using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;
using System.Linq.Expressions;

namespace SqlSugar
{
    public class InsertBuilder : IDMLBuilder
    {
        #region Init

        public InsertBuilder()
        {
            this.sql = new StringBuilder();
            this.Parameters = new List<SugarParameter>();
            this.DbColumnInfoList = new List<DbColumnInfo>();
        }

        #endregion Init

        #region Common Properties

        public SqlSugarClient Context { get; set; }
        public ILambdaExpressions LambdaExpressions { get; set; }
        public ISqlBuilder Builder { get; set; }
        public StringBuilder sql { get; set; }
        public List<SugarParameter> Parameters { get; set; }
        public string TableWithString { get; set; }
        public List<DbColumnInfo> DbColumnInfoList { get; set; }
        public bool IsNoInsertNull { get; set; }
        public bool IsReturnIdentity { get; set; }
        public EntityInfo EntityInfo { get; set; }
        public Dictionary<string, int> OracleSeqInfoList { get; set; }

        #endregion Common Properties

        #region SqlTemplate

        public virtual string SqlTemplate
        {
            get
            {
                if (IsReturnIdentity)
                {
                    return @"INSERT INTO {0}
           ({1})
     VALUES
           ({2}) ;SELECT SCOPE_IDENTITY();";
                }
                else
                {
                    return @"INSERT INTO {0}
           ({1})
     VALUES
           ({2}) ;";
                }
            }
        }

        public virtual string SqlTemplateBatch
        {
            get
            {
                return "INSERT {0} ({1})";
            }
        }

        public virtual string SqlTemplateBatchSelect
        {
            get
            {
                return "{0} AS {1}";
            }
        }

        public virtual string SqlTemplateBatchUnion
        {
            get
            {
                return "\t\r\nUNION ALL ";
            }
        }

        #endregion SqlTemplate

        #region Methods

        public virtual void Clear()
        {
        }

        public virtual string GetTableNameString
        {
            get
            {
                var result = Builder.GetTranslationTableName(EntityInfo.EntityName);
                result += UtilConstants.Space;
                if (this.TableWithString.HasValue())
                {
                    result += TableWithString + UtilConstants.Space;
                }
                return result;
            }
        }

        public virtual ExpressionResult GetExpressionValue(Expression expression, ResolveExpressType resolveType)
        {
            var resolveExpress = this.LambdaExpressions;
            this.LambdaExpressions.Clear();
            resolveExpress.MappingColumns = Context.MappingColumns;
            resolveExpress.MappingTables = Context.MappingTables;
            resolveExpress.IgnoreComumnList = Context.IgnoreColumns;
            resolveExpress.SqlFuncServices = Context.CurrentConnectionConfig.ConfigureExternalServices?.SqlFuncServices;
            resolveExpress.Resolve(expression, resolveType);
            this.Parameters.AddRange(resolveExpress.Parameters);
            var result = resolveExpress.Result;
            return result;
        }

        public virtual string ToSqlString()
        {
            if (IsNoInsertNull)
            {
                DbColumnInfoList = DbColumnInfoList.Where(it => it.Value != null).ToList();
            }
            var groupList = DbColumnInfoList.GroupBy(it => it.TableId).ToList();
            var isSingle = groupList.Count() == 1;
            var columnsString = string.Join(",", groupList.First().Select(it => Builder.GetTranslationColumnName(it.DbColumnName)));
            if (isSingle)
            {
                var columnParametersString = string.Join(",", this.DbColumnInfoList.Select(it => Builder.SqlParameterKeyWord + it.DbColumnName));
                return string.Format(SqlTemplate, GetTableNameString, columnsString, columnParametersString);
            }
            else
            {
                var batchInsetrSql = new StringBuilder();
                var pageSize = 200;
                var pageIndex = 1;
                var totalRecord = groupList.Count;
                var pageCount = (totalRecord + pageSize - 1) / pageSize;
                while (pageCount >= pageIndex)
                {
                    batchInsetrSql.AppendFormat(SqlTemplateBatch, GetTableNameString, columnsString);
                    var i = 0;
                    foreach (var columns in groupList.Skip((pageIndex - 1) * pageSize).Take(pageSize).ToList())
                    {
                        var isFirst = i == 0;
                        if (!isFirst)
                        {
                            batchInsetrSql.Append(SqlTemplateBatchUnion);
                        }
                        batchInsetrSql.Append("\r\n SELECT " + string.Join(",", columns.Select(it => string.Format(SqlTemplateBatchSelect, FormatValue(it.Value), Builder.GetTranslationColumnName(it.DbColumnName)))));
                        ++i;
                    }
                    pageIndex++;
                    batchInsetrSql.Append("\r\n;\r\n");
                }
                return batchInsetrSql.ToString();
            }
        }

        public virtual object FormatValue(object value)
        {
            if (value == null)
            {
                return "NULL";
            }
            else
            {
                var type = value.GetType();
                if (type == UtilConstants.DateType)
                {
                    var date = value.ObjToDate();
                    if (date < Convert.ToDateTime("1900-1-1"))
                    {
                        date = Convert.ToDateTime("1900-1-1");
                    }
                    return "'" + date.ToString("yyyy-MM-dd HH:mm:ss.fff") + "'";
                }
                else if (type == UtilConstants.ByteArrayType)
                {
                    var bytesString = "0x" + BitConverter.ToString((byte[])value);
                    return bytesString;
                }
                else if (type.IsEnum())
                {
                    return Convert.ToInt64(value);
                }
                else if (type == UtilConstants.BoolType)
                {
                    return value.ObjToBool() ? "1" : "0";
                }
                else if (type == UtilConstants.StringType || type == UtilConstants.ObjType)
                {
                    return "N'" + value.ToString().ToSqlFilter() + "'";
                }
                else
                {
                    return "N'" + value.ToString() + "'";
                }
            }
        }

        #endregion Methods
    }
}