处理聊天数据打印机效果

Visual_Novel_iOS/Src/Modules/Chat/Session/SessionController.swift

@@ -78,6 +78,12 @@ class SessionController: CLBaseViewController {
     var isStreamChatMode = false
     var streamMessages: [StreamChatMessageModel] = []
     private var currentStreamingMessageId: String?
+    private var displayLink: CADisplayLink?
+    private var typingTargetText: String = ""
+    private var typingDisplayedLength: Int = 0
+    private var typingCharactersPerSecond: CGFloat = 20
+    private var lastDisplayLinkTimestamp: CFTimeInterval = 0
+    private var shouldFinishTypingAfterTarget = false
     
     convenience init(accountID: String) {
         self.init()
@@ -598,21 +604,43 @@ extension SessionController {
     }
     
     private func appendOrUpdateIncomingChunk(_ chunk: String) {
-        DispatchQueue.main.async {
+        DispatchQueue.main.async { [weak self] in
+            guard let self = self, chunk.isEmpty == false else { return }
+            
+            var messageIndex: Int
+            var didInsertRow = false
+            
             if let currentId = self.currentStreamingMessageId,
                let index = self.streamMessages.firstIndex(where: { $0.id == currentId }) {
-                self.streamMessages[index].text += chunk
+                self.typingTargetText = self.mergeText(current: self.typingTargetText, incoming: chunk)
+                messageIndex = index
             } else {
                 let message = StreamChatMessageModel(id: UUID().uuidString,
-                                                     text: chunk,
+                                                     text: "",
                                                      isSelf: false,
                                                      isStreaming: true)
                 self.streamMessages.append(message)
                 self.currentStreamingMessageId = message.id
+                self.typingTargetText = chunk
+                self.typingDisplayedLength = 0
+                self.shouldFinishTypingAfterTarget = false
+                messageIndex = self.streamMessages.count - 1
+                didInsertRow = true
             }
             
-            self.tableView?.reloadData()
+            guard let tableView = self.tableView else { return }
-            self.scrollToBottom(self.tableView, animated: true)
+            let indexPath = IndexPath(row: messageIndex, section: 1)
+            
+            if didInsertRow {
+                UIView.performWithoutAnimation {
+                    tableView.beginUpdates()
+                    tableView.insertRows(at: [indexPath], with: .none)
+                    tableView.endUpdates()
+                }
+            }
+            
+            self.startDisplayLinkIfNeeded()
+            self.smoothScrollToLatest()
         }
     }
     
@@ -622,21 +650,37 @@ extension SessionController {
                                              isSelf: true,
                                              isStreaming: false)
         streamMessages.append(message)
-        tableView?.reloadData()
+        guard let tableView = tableView else { return }
-        scrollToBottom(tableView, animated: true)
+        let indexPath = IndexPath(row: streamMessages.count - 1, section: 1)
+        UIView.performWithoutAnimation {
+            tableView.beginUpdates()
+            tableView.insertRows(at: [indexPath], with: .none)
+            tableView.endUpdates()
+        }
+        smoothScrollToLatest()
     }
     
     private func finalizeStreamingMessage() {
-        DispatchQueue.main.async {
+        DispatchQueue.main.async { [weak self] in
+            guard let self = self else { return }
             guard let currentId = self.currentStreamingMessageId,
                   let index = self.streamMessages.firstIndex(where: { $0.id == currentId }) else {
                 IMSSEManager.shared.disconnect()
                 return
             }
             self.streamMessages[index].isStreaming = false
-            self.currentStreamingMessageId = nil
+            self.shouldFinishTypingAfterTarget = true
-            self.tableView?.reloadData()
+            
-            self.scrollToBottom(self.tableView, animated: true)
+            if self.typingTargetText.isEmpty {
+                self.typingTargetText = self.streamMessages[index].text
+            }
+            
+            if self.typingDisplayedLength >= self.typingTargetText.count {
+                self.finishTypingSequence()
+            } else {
+                self.startDisplayLinkIfNeeded()
+            }
+            
             IMSSEManager.shared.disconnect()
         }
     }
@@ -644,28 +688,31 @@ extension SessionController {
     private func parseStreamChunk(_ payload: Any) -> StreamChunkResult {
         if let dict = payload as? [String: Any] {
             let finished = (dict["finished"] as? Bool) ?? (dict["done"] as? Bool) ?? false
-            let text = (dict["message"] as? String)
+            if let text = extractText(from: dict) {
-            ?? (dict["content"] as? String)
-            ?? (dict["data"] as? String)
                 return StreamChunkResult(text: text, finished: finished)
+            }
+            if let data = try? JSONSerialization.data(withJSONObject: dict, options: []),
+               let jsonString = String(data: data, encoding: .utf8) {
+                return StreamChunkResult(text: jsonString, finished: finished)
+            }
+            return StreamChunkResult(text: nil, finished: finished)
         } else if let str = payload as? String {
-            let trimmed = str.trimmingCharacters(in: .whitespacesAndNewlines)
+            let normalized = str.trimmingCharacters(in: .whitespacesAndNewlines)
-            if trimmed.isEmpty {
+            if normalized.isEmpty {
                 return StreamChunkResult(text: nil, finished: false)
             }
             
