--[[
If you want to run PlantLife and mods that depend on it, i.e. MoreTrees, Disable the mapgen by
commenting-out the lines starting with "local mgname = " through "end" (I left a note were to start
and stop) Disabling "Snow's" mapgen allows MoreTrees and PlantLife to do their thing until the
issue is figured out. However, the pine and xmas tree code is still needed for when those
saplings grow into trees. --]]
--The *starting* comment looks like this:  --[[
--The *closing* comment looks like this:  --]]

-- ~ LazyJ, 2014_05_13


-- Part 1: To disable the mapgen, add the *starting* comment under this line.

local perlin_scale, nosmooth_rarity
if not snow.disable_mapgen then
	print("[snow] Mapgen enabled!")

	snow.mapgen = snow.mapgen or {}
	local mg = snow.mapgen

	-- perlin noise "hills" are not peaks but looking like sinus curve
	local function upper_rarity(rarity)
		return math.sign(rarity)*math.sin(math.abs(rarity)*math.pi/2)
	end

	local rarity = snow.mapgen_rarity
	local size = snow.mapgen_size
	local smooth = snow.smooth_biomes

	local function calc_values()
		nosmooth_rarity = 1-rarity/50
		perlin_scale = size*100/rarity
		mg.perlin_scale = perlin_scale
		if smooth then
			local smooth_trans_size = 4 --snow.smooth_trans_size
			mg.smooth_rarity_max = upper_rarity(nosmooth_rarity+smooth_trans_size*2/perlin_scale)
			mg.smooth_rarity_min = upper_rarity(nosmooth_rarity-smooth_trans_size/perlin_scale)
			mg.smooth_rarity_dif = mg.smooth_rarity_max-mg.smooth_rarity_min
		end
		nosmooth_rarity = upper_rarity(nosmooth_rarity)
		mg.nosmooth_rarity = nosmooth_rarity
	end
	calc_values()

	snow.register_on_configuring(function(name, v)
		if name == "mapgen_rarity" then
			rarity = v
		elseif name == "mapgen_size" then
			size = v
		elseif name == "smooth_biomes" then
			smooth = v
		else
			return
		end
		-- TODO: if e.g. size and rarity get changed at once, don't calculate the values more times
		calc_values()
	end)


	--Identify the mapgen.
	local mgname = minetest.get_mapgen_setting"mg_name"
	if not mgname then
		minetest.log("error", "[MOD] Snow Biomes: WARNING! mapgen could not be identifyed!")
	end
	local path = minetest.get_modpath"snow"
	if mgname == "v7" then
		--Load mapgen_v7 compatibility.
		dofile(path.."/src/mapgen_v7.lua")
	else
		--Load mapgen_v6 compatibility.
		dofile(path.."/src/mapgen_v6.lua")
	end
end

-- To complete the commenting-out add the *closing* comment under this line.


local pine_tree = {
	axiom="TABff",
	rules_a="[&T+f+ff+ff+ff+f]GA",
	rules_b="[&T+f+Gf+Gf+Gf]GB",
	trunk="default:pinetree",
	leaves="snow:needles",
	angle=90,
	iterations=1,
	random_level=0,
	trunk_type="single",
	thin_branches=true,
}



local xmas_tree = {
	axiom="TABff",
	rules_a="[&T+f+ff+ff+ff+f]GA",
	rules_b="[&T+f+Gf+Gf+Gf]GB",
	trunk="default:pinetree",
	leaves="snow:needles_decorated",
	angle=90,
	iterations=1,
	random_level=0,
	trunk_type="single",
	thin_branches=true,
}



