local mtsettings = minetest.settings
local settings = Settings(minetest.get_worldpath() .. '/mapgen_rivers.conf')

mapgen_rivers.version = "1.0.2"
mapgen_rivers.settings = settings

local previous_version_mt = mtsettings:get("mapgen_rivers_version") or "0.0"
local previous_version_mgr = settings:get("version") or "0.0"

if mapgen_rivers.version ~= previous_version_mt or mapgen_rivers.version ~= previous_version_mgr then
	local compat_mt, compat_mgr = dofile(minetest.get_modpath(minetest.get_current_modname()) .. "/compatibility.lua")
	if mapgen_rivers.version ~= previous_version_mt then
		compat_mt(mtsettings)
	end
	if mapgen_rivers.version ~= previous_version_mgr then
		compat_mgr(settings)
	end
end

mtsettings:set("mapgen_rivers_version", mapgen_rivers.version)
settings:set("version", mapgen_rivers.version)

local modified = false
local function verify_setting(name, dtype, default)
	if settings:has(name) then
		return
	end

	modified = true
	local v = default
	local mtname = 'mapgen_rivers_' .. name
	local mthas = mtsettings:has(mtname)
	if dtype == "number" or dtype == "string" then
		if mthas then
			v = mtsettings:get(mtname)
			if dtype == "number" and tonumber(v) == nil then
				v = default
			end
		end
		settings:set(name, v)
	elseif dtype == "bool" then
		if mthas then
			v = mtsettings:get(mtname)
		end
		settings:set_bool(name, v)
	elseif dtype == "noise" then
		if mthas then
			v = mtsettings:get_np_group(mtname)
		end
		settings:set_np_group(name, v)
	end
end

verify_setting('center', 'bool', true)
verify_setting('blocksize', 'number', 15)
verify_setting('min_catchment', 'number', 3600)
verify_setting('river_widening_power', 'number', 0.5)
verify_setting('riverbed_slope', 'number', 0.4)
verify_setting('distort', 'bool', true)
verify_setting('biomes', 'bool', true)
verify_setting('glaciers', 'bool', false)
verify_setting('glacier_factor', 'number', 8)
verify_setting('elevation_chill', 'number', 0.25)
verify_setting('grid_x_size', 'number', 1000)
verify_setting('grid_z_size', 'number', 1000)
verify_setting('river_erosion_coef', 'number', 0.5)
verify_setting('river_erosion_power', 'number', 0.4)
verify_setting('diffusive_erosion', 'number', 0.5)
verify_setting('compensation_radius', 'number', 50)
verify_setting('tectonic_speed', 'number', 70)
verify_setting('evol_time', 'number', 10)
verify_setting('evol_time_step', 'number', 1)

verify_setting('np_base', 'noise', {
		offset = 0,
		scale = 300,
		seed = 2469,
		octaves = 8,
		spread = {x=2048, y=2048, z=2048},
		persist = 0.6,
		lacunarity = 2,
		flags = "eased",
})
verify_setting('np_distort_x', 'noise', {
		offset = 0,
		scale = 1,
		seed = -4574,
		spread = {x=64, y=32, z=64},
		octaves = 3,
		persistence = 0.75,
		lacunarity = 2,
})
verify_setting('np_distort_z', 'noise', {
		offset = 0,
		scale = 1,
		seed = -7940,
		spread = {x=64, y=32, z=64},
		octaves = 3,
		persistence = 0.75,
		lacunarity = 2,
})
verify_setting('np_distort_amplitude', 'noise', {
		offset = 0,
		scale = 10,
		seed = 676,
		spread = {x=1024, y=1024, z=1024},
		octaves = 5,
		persistence = 0.5,
		lacunarity = 2,
		flags = "absvalue",
})

if modified then
	settings:write()
end