using UnityEngine;
using System.Collections;
using Mono.Data.Sqlite;
using System.Data;
using System;
using System.Runtime.InteropServices;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;
using System.Runtime.Serialization;

/// <summary>
/// 数据库操作工具类  封装了通用的数据库增、删、改、查接口
/// </summary>
public class DBAccess {
    private SqliteConnection dbConnection;
    private SqliteCommand dbCommand;
    private SqliteDataReader reader;
    public bool isOpen=false;
	public DBAccess(string connectionStr)
    {
        OpenDB(connectionStr);
    }
    private void OpenDB(string connectionStr)
    {
        try
        {
            dbConnection = new SqliteConnection(connectionStr);
            dbConnection.Open();
            isOpen = true;
            Debug.Log("数据库连接成功！");
        }
        catch
        {
            isOpen = false;
            Debug.Log("数据库连接失败");
            throw new Exception("数据库连接异常！"); 
        }
    }
    /// <summary>
    /// 断开数据库连接
    /// </summary>
    public void CloseSqlConnectionDB()
    {
        if(dbCommand!=null)
        {
            dbCommand.Dispose();
        }
        dbCommand = null;
        if(reader!=null)
        {
            reader.Close();
        }
        reader = null;
        if(dbConnection!=null)
        {
            dbConnection.Close();
            dbConnection.Dispose();
        }
        dbConnection = null;
        Debug.Log("数据库连接已断开");
    }
    /// <summary>
    /// 根据键入的命令，操作数据库
    /// </summary>
    /// <param name="sqlQuery">需要读取的方式及内容</param>
    /// <returns></returns>
    public SqliteDataReader ExecuteQuery(string sqlQuery)
    {
        dbCommand = dbConnection.CreateCommand();
        dbCommand.CommandText = sqlQuery;
        reader = dbCommand.ExecuteReader();
        return reader;
    }


    /// <summary>
    /// 直接操作数据库的接口
    /// </summary>
    /// <param name="sqliteParameters"></param>
    /// <param name="CommandText"></param>
    /// <returns></returns>
    public SqliteDataReader ExecuteQuery(SqliteParameter[] sqliteParameters, string CommandText)
    {
        dbCommand = dbConnection.CreateCommand();
        dbCommand.Parameters.AddRange(sqliteParameters);
        dbCommand.CommandText = CommandText;
        reader = dbCommand.ExecuteReader();
        return reader;
    }


    /// <summary>
    /// 读取整张数据表
    /// </summary>
    /// <param name="tableName"></param>
    /// <returns></returns>
    public SqliteDataReader ReaderFullTable( string tableName)
    {
        string query = "SELECT * FROM " + tableName;
        return ExecuteQuery(query);
    }

        /// <summary>
    /// 更新指定数据表内的数据
    /// </summary>
    /// <returns>The values.</returns>
    /// <param name="tableName">数据表名称</param>
    /// <param name="colNames">字段名</param>
    /// <param name="colValues">字段名对应的数据</param>
    /// <param name="key">关键字</param>
    /// <param name="value">关键字对应的值</param>
    public bool UpdateValues(string tableName,string[] colNames,string[] colValues,string key,string operation,string value)
    {
        //当字段名称和字段数值不对应时引发异常
        if(colNames.Length!=colValues.Length) {
            throw new SqliteException("colNames.Length!=colValues.Length");
        }

        string queryString = "UPDATE " + tableName + " SET " + colNames[0] + "=" + $"'{colValues[0]}'";
        for(int i=1; i<colValues.Length; i++) 
        {
            queryString+=", " + colNames[i]  +$"='{colValues[i]}'" ;
        }
        queryString += " WHERE " + key + operation + $" '{value}' ";
        return ExecuteQuery(queryString).RecordsAffected>0;
    }

    /// <summary>
    /// 删除指定数据表内的数据
    /// </summary>
    /// <returns>The values.</returns>
    /// <param name="tableName">数据表名称</param>
    /// <param name="colNames">字段名</param>
    /// <param name="colValues">字段名对应的数据</param>
    public bool  DeleteValuesOR(string tableName,string[] colNames,string[] operations,string[] colValues)
    {
        //当字段名称和字段数值不对应时引发异常
        if(colNames.Length!=colValues.Length || operations.Length!=colNames.Length || operations.Length!=colValues.Length) {
            throw new SqliteException("colNames.Length!=colValues.Length || operations.Length!=colNames.Length || operations.Length!=colValues.Length");
        }

        string queryString = "DELETE FROM " + tableName + " WHERE " + colNames[0] + operations[0] + colValues[0];
        for(int i=1; i<colValues.Length; i++) 
        {
            queryString+="OR " + colNames[i] + operations[0] + colValues[i];
        }
        return ExecuteQuery(queryString).RecordsAffected > 0;
    }

    /// <summary>
    /// 删除指定数据表内的数据
    /// </summary>
    /// <returns>The values.</returns>
    /// <param name="tableName">数据表名称</param>
    /// <param name="colNames">字段名</param>
    /// <param name="operations">运算符</param>
    /// <param name="colValues">字段名对应的数据</param>
    public bool DeleteValuesAND(string tableName,string[] colNames,string[] operations,string[] colValues)
    {
        //当字段名称和字段数值不对应时引发异常
        if(colNames.Length!=colValues.Length || operations.Length!=colNames.Length || operations.Length!=colValues.Length) {
            throw new SqliteException("colNames.Length!=colValues.Length || operations.Length!=colNames.Length || operations.Length!=colValues.Length");
        }
        string queryString = "DELETE FROM " + tableName + " WHERE " + colNames[0] + operations[0] + colValues[0];
        for(int i=1; i<colValues.Length; i++) 
        {
            queryString+=" AND " + colNames[i] + operations[i] + colValues[i];
        }
        return ExecuteQuery(queryString).RecordsAffected>0;
    }