--Makes pine tree
function snow.make_pine(pos,snow,xmas)
	local minetest = minetest
	local function try_node(p, node)
		local n = minetest.get_node(p).name
		if n == "air"
		or n == "ignore" then
			minetest.add_node(p, node)
		end
	end
	if xmas then
		minetest.remove_node(pos)
		minetest.spawn_tree(pos, xmas_tree)
	else
		minetest.spawn_tree(pos, pine_tree)
	end
	if snow then
		local x,z = pos.x,pos.z
		try_node({x=x+1,y=pos.y+3,z=z+1},{name="default:snow"})
		try_node({x=x-1,y=pos.y+3,z=z-1},{name="default:snow"})
		try_node({x=x-1,y=pos.y+3,z=z+1},{name="default:snow"})
		try_node({x=x+1,y=pos.y+3,z=z-1},{name="default:snow"})

		try_node({x=x+1,y=pos.y+5,z=z},{name="default:snow"})
		try_node({x=x-1,y=pos.y+5,z=z},{name="default:snow"})
		try_node({x=x,y=pos.y+5,z=z+1},{name="default:snow"})
		try_node({x=x,y=pos.y+5,z=z-1},{name="default:snow"})
	end
	if xmas then
		try_node({x=pos.x,y=pos.y+7,z=pos.z},{name="snow:star_lit"}) -- Added lit star. ~ LazyJ
	elseif snow
	and minetest.get_perlin(112,3, 0.5, perlin_scale):get2d({x=pos.x,y=pos.z}) > nosmooth_rarity then
		try_node({x=pos.x,y=pos.y+7,z=pos.z},{name="default:snow"})
	end
end



--Makes pine tree
function snow.voxelmanip_pine(pos,a,data)
	local c_snow = minetest.get_content_id("default:snow")
	local c_pine_needles = minetest.get_content_id("snow:needles")
	local c_pinetree = minetest.get_content_id("default:pinetree")

	local perlin1 = minetest.get_perlin(112,3, 0.5, perlin_scale)
	for off_z = -1,1 do
		local z = pos.z + off_z
		for off_x = -1,1 do
			local x = pos.x + off_x

			--Make tree.
			for i = 1,2 do
				data[a:index(x,pos.y+i,z)] = c_pine_needles
				if x ~= 0
				and z ~= 0
				and perlin1:get2d({x=x,y=z}) > nosmooth_rarity then
					local abovenode = a:index(x,pos.y+i+1,z)
					data[abovenode] = c_snow
				end
			end
		end
	end
	for i=3, 4 do
		local x = pos.x
		local y = pos.y+i
		local z = pos.z
		data[a:index(x+1,y,z)] = c_pine_needles
		data[a:index(x-1,y,z)] = c_pine_needles
		data[a:index(x,y,z+1)] = c_pine_needles
		data[a:index(x,y,z-1)] = c_pine_needles
		if perlin1:get2d({x=x+1,y=z}) > nosmooth_rarity then
			data[a:index(x+1,y+1,z)] = c_snow
		end
		if perlin1:get2d({x=x+1,y=z}) > nosmooth_rarity then
			data[a:index(x-1,y+1,z)] = c_snow
		end
		if perlin1:get2d({x=x,y=z+1}) > nosmooth_rarity then
			data[a:index(x,y+1,z+1)] = c_snow
		end
		if perlin1:get2d({x=x,y=z-1}) > nosmooth_rarity then
			data[a:index(x,y+1,z-1)] = c_snow
		end
	end
	for i=0, 4 do
		data[a:index(pos.x,pos.y+i,pos.z)] = c_pinetree
	end
	data[a:index(pos.x,pos.y+5,pos.z)] = c_pine_needles
	data[a:index(pos.x,pos.y+6,pos.z)] = c_pine_needles
	if perlin1:get2d({x=pos.x,y=pos.z}) > nosmooth_rarity then
		data[a:index(pos.x,pos.y+7,pos.z)] = c_snow
	end
end

-- treecapitator support
if minetest.global_exists"treecapitator" then
	treecapitator.register_tree{
		trees = {"default:pine_tree"},
		leaves = {"snow:needles"},
		range = 1,
		range_up = 2,
		range_down = 3,
		stem_height_min = 1,
	}

	treecapitator.register_tree{
		trees = {"default:pine_tree"},
		leaves = {"snow:needles_decorated"},
		fruits = {"snow:star_lit", "snow:star"},
		range = 1,
		range_up = 3,
		range_down = 3,
		stem_height_min = 1,
	}
end