From 91895d4066bf1627015aaba2b47bc74379f8552c Mon Sep 17 00:00:00 2001
From: Brent Simmons <brent@ranchero.com>
Date: Mon, 20 Nov 2017 13:16:06 -0800
Subject: [PATCH] Create FaviconURLFinder, which pulls the favicon URL from the
 metadata of a web page.

---
 Evergreen.xcodeproj/project.pbxproj       |  4 +++
 Evergreen/Favicons/FaviconURLFinder.swift | 43 +++++++++++++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 Evergreen/Favicons/FaviconURLFinder.swift

diff --git a/Evergreen.xcodeproj/project.pbxproj b/Evergreen.xcodeproj/project.pbxproj
index 5d3c845ed..827e6f99d 100644
--- a/Evergreen.xcodeproj/project.pbxproj
+++ b/Evergreen.xcodeproj/project.pbxproj
@@ -106,6 +106,7 @@
 		84F2D53A1FC2308B00998D64 /* UnreadFeed.swift in Sources */ = {isa = PBXBuildFile; fileRef = 84F2D5391FC2308B00998D64 /* UnreadFeed.swift */; };
 		84FB9A2F1EDCD6C4003D53B9 /* Sparkle.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 84FB9A2D1EDCD6B8003D53B9 /* Sparkle.framework */; };
 		84FB9A301EDCD6C4003D53B9 /* Sparkle.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 84FB9A2D1EDCD6B8003D53B9 /* Sparkle.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
+		84FF69B11FC3793300DC198E /* FaviconURLFinder.swift in Sources */ = {isa = PBXBuildFile; fileRef = 84FF69B01FC3793300DC198E /* FaviconURLFinder.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -488,6 +489,7 @@
 		84F2D5361FC22FCB00998D64 /* TodayFeedDelegate.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TodayFeedDelegate.swift; sourceTree = "<group>"; };
 		84F2D5391FC2308B00998D64 /* UnreadFeed.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UnreadFeed.swift; sourceTree = "<group>"; };
 		84FB9A2D1EDCD6B8003D53B9 /* Sparkle.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Sparkle.framework; path = Frameworks/Vendor/Sparkle.framework; sourceTree = SOURCE_ROOT; };
+		84FF69B01FC3793300DC198E /* FaviconURLFinder.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FaviconURLFinder.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -579,6 +581,7 @@
 			isa = PBXGroup;
 			children = (
 				848F6AE41FC29CFA002D422E /* FaviconDownloader.swift */,
+				84FF69B01FC3793300DC198E /* FaviconURLFinder.swift */,
 			);
 			name = Favicons;
 			path = Evergreen/Favicons;
@@ -1315,6 +1318,7 @@
 				84DAEE301F86CAFE0058304B /* OPMLImporter.swift in Sources */,
 				849A975C1ED9EB0D007D329B /* DefaultFeedsImporter.swift in Sources */,
 				849A97891ED9ECEF007D329B /* ArticleStyle.swift in Sources */,
+				84FF69B11FC3793300DC198E /* FaviconURLFinder.swift in Sources */,
 				849A978A1ED9ECEF007D329B /* ArticleStylesManager.swift in Sources */,
 				849A97791ED9EC04007D329B /* TimelineStringUtilities.swift in Sources */,
 				84F204CE1FAACB660076E152 /* FeedListViewController.swift in Sources */,
diff --git a/Evergreen/Favicons/FaviconURLFinder.swift b/Evergreen/Favicons/FaviconURLFinder.swift
new file mode 100644
index 000000000..36511637e
--- /dev/null
+++ b/Evergreen/Favicons/FaviconURLFinder.swift
@@ -0,0 +1,43 @@
+//
+//  FaviconURLFinder.swift
+//  Evergreen
+//
+//  Created by Brent Simmons on 11/20/17.
+//  Copyright © 2017 Ranchero Software. All rights reserved.
+//
+
+import Foundation
+import RSParser
+import RSWeb
+
+// The favicon URL may be specified in the head section of the home page.
+
+struct FaviconURLFinder {
+
+	static func findFaviconURL(_ homePageURL: String, _ callback: @escaping (String?) -> Void) {
+
+		guard let url = URL(string: homePageURL) else {
+			callback(nil)
+			return
+		}
+
+		download(url) { (data, response, error) in
+
+			guard let data = data, let response = response, response.statusIsOK else {
+				callback(nil)
+				return
+			}
+
+			let link = faviconURL(homePageURL, data)
+			callback(link)
+		}
+	}
+
+	static private func faviconURL(_ url: String, _ webPageData: Data) -> String? {
+
+		let parserData = ParserData(url: url, data: webPageData)
+		let htmlMetadata = RSHTMLMetadataParser.htmlMetadata(with: parserData)
+		return htmlMetadata.faviconLink
+	}
+}
+