package world

import (
	"image"
	"image/color"

	"github.com/bedrock-tool/bedrocktool/utils"

	"github.com/df-mc/dragonfly/server/block"
	"github.com/df-mc/dragonfly/server/block/cube"
	"github.com/df-mc/dragonfly/server/world"
	"github.com/df-mc/dragonfly/server/world/chunk"
)

func isBlockLightblocking(b world.Block) bool {
	d, isDiffuser := b.(block.LightDiffuser)
	_, isSlab := b.(block.Slab)
	noDiffuse := isDiffuser && d.LightDiffusionLevel() == 0
	return noDiffuse && !isSlab
}

func blockColorAt(c *chunk.Chunk, x uint8, y int16, z uint8) (blockColor color.RGBA) {
	if y <= int16(c.Range().Min()) {
		return color.RGBA{0, 0, 0, 0}
	}
	blockColor = color.RGBA{255, 0, 255, 255}
	rid := c.Block(x, y, z, 0)
	if rid == 0 && y == int16(c.Range().Min()) { // void
		blockColor = color.RGBA{0, 0, 0, 255}
	} else {
		b, found := world.BlockByRuntimeID(rid)
		if found {
			if isBlockLightblocking(b) {
				return blockColorAt(c, x, y-1, z)
			}
			_, isWater := b.(block.Water)
			if !isWater {
				return b.Color()
			}
			// get the first non water block at the position
			heightBlock := c.HeightMap().At(x, z)
			depth := y - heightBlock
			if depth > 0 {
				blockColor = blockColorAt(c, x, heightBlock, z)
			}

			// blend that blocks color with water depending on depth
			waterColor := (&block.Water{}).Color()
			waterColor.A = uint8(utils.Clamp(int(150+depth*7), 255))
			blockColor = utils.BlendColors(blockColor, waterColor)
			blockColor.R -= uint8(depth * 2)
			blockColor.G -= uint8(depth * 2)
			blockColor.B -= uint8(depth * 2)
		}
		/*
			if blockColor.R == 0 || blockColor.R == 255 && blockColor.B == 255 {
				name, nbt := b.EncodeBlock()
				fmt.Printf("unknown color %d  %s %s %s\n", rid, reflect.TypeOf(b), name, nbt)
				b.Color()
			}
		*/
	}
	return blockColor
}

func chunkGetColorAt(c *chunk.Chunk, x uint8, y int16, z uint8) color.RGBA {
	haveUp := false
	cube.Pos{int(x), int(y), int(z)}.
		Side(cube.FaceUp).
		Neighbours(func(neighbour cube.Pos) {
			if neighbour.X() < 0 || neighbour.X() >= 16 || neighbour.Z() < 0 || neighbour.Z() >= 16 || neighbour.Y() > c.Range().Max() || haveUp {
				return
			}
			blockRid := c.Block(uint8(neighbour[0]), int16(neighbour[1]), uint8(neighbour[2]), 0)
			if blockRid > 0 {
				b, found := world.BlockByRuntimeID(blockRid)
				if found {
					if isBlockLightblocking(b) {
						haveUp = true
					}
				}
			}
		}, cube.Range{int(y + 1), int(y + 1)})

	blockColor := blockColorAt(c, x, y, z)
	if haveUp {
		if blockColor.R > 10 {
			blockColor.R -= 10
		}
		if blockColor.G > 10 {
			blockColor.G -= 10
		}
		if blockColor.B > 10 {
			blockColor.B -= 10
		}
	}
	return blockColor
}

func Chunk2Img(c *chunk.Chunk) *image.RGBA {
	img := image.NewRGBA(image.Rect(0, 0, 16, 16))
	hm := c.HeightMapWithWater()

	for x := uint8(0); x < 16; x++ {
		for z := uint8(0); z < 16; z++ {
			img.SetRGBA(
				int(x), int(z),
				chunkGetColorAt(c, x, hm.At(x, z), z),
			)
		}
	}
	return img
}