-            if let data = trimmed.data(using: .utf8),
+            if let data = normalized.data(using: .utf8),
-               let jsonObj = try? JSONSerialization.jsonObject(with: data, options: []),
+               let jsonObj = try? JSONSerialization.jsonObject(with: data, options: []) {
-               let dict = jsonObj as? [String: Any] {
+                return parseStreamChunk(jsonObj)
-                return parseStreamChunk(dict)
             }
             
-            if trimmed.lowercased() == "[done]" {
+            if normalized.lowercased() == "[done]" {
                 return StreamChunkResult(text: nil, finished: true)
             }
             
-            let containsDoneFlag = trimmed.lowercased().contains("__end__") || trimmed.lowercased().contains("<end>")
+            let containsDoneFlag = normalized.lowercased().contains("__end__") || normalized.lowercased().contains("<end>")
-            return StreamChunkResult(text: trimmed, finished: containsDoneFlag)
+            return StreamChunkResult(text: str, finished: containsDoneFlag)
         }
         return StreamChunkResult(text: nil, finished: false)
     }
@@ -675,6 +722,193 @@ extension SessionController {
            let index = streamMessages.firstIndex(where: { $0.id == currentId }) {
             streamMessages[index].isStreaming = false
         }
+        cleanupTypingState()
+    }
+    
+    private func smoothScrollToLatest() {
+        guard let tableView = tableView else { return }
+        let contentHeight = tableView.contentSize.height
+        let tableViewHeight = tableView.bounds.height
+        let offsetY = tableView.contentOffset.y
+        let distanceFromBottom = contentHeight - offsetY - tableViewHeight
+        let shouldAutoScroll = distanceFromBottom <= 200 || contentHeight <= tableViewHeight
+        guard shouldAutoScroll else { return }
+        let lastIndex = streamMessages.count - 1
+        guard lastIndex >= 0 else { return }
+        let indexPath = IndexPath(row: lastIndex, section: 1)
+        tableView.scrollToRow(at: indexPath, at: .bottom, animated: false)
+    }
+    
+    private func startDisplayLinkIfNeeded() {
+        guard displayLink == nil else { return }
+        lastDisplayLinkTimestamp = 0
+        let link = CADisplayLink(target: self, selector: #selector(handleDisplayLink(_:)))
+        link.add(to: .main, forMode: .common)
+        displayLink = link
+    }
+    
+    private func stopDisplayLink() {
+        displayLink?.invalidate()
+        displayLink = nil
+        lastDisplayLinkTimestamp = 0
+    }
+    
+    @objc private func handleDisplayLink(_ link: CADisplayLink) {
+        guard let currentId = currentStreamingMessageId,
+              let index = streamMessages.firstIndex(where: { $0.id == currentId }),
+              typingTargetText.isEmpty == false else {
+            stopDisplayLink()
+            return
+        }
+        
+        let delta: CFTimeInterval
+        if lastDisplayLinkTimestamp == 0 {
+            delta = link.duration
+        } else {
+            delta = link.timestamp - lastDisplayLinkTimestamp
+        }
+        lastDisplayLinkTimestamp = link.timestamp
+        let rawCharacters = typingCharactersPerSecond * CGFloat(delta)
+        let charactersThisFrame = max(1, Int(floor(rawCharacters)))
+        guard charactersThisFrame > 0 else { return }
+        
+        let newLength = min(typingTargetText.count, typingDisplayedLength + charactersThisFrame)
+        guard newLength > typingDisplayedLength else { return }
+        
+        typingDisplayedLength = newLength
+        let newText = String(typingTargetText.prefix(newLength))
+        streamMessages[index].text = newText
+        
+        if let tableView = tableView {
+            let indexPath = IndexPath(row: index, section: 1)
+            if let cell = tableView.cellForRow(at: indexPath) as? StreamChatBubbleCell {
+                cell.updateText(newText)
+                UIView.performWithoutAnimation {
+                    tableView.beginUpdates()
+                    tableView.endUpdates()
+                }
+            } else {
