ASMR/src/main/kotlin/net/shadowfacts/cacao/view/NinePatchView.kt

package net.shadowfacts.cacao.view

import net.shadowfacts.cacao.geometry.Point
import net.shadowfacts.cacao.geometry.Rect
import net.shadowfacts.cacao.util.NinePatchTexture
import net.shadowfacts.cacao.util.RenderHelper
import net.shadowfacts.cacao.util.properties.ResettableLazyProperty

/**
 * A helper class for drawing a [NinePatchTexture] in a view.
 * `NinePatchView` will draw the given nine patch texture filling its bounds.
 *
 * This class and the region properties are left open for internal framework use, overriding them is not recommended.
 *
 * @author shadowfacts
 * @param ninePatch The nine patch texture that this view will draw.
 */
open class NinePatchView(val ninePatch: NinePatchTexture): View() {

	// Corners
	private val topLeftDelegate = ResettableLazyProperty {
		Rect(0.0, 0.0, ninePatch.cornerWidth.toDouble(), ninePatch.cornerHeight.toDouble())
	}
	protected open val topLeft by topLeftDelegate

	private val topRightDelegate = ResettableLazyProperty {
		Rect(bounds.width - ninePatch.cornerWidth, 0.0, ninePatch.cornerWidth.toDouble(), ninePatch.cornerHeight.toDouble())
	}
	protected open val topRight by topRightDelegate

	private val bottomLeftDelegate = ResettableLazyProperty {
		Rect(0.0, bounds.height - ninePatch.cornerHeight, ninePatch.cornerWidth.toDouble(), ninePatch.cornerHeight.toDouble())
	}
	protected open val bottomLeft by bottomLeftDelegate

	private val bottomRightDelegate = ResettableLazyProperty {
		Rect(bounds.width - ninePatch.cornerWidth, bounds.height - ninePatch.cornerHeight, ninePatch.cornerWidth.toDouble(), ninePatch.cornerHeight.toDouble())
	}
	protected open val bottomRight by bottomRightDelegate


	// Edges
	private val topMiddleDelegate = ResettableLazyProperty {
		Rect(ninePatch.cornerWidth.toDouble(), topLeft.top, bounds.width - 2 * ninePatch.cornerWidth, ninePatch.cornerHeight.toDouble())
	}
	protected open val topMiddle by topMiddleDelegate

	private val bottomMiddleDelegate = ResettableLazyProperty {
		Rect(topMiddle.left, bottomLeft.top, topMiddle.width, topMiddle.height)
	}
	protected open val bottomMiddle by bottomMiddleDelegate

	private val leftMiddleDelegate = ResettableLazyProperty {
		Rect(topLeft.left, ninePatch.cornerHeight.toDouble(), ninePatch.cornerWidth.toDouble(), bounds.height - 2 * ninePatch.cornerHeight)
	}
	protected open val leftMiddle by leftMiddleDelegate

	private val rightMiddleDelegate = ResettableLazyProperty {
		Rect(topRight.left, leftMiddle.top, leftMiddle.width, leftMiddle.height)
	}
	protected open val rightMiddle by rightMiddleDelegate


	// Center
	private val centerDelegate = ResettableLazyProperty {
		Rect(topLeft.right, topLeft.bottom, topMiddle.width, leftMiddle.height)
	}
	protected open val center by centerDelegate

	private val delegates = listOf(topLeftDelegate, topRightDelegate, bottomLeftDelegate, bottomRightDelegate, topMiddleDelegate, bottomMiddleDelegate, leftMiddleDelegate, rightMiddleDelegate, centerDelegate)

	override fun didLayout() {
		super.didLayout()

		delegates.forEach(ResettableLazyProperty<Rect>::reset)
	}

	override fun drawContent(mouse: Point, delta: Float) {
		drawCorners()
		drawEdges()
		drawCenter()
	}

	private fun drawCorners() {
		RenderHelper.draw(topLeft, ninePatch.topLeft)
		RenderHelper.draw(topRight, ninePatch.topRight)
		RenderHelper.draw(bottomLeft, ninePatch.bottomLeft)
		RenderHelper.draw(bottomRight, ninePatch.bottomRight)
	}

