ? null : "Alt Left");

      /// Represents the logical "Meta Left" key on the keyboard.
      ///
      /// See the function [RawKeyEvent.logicalKey] for more information.
      public static readonly LogicalKeyboardKey metaLeft = new LogicalKeyboardKey(0x001000700e3, debugName: foundation_.kReleaseMode ? null : "Meta Left");

      /// Represents the logical "Control Right" key on the keyboard.
      ///
      /// See the function [RawKeyEvent.logicalKey] for more information.
      public static readonly LogicalKeyboardKey controlRight = new LogicalKeyboardKey(0x001000700e4, debugName: foundation_.kReleaseMode ? null : "Control Right");

      /// Represents the logical "Shift Right" key on the keyboard.
      ///
      /// See the function [RawKeyEvent.logicalKey] for more information.
      public static readonly LogicalKeyboardKey shiftRight = new LogicalKeyboardKey(0x001000700e5, debugName: foundation_.kReleaseMode ? null : "Shift Right");

      /// Represents the logical "Alt Right" key on the keyboard.
      ///
      /// See the function [RawKeyEvent.logicalKey] for more information.
      public static readonly LogicalKeyboardKey altRight = new LogicalKeyboardKey(0x001000700e6, debugName: foundation_.kReleaseMode ? null : "Alt Right");

      /// Represents the logical "Meta Right" key on the keyboard.
      ///
      /// See the function [RawKeyEvent.logicalKey] for more information.
      public static readonly LogicalKeyboardKey metaRight = new LogicalKeyboardKey(0x001000700e7, debugName: foundation_.kReleaseMode ? null : "Meta Right");

      /// Represents the logical "Shift" key on the keyboard.
      ///
      /// This key represents the union of the keys {shiftLeft, shiftRight} when
      /// comparing keys. This key will never be generated directly, its main use is
      /// in defining key maps.
      public static readonly LogicalKeyboardKey shift = new LogicalKeyboardKey(0x201000700e1, debugName: foundation_.kReleaseMode ? null : "Shift");

      /// Represents the logical "Meta" key on the keyboard.
      ///
      /// This key represents the union of the keys {metaLeft, metaRight} when
      /// comparing keys. This key will never be generated directly, its main use is
      /// in defining key maps.
      public static readonly LogicalKeyboardKey meta = new LogicalKeyboardKey(0x201000700e3, debugName: foundation_.kReleaseMode ? null : "Meta");

      /// Represents the logical "Alt" key on the keyboard.
      ///
      /// This key represents the union of the keys {altLeft, altRight} when
      /// comparing keys. This key will never be generated directly, its main use is
      /// in defining key maps.
      public static readonly LogicalKeyboardKey alt = new LogicalKeyboardKey(0x201000700e2, debugName: foundation_.kReleaseMode ? null : "Alt");

      /// Represents the logical "Control" key on the keyboard.
      ///
      /// This key represents the union of the keys {controlLeft, controlRight} when
      /// comparing keys. This key will never be generated directly, its main use is
      /// in defining key maps.
      public static readonly LogicalKeyboardKey control = new LogicalKeyboardKey(0x201000700e0, debugName: foundation_.kReleaseMode ? null : "Control");

      // A list of all predefined constant LogicalKeyboardKeys so they can be
      // searched.
      public static readonly Dictionary<long, LogicalKeyboardKey> _knownLogicalKeys = new Dictionary<long, LogicalKeyboardKey>{
          {0x0100000000, none},
          {0x201000700e1, shift},
          {0x201000700e3, meta},
          {0x201000700e2, alt},
          {0x201000700e0, control},
      };

      // A map of keys to the pseudo-key synonym for that key. Used by getSynonyms.
      public static readonly Dictionary<LogicalKeyboardKey, LogicalKeyboardKey> _synonyms = new Dictionary<LogicalKeyboardKey, LogicalKeyboardKey>{
          {shiftLeft, shift},
          {shiftRight, shift},
          {metaLeft, meta},
          {metaRight, meta},
          {altLeft, alt},
          {altRight, alt},
          {controlLeft, control},
          {controlRight, control},
      };
    }
    
    public class PhysicalKeyboardKey : KeyboardKey, IEquatable<PhysicalKeyboardKey>  
    {

        protected PhysicalKeyboardKey(int usbHidUsage, string debugName = null) 
        {
            D.assert(usbHidUsage != null);
            this.usbHidUsage = usbHidUsage;
            this.debugName = debugName;
        }
        

        /// The unique USB HID usage ID of this physical key on the keyboard.
        ///
        /// Due to the variations in platform APIs, this may not be the actual HID
        /// usage code from the hardware, but a value derived from available
        /// information on the platform.
        ///
        /// See <https://www.usb.org/sites/default/files/documents/hut1_12v2.pdf>
        /// for the HID usage values and their meanings.
        public readonly int usbHidUsage;

