1 files changed, 74 insertions, 0 deletions
diff --git a/Sources/NorgUI/Extensions/AttributedString+Norg.swift b/Sources/NorgUI/Extensions/AttributedString+Norg.swift
new file mode 100644
index 0000000..286e0c8
--- /dev/null
+++ b/Sources/NorgUI/Extensions/AttributedString+Norg.swift
@@ -0,0 +1,74 @@
+import NorgKit
+import SwiftUI
+
+/// Extensions to AttributedString to generate from NorgKit models.
+extension AttributedString {
+
+  /// Builds a styled attributed string from parsed Norg inline spans.
+  public init(norg spans: [InlineSpan], baseFont: Font = .body, theme: NorgTheme = .default) {
+    var result = AttributedString()
+    for span in spans {
+      result.append(Self.render(span, baseFont: baseFont, theme: theme))
+    }
+    self = result
+  }
+
+  private static func render(_ span: InlineSpan, baseFont: Font, theme: NorgTheme)
+    -> AttributedString {
+    var run = AttributedString(span.text)
+    run.font = font(for: span.styles, baseFont: baseFont)
+    applyDecorations(to: &run, styles: span.styles, theme: theme)
+    if let link = span.link {
+      applyLink(link, to: &run, theme: theme)
+    }
+    return run
+  }
+
+  private static func font(for styles: InlineStyle, baseFont: Font) -> Font {
+    var font = baseFont
+    if styles.contains(.verbatim) || styles.contains(.math) { font = font.monospaced() }
+    if styles.contains(.bold) { font = font.bold() }
+    if styles.contains(.italic) { font = font.italic() }
+    return font
+  }
+
+  private static func applyDecorations(
+    to run: inout AttributedString, styles: InlineStyle, theme: NorgTheme
+  ) {
+    if styles.contains(.underline) { run.underlineStyle = .single }
+    if styles.contains(.strikethrough) { run.strikethroughStyle = .single }
+    if styles.contains(.superscript) { run.baselineOffset = theme.superscriptOffset }
+    if styles.contains(.subscript) { run.baselineOffset = theme.subscriptOffset }
+    if styles.contains(.spoiler) {
+      run.foregroundColor = theme.spoilerForeground
+      run.backgroundColor = theme.spoilerBackground
+    }
+    if styles.contains(.verbatim) {
+      run.foregroundColor = theme.verbatimColor
+    }
+  }
+
+  private static func applyLink(
+    _ link: InlineLink, to run: inout AttributedString, theme: NorgTheme
+  ) {
+    run.foregroundColor = theme.linkColor
+    run.underlineStyle = .single
+    run.link = url(for: link)
+  }
+
+  private static func url(for link: InlineLink) -> URL? {
+    if link.kind == .link, let target = link.target, let external = externalURL(for: target) {
+      return external
+    }
+    return NorgLinkURL.encode(link)
+  }
+
+  private static func externalURL(for target: String) -> URL? {
+    let lower = target.lowercased()
+    guard lower.hasPrefix("http://") || lower.hasPrefix("https://") || lower.hasPrefix("file://")
+    else {
+      return nil
+    }
+    return URL(string: target)
+  }
+}