package coffee.liz.ecs

import kotlin.test.*

// Test components
data class Position(
    val x: Float,
    val y: Float,
) : Component

data class Velocity(
    val dx: Float,
    val dy: Float,
) : Component

data class Health(
    val value: Int,
) : Component

class EntityTest {
    @Test
    fun `entity has unique id`() {
        val entity1 = Entity(1)
        val entity2 = Entity(2)

        assertNotEquals(entity1.id, entity2.id)
    }

    @Test
    fun `can add component to entity`() {
        val entity = Entity(0)
        val position = Position(10f, 20f)

        entity.add(position)

        assertTrue(entity.has<Position>())
        assertEquals(position, entity.get<Position>())
    }

    @Test
    fun `can remove component from entity`() {
        val entity = Entity(0)
        entity.add(Position(10f, 20f))

        entity.remove<Position>()

        assertFalse(entity.has<Position>())
        assertNull(entity.get<Position>())
    }

    @Test
    fun `add returns entity for chaining`() {
        val entity = Entity(0)

        val result =
            entity
                .add(Position(10f, 20f))
                .add(Velocity(1f, 2f))

        assertSame(entity, result)
        assertTrue(entity.has<Position>())
        assertTrue(entity.has<Velocity>())
    }

    @Test
    fun `can replace component by adding same type`() {
        val entity = Entity(0)
        entity.add(Position(10f, 20f))
        entity.add(Position(30f, 40f))

        val position = entity.get<Position>()

        assertNotNull(position)
        assertEquals(30f, position.x)
        assertEquals(40f, position.y)
    }

    @Test
    fun `hasAll returns true when entity has all components`() {
        val entity = Entity(0)
        entity.add(Position(10f, 20f))
        entity.add(Velocity(1f, 2f))

        assertTrue(entity.hasAll(Position::class, Velocity::class))
    }

    @Test
    fun `hasAll returns false when entity missing component`() {
        val entity = Entity(0)
        entity.add(Position(10f, 20f))

        assertFalse(entity.hasAll(Position::class, Velocity::class))
    }

    @Test
    fun `componentTypes returns all component types`() {
        val entity = Entity(0)
        entity.add(Position(10f, 20f))
        entity.add(Velocity(1f, 2f))
        entity.add(Health(100))

        val types = entity.componentTypes()

        assertEquals(3, types.size)
        assertTrue(types.contains(Position::class))
        assertTrue(types.contains(Velocity::class))
        assertTrue(types.contains(Health::class))
    }

    @Test
    fun `entities with same id are equal`() {
        val entity1 = Entity(1)
        val entity2 = Entity(1)

        assertEquals(entity1, entity2)
        assertEquals(entity1.hashCode(), entity2.hashCode())
    }

    @Test
    fun `entities with different id are not equal`() {
        val entity1 = Entity(1)
        val entity2 = Entity(2)

        assertNotEquals(entity1, entity2)
    }
}