Load comments

Noosh.xcodeproj/xcshareddata/xcschemes/Noosh.xcscheme

@@ -26,7 +26,8 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      shouldUseLaunchSchemeArgsEnv = "YES">
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      codeCoverageEnabled = "YES">
       <Testables>
          <TestableReference
             skipped = "NO">

Noosh/API/ListingsEndpoint.swift

@@ -0,0 +1,53 @@
+import Foundation
+import RxSwift
+import reddift
+
+class ListingsEndpoint {
+	let session: Session
+
+	init(session: Session) {
+		self.session = session
+	}
+
+	func getListing(
+		paginator: Paginator,
+		subreddit: SubredditURLPath?,
+		sort: LinkSortType,
+		timeFilterWithin: TimeFilterWithin,
+		limit: Int = 25
+	) -> Observable<Listing> {
+		return RxHelper().createObservable { [weak self] resultHandler in
+			guard let strongSelf = self else { return }
+
+			try strongSelf.session.getList(
+				paginator,
+				subreddit: subreddit,
+				sort: sort,
+				timeFilterWithin: timeFilterWithin,
+				limit: limit,
+				completion: resultHandler
+			)
+		}
+	}
+
+	func getComments(
+		linkId: String,
+		sort: CommentSort,
+		commentIds: [String]? = nil,
+		depth: Int? = nil,
+		limit: Int? = nil
+	) -> Observable<(Listing, Listing)> {
+		return RxHelper().createObservable { [weak self] resultHandler in
+			guard let strongSelf = self else { return }
+
+			try strongSelf.session.getArticles(
+				Link(id: linkId),
+				sort: sort,
+				comments: commentIds,
+				depth: depth,
+				limit: limit,
+				completion: resultHandler
+			)
+		}
+	}
+}

Noosh/Core/CommentConversionService.swift

@@ -0,0 +1,46 @@
+import Foundation
+import reddift
+
+class CommentConversionService {
+	private typealias ReplyLevels = [String : Int]
+
+	func process(commentsListing: Listing) -> [[CommentViewModel]] {
+		guard let comments = commentsListing.children.filter({ $0 is Comment }) as? [Comment] else {
+			// FIXME do not crash in production
+			fatalError("could not covert comment listings to [Comment]")
+		}
+
+		return comments.flatMap { buildViewModels(comment: $0) }
+	}
+
+
+	private func buildViewModels(comment: Comment, cache: ReplyLevels? = nil) -> [CommentViewModel] {
+		let replyLevels = cache ?? buildReplyLevels(comment: comment)
+		guard let replyLevel = replyLevels[comment.id] else {
+			// FIXME do not crash in production
+			fatalError("Could not determine reply level for comment \(comment.id)")
+		}
+
+		var comments: [CommentViewModel] =
+			[CommentViewModelImpl(comment: comment, replyLevel: replyLevel)]
+
+		let replies = (comment.replies.children as? [Comment] ?? []).flatMap {
+			buildViewModels(comment: $0, cache: replyLevels)
+		}
+
+		comments.append(contentsOf: replies)
+
+		return comments
+	}
+
+	private func buildReplyLevels(cache: ReplyLevels = [:], comment: Comment, currentLevel: Int = 0)
+		-> ReplyLevels {
+		var levels = cache
+		levels[comment.id] = currentLevel
+
+		let replies = comment.replies.children as? [Comment] ?? []
+		return replies.reduce(levels) {
+			buildReplyLevels(cache: $0, comment: $1, currentLevel: currentLevel + 1)
+		}
+	}
+}

Noosh/Core/RxHelper.swift

@@ -0,0 +1,21 @@
+import Foundation
+import reddift
+import RxSwift
+
+class RxHelper {
+	func createObservable<T>(request: @escaping (@escaping (Result<T>) -> Void) throws -> Void) -> Observable<T> {
+		return Observable.create { observer in
+			do {
+				try request { result in
+					guard let value = result.value else { return }
+					observer.onNext(value)
+					observer.onCompleted()
+				}
+			} catch {
+				observer.onError(error)
+			}
+
+			return Disposables.create()
+		}
+	}
+}

Noosh/Features/LinkDetails/ArticleViewModel.swift

@@ -0,0 +1,50 @@
+import Foundation
+import reddift
+
+protocol ArticleViewModel {
+	var author: String { get }
+	var authorFlair: String? { get }
+	var body: String? { get }
+	var commentCount: String { get }
+	var createdAt: String { get }
+	var subreddit: String { get }
+	var title: String { get }
+	var voteCount: String { get }
+}
+
+struct ArticleViewModelImpl: ArticleViewModel {
+	let subreddit: String
+	let title: String
+	let body: String?
+	let author: String
+	let authorFlair: String?
+	let createdAt: String
+	let voteCount: String
+	let commentCount: String
+}
+
+extension ArticleViewModelImpl {
+	init(link: LinkCellViewModel) {
+		self.author = link.username
+		self.authorFlair = link.authorFlair
+		self.body = link.body
+		self.commentCount = link.commentCount
+		self.createdAt = link.createdAt
+		self.subreddit = link.subreddit
+		self.title = link.title
+		self.voteCount = link.voteCount
+	}
+}
+
+extension ArticleViewModelImpl {
+	init(link: Link, prettyNumbers: PrettyNumbers = PrettyNumbers(dateProvider: DateProviderImpl())) {
+		self.author = link.author
+		self.authorFlair = link.authorFlairText
+		self.body = link.selftext
+		self.commentCount = prettyNumbers.commentCount(link.numComments)
+		self.createdAt = prettyNumbers.timeAgo(epochUtc: link.createdUtc)
+		self.subreddit = "r/\(link.subreddit)"
+		self.title = link.title
+		self.voteCount = prettyNumbers.voteCount(link.ups - link.downs)
+	}
+}

