feat(chat): share SwiftUI chat across macOS+iOS

apps/shared/ClawdisKit/Sources/ClawdisChatUI/ChatMarkdownSplitter.swift

@@ -0,0 +1,114 @@
+import Foundation
+
+enum ChatMarkdownSplitter {
+    struct InlineImage: Identifiable {
+        let id = UUID()
+        let label: String
+        let image: ClawdisPlatformImage?
+    }
+
+    struct Block: Identifiable {
+        enum Kind: Equatable {
+            case text
+            case code(language: String?)
+        }
+
+        let id = UUID()
+        let kind: Kind
+        let text: String
+    }
+
+    struct SplitResult {
+        let blocks: [Block]
+        let images: [InlineImage]
+    }
+
+    static func split(markdown raw: String) -> SplitResult {
+        let extracted = self.extractInlineImages(from: raw)
+        let blocks = self.splitCodeBlocks(from: extracted.cleaned)
+        return SplitResult(blocks: blocks, images: extracted.images)
+    }
+
+    private static func splitCodeBlocks(from raw: String) -> [Block] {
+        var blocks: [Block] = []
+        var buffer: [String] = []
+        var inCode = false
+        var codeLang: String?
+        var codeLines: [String] = []
+
+        for line in raw.split(separator: "\n", omittingEmptySubsequences: false).map(String.init) {
+            if line.hasPrefix("```") {
+                if inCode {
+                    blocks.append(Block(kind: .code(language: codeLang), text: codeLines.joined(separator: "\n")))
+                    codeLines.removeAll(keepingCapacity: true)
+                    inCode = false
+                    codeLang = nil
+                } else {
+                    let text = buffer.joined(separator: "\n").trimmingCharacters(in: .whitespacesAndNewlines)
+                    if !text.isEmpty {
+                        blocks.append(Block(kind: .text, text: text))
+                    }
+                    buffer.removeAll(keepingCapacity: true)
+                    inCode = true
+                    codeLang = line.dropFirst(3).trimmingCharacters(in: .whitespacesAndNewlines)
+                    if codeLang?.isEmpty == true { codeLang = nil }
+                }
+                continue
+            }
+
+            if inCode {
+                codeLines.append(line)
+            } else {
+                buffer.append(line)
+            }
+        }
+
+        if inCode {
+            blocks.append(Block(kind: .code(language: codeLang), text: codeLines.joined(separator: "\n")))
+        } else {
+            let text = buffer.joined(separator: "\n").trimmingCharacters(in: .whitespacesAndNewlines)
+            if !text.isEmpty {
+                blocks.append(Block(kind: .text, text: text))
+            }
+        }
+
+        return blocks.isEmpty ? [Block(kind: .text, text: raw)] : blocks
+    }
+
+    private static func extractInlineImages(from raw: String) -> (cleaned: String, images: [InlineImage]) {
+        let pattern = #"!\[([^\]]*)\]\((data:image\/[^;]+;base64,[^)]+)\)"#
+        guard let re = try? NSRegularExpression(pattern: pattern) else {
+            return (raw, [])
+        }
+
+        let ns = raw as NSString
+        let matches = re.matches(in: raw, range: NSRange(location: 0, length: ns.length))
+        if matches.isEmpty { return (raw, []) }
+
+        var images: [InlineImage] = []
+        var cleaned = raw
+
+        for match in matches.reversed() {
+            guard match.numberOfRanges >= 3 else { continue }
+            let label = ns.substring(with: match.range(at: 1))
+            let dataURL = ns.substring(with: match.range(at: 2))
+
+            let image: ClawdisPlatformImage? = {
+                guard let comma = dataURL.firstIndex(of: ",") else { return nil }
+                let b64 = String(dataURL[dataURL.index(after: comma)...])
+                guard let data = Data(base64Encoded: b64) else { return nil }
+                return ClawdisPlatformImage(data: data)
+            }()
+            images.append(InlineImage(label: label, image: image))
+
+            let start = cleaned.index(cleaned.startIndex, offsetBy: match.range.location)
+            let end = cleaned.index(start, offsetBy: match.range.length)
+            cleaned.replaceSubrange(start..<end, with: "")
+        }
+
+        let normalized = cleaned
+            .replacingOccurrences(of: "\n\n\n", with: "\n\n")
+            .trimmingCharacters(in: .whitespacesAndNewlines)
+        return (normalized, images.reversed())
+    }
+}