﻿/*
 * Licensed 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.
 */

namespace DotPulsar.Extensions
{
    using DotPulsar.Abstractions;
    using System.Threading;
    using System.Threading.Tasks;

    /// <summary>
    /// Extensions for IReader.
    /// </summary>
    public static class ReaderExtensions
    {
        /// <summary>
        /// Wait for the state to change to a specific state.
        /// </summary>
        /// <returns>
        /// The current state.
        /// </returns>
        /// <remarks>
        /// If the state change to a final state, then all awaiting tasks will complete.
        /// </remarks>
        public static async ValueTask<ReaderStateChanged> StateChangedTo(this IReader reader, ReaderState state, CancellationToken cancellationToken = default)
        {
            var newState = await reader.OnStateChangeTo(state, cancellationToken).ConfigureAwait(false);
            return new ReaderStateChanged(reader, newState);
        }

        /// <summary>
        /// Wait for the state to change from a specific state.
        /// </summary>
        /// <returns>
        /// The current state.
        /// </returns>
        /// <remarks>
        /// If the state change to a final state, then all awaiting tasks will complete.
        /// </remarks>
        public static async ValueTask<ReaderStateChanged> StateChangedFrom(this IReader reader, ReaderState state, CancellationToken cancellationToken = default)
        {
            var newState = await reader.OnStateChangeFrom(state, cancellationToken).ConfigureAwait(false);
            return new ReaderStateChanged(reader, newState);
        }
    }
}