Syntax highlighting

2026-04-10 22:47:39 +02:00
parent 2e7e931c3b
commit 389b051ca1
7 changed files with 394 additions and 10 deletions
@@ -0,0 +1,134 @@
+import UIKit
+import SwiftUI
+
+/// Tokenises .env file text into a syntax-highlighted NSAttributedString.
+/// Handles KEY=value pairs, comments, and quoted values.
+enum ENVHighlighter {
+
+    // MARK: - Palette
+
+    private static let keyColor     = UIColor(hex: "#3b82f6")   // blue   — variable names
+    private static let stringColor  = UIColor(hex: "#22c55e")   // green  — quoted values
+    private static let numberColor  = UIColor(hex: "#f59e0b")   // amber  — numeric values
+    private static let boolColor    = UIColor(hex: "#c084fc")   // violet — true/false
+    private static let commentColor = UIColor(hex: "#6b7280")   // gray   — # comments
+    private static let eqColor      = UIColor(hex: "#94a3b8")   // slate  — = sign
+    private static let plainColor   = UIColor(hex: "#e2e8f0")   // slate  — plain values
+
+    private static let monoFont = UIFont.monospacedSystemFont(ofSize: 14, weight: .regular)
+
+    // MARK: - Public API
+
+    static func nsAttributedString(from env: String) -> NSAttributedString {
+        let result = NSMutableAttributedString()
+        let lines = env.components(separatedBy: "\n")
+        for (i, line) in lines.enumerated() {
+            result.append(processLine(line))
+            if i < lines.count - 1 {
+                result.append(seg("\n", plainColor))
+            }
+        }
+        return result
+    }
+
+    static func attributedString(from env: String) -> AttributedString {
+        (try? AttributedString(nsAttributedString(from: env), including: \.uiKit)) ?? AttributedString(env)
+    }
+
+    // MARK: - Line processing
+
+    private static func processLine(_ line: String) -> NSAttributedString {
+        guard !line.isEmpty else { return seg("", plainColor) }
+
+        let stripped = line.trimmingCharacters(in: .whitespaces)
+
+        // Blank / whitespace-only
+        if stripped.isEmpty { return seg(line, plainColor) }
+
+        // Comment
+        if stripped.hasPrefix("#") { return seg(line, commentColor) }
+
+        // KEY=value  or  export KEY=value
+        var workLine = line
+        let result = NSMutableAttributedString()
+
+        // Strip optional "export " prefix
+        if workLine.hasPrefix("export ") {
+            result.append(seg("export ", eqColor))
+            workLine = String(workLine.dropFirst(7))
+        }
+
+        if let eqIdx = workLine.firstIndex(of: "=") {
+            let key   = String(workLine[..<eqIdx])
+            let value = String(workLine[workLine.index(after: eqIdx)...])
+
+            result.append(seg(key, keyColor))
+            result.append(seg("=", eqColor))
+            result.append(colorValue(value))
+        } else {
+            // No `=` found — render as plain
+            result.append(seg(workLine, plainColor))
+        }
+
+        return result
+    }
+
+    // MARK: - Value colouring
+
+    private static func colorValue(_ value: String) -> NSAttributedString {
+        // Split inline comment: " # …"
+        if let commentStart = inlineCommentIndex(in: value) {
+            let valuePart   = String(value[..<commentStart])
+            let commentPart = String(value[commentStart...])
