using UnityEngine;
using UnityEngine.TextCore;
using UnityEngine.TextCore.LowLevel;
using UnityEditor;
using System.Collections;
using System.Text.RegularExpressions;


namespace TMPro.EditorUtilities
{

    [CustomPropertyDrawer(typeof(TMP_GlyphPairAdjustmentRecord))]
    public class TMP_GlyphPairAdjustmentRecordPropertyDrawer : PropertyDrawer
    {
        private bool isEditingEnabled = false;
        private bool isSelectable = false;

        private string m_FirstCharacter = string.Empty;
        private string m_SecondCharacter = string.Empty;
        private string m_PreviousInput;

        static GUIContent s_CharacterTextFieldLabel = new GUIContent("Char:", "Enter the character or its UTF16 or UTF32 Unicode character escape sequence. For UTF16 use \"\\uFF00\" and for UTF32 use \"\\UFF00FF00\" representation.");

        public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
        {
            SerializedProperty prop_FirstAdjustmentRecord = property.FindPropertyRelative("m_FirstAdjustmentRecord");
            SerializedProperty prop_SecondAdjustmentRecord = property.FindPropertyRelative("m_SecondAdjustmentRecord");

            SerializedProperty prop_FirstGlyphIndex = prop_FirstAdjustmentRecord.FindPropertyRelative("m_GlyphIndex");
            SerializedProperty prop_FirstGlyphValueRecord = prop_FirstAdjustmentRecord.FindPropertyRelative("m_GlyphValueRecord");

            SerializedProperty prop_SecondGlyphIndex = prop_SecondAdjustmentRecord.FindPropertyRelative("m_GlyphIndex");
            SerializedProperty prop_SecondGlyphValueRecord = prop_SecondAdjustmentRecord.FindPropertyRelative("m_GlyphValueRecord");

            SerializedProperty prop_FontFeatureLookupFlags = property.FindPropertyRelative("m_FeatureLookupFlags");

            position.yMin += 2;

            float width = position.width / 2;
            float padding = 5.0f;

            Rect rect;

            isEditingEnabled = GUI.enabled;
            isSelectable = label.text == "Selectable" ? true : false;

            if (isSelectable)
                GUILayoutUtility.GetRect(position.width, 75);
            else
                GUILayoutUtility.GetRect(position.width, 55);

            GUIStyle style = new GUIStyle(EditorStyles.label);
            style.richText = true;

            // First Glyph
            GUI.enabled = isEditingEnabled;
            if (isSelectable)
            {
                rect = new Rect(position.x + 70, position.y, position.width, 49);

                float labelWidth = GUI.skin.label.CalcSize(new GUIContent("ID: " + prop_FirstGlyphIndex.intValue)).x;
                EditorGUI.LabelField(new Rect(position.x + (64 - labelWidth) / 2, position.y + 60, 64f, 18f), new GUIContent("ID: <color=#FFFF80>" + prop_FirstGlyphIndex.intValue + "</color>"), style);

                GUI.enabled = isEditingEnabled;
                EditorGUIUtility.labelWidth = 30f;

                rect = new Rect(position.x + 70, position.y + 10, (width - 70) - padding, 18);
                EditorGUI.PropertyField(rect, prop_FirstGlyphValueRecord.FindPropertyRelative("m_XPlacement"), new GUIContent("OX:"));

                rect.y += 20;
                EditorGUI.PropertyField(rect, prop_FirstGlyphValueRecord.FindPropertyRelative("m_YPlacement"), new GUIContent("OY:"));

                rect.y += 20;
                EditorGUI.PropertyField(rect, prop_FirstGlyphValueRecord.FindPropertyRelative("m_XAdvance"), new GUIContent("AX:"));

                //rect.y += 20;
                //EditorGUI.PropertyField(rect, prop_FirstGlyphValueRecord.FindPropertyRelative("m_YAdvance"), new GUIContent("AY:"));

                DrawGlyph((uint)prop_FirstGlyphIndex.intValue, new Rect(position.x, position.y, position.width, position.height), property);
            }
            else
            {
                rect = new Rect(position.x, position.y, width / 2 * 0.8f - padding, 18);
                EditorGUIUtility.labelWidth = 40f;

