local cache = {}
local lastUpdate = {}
local searchCooldown = 5
local tickCounter = 0

registerBlockUpdate(function(update)
    local x, y, z = update.x, update.y, update.z
    local key = x .. "_" .. y .. "_" .. z
    cache[key] = update.new
    lastUpdate[key] = true
end)

local function findNearestBlock(centerX, centerY, centerZ, horizontal, vertical)
    local nodes = {}
    
    for dx = -horizontal, horizontal do
        local x = centerX + dx
        for dz = -horizontal, horizontal do
            local z = centerZ + dz
            for dy = -vertical, vertical do
                local y = centerY + dy
                local key = x .. "_" .. y .. "_" .. z
                
                local blockInfo = cache[key]
                if not blockInfo or lastUpdate[key] then
                    blockInfo = world.getBlock(x, y, z)
                    cache[key] = blockInfo
                    lastUpdate[key] = nil
                end
                
                if blockInfo and (blockInfo.name == "block.minecraft.purple_terracotta") then
                    table.insert(nodes, { x = x, y = y, z = z})
				end
            end
        end
    end
    
    return nodes
end

local nodes = {}

registerClientTickPost(function()
    tickCounter = tickCounter + 1
    
    if tickCounter >= searchCooldown then
        tickCounter = 0
        local centerX = math.floor(player.getPos().x)
        local centerY = math.floor(player.getPos().y)
        local centerZ = math.floor(player.getPos().z)
		threads.startThread(function()
			nodes = findNearestBlock(centerX, centerY, centerZ, 21, 13)
		end)
    end
end)

registerWorldRenderer(function(context)
    local renderColors = {
        {blocks = nodes, r = 255, g = 85, b = 255},
    }
    
    for _, config in ipairs(renderColors) do
        for _, block in ipairs(config.blocks) do
            context.renderFilled({
                x = block.x, y = block.y, z = block.z,
                red = config.r, green = config.g, blue = config.b,
                alpha = 190, through_walls = true
            })
        end
    end
end)