//------------------------------------------------------------------------------
// <copyright file="OdbcConnectionStringBuilder.cs" company="Microsoft">
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>
// <owner current="true" primary="true">Microsoft</owner>
// <owner current="true" primary="false">Microsoft</owner>
//------------------------------------------------------------------------------

    using System;
    using System.Collections;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Data.Common;
    using System.Diagnostics;
    using System.Globalization;
    using System.Runtime.Serialization;
    using System.Security.Permissions;
    using System.Text;

namespace System.Data.Odbc {

    [DefaultProperty("Driver")]
    [System.ComponentModel.TypeConverterAttribute(typeof(OdbcConnectionStringBuilder.OdbcConnectionStringBuilderConverter))]
    public sealed class OdbcConnectionStringBuilder : DbConnectionStringBuilder {

        private enum Keywords { // must maintain same ordering as _validKeywords array
//            NamedConnection,
            Dsn,

            Driver,
        }

        private static readonly string[] _validKeywords;
        private static readonly Dictionary<string,Keywords> _keywords;

        private string[] _knownKeywords;

        private string _dsn    = DbConnectionStringDefaults.Dsn;
//        private string _namedConnection  = DbConnectionStringDefaults.NamedConnection;

        private string _driver = DbConnectionStringDefaults.Driver;

        static OdbcConnectionStringBuilder() {
            string[] validKeywords = new string[2];
            validKeywords[(int)Keywords.Driver]          = DbConnectionStringKeywords.Driver;
            validKeywords[(int)Keywords.Dsn]             = DbConnectionStringKeywords.Dsn;
//            validKeywords[(int)Keywords.NamedConnection] = DbConnectionStringKeywords.NamedConnection;
            _validKeywords = validKeywords;

            Dictionary<string,Keywords> hash = new Dictionary<string,Keywords>(2, StringComparer.OrdinalIgnoreCase);
            hash.Add(DbConnectionStringKeywords.Driver,          Keywords.Driver);
            hash.Add(DbConnectionStringKeywords.Dsn,             Keywords.Dsn);
//            hash.Add(DbConnectionStringKeywords.NamedConnection, Keywords.NamedConnection);
            Debug.Assert(2 == hash.Count, "initial expected size is incorrect");
            _keywords = hash;
        }

        public OdbcConnectionStringBuilder() : this((string)null) {
        }

        public OdbcConnectionStringBuilder(string connectionString) : base(true) {
            if (!ADP.IsEmpty(connectionString)) {
                ConnectionString = connectionString;
            }
        }

        public override object this[string keyword] {
            get {
                ADP.CheckArgumentNull(keyword, "keyword");
                Keywords index;
                if (_keywords.TryGetValue(keyword, out index)) {
                    return GetAt(index);
                }
                else {
                    return base[keyword];
                }
            }
            set {
                ADP.CheckArgumentNull(keyword, "keyword");
                if (null != value) {
                    Keywords index;
                    if (_keywords.TryGetValue(keyword, out index)) {
                        switch(index) {
                        case Keywords.Driver:          Driver = ConvertToString(value); break;
                        case Keywords.Dsn:             Dsn = ConvertToString(value); break;
//                      case Keywords.NamedConnection: NamedConnection = ConvertToString(value); break;
                        default:
                            Debug.Assert(false, "unexpected keyword");
                            throw ADP.KeywordNotSupported(keyword);
                        }
                    }
                    else {
                        base[keyword] = value;
                        ClearPropertyDescriptors();
                        _knownKeywords = null;
                    }
                }
                else {
                    Remove(keyword);
                }
            }
        }

        [DisplayName(DbConnectionStringKeywords.Driver)]
        [ResCategoryAttribute(Res.DataCategory_Source)]
        [ResDescriptionAttribute(Res.DbConnectionString_Driver)]
        [RefreshPropertiesAttribute(RefreshProperties.All)]
        public string Driver {
            get { return _driver; }
            set {
                SetValue(DbConnectionStringKeywords.Driver, value);
                _driver = value;
            }
        }

