namespace Yes.Infrastructure.ViewEngine
{
    // thin wrapper around string; use type system to help ensure we
    // are doing canonicalization right/consistently
    internal class UriTemplateLiteralQueryValue : UriTemplateQueryValue, IComparable<UriTemplateLiteralQueryValue>
    {
        private readonly string _value; // an unescaped representation

        private UriTemplateLiteralQueryValue(string value)
            : base(UriTemplatePartType.Literal)
        {
            Ensure.NotNull(value, "bad literal value");
            _value = value;
        }
        public static UriTemplateLiteralQueryValue CreateFromUriTemplate(string value)
        {
            return new UriTemplateLiteralQueryValue(UrlUtility.UrlDecode(value, Encoding.UTF8));
        }

        public string AsEscapedString()
        {
            return UrlUtility.UrlEncode(_value, Encoding.UTF8);
        }
        public string AsRawUnescapedString()
        {
            return _value;
        }
        public override void Bind(string keyName, string[] values, ref int valueIndex, StringBuilder query)
        {
            query.AppendFormat("&{0}={1}", UrlUtility.UrlEncode(keyName, Encoding.UTF8), AsEscapedString());
        }

        public int CompareTo(UriTemplateLiteralQueryValue other)
        {
            return string.Compare(_value, other._value, StringComparison.Ordinal);
        }

        public override bool Equals(object obj)
        {
            var lqv = obj as UriTemplateLiteralQueryValue;
            Ensure.NotNull(lqv, "why would we ever call this?");
            //if (lqv == null) {
            //	Fx.Assert("why would we ever call this?");
            //	return false;
            //} else {
            return _value == lqv._value;
            //}
        }
        public override int GetHashCode()
        {
            return _value.GetHashCode();
        }

        public override bool IsEquivalentTo(UriTemplateQueryValue other)
        {
            Ensure.NotNull(other, "why would we ever call this?");
            //if (other == null) {
            //	Fx.Assert("why would we ever call this?");
            //	return false;
            //}
            if (other.Nature != UriTemplatePartType.Literal)
            {
                return false;
            }
            var otherAsLiteral = other as UriTemplateLiteralQueryValue;
            Ensure.NotNull(otherAsLiteral, "The nature requires that this will be OK");
            return CompareTo(otherAsLiteral) == 0;
        }
        public override void Lookup(string value, NameValueCollection boundParameters)
        {
            var ret = string.Compare(_value, value, StringComparison.Ordinal) == 0;
            if (ret == false)
            {
                throw new Exception("How can that be?");
            }
        }
    }
}