Noosh/Features/LinkDetails/CommentViewModel.swift

@@ -0,0 +1,48 @@
+import Foundation
+import reddift
+
+protocol CommentViewModel {
+	var id: String { get }
+	var author: String { get }
+	var authorFlair: String? { get }
+	var body: String { get }
+	var createdAt: String { get }
+	var edited: Bool { get }
+	var parentId: String? { get }
+	var replyLevel: Int { get }
+	var score: Int? { get }
+}
+
+struct CommentViewModelImpl: CommentViewModel, Factory {
+	/// sourcery:begin: factoryFields
+	let id: String
+	let author: String
+	let authorFlair: String?
+	let body: String
+	let createdAt: String
+	let edited: Bool
+	let parentId: String?
+	let replyLevel: Int
+	let score: Int?
+	/// sourcery:end
+}
+
+extension CommentViewModelImpl {
+	init(
+		comment: Comment,
+		replyLevel: Int,
+		prettyNumbers: PrettyNumbers = PrettyNumbers(dateProvider: DateProviderImpl())
+	) {
+		self.init(
+			id: comment.id,
+			author: comment.author,
+			authorFlair: comment.authorFlairText,
+			body: comment.body,
+			createdAt: prettyNumbers.timeAgo(epochUtc: comment.createdUtc),
+			edited: comment.edited,
+			parentId: comment.parentId,
+			replyLevel: replyLevel,
+			score: comment.score
+		)
+	}
+}

Noosh/Features/LinkDetails/CommentsViewModel.swift

@@ -0,0 +1,10 @@
+import Foundation
+import RxSwift
+
+protocol CommentsViewModel {
+	var threads: Variable<[[CommentViewModel]]> { get }
+}
+
+struct CommentsViewModelImpl: CommentsViewModel {
+	let threads: Variable<[[CommentViewModel]]>
+}

Noosh/Features/LinkDetails/LinkDetailCoordinator.swift

@@ -1,17 +1,34 @@
 import Foundation
 import UIKit
 import reddift
+import RxSwift
 
 class LinkDetailCoordinator: Coordinator {
 	let navigationController: UINavigationController
 	private var linkDetailController: LinkDetailViewController?
+	let listingsEndpoint: ListingsEndpoint
 
 	init(navigationController: UINavigationController, session: Session) {
 		self.navigationController = navigationController
+		self.listingsEndpoint = ListingsEndpoint(session: session)
 	}
 
 	func start(link: LinkCellViewModel) {
-		let controller = LinkDetailViewController(link: LinkDetailViewModelImpl(link: link))
+		let article: Variable<ArticleViewModel> = Variable(ArticleViewModelImpl(link: link))
+		let comments = Variable<[[CommentViewModel]]>([])
+		let details =
+			LinkDetailViewModelImpl(article: article, comments: CommentsViewModelImpl(threads: comments))
+
+		_ = listingsEndpoint.getComments(linkId: link.id, sort: .hot)
+			.observeOn(MainScheduler.instance)
+			.subscribe(onNext: { (newArticle, newComments) in
+				guard let newArticle = newArticle.children.first as? Link else { return }
+				article.value = ArticleViewModelImpl(link: newArticle)
+				comments.value = CommentConversionService().process(commentsListing: newComments)
+			})
+
+		let controller = LinkDetailViewController(link: details)
+
 		linkDetailController = controller
 		navigationController.pushViewController(controller, animated: true)
 	}

Noosh/Features/LinkDetails/LinkDetailViewController.swift

@@ -19,26 +19,32 @@ class LinkDetailViewController: UIViewController {
 	}
 
 	override func viewDidLoad() {
-		createdAt.text = link.createdAt
-		subreddit.text = link.subreddit
-		username.text = link.author
+		super.viewDidLoad()
 
-		if let authorFlair = link.authorFlair {
+		_ = link.article.asObservable().subscribe(onNext: { [weak self] in self?.update(article: $0) })
+	}
+
+	private func update(article: ArticleViewModel) {
+		createdAt.text = article.createdAt
+		subreddit.text = article.subreddit
+		username.text = article.author
+
+		if let authorFlair = article.authorFlair {
 			self.authorFlair.text = authorFlair
 		} else {
 			authorFlair.text = "hi"
 		}
 
-		linkTitle.text = link.title
+		linkTitle.text = article.title
 
-		if let body = link.body {
+		if let body = article.body {
 			self.body.text = body
 		} else {
 			self.body.text = "bod"
 		}
 
-		voteCount.text = link.voteCount
-		commentCount.text = link.commentCount
+		voteCount.text = article.voteCount
+		commentCount.text = article.commentCount
 	}
 
 	required init?(coder aDecoder: NSCoder) {