Merge pull request #186 from NBull92/master

Created GitlabSource.

src/Squirrel/Sources/GitlabSource.cs

@@ -0,0 +1,233 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.Serialization;
+using System.Threading.Tasks;
+using Squirrel.Json;
+
+namespace Squirrel.Sources
+{
+    /// <summary>
+    /// Describes a Gitlab release, plus any assets that are attached.
+    /// </summary>
+    [DataContract]
+    public class GitlabRelease
+    {
+        /// <summary>
+        /// The name of the release.
+        /// </summary>
+        [DataMember(Name = "name")]
+        public string Name { get; set; }
+
+        /// <summary>
+        /// True if this is intended for an upcoming release.
+        /// </summary>
+        [DataMember(Name = "upcoming_release")]
+        public bool UpcomingRelease { get; set; }
+
+        /// <summary>
+        /// The date which this release was published publically.
+        /// </summary>
+        [DataMember(Name = "released_at")]
+        public DateTime ReleasedAt { get; set; }
+
+        /// <summary>
+        /// A container for the assets (files) uploaded to this release.
+        /// </summary>
+        [DataMember(Name = "assets")]
+        public GitlabReleaseAsset Assets { get; set; }
+    }
+
+    /// <summary>
+    /// Describes a container for the assets attached to a release.
+    /// </summary>
+    [DataContract]
+    public class GitlabReleaseAsset
+    {
+        /// <summary>
+        /// The amount of assets linked to the release.
+        /// </summary>
+        [DataMember(Name = "count")]
+        public int Count { get; set; }
+
+        /// <summary>
+        /// A list of asset (file) links.
+        /// </summary>
+        [DataMember(Name = "links")]
+        public GitlabReleaseLink[] Links { get; set; }
+    }
+
+    /// <summary>
+    /// Describes a container for the links of assets attached to a release.
+    /// </summary>
+    [DataContract]
+    public class GitlabReleaseLink
+    {
+        /// <summary>
+        /// Name of the asset (file) linked.
+        /// </summary>
+        [DataMember(Name = "name")]
+        public string Name { get; set; }
+
+        /// <summary>
+        /// The url for the asset. This make use of the Gitlab API.
+        /// </summary>
+        [DataMember(Name = "url")]
+        public string Url { get; set; }
+
+        /// <summary>
+        /// A direct url to the asset, via a traditional URl. 
+        /// As a posed to using the API.
+        /// This links directly to the raw asset (file).
+        /// </summary>
+        [DataMember(Name = "direct_asset_url")]
+        public string DirectAssetUrl { get; set; }
+
+        /// <summary>
+        /// The category type that the asset is listed under.
+        /// Options: 'Package', 'Image', 'Runbook', 'Other'
+        /// </summary>
+        [DataMember(Name = "link_type")]
+        public string Type { get; set; }
+    }
+
+    /// <summary>
+    /// Retrieves available releases from a GitLab repository. This class only
+    /// downloads assets from the very latest GitLab release.
+    /// </summary>
+    public class GitlabSource : IUpdateSource
+    {
+        /// <summary> 
+        /// The URL of the GitLab repository to download releases from 
+        /// (e.g. https://gitlab.com/api/v4/projects/ProjectId)
+        /// </summary>
+        public virtual Uri RepoUri { get; }
+
+        /// <summary>  
+        /// If true, the latest upcoming release will be downloaded. If false, the latest 
+        /// stable release will be downloaded.
+        /// </summary>
+        public virtual bool UpcomingRelease { get; }
+
+        /// <summary> 
+        /// The file downloader used to perform HTTP requests. 
+        /// </summary>
+        public virtual IFileDownloader Downloader { get; }
+
+        /// <summary>  
+        /// The GitLab release which this class should download assets from when 
+        /// executing <see cref="DownloadReleaseEntry"/>. This property can be set
+        /// explicitly, otherwise it will also be set automatically when executing
+        /// <see cref="GetReleaseFeed(Guid?, ReleaseEntry)"/>.
+        /// </summary>
+        public virtual GitlabRelease Release { get; set; }
+
+        /// <summary>
+        /// The GitLab access token to use with the request to download releases.
+        /// </summary>
+        protected virtual string AccessToken { get; }
+
+        /// <summary>
+        /// The Bearer token used in the request.
+        /// </summary>
+        protected virtual string Authorization => string.IsNullOrWhiteSpace(AccessToken) ? null : "Bearer " + AccessToken;
+
+        /// <inheritdoc cref="GitlabSource" />
+        /// <param name="repoUrl">
+        /// The URL of the GitLab repository to download releases from 
+        /// (e.g. https://gitlab.com/api/v4/projects/ProjectId)
