Improve URL handling

Shared/URLParser.swift

@@ -0,0 +1,155 @@
+import CoreMedia
+import Foundation
+
+struct URLParser {
+    static let prefixes: [Destination: [String]] = [
+        .playlist: ["/playlist", "playlist"],
+        .channel: ["/c", "c", "/channel", "channel"],
+        .search: ["/results", "search"]
+    ]
+
+    enum Destination {
+        case video, playlist, channel, search
+        case favorites, subscriptions, popular, trending
+    }
+
+    var destination: Destination? {
+        if hasAnyOfPrefixes(path, ["favorites"]) { return .favorites }
+        if hasAnyOfPrefixes(path, ["subscriptions"]) { return .subscriptions }
+        if hasAnyOfPrefixes(path, ["popular"]) { return .popular }
+        if hasAnyOfPrefixes(path, ["trending"]) { return .trending }
+
+        if hasAnyOfPrefixes(path, Self.prefixes[.playlist]!) || queryItemValue("v") == "playlist" {
+            return .playlist
+        } else if hasAnyOfPrefixes(path, Self.prefixes[.channel]!) {
+            return .channel
+        } else if hasAnyOfPrefixes(path, Self.prefixes[.search]!) {
+            return .search
+        }
+
+        guard let id = videoID, !id.isEmpty else {
+            return nil
+        }
+
+        return .video
+    }
+
+    var url: URL
+
+    var videoID: String? {
+        if host == "youtu.be", !path.isEmpty {
+            return String(path.suffix(from: path.index(path.startIndex, offsetBy: 1)))
+        }
+
+        return queryItemValue("v")
+    }
+
+    var time: Int? {
+        guard let time = queryItemValue("t") else {
+            return nil
+        }
+
+        let timeComponents = parseTime(time)
+
+        guard !timeComponents.isEmpty,
+              let hours = Int(timeComponents["hours"] ?? "0"),
+              let minutes = Int(timeComponents["minutes"] ?? "0"),
+              let seconds = Int(timeComponents["seconds"] ?? "0")
+        else {
+            return Int(time)
+        }
+
+        return Int(seconds + (minutes * 60) + (hours * 60 * 60))
+    }
+
+    var playlistID: String? {
+        guard destination == .playlist else { return nil }
+
+        return queryItemValue("list")
+    }
+
+    var searchQuery: String? {
+        guard destination == .search else { return nil }
+
+        return queryItemValue("search_query")?.replacingOccurrences(of: "+", with: " ")
+    }
+
+    var channelName: String? {
+        guard destination == .channel else { return nil }
+
+        return removePrefixes(path, Self.prefixes[.channel]!.map { [$0, "/"].joined() })
+    }
+
+    var channelID: String? {
+        guard destination == .channel else { return nil }
+
+        return removePrefixes(path, Self.prefixes[.channel]!.map { [$0, "/"].joined() })
+    }
+
+    private var host: String {
+        urlComponents?.host ?? ""
+    }
+
+    private var path: String {
+        removePrefixes(urlComponents?.path ?? "", ["www.youtube.com", "youtube.com"])
+    }
+
+    private func hasAnyOfPrefixes(_ value: String, _ prefixes: [String]) -> Bool {
+        return prefixes.contains { value.hasPrefix($0) }
+    }
+
+    private func removePrefixes(_ value: String, _ prefixes: [String]) -> String {
+        var value = value
+
+        prefixes.forEach { prefix in
+            if value.hasPrefix(prefix) {
+                value.removeFirst(prefix.count)
+            }
+        }
+
+        return value
+    }
+
+    private var queryItems: [URLQueryItem] {
+        urlComponents?.queryItems ?? []
+    }
+
+    private func queryItemValue(_ name: String) -> String? {
+        queryItems.first { $0.name == name }?.value
+    }
+
+    private var urlComponents: URLComponents? {
+        URLComponents(url: url, resolvingAgainstBaseURL: false)
+    }
+
+    private func parseTime(_ time: String) -> [String: String] {
+        let results = timeRegularExpression.matches(
+            in: time,
+            range: NSRange(time.startIndex..., in: time)
+        )
+
+        guard let match = results.first else {
+            return [:]
+        }
+
+        var components: [String: String] = [:]
+
+        for name in ["hours", "minutes", "seconds"] {
+            let matchRange = match.range(withName: name)
+
+            if let substringRange = Range(matchRange, in: time) {
+                let capture = String(time[substringRange])
+                components[name] = capture
+            }
+        }
+
+        return components
+    }
+
+    private var timeRegularExpression: NSRegularExpression {
+        try! NSRegularExpression(
+            pattern: "(?:(?<hours>[0-9+])+h)?(?:(?<minutes>[0-9]+)m)?(?:(?<seconds>[0-9]*)s)?",
+            options: .caseInsensitive
+        )
+    }
+}