namespace Yes.Infrastructure.ViewEngine
{
    internal class UriTemplateVariablePathSegment : UriTemplatePathSegment
    {
        private readonly string _varName;

        public UriTemplateVariablePathSegment(string originalSegment, bool endsWithSlash, string varName)
            : base(originalSegment, UriTemplatePartType.Variable, endsWithSlash)
        {
            if (!string.IsNullOrEmpty(varName) == false) throw new Exception("bad variable segment");
            _varName = varName;
        }

        public string VarName
        {
            get
            {
                return _varName;
            }
        }
        public override void Bind(string[] values, ref int valueIndex, StringBuilder path)
        {
            if (valueIndex < values.Length == false) throw new Exception("Not enough values to bind");
            if (EndsWithSlash)
            {
                path.AppendFormat("{0}/", values[valueIndex++]);
            }
            else
            {
                path.Append(values[valueIndex++]);
            }
        }

        public override bool IsEquivalentTo(UriTemplatePathSegment other, bool ignoreTrailingSlash)
        {
            Ensure.NotNull(other, "why would we ever call this?");
            //if (other == null) {
            //	Fx.Assert("why would we ever call this?");
            //	return false;
            //}
            if (!ignoreTrailingSlash && EndsWithSlash != other.EndsWithSlash)
            {
                return false;
            }
            return other.Nature == UriTemplatePartType.Variable;
        }
        public override bool IsMatch(UriTemplateLiteralPathSegment segment, bool ignoreTrailingSlash)
        {
            if (!ignoreTrailingSlash && EndsWithSlash != segment.EndsWithSlash)
            {
                return false;
            }
            return !segment.IsNullOrEmpty();
        }
        public override void Lookup(string segment, NameValueCollection boundParameters)
        {
            Ensure.NotNullOrEmpty(segment, "How can that be? Lookup is expected to be called after IsMatch");
            boundParameters.Add(_varName, segment);
        }
    }
}