package coffee.liz.ecs.animation

import coffee.liz.ecs.Component
import coffee.liz.ecs.Rect
import kotlin.jvm.JvmInline

/**
 * Loop modes for animation playback.
 */
enum class LoopMode {
    /** Play once **/
    ONCE,
    /** Repeat **/
    LOOP,
    /** Play forward, then backward, repeat **/
    PING_PONG
}

/**
 * Name of an animation clip.
 */
@JvmInline
value class AnimationName(val value: String)

/**
 * Name of a frame.
 */
@JvmInline
value class FrameName(val value: String)


/**
 * Animation Clip details.
 */
data class AnimationClip(
    val frameNames: List<FrameName>,
    val frameTicks: Int,
    val loopMode: LoopMode = LoopMode.LOOP
)

/**
 * Component containing sprite sheet data - the image and frame definitions.
 */
data class SpriteSheet(
    val imagePath: String,
    val frames: Map<FrameName, Rect>
) : Component

enum class AnimationDirection(val step: Int) {
    /** Play in forward direction **/
    FORWARD(step = 1),
    /** Play in reverse direction **/
    BACKWARD(step = -1);
}
/**
 * Current state of an animation.
 */
data class Animator(
    val clips: Map<AnimationName, AnimationClip>,
    var currentClip: AnimationName,
    var frameIndex: Int = 0,
    var elapsedTicks: Int = 0,
    var playing: Boolean = true,
    var direction: AnimationDirection = AnimationDirection.FORWARD
) : Component {
    /**
     * Play a specific animation clip by name.
     */
    fun play(clipName: AnimationName, restart: Boolean = true) {
        clipName.takeIf { currentClip != it || restart }
            .run {
                currentClip = clipName
                reset()
            }
    }

    /**
     * Pause the current animation.
     */
    fun pause() {
        playing = false
    }

    /**
     * Resume the current animation.
     */
    fun resume() {
        playing = true
    }

    /**
     * Get the current frame name being displayed.
     */
    fun getCurrentFrameName(): FrameName? {
        val clip = clips[currentClip] ?: return null
        return clip.frameNames.getOrNull(frameIndex)
    }

    private fun reset() {
        frameIndex = 0
        elapsedTicks = 0
        direction = AnimationDirection.FORWARD
        playing = true
    }
}