+            let result = NSMutableAttributedString(attributedString:
+                seg(valuePart, typeColor(for: valuePart)))
+            result.append(seg(commentPart, commentColor))
+            return result
+        }
+        return seg(value, typeColor(for: value))
+    }
+
+    private static func typeColor(for raw: String) -> UIColor {
+        let v = raw.trimmingCharacters(in: .whitespaces)
+        guard !v.isEmpty else { return plainColor }
+
+        // Quoted strings
+        if v.count >= 2,
+           (v.hasPrefix("\"") && v.hasSuffix("\"")) ||
+           (v.hasPrefix("'")  && v.hasSuffix("'")) { return stringColor }
+
+        // Booleans
+        switch v.lowercased() {
+        case "true", "false", "yes", "no", "1", "0": return boolColor
+        default: break
+        }
+
+        // Numbers
+        if Int(v) != nil || Double(v) != nil { return numberColor }
+
+        return plainColor
+    }
+
+    private static func inlineCommentIndex(in text: String) -> String.Index? {
+        var inSingle = false, inDouble = false, prev: Character = " "
+        for idx in text.indices {
+            let ch = text[idx]
+            if ch == "\"" && !inSingle { inDouble.toggle() }
+            else if ch == "'" && !inDouble { inSingle.toggle() }
+            else if ch == "#" && !inSingle && !inDouble && prev == " " {
+                return text.index(before: idx)
+            }
+            prev = ch
+        }
+        return nil
+    }
+
+    // MARK: - Helpers
+
+    private static func seg(_ text: String, _ color: UIColor) -> NSAttributedString {
+        NSAttributedString(string: text, attributes: [
+            .font: monoFont,
+            .foregroundColor: color
+        ])
+    }
+}
@@ -0,0 +1,64 @@
+import SwiftUI
+import UIKit
+
+/// A UITextView-backed editor that applies syntax highlighting on every keystroke.
+/// Pass any `(String) -> NSAttributedString` highlighter — shared by YAML and ENV.
+struct SyntaxHighlightingEditor: UIViewRepresentable {
+    @Binding var text: String
+    let highlight: (String) -> NSAttributedString
+
+    func makeUIView(context: Context) -> UITextView {
+        let tv = UITextView()
+        tv.delegate = context.coordinator
+        tv.backgroundColor        = UIColor(Color.terminalBg)
+        tv.isScrollEnabled        = false   // outer ScrollView drives scrolling
+        tv.textContainerInset     = UIEdgeInsets(top: 8, left: 4, bottom: 8, right: 4)
+        tv.autocorrectionType     = .no
+        tv.autocapitalizationType = .none
+        tv.spellCheckingType      = .no
+        tv.smartDashesType        = .no
+        tv.smartQuotesType        = .no
+        tv.keyboardType           = .asciiCapable
+        tv.tintColor              = UIColor(Color.appAccent)
+        tv.attributedText         = highlight(text)
+        context.coordinator.lastText = text
+        return tv
+    }
+
+    func updateUIView(_ tv: UITextView, context: Context) {
+        // Only re-highlight when text changed from outside (e.g. initial load / save)
+        guard context.coordinator.lastText != text else { return }
+        context.coordinator.lastText = text
+        let sel = tv.selectedRange
+        tv.attributedText = highlight(text)
+        // Clamp selection to new length
+        let len = (tv.text as NSString).length
+        tv.selectedRange = NSRange(location: min(sel.location, len), length: 0)
+    }
+
+    func makeCoordinator() -> Coordinator { Coordinator(self) }
+
+    // MARK: - Coordinator
+
+    final class Coordinator: NSObject, UITextViewDelegate {
+        var parent: SyntaxHighlightingEditor
+        var lastText: String = ""
+
+        init(_ parent: SyntaxHighlightingEditor) { self.parent = parent }
+
+        func textViewDidChange(_ tv: UITextView) {
+            let newText = tv.text ?? ""
+            lastText = newText
+            parent.text = newText
+
+            // Re-apply highlighting, preserving cursor position
+            let sel = tv.selectedRange
+            tv.attributedText = parent.highlight(newText)
+            let len = (tv.text as NSString).length
+            tv.selectedRange = NSRange(
+                location: min(sel.location, len),
+                length:   min(sel.length, max(0, len - sel.location))
+            )
+        }
+    }
+}
@@ -0,0 +1,179 @@
+import UIKit
+import SwiftUI
+
+/// Tokenises YAML text into a syntax-highlighted NSAttributedString.
+/// Designed for docker-compose files displayed on a dark terminal background.
