1 files changed, 104 insertions, 0 deletions
diff --git a/src/Godosa.Core/Runs/Scripts/StepLexer.cs b/src/Godosa.Core/Runs/Scripts/StepLexer.cs
new file mode 100644
index 0000000..4c54544
--- /dev/null
+++ b/src/Godosa.Core/Runs/Scripts/StepLexer.cs
@@ -0,0 +1,104 @@
+// Provenance: own design — shared run scripts
+using System.Globalization;
+using System.Text;
+
+namespace Godosa.Core.Runs.Scripts;
+
+public sealed record Token(string Text, bool Quoted);
+
+/// <summary>Line lexing for <c>.steps</c>: <c>#</c> comments outside quotes; tokens split on spaces, <c>"…"</c> (escapes
+/// <c>\"</c>, <c>\\</c>) and <c>(…)</c> groups stay one token.</summary>
+public static class StepLexer
+{
+    public static string StripComment(string line)
+    {
+        var quoted = false;
+        for (var i = 0; i < line.Length; i++)
+        {
+            var c = line[i];
+            if (quoted && c == '\\' && i + 1 < line.Length)
+            {
+                i++;
+                continue;
+            }
+            if (c == '"')
+                quoted = !quoted;
+            else if (c == '#' && !quoted)
+                return line[..i];
+        }
+        return line;
+    }
+
+    public static List<Token> Tokens(string text)
+    {
+        var tokens = new List<Token>();
+        var i = 0;
+        while (i < text.Length)
+        {
+            if (text[i] == ' ')
+            {
+                i++;
+                continue;
+            }
+            if (text[i] == '"')
+            {
+                var sb = new StringBuilder();
+                i++;
+                while (true)
+                {
+                    if (i >= text.Length)
+                        throw new FormatException("unterminated quote");
+                    var c = text[i];
+                    if (c == '\\' && i + 1 < text.Length)
+                    {
+                        sb.Append(text[i + 1]);
+                        i += 2;
+                        continue;
+                    }
+                    if (c == '"')
+                    {
+                        i++;
+                        break;
+                    }
+                    sb.Append(c);
+                    i++;
+                }
+                tokens.Add(new Token(sb.ToString(), true));
+                continue;
+            }
+            var start = i;
+            var depth = 0;
+            while (i < text.Length && (depth > 0 || text[i] != ' '))
+            {
+                if (text[i] == '(')
+                    depth++;
+                else if (text[i] == ')' && depth > 0)
+                    depth--;
+                i++;
+            }
+            tokens.Add(new Token(text[start..i], false));
+        }
+        return tokens;
+    }
+}
+
+/// <summary>Timeouts and waits in frames (1 frame = 1/60 s): <c>120</c> = 120 frames, <c>2s</c> = 120, <c>0.5s</c> = 30;
+/// negative, non-whole frame counts and other units → null.</summary>
+public static class Durations
+{
+    public const int FramesPerSecond = 60;
+
+    public static int? Frames(string text)
+    {
+        if (text.EndsWith('s'))
+        {
+            var number = text[..^1];
+            if (number.Length == 0 || !number.All(c => char.IsAsciiDigit(c) || c == '.')
+                || !decimal.TryParse(number, NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out var seconds))
+                return null;
+            var frames = seconds * FramesPerSecond;
+            return frames == decimal.Truncate(frames) ? (int)frames : null;
+        }
+        return text.Length > 0 && text.All(char.IsAsciiDigit) && int.TryParse(text, CultureInfo.InvariantCulture, out var n) ? n : null;
+    }
+}