using UnityEngine;
using UnityEditor;
using System;
using System.IO;
using System.Text;

namespace litefeel
{
    public class BFImporter : AssetPostprocessor
    {
        static void OnPostprocessAllAssets(string[] importedAssets, string[] deletedAssets, string[] movedAssets, string[] movedFromAssetPaths)
        {
            foreach (string str in importedAssets)
            {
                //Debug.Log("Reimported Asset: " + str);
                DoImportBitmapFont(str);
            }
            foreach (string str in deletedAssets)
            {
                //Debug.Log("Deleted Asset: " + str);
                DelBitmapFont(str);
            }

            for (var i = 0; i < movedAssets.Length; i++)
            {
                //Debug.Log("Moved Asset: " + movedAssets[i] + " from: " + movedFromAssetPaths[i]);
                MoveBitmapFont(movedFromAssetPaths[i], movedAssets[i]);
            }
        }

        public static bool IsFnt(string path)
        {
            return path.EndsWith(".fnt", StringComparison.OrdinalIgnoreCase);
        }

        public static void DoImportBitmapFont(string fntPatn)
        {
            if (!IsFnt(fntPatn)) return;

            TextAsset fnt = AssetDatabase.LoadMainAssetAtPath(fntPatn) as TextAsset;
            string text = fnt.text;
            FntParse parse = FntParse.GetFntParse(ref text);
            if (parse == null) return;

            string fntName = Path.GetFileNameWithoutExtension(fntPatn);
            string rootPath = Path.GetDirectoryName(fntPatn);
            string fontPath = string.Format("{0}/{1}.fontsettings", rootPath, fntName);
            Texture2D[] textures = DoImportTextures(parse, rootPath, fnt);
            
            Font font = AssetDatabase.LoadMainAssetAtPath(fontPath) as Font;
            if (font == null)
            {
                font = new Font();
                AssetDatabase.CreateAsset(font, fontPath);
                AssetDatabase.WriteImportSettingsIfDirty(fontPath);
                AssetDatabase.ImportAsset(fontPath);
            }
            Material material = AssetDatabase.LoadAssetAtPath(fontPath, typeof(Material)) as Material;
            if (material == null)
            {
                material = new Material(Shader.Find("UI/Default"));
                material.name = "Font Material";
                AssetDatabase.AddObjectToAsset(material, fontPath);
                // unity 5.4+ cannot refresh it immediately, must import it
                AssetDatabase.ImportAsset(fontPath);
            }
            
            font.material = material;
            material.shader = Shader.Find(textures.Length > 1 ? "BFI/Font" + textures.Length : "UI/Default");
            material.mainTexture = textures[0];
            for (int i = 1; i < textures.Length; i++)
            {
                material.SetTexture("_MainTex" + (i + 1), textures[i]);
            }
            font.characterInfo = parse.charInfos;

            SerializedObject so = new SerializedObject(font);
            so.Update();
            so.FindProperty("m_FontSize").floatValue = Mathf.Abs(parse.fontSize);
            so.FindProperty("m_LineSpacing").floatValue = parse.lineHeight;
            so.FindProperty("m_Ascent").floatValue = parse.lineBaseHeight;
            SerializedProperty prop = so.FindProperty("m_Descent");
            if (prop != null)
                prop.floatValue = parse.lineBaseHeight - parse.lineHeight;
            UpdateKernings(so, parse.kernings);
            so.ApplyModifiedProperties();
            so.SetIsDifferentCacheDirty();
            
            AssetDatabase.SaveAssets();

#if UNITY_5_5_OR_NEWER
            // unity 5.5 can not load custom font
            ReloadFont(fontPath);
#endif
        }

        private static Texture2D[] DoImportTextures(FntParse parse, string rootPath, TextAsset fnt)
        {
            int len = parse.textureNames.Length;
            Texture2D[] textures = new Texture2D[len];
            for (int i = 0; i < len; i++)
            {
                // The texture name of the file generated by ShoeBox uses an absolute path
                string textureName = Path.GetFileName(parse.textureNames[i]);
                string texPath = string.Format("{0}/{1}", rootPath, textureName);

                Texture2D texture = AssetDatabase.LoadMainAssetAtPath(texPath) as Texture2D;
                if (texture == null)
                {
                    Debug.LogErrorFormat(fnt, "{0}: not found '{1}'.", typeof(BFImporter), texPath);
                    return textures;
                }

                TextureImporter texImporter = AssetImporter.GetAtPath(texPath) as TextureImporter;
                texImporter.textureType = TextureImporterType.GUI;
                texImporter.mipmapEnabled = false;
                texImporter.SaveAndReimport();
                textures[i] = texture;
            }
            return textures;
        }
        
        private static void UpdateKernings(SerializedObject so, Kerning[] kernings)
        {
            int len = kernings != null ? kernings.Length : 0;
            SerializedProperty kerningsProp = so.FindProperty("m_KerningValues");

            if (len == 0)
            {
                kerningsProp.ClearArray();
                return;
            }

            int propLen = kerningsProp.arraySize;
            for (int i = 0; i < len; i++)
            {
                if (propLen <= i)
                {
                    kerningsProp.InsertArrayElementAtIndex(i);
                }

                SerializedProperty kerningProp = kerningsProp.GetArrayElementAtIndex(i);
                kerningProp.FindPropertyRelative("second").floatValue = kernings[i].amount;
                SerializedProperty pairProp = kerningProp.FindPropertyRelative("first");
                pairProp.Next(true);
                pairProp.intValue = kernings[i].first;
                pairProp.Next(false);
                pairProp.intValue = kernings[i].second;
            }
            for (int i = propLen - 1; i >= len; i--)
            {
                kerningsProp.DeleteArrayElementAtIndex(i);
            }
        }
        
        private static void DelBitmapFont(string fntPath)
        {
            if (!IsFnt(fntPath)) return;

            string fontPath = fntPath.Substring(0, fntPath.Length - 4) + ".fontsettings";
            AssetDatabase.DeleteAsset(fontPath);
        }

        private static void MoveBitmapFont(string oldFntPath, string nowFntPath)
        {
            if (!IsFnt(nowFntPath)) return;

            string oldFontPath = oldFntPath.Substring(0, oldFntPath.Length - 4) + ".fontsettings";
            string nowFontPath = nowFntPath.Substring(0, nowFntPath.Length - 4) + ".fontsettings";
            AssetDatabase.MoveAsset(oldFontPath, nowFontPath);
        }

        // new font can not display via Text in unity 5.5
        // must import import it
        private static void ReloadFont(string fontPath)
        {
            var tmpPath = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
            AssetDatabase.ExportPackage(fontPath, tmpPath);
            AssetDatabase.DeleteAsset(fontPath);
            
            var startTime = DateTime.Now;
            EditorApplication.CallbackFunction func = null;
            func = () =>
            {
                TimeSpan dalt = DateTime.Now - startTime;
                if (dalt.TotalSeconds >= 0.1)
                {
                    EditorApplication.update -= func;
                    AssetDatabase.ImportPackage(tmpPath, false);
                    File.Delete(tmpPath);
                }
            };

            EditorApplication.update += func;
        }
    }

}