--[[
	This file generates:
	darkage:mud
	darkage:silt
	darkage:chalk
	darkage:ors
	darkage:shale
	darkage:slate
	darkage:schist
	darkage:basalt
	darkage:marble
	darkage:serpentine
	darkage:gneiss
--]]

local function generate_stratus(name, wherein, ceilin, ceil, minp, maxp, seed, stratus_chance, radius, radius_y, deep, height_min, height_max)
	if maxp.y < height_min or minp.y > height_max then
		return
	end
	local stratus_per_volume = 1
	local area = 45
	local y_min = math.max(minp.y, height_min)
	local y_max = math.min(maxp.y, height_max)
	local volume = ((maxp.x-minp.x+1)/area)*((y_max-y_min+1)/area)*((maxp.z-minp.z+1)/area)
	local pr = PseudoRandom(seed)
	local blocks = math.floor(stratus_per_volume*volume)
	print("  <<"..dump(name)..">>");
	if blocks == 0 then
		blocks = 1
	end
	print("    blocks: "..dump(blocks).." in vol: "..dump(volume).." ("..dump(maxp.x-minp.x+1)..","..dump(y_max-y_min+1)..","..dump(maxp.z-minp.z+1)..")")
	for i=1,blocks do
		local x = pr:next(1,stratus_chance)
		if x == 1 then
			local y0=y_max-radius_y+1
			if y0 < y_min then
				y0=y_min
			else
				y0=pr:next(y_min, y0)
			end
			local x0 = maxp.x-radius+1
			if x0 < minp.x then
				x0 = minp.x
			else
				x0 = pr:next(minp.x, x0)
			end
			local z0 = maxp.z-radius+1
			if z0 < minp.z then
				x0 = minp.z
			else
				z0 = pr:next(minp.z, z0)
			end
			local p0 = {x=x0, y=y0, z=z0}
			local n = minetest.get_node(p0).name
			local i = 0
			x = 0
			for k, v in ipairs(ceilin) do
				if n == v then
					x = 1
				break
			end
		end
		if x == 1 then
			for y1=y0-1,y_min,-1 do
				p0.y=y1
				n = minetest.get_node(p0).name
				x = 0
				for k, v in ipairs(wherein) do
					if n == v then
						x = 1
					break
				end
			end
			if x == 1 then
				y0=y1-deep
				if y0 < y_min then
					y0 = y_min
				end
				break
			end
		end
		local rx=pr:next(radius/2,radius)+1
		local rz=pr:next(radius/2,radius)+1
		local ry=pr:next(radius_y/2,radius_y)+1
		for x1=0,rx do
			rz = rz + 3 - pr:next(1,6)
			if rz < 1 then
				rz = 1
			end
			for z1=pr:next(1,3),rz do
				local ry0=ry+ pr:next(1,3)
				for y1=pr:next(1,3),ry0 do
					local x2 = x0+x1
					local y2 = y0+y1
					local z2 = z0+z1
					local p2 = {x=x2, y=y2, z=z2}
					n = minetest.get_node(p2).name
					x = 0
						for k, v in ipairs(wherein) do
							if n == v then
								x = 1
							break
						end
				end
				if x == 1 then
					if ceil == nil then
						minetest.set_node(p2, {name=name})
						i = i +1
					else
						local p3 = {p2.x,p2.y+1,p2}
						if minetest.get_node(p3).name == ceil then
							minetest.set_node(p2, {name=name})
							i = i +1
						end
					end
				end
			end
		end
	end
	print("    generated "..dump(i).." blocks in ("..dump(x0)..","..dump(y0)..","..dump(z0)..")")
-- end end end end!
end
end
end
end

