From 139df9ad51472c9c4eab9427aa172969fb8f9924 Mon Sep 17 00:00:00 2001
From: Maurice Parker <mo@vincode.io>
Date: Fri, 14 Aug 2020 19:31:54 -0500
Subject: [PATCH] Initial support for Twitter lists

---
 .../Twitter/TwitterFeedProvider.swift         | 56 ++++++++++++++++---
 .../FeedProvider/Twitter/TwitterList.swift    | 17 ++++++
 2 files changed, 66 insertions(+), 7 deletions(-)
 create mode 100644 Account/Sources/Account/FeedProvider/Twitter/TwitterList.swift

diff --git a/Account/Sources/Account/FeedProvider/Twitter/TwitterFeedProvider.swift b/Account/Sources/Account/FeedProvider/Twitter/TwitterFeedProvider.swift
index 7ab04827b..1e6a5a5d9 100644
--- a/Account/Sources/Account/FeedProvider/Twitter/TwitterFeedProvider.swift
+++ b/Account/Sources/Account/FeedProvider/Twitter/TwitterFeedProvider.swift
@@ -158,6 +158,21 @@ public final class TwitterFeedProvider: FeedProvider {
 		default:
 			if let hashtag = deriveHashtag(urlComponents) {
 				completion(.success(FeedProviderFeedMetaData(name: "#\(hashtag)", homePageURL: Self.homeURL)))
+			} else if let listID = deriveListID(urlComponents) {
+				retrieveList(listID: listID) { result in
+					switch result {
+					case .success(let list):
+						if let userName = list.name {
+							var urlComponents = URLComponents(string: Self.homeURL)
+							urlComponents?.path = "/i/lists/\(listID)"
+							completion(.success(FeedProviderFeedMetaData(name: userName, homePageURL: urlComponents?.url?.absoluteString)))
+						} else {
+							completion(.failure(TwitterFeedProviderError.screenNameNotFound))
+						}
+					case .failure(let error):
+						completion(.failure(error))
+					}
+				}
 			} else if let screenName = deriveScreenName(urlComponents) {
 				retrieveUser(screenName: screenName) { result in
 					switch result {
@@ -211,15 +226,16 @@ public final class TwitterFeedProvider: FeedProvider {
 				api = "search/tweets.json"
 				parameters["q"] = "#\(hashtag)"
 				isSearch = true
-			} else {
+			} else if let listID = deriveListID(urlComponents) {
+				api = "lists/statuses.json"
+				parameters["list_id"] = listID
+			} else if let screenName = deriveScreenName(urlComponents) {
 				api = "statuses/user_timeline.json"
 				parameters["exclude_replies"] = true
-				if let screenName = deriveScreenName(urlComponents) {
-					parameters["screen_name"] = screenName
-				} else {
-					completion(.failure(TwitterFeedProviderError.unknown))
-					return
-				}
+				parameters["screen_name"] = screenName
+			} else {
+				completion(.failure(TwitterFeedProviderError.unknown))
+				return
 			}
 		}
 
@@ -319,6 +335,12 @@ private extension TwitterFeedProvider {
 		}
 	}
 	
+	func deriveListID(_ urlComponents: URLComponents) -> String? {
+		let path = urlComponents.path
+		guard path.starts(with: "/i/lists/") else { return nil }
+		return String(path.suffix(from: path.index(path.startIndex, offsetBy: 9)))
+	}
+	
 	func retrieveUser(screenName: String, completion: @escaping (Result<TwitterUser, Error>) -> Void) {
 		let url = "\(Self.apiBase)users/show.json"
 		let parameters = ["screen_name": screenName]
@@ -339,6 +361,26 @@ private extension TwitterFeedProvider {
 		}
 	}
 	
+	func retrieveList(listID: String, completion: @escaping (Result<TwitterList, Error>) -> Void) {
+		let url = "\(Self.apiBase)lists/show.json"
+		let parameters = ["list_id": listID]
+		
+		client.get(url, parameters: parameters, headers: Self.userAgentHeaders) { result in
+			switch result {
+			case .success(let response):
+				let decoder = JSONDecoder()
+				do {
+					let collection = try decoder.decode(TwitterList.self, from: response.data)
+					completion(.success(collection))
+				} catch {
+					completion(.failure(error))
+				}
+			case .failure(let error):
+				completion(.failure(error))
+			}
+		}
+	}
+	
 	func retrieveTweets(api: String, parameters: [String: Any], isSearch: Bool, completion: @escaping (Result<[TwitterStatus], Error>) -> Void) {
 		let url = "\(Self.apiBase)\(api)"
 		var expandedParameters = parameters
diff --git a/Account/Sources/Account/FeedProvider/Twitter/TwitterList.swift b/Account/Sources/Account/FeedProvider/Twitter/TwitterList.swift
new file mode 100644
index 000000000..96427fe94
--- /dev/null
+++ b/Account/Sources/Account/FeedProvider/Twitter/TwitterList.swift
@@ -0,0 +1,17 @@
+//
+//  TwitterList.swift
+//  
+//
+//  Created by Maurice Parker on 8/14/20.
+//
+
+import Foundation
+
+struct TwitterList: Codable {
+	
+	let name: String?
+
+	enum CodingKeys: String, CodingKey {
+		case name = "name"
+	}
+}