    ///<summary>
    ///在数据库中创建表格
    ///</summary>
    ///<param name="name">表格名称</param>
    ///<param name="col">表格所有的列名</param>
    ///<param name="colType">表格所有列所对应的格式</param>
    ///<returns></returns>
    public SqliteDataReader CreatTable(string name,string [] col,string []colType)
    {
        if(col.Length!=colType.Length)
        {
            throw new SqliteException("创建的数据类型与数据本身未对应！");
        }
        string query = "CREATE TABLE " + name + " (" + col[0] + " "+colType[0];
        for (int i = 1; i < col.Length; i++)
        {
            query += ", " + col[i] + " "+colType[i];
        }
        query += ")";
        return ExecuteQuery(query);
    }

    /// <summary>
    /// 插入表格内容
    /// </summary>
    /// <param name="tableName">表格名称</param>
    /// <param name="values">插入的值，需对应数据库中该表格的行格式</param>
    /// <returns></returns>
    public SqliteDataReader InsterInto(string tableName, string[] values)
    {
        string query = "INSERT INTO " + tableName + " VALUES(" + $"'{values[0]}'";
        for (int i = 1; i < values.Length; i++)
        {
            query += (", " + $"'{values[i]}'");
        }
        query += ")";
        return ExecuteQuery(query);
    }




    /// <summary>
    /// 根据条件查找相应的值
    /// </summary>
    /// <param name="tableName">表格命</param>
    /// <param name="items">需要得到值的列名</param>
    /// <param name="key">条件的列名</param>
    /// <param name="value">条件值</param>
    /// <returns></returns>
    public SqliteDataReader Select(string tableName, string[] items, string[] key,string[] value)
    {
        if(key.Length!=value.Length)
        {
            throw new SqliteException("比较条件未满足！");
        }
        string query = "SELECT " + items[0];
        for (int i = 1; i < items.Length; i++)
        {
            query += "," + items[i];
        }
        query += " FROM " + tableName + " WHERE " + key[0] + "=" + $"'{value[0]}'";
        for (int i = 1; i < key.Length; i++)
        {
            query += " AND " + key[i] + "=" + $"'{value[i]}'";
        }
        return ExecuteQuery(query);
    }

    /// <summary>
    /// 查询一个表中指定列的所有数据
    /// </summary>
    /// <param name="tableName"></param>
    /// <param name="item">列名称</param>
    /// <returns></returns>
    public SqliteDataReader GetAllLineMess(string tableName,string item)
    {
        string query="SELECT DISTINCT "+item+" FROM "+tableName;
        return ExecuteQuery(query);
    }

    /// <summary>
    /// 按时间段查找所有的值
    /// </summary>
    /// <param name="tableName"></param>
    /// <param name="startTime">开始时间  注意格式为"yyyy-m-dd hh:mm:ss"</param>
    /// <param name="finishTime">结束时间 注意格式为"yyyy-m-dd hh:mm:ss"</param>
    /// <returns></returns>
    public SqliteDataReader SelectTime(string tableName,string key,string startTime,string finishTime)
    {
        string query = "SELECT * FROM " + tableName + " WHERE " + key + " BETWEEN " + $"'{startTime}'" + " AND " + $"'{finishTime}'";
        return ExecuteQuery(query);
    }

    /// <summary>
    /// 根据一个键和值查找
    /// </summary>
    /// <param name="tableName"></param>
    /// <param name="key"></param>
    /// <param name="value"></param>
    /// <returns></returns>
    public SqliteDataReader Select(string tableName, string key, string value)
    {
        string query = "SELECT * FROM " + tableName + " WHERE " + key + "=" +$"'{value}'"  ;
        return ExecuteQuery(query);
    }

    /// <summary>
    /// 根据时间段和一个键和值进行查找
    /// </summary>
    /// <param name="tableName"></param>
    /// <param name="timeKey"></param>
    /// <param name="startTime">注意格式为"yyyy-m-dd hh:mm:ss"</param>
    /// <param name="finishTime">注意格式为"yyyy-m-dd hh:mm:ss"</param>
    /// <param name="nameKey"></param>
    /// <param name="nameValue"></param>
    /// <returns></returns>
    public SqliteDataReader SelectDataAndName(string tableName, string timeKey, string startTime, string finishTime,string nameKey,string nameValue)
    {
        string query = "SELECT * FROM " + tableName + " WHERE " + timeKey + " BETWEEN " +$"'{startTime}'"  + " AND " + $"'{finishTime}'" + " AND " + nameKey + "=" + $"'{nameValue}'";
        return ExecuteQuery(query);
    }

    /// <summary>
    /// 根据多个条件查询所有数据
    /// </summary>
    /// <param name="tableName"></param>
    /// <param name="key"></param>
    /// <param name="value"></param>
    /// <returns></returns>
    public SqliteDataReader Select(string tableName, string[] key, string[] value)
    {
        string query = "SELECT *";
        query += " FROM " + tableName + " WHERE " + key[0] + "=" +  $"'{value[0]}'";
        for (int i = 1; i < key.Length; i++)
        {
            query += " AND " + key[i] + "=" + $"'{value[i]}'";
        }
        return ExecuteQuery(query);
    }


 
}