+enum YAMLHighlighter {
+
+    // MARK: - Palette (dark-terminal optimised, UIColor)
+
+    private static let keyColor     = UIColor(hex: "#3b82f6")   // blue   — keys
+    private static let stringColor  = UIColor(hex: "#22c55e")   // green  — quoted strings / block scalars
+    private static let numberColor  = UIColor(hex: "#f59e0b")   // amber  — numbers
+    private static let boolColor    = UIColor(hex: "#c084fc")   // violet — true/false/yes/no
+    private static let nullColor    = UIColor(hex: "#6b7280")   // gray   — null / ~
+    private static let commentColor = UIColor(hex: "#6b7280")   // gray   — # comments
+    private static let anchorColor  = UIColor(hex: "#fb923c")   // orange — &anchors / *aliases
+    private static let plainColor   = UIColor(hex: "#e2e8f0")   // slate  — plain values
+
+    private static let monoFont = UIFont.monospacedSystemFont(ofSize: 14, weight: .regular)
+
+    // MARK: - Public API
+
+    static func nsAttributedString(from yaml: String) -> NSAttributedString {
+        let result = NSMutableAttributedString()
+        let lines = yaml.components(separatedBy: "\n")
+        for (i, line) in lines.enumerated() {
+            result.append(processLine(line))
+            if i < lines.count - 1 {
+                result.append(seg("\n", plainColor))
+            }
+        }
+        return result
+    }
+
+    /// SwiftUI AttributedString wrapper — use for Text() display.
+    static func attributedString(from yaml: String) -> AttributedString {
+        (try? AttributedString(nsAttributedString(from: yaml), including: \.uiKit)) ?? AttributedString(yaml)
+    }
+
+    // MARK: - Line processing
+
+    private static func processLine(_ line: String) -> NSAttributedString {
+        guard !line.isEmpty else { return seg("", plainColor) }
+
+        let indentEnd = line.firstIndex(where: { $0 != " " && $0 != "\t" }) ?? line.endIndex
+        let indent    = String(line[..<indentEnd])
+        let content   = String(line[indentEnd...])
+
+        let result = NSMutableAttributedString(attributedString: seg(indent, plainColor))
+        guard !content.isEmpty else { return result }
+
+        // Comment
+        if content.hasPrefix("#") {
+            result.append(seg(content, commentColor))
+            return result
+        }
+
+        // Document markers
+        if content == "---" || content == "..." {
+            result.append(seg(content, commentColor))
+            return result
+        }
+
+        // List item: "- …"
+        if content.hasPrefix("- ") || content == "-" {
+            result.append(seg("- ", keyColor))
+            if content.count > 2 {
+                result.append(colorAsKeyValueOrValue(String(content.dropFirst(2))))
+            }
+            return result
+        }
+
+        result.append(colorAsKeyValueOrValue(content))
+        return result
+    }
+
+    /// Tries "key: value"; falls back to plain value colouring.
+    private static func colorAsKeyValueOrValue(_ text: String) -> NSAttributedString {
+        guard let colonIdx = keySeparatorIndex(in: text) else {
+            return colorValue(text)
+        }
+        let key  = String(text[..<colonIdx])
+        let rest = String(text[text.index(after: colonIdx)...])
+
+        let result = NSMutableAttributedString(attributedString: seg(key, keyColor))
+        result.append(seg(":", keyColor))
+
+        guard !rest.isEmpty else { return result }
+
+        if rest.hasPrefix(" ") {
+            result.append(seg(" ", plainColor))
+            result.append(colorValue(String(rest.dropFirst())))
+        } else {
+            result.append(colorValue(rest))
+        }
+        return result
+    }
+
+    /// Returns the `:` index that acts as a YAML key separator.
+    private static func keySeparatorIndex(in text: String) -> String.Index? {
+        var idx = text.startIndex
+        while idx < text.endIndex {
+            let ch = text[idx]
+            if ch == " " || ch == "\t" || ch == "\"" || ch == "'" { return nil }
+            if ch == ":" {
+                guard idx != text.startIndex else { return nil }
+                let next = text.index(after: idx)
+                if next == text.endIndex || text[next] == " " || text[next] == "\t" {
+                    return idx
+                }
+                return nil  // colon inside a value (e.g. nginx:latest)
+            }
+            idx = text.index(after: idx)
+        }
+        return nil
+    }
+
+    // MARK: - Value colouring
+
+    private static func colorValue(_ raw: String) -> NSAttributedString {
+        if let commentStart = inlineCommentIndex(in: raw) {
+            let valuePart   = String(raw[..<commentStart])
+            let commentPart = String(raw[commentStart...])