local function generate_claylike(name, minp, maxp, seed, chance, minh, maxh, dirt)
	if maxp.y >= maxh+1 and minp.y <= minh-1 then
	local pr = PseudoRandom(seed)
	local divlen = 4
	local divs = (maxp.x-minp.x)/divlen+1;
		for yy=minh,maxh do
			local x = pr:next(1,chance)
			if x == 1 then
				for divx=0+1,divs-1-1 do
					for divz=0+1,divs-1-1 do
						local cx = minp.x + math.floor((divx+0.5)*divlen)
						local cz = minp.z + math.floor((divz+0.5)*divlen)
						local up = minetest.get_node({x=cx,y=yy,z=cz}).name
						local down = minetest.get_node({x=cx,y=yy-1,z=cz}).name
						if ( up == "default:water_source" or up == "air" ) and ( down == "default:sand" or (dirt == 1 and (down == "default:dirt" or down == "default:dirt_with_grass" ))) then
							local is_shallow = true
							local num_water_around = 0
							if minetest.get_node({x=cx-divlen*2,y=yy,z=cz}).name == "default:water_source" then
								num_water_around = num_water_around + 1
							end
							if minetest.get_node({x=cx+divlen*2,y=yy,z=cz}).name == "default:water_source" then
								num_water_around = num_water_around + 1
							end
							if minetest.get_node({x=cx,y=yy,z=cz-divlen*2}).name == "default:water_source" then
								num_water_around = num_water_around + 1
							end
							if minetest.get_node({x=cx,y=yy,z=cz+divlen*2}).name == "default:water_source" then
								num_water_around = num_water_around + 1
							end
							if num_water_around >= 3 then
								is_shallow = false
							end
							if is_shallow then
								for x1=-divlen,divlen do
									for z1=-divlen,divlen do
										local p={x=cx+x1,y=yy-1,z=cz+z1}
										down = minetest.get_node(p).name
										if down == "default:sand" or (dirt == 1 and (down == "default:dirt" or down == "default:dirt_with_grass")) then
											minetest.set_node(p, {name=name})
										end
									end
								end
							end
						end
					end
				end
			end
		end
	end
end


local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, chunk_size, ore_per_chunk, height_min, height_max)
	if maxp.y < height_min or minp.y > height_max then
		return
	end
	local y_min = math.max(minp.y, height_min)
	local y_max = math.min(maxp.y, height_max)
	local volume = (maxp.x-minp.x+1)*(y_max-y_min+1)*(maxp.z-minp.z+1)
	local pr = PseudoRandom(seed)
	local num_chunks = math.floor(chunks_per_volume * volume)
	local inverse_chance = math.floor(chunk_size*chunk_size*chunk_size / ore_per_chunk)
	for i=1,num_chunks do
		local y0 = pr:next(y_min, y_max-chunk_size+1)
		if y0 >= height_min and y0 <= height_max then
			local x0 = pr:next(minp.x, maxp.x-chunk_size+1)
			local z0 = pr:next(minp.z, maxp.z-chunk_size+1)
			local p0 = {x=x0, y=y0, z=z0}
			for x1=0,chunk_size-1 do
				for y1=0,chunk_size-1 do
					for z1=0,chunk_size-1 do
						if pr:next(1,inverse_chance) == 1 then
							local x2 = x0+x1
							local y2 = y0+y1
							local z2 = z0+z1
							local p2 = {x=x2, y=y2, z=z2}
							if minetest.get_node(p2).name == wherein then
								minetest.set_node(p2, {name=name})
							end
						end
					end
				end
			end
		end
	end
end

minetest.register_on_generated(function(minp, maxp, seed)
if minp.y < -19600 then return end
print("DARKAGE: Generate stratus");
generate_claylike("darkage:mud", minp, maxp, seed+1, 4, 0, 2, 0)
generate_claylike("darkage:silt", minp, maxp, seed+2, 4, -1, 1, 1)
generate_stratus("darkage:chalk",
				{"default:stone"},
				{"default:stone","air"}, nil,
				minp, maxp, seed+3, 4, 25, 8, 0, -20,  50)
generate_stratus("darkage:ors",
				{"default:stone"},
				{"default:stone","air","default:water_source"}, nil,
				minp, maxp, seed+4, 4, 25, 7, 50, -200,  500)
generate_stratus("darkage:shale",
				{"default:stone"},
				{"default:stone","air"}, nil,
				minp, maxp, seed+5, 4, 23, 7, 50, -50,  20)
generate_stratus("darkage:slate",
				{"default:stone"},
				{"default:stone","air"}, nil,
				minp, maxp, seed+6, 6, 23, 5, 50, -500, 0)
generate_stratus("darkage:schist",
				{"default:stone"},
				{"default:stone","air"}, nil,
				minp, maxp, seed+7, 6, 19, 6, 50, -31000, -10)
generate_stratus("darkage:basalt",
				{"default:stone"},
				{"default:stone","air"}, nil,
				minp, maxp, seed+8, 5, 20, 5, 20, -31000, -50)
generate_stratus("darkage:marble",
				{"default:stone"},
				{"default:stone","air"}, nil,
				minp, maxp, seed+9, 4, 25, 6, 50, -31000,  -75)
generate_stratus("darkage:serpentine",
				{"default:stone"},
				{"default:stone","air"}, nil,
				minp, maxp, seed+10, 4, 28, 8, 50, -31000,  -350)
generate_stratus("darkage:gneiss",
				{"default:stone"},
				{"default:stone","air"}, nil,
				minp, maxp, seed+11, 4, 15, 5, 50, -31000, -250)
end)