package net.shadowfacts.cacao.viewcontroller

import net.minecraft.text.Text
import net.minecraft.util.Identifier
import net.shadowfacts.cacao.geometry.Axis
import net.shadowfacts.cacao.geometry.Point
import net.shadowfacts.cacao.geometry.Rect
import net.shadowfacts.cacao.geometry.Size
import net.shadowfacts.cacao.util.MouseButton
import net.shadowfacts.cacao.util.texture.NinePatchTexture
import net.shadowfacts.cacao.util.texture.Texture
import net.shadowfacts.cacao.view.NinePatchView
import net.shadowfacts.cacao.view.StackView
import net.shadowfacts.cacao.view.TextureView
import net.shadowfacts.cacao.view.View
import net.shadowfacts.cacao.view.button.AbstractButton
import net.shadowfacts.kiwidsl.dsl

/**
 * @author shadowfacts
 */
class TabViewController<T: TabViewController.Tab>(
	val tabs: Array<T>,
	initalTab: T = tabs.first()
): ViewController() {

	interface Tab {
		val tabView: View
		val tooltip: Text?
		val controller: ViewController
	}

	var currentTab: T = initalTab
		private set

	private lateinit var tabButtons: List<TabButton<T>>

	private lateinit var outerStack: StackView
	private lateinit var tabStack: StackView
	private lateinit var tabVCContainer: View

	override fun viewDidLoad() {
		super.viewDidLoad()

		// padding is -4 so tab button texture overlaps with panel BG as expected
		outerStack = StackView(Axis.VERTICAL, StackView.Distribution.FILL, -4.0)
		view.addSubview(outerStack)

		tabStack = StackView(Axis.HORIZONTAL, StackView.Distribution.FILL)
		tabStack.zIndex = 1.0
		outerStack.addArrangedSubview(tabStack)

		tabVCContainer = View()
		outerStack.addArrangedSubview(tabVCContainer)

		tabButtons = tabs.mapIndexed { index, tab ->
			val btn = TabButton(tab)
			btn.handler = this::selectTab
			if (tab == currentTab) {
				btn.setSelected(true)
			}
			btn
		}
		// todo: batch calls to addArrangedSubview
		tabButtons.forEach(tabStack::addArrangedSubview)

		// spacer
		tabStack.addArrangedSubview(View())

		val background = NinePatchView(NinePatchTexture.PANEL_BG)
		background.zIndex = -1.0
		tabVCContainer.addSubview(background)

		embedChild(currentTab.controller, tabVCContainer)

		view.solver.dsl {
			outerStack.leftAnchor equalTo view.leftAnchor
			outerStack.rightAnchor equalTo view.rightAnchor
			outerStack.topAnchor equalTo view.topAnchor
			outerStack.bottomAnchor equalTo view.bottomAnchor

			background.leftAnchor equalTo tabVCContainer.leftAnchor
			background.rightAnchor equalTo tabVCContainer.rightAnchor
			background.topAnchor equalTo tabVCContainer.topAnchor
			background.bottomAnchor equalTo tabVCContainer.bottomAnchor
		}
	}

	private fun selectTab(button: TabButton<T>) {
		val oldTab = currentTab
		currentTab = button.tab

		// todo: unselect old button
		tabButtons.forEach { it.setSelected(false) }
		oldTab.controller.removeFromParent()

		button.setSelected(true)
		embedChild(currentTab.controller, tabVCContainer)
		// todo: setNeedsLayout
		window!!.layout()
	}

	private class TabButton<T: Tab>(
		val tab: T,
	): AbstractButton<TabButton<T>>(
		tab.tabView,
		padding = 2.0
	) {
		companion object {
			val BACKGROUND = Identifier("textures/gui/container/creative_inventory/tabs.png")
		}

		private var selected = false
		private var backgroundView = TextureView(Texture(BACKGROUND, 0, 0))

		init {
			intrinsicContentSize = Size(28.0, 32.0)
			background = null
			hoveredBackground = null
			disabledBackground = null
		}

		override fun wasAdded() {
			super.wasAdded()
			backgroundView.usesConstraintBasedLayout = false
			backgroundView.frame = Rect(0.0, 0.0, 28.0, 32.0)
			addSubview(backgroundView)
		}

		override fun didLayout() {
			super.didLayout()
			updateBackgroundTexture()
		}

		fun setSelected(selected: Boolean) {
			this.selected = selected
			updateBackgroundTexture()
		}

		override fun getCurrentBackground(mouse: Point) = backgroundView

		override fun mouseClicked(point: Point, mouseButton: MouseButton): Boolean {
			if (selected) return false
			else return super.mouseClicked(point, mouseButton)
		}

		private fun updateBackgroundTexture() {
			val v = if (selected) 32 else 0
			val u = when {
				superview == null -> 0
				frame.left == 0.0 -> 0
				frame.right == superview!!.bounds.right -> 140
				else -> 28
			}
			backgroundView.texture = Texture(BACKGROUND, u, v)
			backgroundView.frame = Rect(0.0, 0.0, 28.0, if (selected) 32.0 else 28.0)
		}
	}

}