/* SPDX-License-Identifier: Apache-2.0
*
* The OpenSearch Contributors require contributions made to
* this file be licensed under the Apache-2.0 license or a
* compatible open source license.
*/
/*
* Modifications Copyright OpenSearch Contributors. See
* GitHub history for details.
*
*  Licensed to Elasticsearch B.V. under one or more contributor
*  license agreements. See the NOTICE file distributed with
*  this work for additional information regarding copyright
*  ownership. Elasticsearch B.V. licenses this file to you under
*  the Apache License, Version 2.0 (the "License"); you may
*  not use this file except in compliance with the License.
*  You may obtain a copy of the License at
*
* 	http://www.apache.org/licenses/LICENSE-2.0
*
*  Unless required by applicable law or agreed to in writing,
*  software distributed under the License is distributed on an
*  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
*  KIND, either express or implied.  See the License for the
*  specific language governing permissions and limitations
*  under the License.
*/

using System;
using System.Linq;
using System.Text;

namespace OpenSearch.Client
{
	internal class UrlLookup
	{
		private readonly string[] _parts;
		private readonly string _route;
		private readonly string[] _tokenized;
		private readonly int _length;

		public UrlLookup(string route)
		{
			_route = route;
			_tokenized = route.Replace("{", "{@")
				.Split(new[] { '{', '}' }, StringSplitOptions.RemoveEmptyEntries);

			_parts = _tokenized
				.Where(p => p.StartsWith("@"))
				.Select(p => p.Remove(0, 1))
				.ToArray();

			_length = _route.Length + (_parts.Length * 4);
		}

		public bool Matches(ResolvedRouteValues values)
		{
			for (var i = 0; i < _parts.Length; i++)
			{
				if (!values.ContainsKey(_parts[i]))
					return false;
			}
			return true;
		}

		public string ToUrl(ResolvedRouteValues values)
		{
			if (values.Count == 0 && _tokenized.Length == 1 && _tokenized[0][0] != '@')
				return _tokenized[0];

			var sb = new StringBuilder(_length);
			var i = 0;
			for (var index = 0; index < _tokenized.Length; index++)
			{
				var t = _tokenized[index];
				if (t[0] == '@')
				{
					if (values.TryGetValue(_parts[i], out var v))
					{
						if (string.IsNullOrEmpty(v))
							throw new Exception($"'{_parts[i]}' defined but is empty on url: {_route}");

						sb.Append(Uri.EscapeDataString(v));
					}
					else throw new Exception($"No value provided for '{_parts[i]}' on url: {_route}");

					i++;
				}
				else sb.Append(t);
			}
			return sb.ToString();
		}
	}
}