package net.shadowfacts.cacao

import net.minecraft.client.MinecraftClient
import net.minecraft.client.gui.screen.Screen
import net.minecraft.sound.SoundEvents
import net.minecraft.text.LiteralText
import net.shadowfacts.cacao.geometry.Point
import net.shadowfacts.cacao.util.MouseButton
import net.shadowfacts.cacao.util.RenderHelper
import net.shadowfacts.kiwidsl.dsl
import java.util.*

/**
 * This class serves as the bridge between Cacao and a Minecraft [Screen]. It renders Cacao [Window]s in Minecraft and
 * sends input events from Minecraft back to Cacao objects.
 *
 * @author shadowfacts
 */
open class CacaoScreen: Screen(LiteralText("CacaoScreen")) {

	// _windows is the internal, mutable object, since we only want it to by mutated by the add/removeWindow methods.
	private val _windows = LinkedList<Window>()
	/**
	 * The list of windows that belong to this screen.
	 * This list should never be modified directly, only by using the [addWindow]/[removeWindow] methods.
	 */
	val windows: List<Window> = _windows

	/**
	 * Adds the given window to this screen's window list.
	 * By default, the new window is added at the tail of the window list, making it the active window.
	 * Only the active window will receive input events.
	 *
	 * @param window The Window to add to this screen.
	 * @param index The index to insert the window into the window list at.
	 * @return The window that was added, as a convenience.
	 */
	fun <T: Window> addWindow(window: T, index: Int = _windows.size): T {
		_windows.add(index, window)

		window.screen = this
		window.wasAdded()
		window.resize(width, height)

		return window
	}

	/**
	 * Removes the given window from this screen's window list.
	 */
	fun removeWindow(window: Window) {
		_windows.remove(window)
	}

	override fun init() {
		super.init()

		windows.forEach {
			it.resize(width, height)
		}
	}

	override fun render(mouseX: Int, mouseY: Int, delta: Float) {
		if (minecraft != null) {
			// workaround this.minecraft sometimes being null causing a crash
			renderBackground()
		}

		val mouse = Point(mouseX, mouseY)
		windows.forEach {
			it.draw(mouse, delta)
		}
	}

	override fun mouseClicked(mouseX: Double, mouseY: Double, button: Int): Boolean {
		val window = windows.lastOrNull()
		val result = window?.mouseClicked(Point(mouseX, mouseY), MouseButton.fromMC(button))
		return if (result == true) {
			RenderHelper.playSound(SoundEvents.UI_BUTTON_CLICK)
			true
		} else {
			false
		}
	}

	override fun mouseDragged(mouseX: Double, mouseY: Double, button: Int, deltaX: Double, deltaY: Double): Boolean {
		val window = windows.lastOrNull()
		val startPoint = Point(mouseX, mouseY)
		val delta = Point(deltaX, deltaY)
		val result = window?.mouseDragged(startPoint, delta, MouseButton.fromMC(button))
		return result == true
	}

	override fun mouseReleased(mouseX: Double, mouseY: Double, button: Int): Boolean {
		val window = windows.lastOrNull()
		val result = window?.mouseReleased(Point(mouseX, mouseY), MouseButton.fromMC(button))
		return result == true
	}

}