namespace Guru
{
    using SQLite4Unity3d;
    using UnityEngine;
    using System.Collections;
    using System;
    using System.IO;
    using System.Collections.Generic;
    using System.Linq;
    using System.Linq.Expressions;
    using UnityEngine.Networking;
    
    public class DBService
    {
	    internal const string DefaultDBName = "data";
	    internal const string DefaultDBExtension = ".db";
	    internal static string DebugDBPath = "mocks_dir/db";
	    private SQLiteConnection _connection;
        private string _dbName;
        private string _dbPath;
		private bool _isDebug = false;
		
		/// <summary>
		/// 获取数据库的路径
		/// </summary>
		public string DatabasePath => _dbPath;

        /// <summary>
        /// 启动服务
        /// </summary>
        /// <param name="name"></param>
        /// <param name="isDebug"></param>
        public DBService(string name, bool isDebug = false)
        {
	        _isDebug = isDebug;
	        if (string.IsNullOrEmpty(name)) name = DefaultDBName;
	        _dbName = name;
	        _dbPath = Path.GetFullPath($"{Application.persistentDataPath}/{_dbName}{DefaultDBExtension}");

	        if (isDebug)
	        {
		        _dbPath = Path.GetFullPath($"{Application.persistentDataPath}/{_dbName}_debug{DefaultDBExtension}");
	        }
        }


        public static DBService Open(string name, bool isDebug = false)
        {
	        var ds = new DBService(name, isDebug);
	        ds.Connect();
	        return ds;
        }

        /// <summary>
        /// 关闭连接
        /// </summary>
        public void Close() => _connection?.Close();
        
        /// <summary>
		/// 建立连接, 若不存在则创建数据库
		/// </summary>
        public void Connect(string dbPath = "")
        {
	        if(!string.IsNullOrEmpty(dbPath)) _dbPath = dbPath;
	        _connection = new SQLiteConnection(_dbPath, SQLiteOpenFlags.ReadWrite | SQLiteOpenFlags.Create);
        }

        public bool Exists => File.Exists(_dbPath);

		/// <summary>
		/// 部署默认的 Database
		/// 将内置在 StreamingAssets 中的数据库文件部署到 PersistentDataPath 中
		/// </summary>
		/// <returns></returns>
        public void DeployEmbeddedDB(string embeddedPath, Action<bool> onComplete)
        {
	        string from = Path.Combine(Application.streamingAssetsPath, embeddedPath);

	        var uwr = new UnityWebRequest(from);
	        uwr.SendWebRequest().completed += ao =>
	        {
		        var success = false;
		        try
		        {
			        if ( uwr.result == UnityWebRequest.Result.Success)
			        {
				        File.WriteAllBytes(_dbPath, uwr.downloadHandler.data);
				        success = true;
			        }
		        }
		        catch (Exception e)
		        {
			        Debug.LogError(e);
		        }
		        onComplete?.Invoke(success);
	        };
        }




		/// <summary>
		/// 获取表格
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <returns></returns>
        public IEnumerable<T> CreatOrLoadTable<T>() where T: new()
        {
	       _connection.CreateTable<T>();
	       return  _connection.Table<T>();
        }
		
        public List<T> GetTableList<T>()  where T: new()
        {
	        var tb = CreatOrLoadTable<T>();
	        return tb?.ToList() ?? new List<T>();
        }
		
		
		
        public int Insert<T>(T value)
        {
	        return _connection.Insert(value);
        }

        public int InsertAll(IEnumerable data)
        {
	        return _connection.InsertAll(data);
        }

        public int Remove(object primaryKey)
        {
	        return _connection.Delete(primaryKey);
        }


        public int Remove<T>(object primaryKey)
        {
	        return _connection.Delete<T>(primaryKey);
        }

        public int UpdateAll(IEnumerable data)
        {
	        return _connection.UpdateAll(data);
        }

        public T Get<T>(object primaryKey) where T : new()
        {
	        return _connection.Get<T>(primaryKey);
        }


        public T Find<T>(Expression<Func<T, bool>> predicate) where T : new()
        {
	        return _connection.Find<T>(predicate);
        }

        private bool _onCmdExecution = false;
        /// <summary>
        /// 执行 SQL 语句
        /// </summary>
        /// <param name="query"></param>
        /// <param name="onExecutionComplete"></param>
        /// <param name="args"></param>
        /// <returns></returns>
        public int Execute(string query, Action<double> onExecutionComplete = null,  params object[] args)
        {
	        if (_onCmdExecution) return -1;
	        
	        SQLiteConnection.TimeExecutionHandler del = null;
	        del = (t1, t2) =>
	        {
		        _onCmdExecution = false;
		        _connection.TimeExecutionEvent -= del;
		        onExecutionComplete?.Invoke(t2.TotalSeconds);
	        };
	        _connection.TimeExecutionEvent += del;
	        _onCmdExecution = true;
	        return _connection.Execute(query, args);
        }


    }
    
    
    
    
}