        [DisplayName(DbConnectionStringKeywords.Dsn)]
        [ResCategoryAttribute(Res.DataCategory_NamedConnectionString)]
        [ResDescriptionAttribute(Res.DbConnectionString_DSN)]
        [RefreshPropertiesAttribute(RefreshProperties.All)]
        public string Dsn {
            get { return _dsn; }
            set {
                SetValue(DbConnectionStringKeywords.Dsn, value);
                _dsn = value;
            }
        }
/*
        [DisplayName(DbConnectionStringKeywords.NamedConnection)]
        [ResCategoryAttribute(Res.DataCategory_NamedConnectionString)]
        [ResDescriptionAttribute(Res.DbConnectionString_NamedConnection)]
        [RefreshPropertiesAttribute(RefreshProperties.All)]
        [TypeConverter(typeof(NamedConnectionStringConverter))]
        public string NamedConnection {
            get { return _namedConnection; }
            set {
                SetValue(DbConnectionStringKeywords.NamedConnection, value);
                _namedConnection = value;
            }
        }
*/
        public override ICollection Keys {
            get {
                string[] knownKeywords = _knownKeywords;
                if (null == knownKeywords) {
                    knownKeywords = _validKeywords;

                    int count = 0;
                    foreach(string keyword in base.Keys) {
                        bool flag = true;
                        foreach(string s in knownKeywords) {
                            if (s == keyword) {
                                flag = false;
                                break;
                            }
                        }
                        if (flag) {
                            count++;
                        }
                    }
                    if (0 < count) {
                        string[] tmp = new string[knownKeywords.Length + count];
                        knownKeywords.CopyTo(tmp, 0);

                        int index = knownKeywords.Length;
                        foreach(string keyword in base.Keys) {
                            bool flag = true;
                            foreach(string s in knownKeywords) {
                                if (s == keyword) {
                                    flag = false;
                                    break;
                                }
                            }
                            if (flag) {
                                tmp[index++] = keyword;
                            }
                        }
                        knownKeywords = tmp;
                    }
                    _knownKeywords = knownKeywords;
                }
                return new System.Data.Common.ReadOnlyCollection<string>(knownKeywords);
            }
        }

        public override void Clear() {
            base.Clear();
            for(int i = 0; i < _validKeywords.Length; ++i) {
                Reset((Keywords)i);
            }
            _knownKeywords = _validKeywords;
        }

        public override bool ContainsKey(string keyword) {
            ADP.CheckArgumentNull(keyword, "keyword");
            return _keywords.ContainsKey(keyword) || base.ContainsKey(keyword);
        }

        private static string ConvertToString(object value) {
            return DbConnectionStringBuilderUtil.ConvertToString(value);
        }

        private object GetAt(Keywords index) {
            switch(index) {
            case Keywords.Driver:          return Driver;
            case Keywords.Dsn:             return Dsn;
//          case Keywords.NamedConnection: return NamedConnection;
            default:
            Debug.Assert(false, "unexpected keyword");
            throw ADP.KeywordNotSupported(_validKeywords[(int)index]);
            }
        }

        /*
        protected override void GetProperties(Hashtable propertyDescriptors) {
            object value;
            if (TryGetValue(DbConnectionStringSynonyms.TRUSTEDCONNECTION, out value)) {
                bool trusted = false;
                if (value is bool) {
                    trusted = (bool)value;
                }
                else if ((value is string) && !Boolean.TryParse((string)value, out trusted)) {
                    trusted = false;
                }