                // First Character Lookup
                GUI.SetNextControlName("FirstCharacterField");
                EditorGUI.BeginChangeCheck();
                string firstCharacter = EditorGUI.TextField(rect, s_CharacterTextFieldLabel, m_FirstCharacter);

                if (GUI.GetNameOfFocusedControl() == "FirstCharacterField")
                {
                    if (ValidateInput(firstCharacter))
                    {
                        //Debug.Log("1st Unicode value: [" + firstCharacter + "]");

                        uint unicode = GetUnicodeCharacter(firstCharacter);

                        // Lookup glyph index
                        TMP_SerializedPropertyHolder propertyHolder = property.serializedObject.targetObject as TMP_SerializedPropertyHolder;
                        TMP_FontAsset fontAsset = propertyHolder.fontAsset;
                        if (fontAsset != null)
                        {
                            prop_FirstGlyphIndex.intValue = (int)fontAsset.GetGlyphIndex(unicode);
                            propertyHolder.firstCharacter = unicode;
                        }
                    }
                }

                if (EditorGUI.EndChangeCheck())
                    m_FirstCharacter = firstCharacter;

                // First Glyph Index
                rect.x += width / 2 * 0.8f;

                EditorGUIUtility.labelWidth = 25f;
                EditorGUI.BeginChangeCheck();
                EditorGUI.PropertyField(rect, prop_FirstGlyphIndex, new GUIContent("ID:"));
                if (EditorGUI.EndChangeCheck())
                {

                }

                GUI.enabled = isEditingEnabled;
                EditorGUIUtility.labelWidth = 25f;

                rect = new Rect(position.x, position.y + 20, width * 0.5f - padding, 18);
                EditorGUI.PropertyField(rect, prop_FirstGlyphValueRecord.FindPropertyRelative("m_XPlacement"), new GUIContent("OX"));

                rect.x += width * 0.5f;
                EditorGUI.PropertyField(rect, prop_FirstGlyphValueRecord.FindPropertyRelative("m_YPlacement"), new GUIContent("OY"));

                rect.x = position.x;
                rect.y += 20;
                EditorGUI.PropertyField(rect, prop_FirstGlyphValueRecord.FindPropertyRelative("m_XAdvance"), new GUIContent("AX"));

                //rect.x += width * 0.5f;
                //EditorGUI.PropertyField(rect, prop_FirstGlyphAdjustment.FindPropertyRelative("m_YAdvance"), new GUIContent("AY"));

            }


            // Second Glyph
            GUI.enabled = isEditingEnabled;
            if (isSelectable)
            {
                float labelWidth = GUI.skin.label.CalcSize(new GUIContent("ID: " + prop_SecondGlyphIndex.intValue)).x;
                EditorGUI.LabelField(new Rect(position.width / 2 + 20 + (64 - labelWidth) / 2, position.y + 60, 64f, 18f), new GUIContent("ID: <color=#FFFF80>" + prop_SecondGlyphIndex.intValue + "</color>"), style);

                GUI.enabled = isEditingEnabled;
                EditorGUIUtility.labelWidth = 30f;

                rect = new Rect(position.width / 2 + 20 + 70, position.y + 10, (width - 70) - padding, 18);
                EditorGUI.PropertyField(rect, prop_SecondGlyphValueRecord.FindPropertyRelative("m_XPlacement"), new GUIContent("OX:"));

                rect.y += 20;
                EditorGUI.PropertyField(rect, prop_SecondGlyphValueRecord.FindPropertyRelative("m_YPlacement"), new GUIContent("OY:"));

                rect.y += 20;
                EditorGUI.PropertyField(rect, prop_SecondGlyphValueRecord.FindPropertyRelative("m_XAdvance"), new GUIContent("AX:"));

                //rect.y += 20;
                //EditorGUI.PropertyField(rect, prop_SecondGlyphAdjustment.FindPropertyRelative("m_YAdvance"), new GUIContent("AY"));

