// // MastodonStatusContent.swift // Mastodon // // Created by MainasuK Cirno on 2021/2/1. // import UIKit import Combine import ActiveLabel import Fuzi enum MastodonStatusContent { typealias EmojiShortcode = String typealias EmojiDict = [EmojiShortcode: URL] static let workingQueue = DispatchQueue(label: "org.joinmastodon.app.ActiveLabel.working-queue", qos: .userInteractive) static func parseResult(content: String, emojiDict: MastodonStatusContent.EmojiDict) -> AnyPublisher { return Future { promise in self.workingQueue.async { let parseResult = try? MastodonStatusContent.parse(content: content, emojiDict: emojiDict) promise(.success(parseResult)) } } .eraseToAnyPublisher() } static func parse(content: String, emojiDict: EmojiDict) throws -> MastodonStatusContent.ParseResult { let document: String = { var content = content for (shortcode, url) in emojiDict { let emojiNode = "\(shortcode)" let pattern = ":\(shortcode):" content = content.replacingOccurrences(of: pattern, with: emojiNode) } return content.trimmingCharacters(in: .whitespacesAndNewlines) }() let rootNode = try Node.parse(document: document) let text = String(rootNode.text) var activeEntities: [ActiveEntity] = [] let entities = MastodonStatusContent.Node.entities(in: rootNode) for entity in entities { let range = NSRange(entity.text.startIndex.. String { guard self.hasPrefix(prefix) else { return self } return String(self.dropFirst(prefix.count)) } } extension MastodonStatusContent { class Node { let level: Int let type: Type? // substring text let text: Substring // range in parent String var range: Range { return text.startIndex.. = { guard let className = attributes["class"] else { return Set() } return Set(className.components(separatedBy: " ")) }() let _type: Type? = { if tagName == "a" { if _classNames.contains("u-url") { return .mention } if _classNames.contains("hashtag") { return .hashtag } return .url } else { if _classNames.contains("emoji") { return .emoji } return nil } }() self.level = level self.type = _type self.text = text self.tagName = tagName self.attributes = attributes self.href = href self.hrefEllipsis = hrefEllipsis self.children = children } static func parse(document: String) throws -> MastodonStatusContent.Node { let document = document.replacingOccurrences(of: "
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", with: "\r\n", options: .regularExpression, range: nil) let html = try HTMLDocument(string: document) let body = html.body ?? nil let text = body?.stringValue ?? "" let level = 0 let children: [MastodonStatusContent.Node] = body.flatMap { body in return Node.parse(element: body, parentText: text[...], parentLevel: level + 1) } ?? [] let node = Node( level: level, text: text[...], tagName: body?.tag, attributes: body?.attributes ?? [:], href: nil, hrefEllipsis: nil, children: children ) return node } static func parse(element: XMLElement, parentText: Substring, parentLevel: Int) -> [Node] { let parent = element let scanner = Scanner(string: String(parentText)) scanner.charactersToBeSkipped = .none var children: [Node] = [] for _element in parent.children { let _text = _element.stringValue // scan element text _ = scanner.scanUpToString(_text) let startIndexOffset = scanner.currentIndex.utf16Offset(in: scanner.string) guard scanner.scanString(_text) != nil else { assertionFailure() continue } let endIndexOffset = scanner.currentIndex.utf16Offset(in: scanner.string) // locate substring let startIndex = parentText.utf16.index(parentText.utf16.startIndex, offsetBy: startIndexOffset) let endIndex = parentText.utf16.index(parentText.utf16.startIndex, offsetBy: endIndexOffset) let text = Substring(parentText.utf16[startIndex.. Bool ) -> [Node] { var nodes: [Node] = [] if predicate(node) { nodes.append(node) } for child in node.children { nodes.append(contentsOf: Node.collect(node: child, where: predicate)) } return nodes } } } extension MastodonStatusContent.Node { enum `Type` { case url case mention case hashtag case emoji } static func entities(in node: MastodonStatusContent.Node) -> [MastodonStatusContent.Node] { return MastodonStatusContent.Node.collect(node: node) { node in node.type != nil } } static func hashtags(in node: MastodonStatusContent.Node) -> [MastodonStatusContent.Node] { return MastodonStatusContent.Node.collect(node: node) { node in node.type == .hashtag } } static func mentions(in node: MastodonStatusContent.Node) -> [MastodonStatusContent.Node] { return MastodonStatusContent.Node.collect(node: node) { node in node.type == .mention } } static func urls(in node: MastodonStatusContent.Node) -> [MastodonStatusContent.Node] { return MastodonStatusContent.Node.collect(node: node) { node in node.type == .url } } } extension MastodonStatusContent.Node: CustomDebugStringConvertible { var debugDescription: String { let linkInfo: String = { switch (href, hrefEllipsis) { case (nil, nil): return "" case (let href, let hrefEllipsis): return "(\(href ?? "nil") - \(hrefEllipsis ?? "nil"))" } }() let classNamesInfo: String = { guard let className = attributes["class"] else { return "" } return "@[\(className)]" }() let nodeDescription = String( format: "<%@>%@%@: %@", tagName ?? "", classNamesInfo, linkInfo, String(text) ) guard !children.isEmpty else { return nodeDescription } let indent = Array(repeating: " ", count: level).joined() let childrenDescription = children .map { indent + $0.debugDescription } .joined(separator: "\n") return nodeDescription + "\n" + childrenDescription } }