local Bi_Industries = {}

Bi_Industries.fertility = {  -- out of 100, so 100 = always
	-- Vanilla
	["grass-medium"]    = 100, 
	["grass"]           = 85, 
	["grass-dry"]       = 75,
	["dirt"]            = 45,
	["dirt-dark"]       = 35,
	["sand"]            = 25,
	["sand-dark"]       = 15,
	["red-desert"]      = 10,
	["red-desert-dark"] = 5,
	-- Alien biomes
	["grass-red"]         = 95,
	["grass-orange"]      = 95,
	["grass-yellow"]      = 95,
	["grass-yellow-fade"] = 90,
	["grass-purple-fade"] = 90,
	["grass-purple"]      = 95,
	["dirt-red-dark"]     = 45,
	["dirt-brown-dark"]   = 45,
	["grass-blue-fade"]   = 90,
	["grass-blue"]        = 95,
	["dirt-red"]          = 35,
	["dirt-brown"]        = 35,
	["dirt-tan-dark"]     = 45,
	["dirt-dull-dark"]    = 45,
	["dirt-grey-dark"]    = 45,
	["dirt-tan"]          = 25,
	["dirt-dull"]         = 25,
	["dirt-grey"]         = 25,
	["sand-red-dark"]     = 15,
	["sand-orange-dark"]  = 15,
	["sand-gold-dark"]    = 15,
	["sand-dull-dark"]    = 10,
	["sand-grey-dark"]    = 10,
	["sand-red"]          = 10,
	["sand-orange"]       = 10,
	["sand-gold"]         = 10,
	["sand-dull"]         = 7.5,
	["sand-grey"]         = 7.5,
	["snow"]              = 5,
	["volcanic-cool"]     = 5,
}



function Grow_tree(pos)
	
	local foundtree = false
	local surface = game.surfaces['nauvis']
	local tree = surface.find_entity("seedling", pos)
	local currentTilename = surface.get_tile(pos.x, pos.y).name
	local fertility = 5
	local growth_chance = math.random(100) -- Random value. Tree will grow if it's this value is smaller that the 'Fertility' value

				
	if tree then
		foundtree = true
		tree.destroy()
		
		--- Depending on Terain, choose tree type & Convert seedling into a tree
		
		if Bi_Industries.fertility[currentTilename] then
			fertility = Bi_Industries.fertility[currentTilename]
		end
		
		if 	currentTilename == "grass" then 
			treetype = "tree-05"

			if growth_chance <= fertility and foundtree and surface.can_place_entity({ name=treetype, position=pos}) then
				surface.create_entity({ name=treetype, amount=1, position=pos})
			end
					
		elseif currentTilename == "grass-medium" then 
			treetype = "tree-04"

			if growth_chance <= fertility and foundtree and surface.can_place_entity({ name=treetype, position=pos}) then
				surface.create_entity({ name=treetype, amount=1, position=pos})
			end
		
		elseif currentTilename == "grass-dry" then 
			treetype = math.random(2)
			treetype = "tree-0".. treetype

			if growth_chance <= fertility and foundtree and surface.can_place_entity({ name=treetype, position=pos}) then
				surface.create_entity({ name=treetype, amount=1, position=pos})
			end
		
		elseif currentTilename == "dirt" or currentTilename == "dirt-dark" then 
			treetype = math.random(2)
			treetype = treetype + 5
			treetype = "tree-0".. treetype

			if growth_chance <= fertility and foundtree and surface.can_place_entity({ name=treetype, position=pos}) then
				surface.create_entity({ name=treetype, amount=1, position=pos})
			end
				
		elseif currentTilename == "red-desert" or currentTilename == "red-desert-dark" then 
			treetype = math.random(2)
			treetype = treetype + 5
			treetype = "tree-0".. treetype

			if growth_chance <= fertility and foundtree and surface.can_place_entity({ name=treetype, position=pos}) then
				surface.create_entity({ name=treetype, amount=1, position=pos})
			end
		
		---- Sand and Dark Sand & Any other Tile Type
		else
			treetype = math.random(3)
			if treetype == 1 then
				treetype = "tree-03"
			elseif treetype == 2 then
				treetype = "tree-08"
			else
				treetype = "tree-09"
			end

			if growth_chance <= fertility and foundtree and surface.can_place_entity({ name=treetype, position=pos}) then
				surface.create_entity({ name=treetype, amount=1, position=pos})
			end
				
		end		

	end
	
end