using System.Collections.Generic;
using System.Threading.Tasks;

namespace Octokit
{
    /// <summary>
    /// A client for GitHub's Repository Commits API.
    /// </summary>
    /// <remarks>
    /// See the <a href="http://developer.github.com/v3/repos/commits/">Repository Commits API documentation</a> for more information.
    /// </remarks>
    public class RepositoryCommitsClient : IRepositoryCommitsClient
    {
        readonly IApiConnection _apiConnection;

        public RepositoryCommitsClient(IApiConnection apiConnection)
        {
            _apiConnection = apiConnection;
        }

        /// <summary>
        /// Compare two references in a repository
        /// </summary>
        /// <param name="owner">The owner of the repository</param>
        /// <param name="name">The name of the repository</param>
        /// <param name="base">The reference to use as the base commit</param>
        /// <param name="head">The reference to use as the head commit</param>
        /// <returns></returns>
        public Task<CompareResult> Compare(string owner, string name, string @base, string head)
        {
            Ensure.ArgumentNotNullOrEmptyString(owner, "owner");
            Ensure.ArgumentNotNullOrEmptyString(name, "name");
            Ensure.ArgumentNotNullOrEmptyString(@base, "base");
            Ensure.ArgumentNotNullOrEmptyString(head, "head");

            return _apiConnection.Get<CompareResult>(ApiUrls.RepoCompare(owner, name, @base, head));
        }

        /// <summary>
        /// Gets a single commit for a given repository
        /// </summary>
        /// <param name="owner">The owner of the repository</param>
        /// <param name="name">The name of the repository</param>
        /// <param name="reference">The reference for the commit (SHA)</param>
        /// <returns></returns>
        public Task<GitHubCommit> Get(string owner, string name, string reference)
        {
            Ensure.ArgumentNotNullOrEmptyString(owner, "owner");
            Ensure.ArgumentNotNullOrEmptyString(name, "name");
            Ensure.ArgumentNotNullOrEmptyString(reference, "reference");

            return _apiConnection.Get<GitHubCommit>(ApiUrls.RepositoryCommit(owner, name, reference));
        }

        /// <summary>
        /// Gets all commits for a given repository
        /// </summary>
        /// <param name="owner">The owner of the repository</param>
        /// <param name="name">The name of the repository</param>
        /// <returns></returns>
        public Task<IReadOnlyList<GitHubCommit>> GetAll(string owner, string name)
        {
            return GetAll(owner, name, new CommitRequest());
        }

        /// <summary>
        /// Gets all commits for a given repository
        /// </summary>
        /// <param name="owner">The owner of the repository</param>
        /// <param name="name">The name of the repository</param>
        /// <param name="request">Used to filter list of commits returned</param>
        /// <returns></returns>
        public Task<IReadOnlyList<GitHubCommit>> GetAll(string owner, string name, CommitRequest request)
        {
            Ensure.ArgumentNotNullOrEmptyString(owner, "owner");
            Ensure.ArgumentNotNullOrEmptyString(name, "name");
            Ensure.ArgumentNotNull(request, "request");

            return _apiConnection.GetAll<GitHubCommit>(ApiUrls.RepositoryCommits(owner, name),
                request.ToParametersDictionary());
        }
    }
}