Initial commit

src/main/kotlin/irc/IrcLineParser.kt

@@ -0,0 +1,47 @@
+package irc
+
+/** A minimally-parsed raw IRC protocol line. */
+data class ParsedLine(
+    val prefix: String?,     // e.g. "nick!user@host" or a server name
+    val command: String,     // e.g. "PRIVMSG", "JOIN", "376", etc.
+    val params: List<String> // trailing param (after ':') is params.last() if present
+)
+
+fun parseIrcLine(line: String): ParsedLine? {
+    if (line.isBlank()) return null
+    var rest = line
+    var prefix: String? = null
+
+    if (rest.startsWith(":")) {
+        val spaceIdx = rest.indexOf(' ')
+        if (spaceIdx == -1) return null
+        prefix = rest.substring(1, spaceIdx)
+        rest = rest.substring(spaceIdx + 1)
+    }
+
+    val trailingSplit = rest.indexOf(" :")
+    val paramsStr: String
+    val trailing: String?
+    if (trailingSplit != -1) {
+        paramsStr = rest.substring(0, trailingSplit)
+        trailing = rest.substring(trailingSplit + 2)
+    } else {
+        paramsStr = rest
+        trailing = null
+    }
+
+    val parts = paramsStr.split(" ").filter { it.isNotEmpty() }
+    if (parts.isEmpty()) return null
+    val command = parts[0].uppercase()
+    val params = parts.drop(1).toMutableList()
+    if (trailing != null) params.add(trailing)
+
+    return ParsedLine(prefix, command, params)
+}
+
+/** Extracts just the nick portion from an IRC prefix like "nick!user@host". */
+fun nickFromPrefix(prefix: String?): String? {
+    if (prefix == null) return null
+    val bangIdx = prefix.indexOf('!')
+    return if (bangIdx != -1) prefix.substring(0, bangIdx) else prefix
+}