                if (trusted) {
                   Attribute[] attributes = new Attribute[] {
                        BrowsableAttribute.Yes,
                        RefreshPropertiesAttribute.All,
                    };
                    DbConnectionStringBuilderDescriptor descriptor;
                    descriptor = new DbConnectionStringBuilderDescriptor(DbConnectionStringSynonyms.TRUSTEDCONNECTION,
                                        this.GetType(), typeof(bool), false, attributes);
                    descriptor.RefreshOnChange = true;
                    propertyDescriptors[DbConnectionStringSynonyms.TRUSTEDCONNECTION] = descriptor;

                    if (ContainsKey(DbConnectionStringSynonyms.Pwd)) {
                        descriptor = new DbConnectionStringBuilderDescriptor(DbConnectionStringSynonyms.Pwd,
                                            this.GetType(), typeof(string), true, attributes);
                        propertyDescriptors[DbConnectionStringSynonyms.Pwd] = descriptor;
                    }
                    if (ContainsKey(DbConnectionStringSynonyms.UID)) {
                        descriptor = new DbConnectionStringBuilderDescriptor(DbConnectionStringSynonyms.UID,
                                            this.GetType(), typeof(string), true, attributes);
                        propertyDescriptors[DbConnectionStringSynonyms.UID] = descriptor;
                    }
                }
            }
            base.GetProperties(propertyDescriptors);
        }
        */

        public override bool Remove(string keyword) {
            ADP.CheckArgumentNull(keyword, "keyword");
            if (base.Remove(keyword)) {
                Keywords index;
                if (_keywords.TryGetValue(keyword, out index)) {
                    Reset(index);
                }
                else {
                    ClearPropertyDescriptors();
                    _knownKeywords = null;
                }
                return true;
            }
            return false;
        }
        private void Reset(Keywords index) {
            switch(index) {
            case Keywords.Driver:
                _driver = DbConnectionStringDefaults.Driver;
                break;
            case Keywords.Dsn:
                _dsn = DbConnectionStringDefaults.Dsn;
                break;
//            case Keywords.NamedConnection:
//               _namedConnection = DbConnectionStringDefaults.NamedConnection;
//                break;
            default:
            Debug.Assert(false, "unexpected keyword");
            throw ADP.KeywordNotSupported(_validKeywords[(int)index]);
            }
        }

        private void SetValue(string keyword, string value) {
            ADP.CheckArgumentNull(value, keyword);
            base[keyword] = value;
        }

        public override bool TryGetValue(string keyword, out object value) {
            ADP.CheckArgumentNull(keyword, "keyword");
            Keywords index;
            if (_keywords.TryGetValue(keyword, out index)) {
                value = GetAt(index);
                return true;
            }
            return base.TryGetValue(keyword, out value);
        }

        sealed internal class OdbcConnectionStringBuilderConverter : ExpandableObjectConverter {

            // converter classes should have public ctor
            public OdbcConnectionStringBuilderConverter() {
            }

            override public bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) {
                if (typeof(System.ComponentModel.Design.Serialization.InstanceDescriptor) == destinationType) {
                    return true;
                }
                return base.CanConvertTo(context, destinationType);
            }

            override public object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) {
                if (destinationType == null) {
                    throw ADP.ArgumentNull("destinationType");
                }
                if (typeof(System.ComponentModel.Design.Serialization.InstanceDescriptor) == destinationType) {
                    OdbcConnectionStringBuilder obj = (value as OdbcConnectionStringBuilder);
                    if (null != obj) {
                        return ConvertToInstanceDescriptor(obj);
                    }
                }
                return base.ConvertTo(context, culture, value, destinationType);
            }

            private System.ComponentModel.Design.Serialization.InstanceDescriptor ConvertToInstanceDescriptor(OdbcConnectionStringBuilder options) {
                Type[] ctorParams = new Type[] { typeof(string) };
                object[] ctorValues = new object[] { options.ConnectionString };
                System.Reflection.ConstructorInfo ctor = typeof(OdbcConnectionStringBuilder).GetConstructor(ctorParams);
                return new System.ComponentModel.Design.Serialization.InstanceDescriptor(ctor, ctorValues);
            }
        }
    }
}