1 files changed, 70 insertions, 0 deletions
diff --git a/composeApp/src/commonMain/kotlin/coffee/liz/ecs/Entity.kt b/composeApp/src/commonMain/kotlin/coffee/liz/ecs/Entity.kt
new file mode 100644
index 0000000..2ceac47
--- /dev/null
+++ b/composeApp/src/commonMain/kotlin/coffee/liz/ecs/Entity.kt
@@ -0,0 +1,70 @@
+package coffee.liz.ecs
+
+import kotlin.reflect.KClass
+
+/**
+ * An entity is a unique identifier with a collection of components.
+ */
+class Entity(val id: Int) {
+    private val components = mutableMapOf<KClass<out Component>, Component>()
+
+    /**
+     * Add a component to this entity.
+     */
+    fun <T : Component> add(component: T): Entity {
+        components[component::class] = component
+        return this
+    }
+
+    /**
+     * Remove a component from this entity.
+     */
+    fun <T : Component> remove(type: KClass<T>): Entity {
+        components.remove(type)
+        return this
+    }
+
+    /**
+     * Get a component by type.
+     */
+    @Suppress("UNCHECKED_CAST")
+    fun <T : Component> get(type: KClass<T>): T? {
+        return components[type] as? T
+    }
+
+    /**
+     * Check if entity has a component.
+     */
+    fun <T : Component> has(type: KClass<T>): Boolean {
+        return components.containsKey(type)
+    }
+
+    /**
+     * Check if entity has all specified components.
+     */
+    fun hasAll(vararg types: KClass<out Component>): Boolean {
+        return types.all { components.containsKey(it) }
+    }
+
+    /**
+     * Get all component types on this entity.
+     */
+    fun componentTypes(): Set<KClass<out Component>> {
+        return components.keys.toSet()
+    }
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (other !is Entity) return false
+        return id == other.id
+    }
+
+    override fun hashCode(): Int = id
+
+    override fun toString(): String = "Entity($id)"
+}
+
+// Convenience extensions for cleaner syntax
+inline fun <reified T : Component> Entity.get(): T? = get(T::class)
+inline fun <reified T : Component> Entity.has(): Boolean = has(T::class)
+inline fun <reified T : Component> Entity.remove(): Entity = remove(T::class)