+        /// </param>
+        /// <param name="accessToken">
+        /// The GitLab access token to use with the request to download releases.
+        /// </param>
+        /// <param name="upcomingRelease">
+        /// If true, the latest upcoming release will be downloaded. If false, the latest 
+        /// stable release will be downloaded.
+        /// </param>
+        /// <param name="downloader">
+        /// The file downloader used to perform HTTP requests. 
+        /// </param>
+        public GitlabSource(string repoUrl, string accessToken, bool upcomingRelease, IFileDownloader downloader = null)
+        {
+            RepoUri = new Uri(repoUrl);
+            AccessToken = accessToken;
+            UpcomingRelease = upcomingRelease;
+            Downloader = downloader ?? Utility.CreateDefaultDownloader();
+        }
+
+        /// <inheritdoc />
+        public Task DownloadReleaseEntry(ReleaseEntry releaseEntry, string localFile, Action<int> progress)
+        {
+            if (Release == null) {
+                throw new InvalidOperationException("No GitLab Release specified. Call GetReleaseFeed or set " +
+                    "GitLabSource.Release before calling this function.");
+            }
+
+            var assetUrl = GetAssetUrlFromName(Release, releaseEntry.Filename);
+            return Downloader.DownloadFile(assetUrl, localFile, progress, Authorization, "application/octet-stream");
+        }
+
+        /// <inheritdoc />
+        public async Task<ReleaseEntry[]> GetReleaseFeed(Guid? stagingId = null, ReleaseEntry latestLocalRelease = null)
+        {
+            var releases = await GetReleases(UpcomingRelease).ConfigureAwait(false);
+            if (releases == null || releases.Count() == 0)
+                throw new Exception($"No Gitlab releases found at '{RepoUri}'.");
+
+            // CS: we 'cache' the release here, so subsequent calls to DownloadReleaseEntry
+            // will download assets from the same release in which we returned ReleaseEntry's
+            // from. A better architecture would be to return an array of "GitlabReleaseEntry"
+            // containing a reference to the GitlabReleaseAsset instead.
+            Release = releases.First();
+
+            var assetUrl = GetAssetUrlFromName(Release, "RELEASES");
+            var releaseBytes = await Downloader.DownloadBytes(assetUrl, Authorization, "application/octet-stream").ConfigureAwait(false);
+            var txt = Utility.RemoveByteOrderMarkerIfPresent(releaseBytes);
+            return ReleaseEntry.ParseReleaseFileAndApplyStaging(txt, stagingId).ToArray();
+        }
+
+        /// <summary>
+        /// Given a <see cref="GitlabRelease"/> and an asset filename (eg. 'RELEASES') this 
+        /// function will return either <see cref="GitlabReleaseLink.DirectAssetUrl"/> or
+        /// <see cref="GitlabReleaseLink.Url"/>, depending whether an access token is available
+        /// or not. Throws if the specified release has no matching assets.
+        /// </summary>
+        protected virtual string GetAssetUrlFromName(GitlabRelease release, string assetName)
+        {
+            if (release.Assets == null || release.Assets.Count == 0) 
+            {
+                throw new ArgumentException($"No assets found in Gitlab Release '{release.Name}'.");
+            }
+
+            GitlabReleaseLink packageFile =
+                release.Assets.Links.FirstOrDefault(a => a.Name.Equals(assetName, StringComparison.InvariantCultureIgnoreCase));
+            if (packageFile == null) 
+            {
+                throw new ArgumentException($"Could not find asset called '{assetName}' in GitLab Release '{release.Name}'.");
+            }
+
+            if (String.IsNullOrWhiteSpace(AccessToken)) 
+            {
+                return packageFile.DirectAssetUrl;
+            } 
+            else 
+            {
+                return packageFile.Url;
+            }
+        }
+
+        /// <summary>
+        /// Retrieves a list of <see cref="GitlabRelease"/> from the current repository.
+        /// </summary>
+        public virtual async Task<GitlabRelease[]> GetReleases(bool includePrereleases, int perPage = 30, int page = 1)
+        {
+            // https://docs.gitlab.com/ee/api/releases/
+            var releasesPath = $"{RepoUri.AbsolutePath}/releases?per_page={perPage}&page={page}";
+            var baseUri = new Uri("https://gitlab.com");
+            var getReleasesUri = new Uri(baseUri, releasesPath);
+            var response = await Downloader.DownloadString(getReleasesUri.ToString(), Authorization).ConfigureAwait(false);
+            var releases = SimpleJson.DeserializeObject<List<GitlabRelease>>(response);
+            return releases.OrderByDescending(d => d.ReleasedAt).Where(x => includePrereleases || !x.UpcomingRelease).ToArray();
+        }
+    }
+}