package moe.nea.notenoughupdates.util.render

import com.mojang.blaze3d.systems.RenderSystem
import org.joml.Matrix4f
import net.minecraft.client.gl.VertexBuffer
import net.minecraft.client.render.BufferBuilder
import net.minecraft.client.render.Camera
import net.minecraft.client.render.GameRenderer
import net.minecraft.client.render.Tessellator
import net.minecraft.client.render.VertexFormat
import net.minecraft.client.render.VertexFormats
import net.minecraft.client.util.math.MatrixStack
import net.minecraft.util.math.BlockPos

class RenderBlockContext private constructor(private val tesselator: Tessellator, private val matrixStack: MatrixStack) {
    private val buffer = tesselator.buffer
    fun color(red: Float, green: Float, blue: Float, alpha: Float) {
        RenderSystem.setShaderColor(red, green, blue, alpha)
    }

    fun block(blockPos: BlockPos) {
        matrixStack.push()
        matrixStack.translate(blockPos.x.toFloat(), blockPos.y.toFloat(), blockPos.z.toFloat())
        RenderSystem.setShader(GameRenderer::getPositionColorProgram)
        buildCube(matrixStack.peek().positionMatrix, buffer)
        tesselator.draw()
        matrixStack.pop()
    }

    companion object {
        private fun buildCube(matrix: Matrix4f, buf: BufferBuilder) {
            buf.begin(VertexFormat.DrawMode.TRIANGLES, VertexFormats.POSITION_COLOR)
            buf.fixedColor(255, 255, 255, 255)
            buf.vertex(matrix, 0.0F, 0.0F, 0.0F).next()
            buf.vertex(matrix, 0.0F, 0.0F, 1.0F).next()
            buf.vertex(matrix, 0.0F, 1.0F, 1.0F).next()
            buf.vertex(matrix, 1.0F, 1.0F, 0.0F).next()
            buf.vertex(matrix, 0.0F, 0.0F, 0.0F).next()
            buf.vertex(matrix, 0.0F, 1.0F, 0.0F).next()
            buf.vertex(matrix, 1.0F, 0.0F, 1.0F).next()
            buf.vertex(matrix, 0.0F, 0.0F, 0.0F).next()
            buf.vertex(matrix, 1.0F, 0.0F, 0.0F).next()
            buf.vertex(matrix, 1.0F, 1.0F, 0.0F).next()
            buf.vertex(matrix, 1.0F, 0.0F, 0.0F).next()
            buf.vertex(matrix, 0.0F, 0.0F, 0.0F).next()
            buf.vertex(matrix, 0.0F, 0.0F, 0.0F).next()
            buf.vertex(matrix, 0.0F, 1.0F, 1.0F).next()
            buf.vertex(matrix, 0.0F, 1.0F, 0.0F).next()
            buf.vertex(matrix, 1.0F, 0.0F, 1.0F).next()
            buf.vertex(matrix, 0.0F, 0.0F, 1.0F).next()
            buf.vertex(matrix, 0.0F, 0.0F, 0.0F).next()
            buf.vertex(matrix, 0.0F, 1.0F, 1.0F).next()
            buf.vertex(matrix, 0.0F, 0.0F, 1.0F).next()
            buf.vertex(matrix, 1.0F, 0.0F, 1.0F).next()
            buf.vertex(matrix, 1.0F, 1.0F, 1.0F).next()
            buf.vertex(matrix, 1.0F, 0.0F, 0.0F).next()
            buf.vertex(matrix, 1.0F, 1.0F, 0.0F).next()
            buf.vertex(matrix, 1.0F, 0.0F, 0.0F).next()
            buf.vertex(matrix, 1.0F, 1.0F, 1.0F).next()
            buf.vertex(matrix, 1.0F, 0.0F, 1.0F).next()
            buf.vertex(matrix, 1.0F, 1.0F, 1.0F).next()
            buf.vertex(matrix, 1.0F, 1.0F, 0.0F).next()
            buf.vertex(matrix, 0.0F, 1.0F, 0.0F).next()
            buf.vertex(matrix, 1.0F, 1.0F, 1.0F).next()
            buf.vertex(matrix, 0.0F, 1.0F, 0.0F).next()
            buf.vertex(matrix, 0.0F, 1.0F, 1.0F).next()
            buf.vertex(matrix, 1.0F, 1.0F, 1.0F).next()
            buf.vertex(matrix, 0.0F, 1.0F, 1.0F).next()
            buf.vertex(matrix, 1.0F, 0.0F, 1.0F).next()
            buf.unfixColor()
        }

        fun renderBlocks(matrices: MatrixStack, camera: Camera, block: RenderBlockContext. () -> Unit) {
            RenderSystem.disableDepthTest()
            RenderSystem.enableBlend()
            RenderSystem.defaultBlendFunc()

            matrices.push()
            matrices.translate(-camera.pos.x, -camera.pos.y, -camera.pos.z)

            val ctx = RenderBlockContext(Tessellator.getInstance(), matrices)
            block(ctx)

            matrices.pop()

            RenderSystem.setShaderColor(1F,1F,1F,1F)
            VertexBuffer.unbind()
            RenderSystem.enableDepthTest()
            RenderSystem.disableBlend()
        }
    }
}