+                UIView.performWithoutAnimation {
+                    tableView.reloadRows(at: [indexPath], with: .none)
+                }
+            }
+            smoothScrollToLatest()
+        }
+        
+        if typingDisplayedLength == typingTargetText.count {
+            if shouldFinishTypingAfterTarget || streamMessages[index].isStreaming == false {
+                finishTypingSequence()
+            } else {
+                stopDisplayLink()
+            }
+        }
+    }
+    
+    private func finishTypingSequence() {
+        guard let currentId = currentStreamingMessageId,
+              let index = streamMessages.firstIndex(where: { $0.id == currentId }) else {
+            cleanupTypingState()
+            return
+        }
+        
+        streamMessages[index].text = typingTargetText
+        
+        if let tableView = tableView {
+            let indexPath = IndexPath(row: index, section: 1)
+            UIView.performWithoutAnimation {
+                tableView.beginUpdates()
+                tableView.reloadRows(at: [indexPath], with: .none)
+                tableView.endUpdates()
+            }
+            smoothScrollToLatest()
+        }
+        cleanupTypingState()
+    }
+    
+    private func cleanupTypingState() {
+        stopDisplayLink()
+        typingTargetText = ""
+        typingDisplayedLength = 0
+        shouldFinishTypingAfterTarget = false
         currentStreamingMessageId = nil
     }
+    
+    /// 将 SSE 片段安全拼接，尽量避免重复，但绝不丢字
+    private func mergeText(current: String, incoming: String) -> String {
+        if current.isEmpty { return incoming }
+        if incoming.isEmpty { return current }
+        
+        // 后端每次返回完整内容：直接用较长的那个
+        if incoming.hasPrefix(current) { return incoming }
+        if current.hasPrefix(incoming) { return current }
+        
+        // 完全重复或包含关系，直接保留已有内容
+        if current.contains(incoming) { return current }
+        if incoming.contains(current) { return incoming }
+        
+        // 其他情况：不做重叠裁剪，直接拼接，保证不丢任意字符
+        return current + incoming
+    }
+    
+    private func extractText(from dictionary: [String: Any]) -> String? {
+        let candidateKeys = ["message", "content", "data", "text", "value", "delta"]
+        for key in candidateKeys {
+            if let value = dictionary[key] as? String, value.isEmpty == false {
+                return value
+            }
+        }
+        
+        if let nestedData = dictionary["data"] as? [String: Any],
+           let text = extractText(from: nestedData) {
+            return text
+        }
+        
+        if let nestedDelta = dictionary["delta"] as? [String: Any],
+           let text = extractText(from: nestedDelta) {
+            return text
+        }
+        
+        if let resultDict = dictionary["result"] as? [String: Any],
+           let text = extractText(from: resultDict) {
+            return text
+        }
+        
+        if let choices = dictionary["choices"] as? [[String: Any]] {
+            for choice in choices {
+                if let text = extractText(from: choice) {
+                    return text
+                }
+                if let delta = choice["delta"] as? [String: Any],
+                   let text = extractText(from: delta) {
+                    return text
+                }
+            }
+        }
+        
+        if let segments = dictionary["segments"] as? [[String: Any]] {
+            var combined = ""
+            for segment in segments {
+                if let text = extractText(from: segment) {
+                    combined += text
+                }
+            }
+            if combined.isEmpty == false {
+                return combined
+            }
+        }
+        
+        if let contentArray = dictionary["content"] as? [[String: Any]] {
+            var combined = ""
+            for item in contentArray {
+                if let text = extractText(from: item) {
+                    combined += text
+                }
+            }
+            if combined.isEmpty == false {
+                return combined
+            }
+        }
+        
+        return nil
+    }
 }

