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

namespace Octokit
{
    public class RepositoryContentsClient : ApiClient, IRepositoryContentsClient
    {
        public RepositoryContentsClient(IApiConnection apiConnection) : base(apiConnection)
        {
        }

        /// <summary>
        /// Returns the contents of a file or directory in a repository.
        /// </summary>
        /// <remarks>
        /// If given a path to a single file, this method returns a collection containing only that file.
        /// </remarks>
        /// <param name="owner">The owner of the repository</param>
        /// <param name="name">The name of the repository</param>
        /// <param name="path">The content path</param>
        /// <returns>
        /// A collection of <see cref="RepositoryContent"/> representing the content at the specified path
        /// </returns>
        public async Task<IReadOnlyList<RepositoryContent>> GetContents(string owner, string name, string path)
        {
            Ensure.ArgumentNotNullOrEmptyString(owner, "owner");
            Ensure.ArgumentNotNullOrEmptyString(name, "name");
            Ensure.ArgumentNotNullOrEmptyString(path, "path");

            var url = ApiUrls.RepositoryContent(owner, name, path);

            return await ApiConnection.GetAll<RepositoryContent>(url);
        }

        /// <summary>
        /// Gets the preferred README for the specified repository.
        /// </summary>
        /// <remarks>
        /// See the <a href="http://developer.github.com/v3/repos/contents/#get-the-readme">API documentation</a> for more information.
        /// </remarks>
        /// <param name="owner">The owner of the repository</param>
        /// <param name="name">The name of the repository</param>
        /// <exception cref="ApiException">Thrown when a general API error occurs.</exception>
        /// <returns></returns>
        public async Task<Readme> GetReadme(string owner, string name)
        {
            Ensure.ArgumentNotNullOrEmptyString(owner, "owner");
            Ensure.ArgumentNotNullOrEmptyString(name, "name");

            var endpoint = ApiUrls.RepositoryReadme(owner, name);
            var readmeInfo = await ApiConnection.Get<ReadmeResponse>(endpoint, null).ConfigureAwait(false);
            
            return new Readme(readmeInfo, ApiConnection);
        }

        /// <summary>
        /// Gets the perferred README's HTML for the specified repository.
        /// </summary>
        /// <remarks>
        /// See the <a href="http://developer.github.com/v3/repos/contents/#get-the-readme">API documentation</a> for more information.
        /// </remarks>
        /// <param name="owner">The owner of the repository</param>
        /// <param name="name">The name of the repository</param>
        /// <exception cref="ApiException">Thrown when a general API error occurs.</exception>
        /// <returns></returns>
        public Task<string> GetReadmeHtml(string owner, string name)
        {
            Ensure.ArgumentNotNullOrEmptyString(owner, "owner");
            Ensure.ArgumentNotNullOrEmptyString(name, "name");

            return ApiConnection.GetHtml(ApiUrls.RepositoryReadme(owner, name), null);
        }

        /// <summary>
        /// Creates a commit that creates a new file in a repository.
        /// </summary>
        /// <param name="owner">The owner of the repository</param>
        /// <param name="name">The name of the repository</param>
        /// <param name="path">The path to the file</param>
        /// <param name="request">Information about the file to create</param>
        /// <returns></returns>
        public Task<RepositoryContentChangeSet> CreateFile(string owner, string name, string path, CreateFileRequest request)
        {
            Ensure.ArgumentNotNullOrEmptyString(owner, "owner");
            Ensure.ArgumentNotNullOrEmptyString(name, "name");
            Ensure.ArgumentNotNullOrEmptyString(path, "path");
            Ensure.ArgumentNotNull(request, "request");

            var createUrl = ApiUrls.RepositoryContent(owner, name, path);
            return ApiConnection.Put<RepositoryContentChangeSet>(createUrl, request);
        }

        /// <summary>
        /// Creates a commit that updates the contents of a file in a repository.
        /// </summary>
        /// <param name="owner">The owner of the repository</param>
        /// <param name="name">The name of the repository</param>
        /// <param name="path">The path to the file</param>
        /// <param name="request">Information about the file to update</param>
        /// <returns>The updated content</returns>
        public Task<RepositoryContentChangeSet> UpdateFile(string owner, string name, string path, UpdateFileRequest request)
        {
            Ensure.ArgumentNotNullOrEmptyString(owner, "owner");
            Ensure.ArgumentNotNullOrEmptyString(name, "name");
            Ensure.ArgumentNotNullOrEmptyString(path, "path");
            Ensure.ArgumentNotNull(request, "request");

            var updateUrl = ApiUrls.RepositoryContent(owner, name, path);
            return ApiConnection.Put<RepositoryContentChangeSet>(updateUrl, request);
        }

        /// <summary>
        /// Creates a commit that deletes a file in a repository.
        /// </summary>
        /// <param name="owner">The owner of the repository</param>
        /// <param name="name">The name of the repository</param>
        /// <param name="path">The path to the file</param>
        /// <param name="request">Information about the file to delete</param>
        public Task DeleteFile(string owner, string name, string path, DeleteFileRequest request)
        {
            Ensure.ArgumentNotNullOrEmptyString(owner, "owner");
            Ensure.ArgumentNotNullOrEmptyString(name, "name");
            Ensure.ArgumentNotNullOrEmptyString(path, "path");
            Ensure.ArgumentNotNull(request, "request");

            var deleteUrl = ApiUrls.RepositoryContent(owner, name, path);
            return ApiConnection.Delete(deleteUrl, request);
        }
    }
}