+            let result = NSMutableAttributedString(attributedString:
+                seg(valuePart, valueColor(valuePart.trimmingCharacters(in: .whitespaces))))
+            result.append(seg(commentPart, commentColor))
+            return result
+        }
+        return seg(raw, valueColor(raw.trimmingCharacters(in: .whitespaces)))
+    }
+
+    private static func inlineCommentIndex(in text: String) -> String.Index? {
+        var inSingle = false, inDouble = false, prev: Character = " "
+        for idx in text.indices {
+            let ch = text[idx]
+            if ch == "\"" && !inSingle { inDouble.toggle() }
+            else if ch == "'" && !inDouble { inSingle.toggle() }
+            else if ch == "#" && !inSingle && !inDouble && prev == " " {
+                return text.index(before: idx) // include the preceding space
+            }
+            prev = ch
+        }
+        return nil
+    }
+
+    private static func valueColor(_ v: String) -> UIColor {
+        guard !v.isEmpty else { return plainColor }
+
+        if v == "|" || v == ">" || v.hasPrefix("|-") || v.hasPrefix("|+")
+                    || v.hasPrefix(">-") || v.hasPrefix(">+") { return stringColor }
+
+        if v.count >= 2,
+           (v.hasPrefix("\"") && v.hasSuffix("\"")) ||
+           (v.hasPrefix("'")  && v.hasSuffix("'")) { return stringColor }
+
+        switch v.lowercased() {
+        case "true", "false", "yes", "no", "on", "off": return boolColor
+        default: break
+        }
+
+        if v.lowercased() == "null" || v == "~" { return nullColor }
+
+        if Int(v) != nil || Double(v) != nil { return numberColor }
+        if v.lowercased().hasPrefix("0x") && Int(v.dropFirst(2), radix: 16) != nil { return numberColor }
+
+        if v.hasPrefix("&") || v.hasPrefix("*") { return anchorColor }
+
+        return plainColor
+    }
+
+    // MARK: - Helpers
+
+    private static func seg(_ text: String, _ color: UIColor) -> NSAttributedString {
+        NSAttributedString(string: text, attributes: [
+            .font: monoFont,
+            .foregroundColor: color
+        ])
+    }
+}
@@ -5,24 +5,32 @@ struct ComposeTabView: View {
    var isEditing: Bool
    var onSave: () async -> Void

+    @State private var highlighted = AttributedString()
+
    var body: some View {
        ScrollView {
            if isEditing {
-                TextEditor(text: $yaml)
-                    .font(.monoBody)
-                    .foregroundStyle(Color.terminalText)
-                    .scrollContentBackground(.hidden)
-                    .frame(minHeight: 400)
-                    .padding(8)
+                SyntaxHighlightingEditor(
+                    text: $yaml,
+                    highlight: YAMLHighlighter.nsAttributedString(from:)
+                )
+                .frame(minHeight: 400)
            } else {
-                Text(yaml.isEmpty ? " " : yaml)
-                    .font(.monoBody)
-                    .foregroundStyle(Color.terminalText)
+                Text(highlighted)
                    .textSelection(.enabled)
                    .frame(maxWidth: .infinity, alignment: .leading)
                    .padding(8)
            }
        }
        .background(Color.terminalBg)
+        .onAppear { reHighlight() }
+        .onChange(of: yaml)      { _, _ in if !isEditing { reHighlight() } }
+        .onChange(of: isEditing) { _, editing in if !editing { reHighlight() } }
+    }
+
+    private func reHighlight() {
+        highlighted = yaml.isEmpty
+            ? { var s = AttributedString(" "); s.font = .monoBody; return s }()
+            : YAMLHighlighter.attributedString(from: yaml)
    }
 }