Visual_Novel_iOS/Src/Modules/Chat/Session/View/StreamChatBubbleCell.swift

@@ -6,7 +6,6 @@ final class StreamChatBubbleCell: UITableViewCell {
     
     private let bubbleView = UIView()
     private let messageLabel = UILabel()
-    private let indicator = UIActivityIndicatorView(style: .medium)
     
     override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
         super.init(style: style, reuseIdentifier: reuseIdentifier)
@@ -19,25 +18,29 @@ final class StreamChatBubbleCell: UITableViewCell {
         fatalError("init(coder:) has not been implemented")
     }
     
+    override func layoutSubviews() {
+        super.layoutSubviews()
+        let maxWidth = UIScreen.width * 2.0 / 3.0 - 28
+        if messageLabel.preferredMaxLayoutWidth != maxWidth {
+            messageLabel.preferredMaxLayoutWidth = maxWidth
+        }
+    }
+    
     private func setupViews() {
         contentView.addSubview(bubbleView)
         bubbleView.layer.cornerRadius = 18
         bubbleView.layer.masksToBounds = true
-        bubbleView.snp.makeConstraints { make in
+        bubbleView.setContentHuggingPriority(.defaultLow, for: .horizontal)
-            make.top.equalToSuperview().offset(6)
+        bubbleView.setContentCompressionResistancePriority(.defaultHigh, for: .horizontal)
-            make.bottom.equalToSuperview().offset(-6)
-            make.width.lessThanOrEqualTo(UIScreen.width * 0.75)
-        }
         
         bubbleView.addSubview(messageLabel)
         messageLabel.numberOfLines = 0
         messageLabel.font = .systemFont(ofSize: 16)
-        messageLabel.snp.makeConstraints { make in
+        messageLabel.lineBreakMode = .byWordWrapping
-            make.edges.equalToSuperview().inset(UIEdgeInsets(top: 10, left: 14, bottom: 10, right: 14))
+        messageLabel.textAlignment = .left
-        }
+        messageLabel.setContentHuggingPriority(.defaultLow, for: .horizontal)
-        
+        messageLabel.setContentCompressionResistancePriority(.required, for: .horizontal)
-        contentView.addSubview(indicator)
+        messageLabel.preferredMaxLayoutWidth = UIScreen.width * 2.0 / 3.0 - 28
-        indicator.hidesWhenStopped = true
     }
     
     func configure(message: StreamChatMessageModel) {
@@ -49,32 +52,32 @@ final class StreamChatBubbleCell: UITableViewCell {
             bubbleView.snp.remakeConstraints { make in
                 make.top.equalToSuperview().offset(6)
                 make.bottom.equalToSuperview().offset(-6)
-                make.width.lessThanOrEqualTo(UIScreen.width * 0.75)
+                make.width.lessThanOrEqualTo(UIScreen.width * 2.0 / 3.0)
+                make.width.greaterThanOrEqualTo(60)
                 make.trailing.equalToSuperview().offset(-16)
             }
-            indicator.snp.remakeConstraints { make in
-                make.centerY.equalTo(bubbleView)
-                make.trailing.equalTo(bubbleView.snp.leading).offset(-8)
-            }
         } else {
             bubbleView.backgroundColor = UIColor.white.withAlphaComponent(0.2)
             messageLabel.textColor = .white
             bubbleView.snp.remakeConstraints { make in
                 make.top.equalToSuperview().offset(6)
                 make.bottom.equalToSuperview().offset(-6)
-                make.width.lessThanOrEqualTo(UIScreen.width * 0.75)
+                make.width.lessThanOrEqualTo(UIScreen.width * 2.0 / 3.0)
+                make.width.greaterThanOrEqualTo(60)
                 make.leading.equalToSuperview().offset(16)
             }
-            indicator.snp.remakeConstraints { make in
-                make.centerY.equalTo(bubbleView)
-                make.leading.equalTo(bubbleView.snp.trailing).offset(8)
-            }
         }
         
-        if message.isStreaming && !message.isSelf {
+        messageLabel.snp.remakeConstraints { make in
-            indicator.startAnimating()
+            make.edges.equalToSuperview().inset(UIEdgeInsets(top: 10, left: 14, bottom: 10, right: 14))
-        } else {
+        }
-            indicator.stopAnimating()
+    }
+    
+    func updateText(_ text: String) {
+        UIView.performWithoutAnimation {
+            messageLabel.text = text
+            setNeedsLayout()
+            layoutIfNeeded()
         }
     }
 }