	private fun drawEdges() {
		// Horizontal
		for (i in 0 until (topMiddle.width.toInt() / ninePatch.centerWidth)) {
			RenderHelper.draw(topMiddle.left + i * ninePatch.centerWidth, topMiddle.top, ninePatch.topMiddle.u, ninePatch.topMiddle.v, ninePatch.centerWidth.toDouble(), topMiddle.height, ninePatch.texture.width, ninePatch.texture.height)
			RenderHelper.draw(bottomMiddle.left + i * ninePatch.centerWidth, bottomMiddle.top, ninePatch.bottomMiddle.u, ninePatch.bottomMiddle.v, ninePatch.centerWidth.toDouble(), bottomMiddle.height, ninePatch.texture.width, ninePatch.texture.height)
		}
		val remWidth = topMiddle.width.toInt() % ninePatch.centerWidth
		if (remWidth > 0) {
			RenderHelper.draw(topMiddle.right - remWidth, topMiddle.top, ninePatch.topMiddle.u, ninePatch.topMiddle.v, remWidth.toDouble(), ninePatch.cornerHeight.toDouble(), ninePatch.texture.width, ninePatch.texture.height)
			RenderHelper.draw(bottomMiddle.right - remWidth, bottomMiddle.top, ninePatch.bottomMiddle.u, ninePatch.bottomMiddle.v, remWidth.toDouble(), ninePatch.cornerHeight.toDouble(), ninePatch.texture.width, ninePatch.texture.height)
		}

		// Vertical
		for (i in 0 until (leftMiddle.height.toInt() / ninePatch.centerHeight)) {
			RenderHelper.draw(leftMiddle.left, leftMiddle.top + i * ninePatch.centerHeight, ninePatch.leftMiddle.u, ninePatch.leftMiddle.v, ninePatch.cornerWidth.toDouble(), ninePatch.centerHeight.toDouble(), ninePatch.texture.width, ninePatch.texture.height)
			RenderHelper.draw(rightMiddle.left, rightMiddle.top + i * ninePatch.centerHeight, ninePatch.rightMiddle.u, ninePatch.rightMiddle.v, ninePatch.cornerWidth.toDouble(), ninePatch.centerHeight.toDouble(), ninePatch.texture.width, ninePatch.texture.height)
		}
		val remHeight = leftMiddle.height.toInt() % ninePatch.centerHeight
		if (remHeight > 0) {
			RenderHelper.draw(leftMiddle.left, leftMiddle.bottom - remHeight, ninePatch.leftMiddle.u, ninePatch.leftMiddle.v, ninePatch.cornerWidth.toDouble(), remHeight.toDouble(), ninePatch.texture.width, ninePatch.texture.height)
			RenderHelper.draw(rightMiddle.left, rightMiddle.bottom - remHeight, ninePatch.rightMiddle.u, ninePatch.rightMiddle.v, ninePatch.cornerWidth.toDouble(), remHeight.toDouble(), ninePatch.texture.width, ninePatch.texture.height)
		}
	}

	private fun drawCenter() {
		for (i in 0 until (center.height.toInt() / ninePatch.centerHeight)) {
			drawCenterRow(center.top + i * ninePatch.centerHeight.toDouble(), ninePatch.centerHeight.toDouble())
		}
		val remHeight = center.height.toInt() % ninePatch.centerHeight
		if (remHeight > 0) {
			drawCenterRow(center.bottom - remHeight, remHeight.toDouble())
		}
	}

	private fun drawCenterRow(y: Double, height: Double) {
		for (i in 0 until (center.width.toInt() / ninePatch.centerWidth)) {
			RenderHelper.draw(center.left + i * ninePatch.centerWidth, y, ninePatch.center.u, ninePatch.center.v, ninePatch.centerWidth.toDouble(), height, ninePatch.texture.width, ninePatch.texture.height)
		}
		val remWidth = center.width.toInt() % ninePatch.centerWidth
		if (remWidth > 0) {
			RenderHelper.draw(center.right - remWidth, y, ninePatch.center.u, ninePatch.center.v, remWidth.toDouble(), height, ninePatch.texture.width, ninePatch.texture.height)
		}
	}

}