namespace Yes.Infrastructure.ViewEngine
{
    // This represents a Path segment, which can either be a Literal, a Variable or a Compound
    [DebuggerDisplay("Segment={_originalSegment} Nature={_nature}")]
    internal abstract class UriTemplatePathSegment
    {
        private readonly bool _endsWithSlash;
        private readonly UriTemplatePartType _nature;
        private readonly string _originalSegment;

        protected UriTemplatePathSegment(string originalSegment, UriTemplatePartType nature,
            bool endsWithSlash)
        {
            _originalSegment = originalSegment;
            _nature = nature;
            _endsWithSlash = endsWithSlash;
        }
        public bool EndsWithSlash
        {
            get
            {
                return _endsWithSlash;
            }
        }
        public UriTemplatePartType Nature
        {
            get
            {
                return _nature;
            }
        }

        public string OriginalSegment
        {
            get
            {
                return _originalSegment;
            }
        }
        public static UriTemplatePathSegment CreateFromUriTemplate(string segment, UriTemplate template)
        {
            // Identifying the type of segment - Literal|Compound|Variable
            switch (UriTemplateHelpers.IdentifyPartType(segment))
            {
                case UriTemplatePartType.Literal:
                    return UriTemplateLiteralPathSegment.CreateFromUriTemplate(segment, template);

                case UriTemplatePartType.Compound:
                    return UriTemplateCompoundPathSegment.CreateFromUriTemplate(segment, template);

                case UriTemplatePartType.Variable:
                    if (segment.EndsWith("/", StringComparison.Ordinal))
                    {
                        var varName = template.AddPathVariable(UriTemplatePartType.Variable,
                            segment.Substring(1, segment.Length - 3));
                        return new UriTemplateVariablePathSegment(segment, true, varName);
                    }
                    else
                    {
                        var varName = template.AddPathVariable(UriTemplatePartType.Variable,
                            segment.Substring(1, segment.Length - 2));
                        return new UriTemplateVariablePathSegment(segment, false, varName);
                    }

                default:
                    throw new Exception("Invalid value from IdentifyStringNature");
            }
        }
        public abstract void Bind(string[] values, ref int valueIndex, StringBuilder path);

        public abstract bool IsEquivalentTo(UriTemplatePathSegment other, bool ignoreTrailingSlash);
        public bool IsMatch(UriTemplateLiteralPathSegment segment)
        {
            return IsMatch(segment, false);
        }
        public abstract bool IsMatch(UriTemplateLiteralPathSegment segment, bool ignoreTrailingSlash);
        public abstract void Lookup(string segment, NameValueCollection boundParameters);
    }
}