// Copyright (c) 2021, Oracle and/or its affiliates.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License, version 2.0, as
// published by the Free Software Foundation.
//
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//
// Without limiting anything contained in the foregoing, this file,
// which is part of MySQL Connector/NET, is also subject to the
// Universal FOSS Exception, version 1.0, a copy of which can be found at
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//
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// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
// See the GNU General Public License, version 2.0, for more details.
//
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// along with this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA

using MySql.Data.Types;
using System;
using System.Reflection;

namespace MySql.Data.MySqlClient
{
    /// <summary>
    /// Represents a query attribute to a <see cref="MySqlCommand"/>.
    /// </summary>
    public class MySqlAttribute
    {
        private const int UNSIGNED_MASK = 0x8000;
        private string _attributeName;
        private object _attributeValue;
        private MySqlDbType _mySqlDbType;
        private int _size;

        #region Constructors

        /// <summary>
        /// Initializes a new instance of the <see cref="MySqlAttribute"/> class.
        /// </summary>
        public MySqlAttribute() { }

        /// <summary>
        /// Initializes a new instance of the <see cref="MySqlAttribute"/> class with the attribute name and its value.
        /// </summary>
        /// <param name="attributeName">Name of the attribute.</param>
        /// <param name="attributeValue">Value of the attribute.</param>
        public MySqlAttribute(string attributeName, object attributeValue)
        {
            this.AttributeName = attributeName;
            this.Value = attributeValue;
        }
        #endregion

        #region Properties
        internal MySqlAttributeCollection Collection { get; set; }

        /// <summary>
        /// Name of the query attribute.
        /// </summary>
        public String AttributeName
        {
            get { return this._attributeName; }
            set
            {
                if (String.IsNullOrWhiteSpace(value))
                {
                    throw new ArgumentException("'AttributeName' property can not be null or empty string.", "AttributeName");
                }

                this._attributeName = value;
            }
        }

        /// <summary>
        /// Value of the query attribute.
        /// </summary>
        public object Value
        {
            get { return this._attributeValue; }
            set
            {
                this._attributeValue = value;

                if (value is byte[] valueAsByte)
                {
                    this._size = valueAsByte.Length;
                }
                else if (value is string valueAsString)
                {
                    this._size = valueAsString.Length;
                }

                this.SetTypeFromValue();
            }
        }

        /// <summary>
        /// Gets or sets the <see cref="MySqlDbType"/> of the attribute.
        /// </summary>
        public MySqlDbType MySqlDbType
        {
            get { return this._mySqlDbType; }
            set
            {
                this.SetMySqlDbType(value);
            }
        }

        internal IMySqlValue ValueObject { get; private set; }
        #endregion

        /// <summary>
        /// Sets the MySqlDbType from the Value
        /// </summary>
        private void SetTypeFromValue()
        {
            if (this._attributeValue == null || this._attributeValue == DBNull.Value)
            {
                return;
            }

            if (this._attributeValue is Guid)
            {
                this.MySqlDbType = MySqlDbType.Guid;
            }
            else if (this._attributeValue is TimeSpan)
            {
                this.MySqlDbType = MySqlDbType.Time;
            }
            else if (this._attributeValue is bool)
            {
                this.MySqlDbType = MySqlDbType.Byte;
            }
            else
            {
                Type t = this._attributeValue.GetType();
                if (t.GetTypeInfo().BaseType == typeof(Enum))
                {
                    t = t.GetTypeInfo().GetEnumUnderlyingType();
                }

                switch (t.Name)
                {
                    case "SByte": this.MySqlDbType = MySqlDbType.Byte; break;
                    case "Byte": this.MySqlDbType = MySqlDbType.UByte; break;
                    case "Int16": this.MySqlDbType = MySqlDbType.Int16; break;
                    case "UInt16": this.MySqlDbType = MySqlDbType.UInt16; break;
                    case "Int32": this.MySqlDbType = MySqlDbType.Int32; break;
                    case "UInt32": this.MySqlDbType = MySqlDbType.UInt32; break;
                    case "Int64": this.MySqlDbType = MySqlDbType.Int64; break;
                    case "UInt64": this.MySqlDbType = MySqlDbType.UInt64; break;
                    case "DateTime": this.MySqlDbType = MySqlDbType.DateTime; break;
                    case "String": this.MySqlDbType = MySqlDbType.VarChar; break;
                    case "Single": this.MySqlDbType = MySqlDbType.Float; break;
                    case "Double": this.MySqlDbType = MySqlDbType.Double; break;
                    case "MySqlGeometry": this.MySqlDbType = MySqlDbType.Geometry; break;
                    case "Decimal": this.MySqlDbType = MySqlDbType.Decimal; break;
                    case "Object":
                    default:
                        this.MySqlDbType = MySqlDbType.Blob;
                        break;
                }
            }
        }

        private void SetMySqlDbType(MySqlDbType mysqlDbtype)
        {
            this._mySqlDbType = mysqlDbtype == MySqlDbType.JSON ? MySqlDbType.VarChar : mysqlDbtype;
            this.ValueObject = MySqlField.GetIMySqlValue(this._mySqlDbType);
        }

        /// <summary>
        /// Gets the value for the attribute type.
        /// </summary>
        internal int GetPSType()
        {
            switch (this._mySqlDbType)
            {
                case MySqlDbType.Bit:
                    return (int)MySqlDbType.Int64 | UNSIGNED_MASK;
                case MySqlDbType.UByte:
                    return (int)MySqlDbType.Byte | UNSIGNED_MASK;
                case MySqlDbType.UInt64:
                    return (int)MySqlDbType.Int64 | UNSIGNED_MASK;
                case MySqlDbType.UInt32:
                    return (int)MySqlDbType.Int32 | UNSIGNED_MASK;
                case MySqlDbType.UInt24:
                    return (int)MySqlDbType.Int32 | UNSIGNED_MASK;
                case MySqlDbType.UInt16:
                    return (int)MySqlDbType.Int16 | UNSIGNED_MASK;
                case MySqlDbType.Guid:
                    return (int)MySqlDbType.Guid - 600;
                default:
                    int value = (int)this._mySqlDbType;
                    value = value > 255 ? value - 500 : value;
                    return value;
            }
        }

        /// <summary>
        /// Serialize the value of the query attribute.
        /// </summary>
        internal void Serialize(MySqlPacket packet, bool binary, MySqlConnectionStringBuilder settings)
        {
            if (!binary && (this._attributeValue == null || this._attributeValue == DBNull.Value))
            {
                packet.WriteStringNoNull("NULL");
            }
            else
            {
                if (this.ValueObject.MySqlDbType == MySqlDbType.Guid)
                {
                    MySqlGuid g = (MySqlGuid)this.ValueObject;
                    g.OldGuids = settings.OldGuids;
                    this.ValueObject = g;
                }

                if (this.ValueObject.MySqlDbType == MySqlDbType.Geometry)
                {
                    MySqlGeometry v = (MySqlGeometry)this.ValueObject;
                    if (v.IsNull && this.Value != null)
                    {
                        MySqlGeometry.TryParse(this.Value.ToString(), out v);
                    }

                    this.ValueObject = v;
                }

                this.ValueObject.WriteValue(packet, binary, this._attributeValue, this._size);
            }
        }
    }
}