                DrawGlyph((uint)prop_SecondGlyphIndex.intValue, new Rect(position.width / 2 + 20, position.y, position.width, position.height), property);
            }
            else
            {
                rect = new Rect(position.width / 2 + 20, position.y, width / 2 * 0.8f - padding, 18);
                EditorGUIUtility.labelWidth = 40f;

                // Second Character Lookup
                GUI.SetNextControlName("SecondCharacterField");
                EditorGUI.BeginChangeCheck();
                string secondCharacter = EditorGUI.TextField(rect, s_CharacterTextFieldLabel, m_SecondCharacter);

                if (GUI.GetNameOfFocusedControl() == "SecondCharacterField")
                {
                    if (ValidateInput(secondCharacter))
                    {
                        //Debug.Log("2nd Unicode value: [" + secondCharacter + "]");

                        uint unicode = GetUnicodeCharacter(secondCharacter);

                        // Lookup glyph index
                        TMP_SerializedPropertyHolder propertyHolder = property.serializedObject.targetObject as TMP_SerializedPropertyHolder;
                        TMP_FontAsset fontAsset = propertyHolder.fontAsset;
                        if (fontAsset != null)
                        {
                            prop_SecondGlyphIndex.intValue = (int)fontAsset.GetGlyphIndex(unicode);
                            propertyHolder.secondCharacter = unicode;
                        }
                    }
                }

                if (EditorGUI.EndChangeCheck())
                    m_SecondCharacter = secondCharacter;

                // Second Glyph Index
                rect.x += width / 2 * 0.8f;

                EditorGUIUtility.labelWidth = 25f;
                EditorGUI.BeginChangeCheck();
                EditorGUI.PropertyField(rect, prop_SecondGlyphIndex, new GUIContent("ID:"));
                if (EditorGUI.EndChangeCheck())
                {

                }

                GUI.enabled = isEditingEnabled;
                EditorGUIUtility.labelWidth = 25f;

                rect = new Rect(position.width / 2 + 20, position.y + 20, width * 0.5f - padding, 18);
                EditorGUI.PropertyField(rect, prop_SecondGlyphValueRecord.FindPropertyRelative("m_XPlacement"), new GUIContent("OX"));

                rect.x += width * 0.5f;
                EditorGUI.PropertyField(rect, prop_SecondGlyphValueRecord.FindPropertyRelative("m_YPlacement"), new GUIContent("OY"));

                rect.x = position.width / 2 + 20;
                rect.y += 20;
                EditorGUI.PropertyField(rect, prop_SecondGlyphValueRecord.FindPropertyRelative("m_XAdvance"), new GUIContent("AX"));

                //rect.x += width * 0.5f;
                //EditorGUI.PropertyField(rect, prop_SecondGlyphAdjustment.FindPropertyRelative("m_YAdvance"), new GUIContent("AY"));
            }

            // Font Feature Lookup Flags
            if (isSelectable)
            {
                EditorGUIUtility.labelWidth = 55f;

                rect.x = position.width - 255;
                rect.y += 23;
                rect.width = 270; // width - 70 - padding;

                FontFeatureLookupFlags flags = (FontFeatureLookupFlags)prop_FontFeatureLookupFlags.intValue;

                EditorGUI.BeginChangeCheck();
                flags = (FontFeatureLookupFlags)EditorGUI.EnumFlagsField(rect, new GUIContent("Options:"), flags);
                if (EditorGUI.EndChangeCheck())
                {
                    prop_FontFeatureLookupFlags.intValue = (int)flags;
                }
            }

        }

        bool ValidateInput(string source)
        {
            int length = string.IsNullOrEmpty(source) ? 0 : source.Length;

            ////Filter out unwanted characters.
            Event evt = Event.current;

            char c = evt.character;

            if (c != '\0')
            {
                switch (length)
                {
                    case 0:
                        break;
                    case 1:
                        if (source != m_PreviousInput)
                            return true;

                        if ((source[0] == '\\' && (c == 'u' || c == 'U')) == false)
                            evt.character = '\0';