        /// The debug string to print for this keyboard key, which will be null in
        /// release mode.
        public readonly string debugName;

        /// Finds a known [PhysicalKeyboardKey] that matches the given USB HID usage
        /// code.
        public static PhysicalKeyboardKey findKeyByCode(int usageCode) => _knownPhysicalKeys[usageCode];
        
        public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
            base.debugFillProperties(properties);
            properties.add(new StringProperty("usbHidUsage", usbHidUsage.ToString().PadLeft(8,'0'), showName: true));
            properties.add(new StringProperty("debugName", debugName, showName: true, defaultValue: null));
        }

        public bool Equals(PhysicalKeyboardKey other)
        {
            if (ReferenceEquals(null, other)) {
                return false;
            }

            if (ReferenceEquals(this, other)) {
                return true;
            }

            return usbHidUsage == other.usbHidUsage;
        }

        public override bool Equals(object obj)
        {
            if (ReferenceEquals(null, obj)) {
                return false;
            }

            if (ReferenceEquals(this, obj)) {
                return true;
            }

            if (obj.GetType() != GetType()) {
                return false;
            }

            return Equals((PhysicalKeyboardKey) obj);
        }

        public override int GetHashCode()
        {
            unchecked
            {
                return (usbHidUsage * 397) ^ (debugName != null ? debugName.GetHashCode() : 0);
            }
        }
        // Key constants for all keyboard keys in the USB HID specification at the
        // time Flutter was built.

        /// Represents the location of the "None" key on a generalized keyboard.
        ///
        /// See the function [RawKeyEvent.physicalKey] for more information.
        public static readonly PhysicalKeyboardKey none = new PhysicalKeyboardKey(0x00000000, debugName: foundation_.kReleaseMode ? null : "None");

        /// Represents the location of the "Control Left" key on a generalized
        /// keyboard.
        ///
        /// See the function [RawKeyEvent.physicalKey] for more information.
        public static readonly PhysicalKeyboardKey controlLeft = new PhysicalKeyboardKey(0x000700e0, debugName: foundation_.kReleaseMode ? null : "Control Left");

        /// Represents the location of the "Shift Left" key on a generalized keyboard.
        ///
        /// See the function [RawKeyEvent.physicalKey] for more information.
        public static readonly PhysicalKeyboardKey shiftLeft = new PhysicalKeyboardKey(0x000700e1, debugName: foundation_.kReleaseMode ? null : "Shift Left");

        /// Represents the location of the "Alt Left" key on a generalized keyboard.
        ///
        /// See the function [RawKeyEvent.physicalKey] for more information.
        public static readonly PhysicalKeyboardKey altLeft = new PhysicalKeyboardKey(0x000700e2, debugName: foundation_.kReleaseMode ? null : "Alt Left");

        /// Represents the location of the "Meta Left" key on a generalized keyboard.
        ///
        /// See the function [RawKeyEvent.physicalKey] for more information.
        public static readonly PhysicalKeyboardKey metaLeft = new PhysicalKeyboardKey(0x000700e3, debugName: foundation_.kReleaseMode ? null : "Meta Left");

        /// Represents the location of the "Control Right" key on a generalized
        /// keyboard.
        ///
        /// See the function [RawKeyEvent.physicalKey] for more information.
        public static readonly PhysicalKeyboardKey controlRight = new PhysicalKeyboardKey(0x000700e4, debugName: foundation_.kReleaseMode ? null : "Control Right");

        /// Represents the location of the "Shift Right" key on a generalized
        /// keyboard.
        ///
        /// See the function [RawKeyEvent.physicalKey] for more information.
        public static readonly PhysicalKeyboardKey shiftRight = new PhysicalKeyboardKey(0x000700e5, debugName: foundation_.kReleaseMode ? null : "Shift Right");

        /// Represents the location of the "Alt Right" key on a generalized keyboard.
        ///
        /// See the function [RawKeyEvent.physicalKey] for more information.
        public static readonly PhysicalKeyboardKey altRight = new PhysicalKeyboardKey(0x000700e6, debugName: foundation_.kReleaseMode ? null : "Alt Right");

        /// Represents the location of the "Meta Right" key on a generalized keyboard.
        ///
        /// See the function [RawKeyEvent.physicalKey] for more information.
        public static readonly PhysicalKeyboardKey metaRight = new PhysicalKeyboardKey(0x000700e7, debugName: foundation_.kReleaseMode ? null : "Meta Right");

        
        public static readonly Dictionary<int, PhysicalKeyboardKey> _knownPhysicalKeys =
            new Dictionary<int, PhysicalKeyboardKey>() {
                {0x00000000, none},
                {0x000700e0, controlLeft},
                {0x000700e1, shiftLeft},
                {0x000700e2, altLeft},
                {0x000700e3, metaLeft},
                {0x000700e4, controlRight},
                {0x000700e5, shiftRight},
                {0x000700e6, altRight},
                {0x000700e7, metaRight},
            };
    }


}