refactor package structure

src/commonMain/kotlin/com/infendro/cli/option/Option.kt

@@ -0,0 +1,83 @@
+package com.infendro.cli.option
+
+import com.infendro.cli.error.build.InvalidOptionName
+import com.infendro.cli.error.build.InvalidRange
+import com.infendro.cli.error.build.MissingOptionName
+import com.infendro.cli.parser.Parser
+import com.infendro.cli.util.Regex.OPTION
+
+sealed class Option<T : Any>(
+    val parser: Parser<T>,
+    val fallback: T?,
+    val names: List<String>,
+    val description: String?,
+    val min: Int,
+    val max: Int?,
+) {
+    val name: String
+        get() = names.maxBy { it.length }
+
+    val flag: Boolean
+        get() = fallback != null
+
+    val required: Boolean
+        get() = min > 0
+    val optional: Boolean
+        get() = !required
+
+    val bounded: Boolean
+        get() = max != null
+    val unbounded: Boolean
+        get() = !bounded
+
+    val count: Int
+        get() = max ?: Int.MAX_VALUE
+
+    init {
+        when {
+            names.isEmpty() -> throw MissingOptionName()
+            names.any { !it.matches(OPTION) } -> throw InvalidOptionName(name)
+            min !in 0..count || max == 0 -> throw InvalidRange()
+        }
+    }
+
+    class Required<T : Any>(
+        parser: Parser<T>,
+        fallback: T?,
+        names: List<String>,
+        description: String?,
+    ) : Option<T>(parser, fallback, names, description, min = 1, max = 1) {
+        fun orElse(other: T) =
+            OrElse(parser, fallback, names, description, other)
+
+        fun orNull() =
+            OrNull(parser, fallback, names, description)
+
+        fun variable(min: Int = 0, max: Int? = null) =
+            Variable(parser, fallback, names, description, min, max)
+    }
+
+    class OrElse<T : Any>(
+        parser: Parser<T>,
+        fallback: T?,
+        names: List<String>,
+        description: String?,
+        val other: T,
+    ) : Option<T>(parser, fallback, names, description, min = 0, max = 1)
+
+    class OrNull<T : Any>(
+        parser: Parser<T>,
+        fallback: T?,
+        names: List<String>,
+        description: String?,
+    ) : Option<T>(parser, fallback, names, description, min = 0, max = 1)
+
+    class Variable<T : Any>(
+        parser: Parser<T>,
+        fallback: T?,
+        names: List<String>,
+        description: String?,
+        min: Int,
+        max: Int?,
+    ) : Option<T>(parser, fallback, names, description, min, max)
+}