                        break;
                    case 2:
                    case 3:
                    case 4:
                    case 5:
                        if ((c < '0' || c > '9') && (c < 'a' || c > 'f') && (c < 'A' || c > 'F'))
                            evt.character = '\0';
                        break;
                    case 6:
                    case 7:
                    case 8:
                    case 9:
                        if (source[1] == 'u' || (c < '0' || c > '9') && (c < 'a' || c > 'f') && (c < 'A' || c > 'F'))
                            evt.character = '\0';

                        // Validate input
                        if (length == 6 && source[1] == 'u' && source != m_PreviousInput)
                            return true;
                        break;
                    case 10:
                        if (source != m_PreviousInput)
                            return true;

                        evt.character = '\0';
                        break;
                }
            }

            m_PreviousInput = source;

            return false;
        }

        uint GetUnicodeCharacter (string source)
        {
            uint unicode;

            if (source.Length == 1)
                unicode = source[0];
            else if (source.Length == 6)
                unicode = (uint)TMP_TextUtilities.StringHexToInt(source.Replace("\\u", ""));
            else
                unicode = (uint)TMP_TextUtilities.StringHexToInt(source.Replace("\\U", ""));

            return unicode;
        }

        void DrawGlyph(uint glyphIndex, Rect position, SerializedProperty property)
        {
            // Get a reference to the font asset
            TMP_FontAsset fontAsset = property.serializedObject.targetObject as TMP_FontAsset;

            if (fontAsset == null)
                return;

            Glyph glyph;

            // Check if glyph is present in the atlas texture.
            if (!fontAsset.glyphLookupTable.TryGetValue(glyphIndex, out glyph))
                return;

            // Get the atlas index of the glyph and lookup its atlas texture
            int atlasIndex = glyph.atlasIndex;
            Texture2D atlasTexture = fontAsset.atlasTextures.Length > atlasIndex ? fontAsset.atlasTextures[atlasIndex] : null;

            if (atlasTexture == null)
                return;

            Material mat;
            if (((GlyphRasterModes)fontAsset.atlasRenderMode & GlyphRasterModes.RASTER_MODE_BITMAP) == GlyphRasterModes.RASTER_MODE_BITMAP)
            {
                mat = TMP_FontAssetEditor.internalBitmapMaterial;

                if (mat == null)
                    return;

                mat.mainTexture = atlasTexture;
            }
            else
            {
                mat = TMP_FontAssetEditor.internalSDFMaterial;

                if (mat == null)
                    return;

                mat.mainTexture = atlasTexture;
                mat.SetFloat(ShaderUtilities.ID_GradientScale, fontAsset.atlasPadding + 1);
            }

            // Draw glyph from atlas texture.
            Rect glyphDrawPosition = new Rect(position.x, position.y + 2, 64, 60);

            GlyphRect glyphRect = glyph.glyphRect;

            int padding = fontAsset.atlasPadding;

            int glyphOriginX = glyphRect.x - padding;
            int glyphOriginY = glyphRect.y - padding;
            int glyphWidth = glyphRect.width + padding * 2;
            int glyphHeight = glyphRect.height + padding * 2;

            float normalizedHeight = fontAsset.faceInfo.ascentLine - fontAsset.faceInfo.descentLine;
            float scale = glyphDrawPosition.width / normalizedHeight;

            // Compute the normalized texture coordinates
            Rect texCoords = new Rect((float)glyphOriginX / atlasTexture.width, (float)glyphOriginY / atlasTexture.height, (float)glyphWidth / atlasTexture.width, (float)glyphHeight / atlasTexture.height);

            if (Event.current.type == EventType.Repaint)
            {
                glyphDrawPosition.x += (glyphDrawPosition.width - glyphWidth * scale) / 2;
                glyphDrawPosition.y += (glyphDrawPosition.height - glyphHeight * scale) / 2;
                glyphDrawPosition.width = glyphWidth * scale;
                glyphDrawPosition.height = glyphHeight * scale;

                // Could switch to using the default material of the font asset which would require passing scale to the shader.
                Graphics.DrawTexture(glyphDrawPosition, atlasTexture, texCoords, 0, 0, 0, 0, new Color(1f, 1f, 1f), mat);
            }
        }


    }
}
