pedology = {}
pedology.wetnames = {[0] = "dry",  "wet", "watery", "sludgy", "muddy", "slurry" }

dofile(minetest.get_modpath("pedology").."/settings.lua")

if pedology.USE_DRIPS == true then
	dofile(minetest.get_modpath("pedology").."/drip.lua")
end

--[[ ABMs ]]

function pedology.ooze(pos, node, active_object_count, active_object_wider)
	local wet = minetest.get_item_group(node.name, "wet")
	if wet == 0 then return end

	--[[ This table contain the nodes which are either neighbors
	of node or which touch the node at an edge or corner and which are
	not on a heigher y-level than
	of node
	]]
	local neighbors = {
		{	-- neighbor directly below
			{x=pos.x, y=pos.y-1, z=pos.z},
			minwet=1
		},
		
		{	-- touching the lower sides
			{x=pos.x, y=pos.y-1, z=pos.z-1},
			{x=pos.x, y=pos.y-1, z=pos.z+1},
			{x=pos.x-1, y=pos.y-1, z=pos.z},
			{x=pos.x+1, y=pos.y-1, z=pos.z},
			minwet=1
		},
		{	-- touching the lower corners
			{x=pos.x-1, y=pos.y-1, z=pos.z-1},
			{x=pos.x-1, y=pos.y-1, z=pos.z+1},
			{x=pos.x-1, y=pos.y-1, z=pos.z-1},
			{x=pos.x+1, y=pos.y-1, z=pos.z+1},
			{x=pos.x+1, y=pos.y-1, z=pos.z+1},
			minwet=1
		},
		{	-- sides on the same level
			{x=pos.x-1, y=pos.y, z=pos.z}, -- left
			{x=pos.x+1, y=pos.y, z=pos.z}, -- right
			{x=pos.x, y=pos.y, z=pos.z-1}, -- before
			{x=pos.x, y=pos.y, z=pos.z+1}, -- behind
			minwet=2
		},
		{	-- touching at the side on the same level
			{x=pos.x-1, y=pos.y, z=pos.z-1},
			{x=pos.x-1, y=pos.y, z=pos.z+1},
			{x=pos.x+1, y=pos.y, z=pos.z-1},
			{x=pos.x+1, y=pos.y, z=pos.z+1},
			minwet=2
		},
	}

	for i=1,#neighbors do
		for j=1,#neighbors[i] do
			local node = minetest.get_node(neighbors[i][j])
			local name = node.name
			local destwet = minetest.get_item_group(name, "wet")
			if(
				(destwet < wet) and 
				(minetest.get_item_group(name, "sucky") >= 1)) and
				(neighbors[i].minwet <= (wet - destwet)) then
					pedology.wetten(neighbors[i][j])
					pedology.dry(pos)
					return
			end
		end
	end
end

--[[ This is an ABM action which wettens the node iff many water nodes
are neighbors of it or touching it at an edge or corner.]]
function pedology.suck(pos, node, active_object_count, active_object_wider)
	local wet = minetest.get_item_group(node.name, "wet")

	local score = 0

	-- These three tables contain the positions of all nodes around node
	local neighbors= {
		{ -- sides
		{x=pos.x, y=pos.y-1, z=pos.z}, -- below
		{x=pos.x-1, y=pos.y, z=pos.z}, -- left
		{x=pos.x+1, y=pos.y, z=pos.z}, -- right
		{x=pos.x, y=pos.y+1, z=pos.z}, -- above
		{x=pos.x, y=pos.y, z=pos.z-1}, -- before
		{x=pos.x, y=pos.y, z=pos.z+1}, -- behind
		rating = 1
		},
		{ -- edges
		{x=pos.x, y=pos.y-1, z=pos.z-1},
		{x=pos.x, y=pos.y-1, z=pos.z+1},
		{x=pos.x, y=pos.y+1, z=pos.z-1},
		{x=pos.x, y=pos.y+1, z=pos.z+1},
		{x=pos.x-1, y=pos.y, z=pos.z-1},
		{x=pos.x-1, y=pos.y, z=pos.z+1},
		{x=pos.x+1, y=pos.y, z=pos.z-1},
		{x=pos.x+1, y=pos.y, z=pos.z+1},
		{x=pos.x-1, y=pos.y-1, z=pos.z},
		{x=pos.x-1, y=pos.y+1, z=pos.z},
		{x=pos.x+1, y=pos.y-1, z=pos.z},
		{x=pos.x+1, y=pos.y+1, z=pos.z},
		rating=0.5
		},
		{ -- corners	
		{x=pos.x-1, y=pos.y-1, z=pos.z-1},
		{x=pos.x-1, y=pos.y-1, z=pos.z+1},
		{x=pos.x-1, y=pos.y+1, z=pos.z-1},
		{x=pos.x-1, y=pos.y+1, z=pos.z+1},
		{x=pos.x-1, y=pos.y-1, z=pos.z-1},
		{x=pos.x+1, y=pos.y+1, z=pos.z+1},
		{x=pos.x+1, y=pos.y+1, z=pos.z-1},
		{x=pos.x+1, y=pos.y-1, z=pos.z+1},
		{x=pos.x+1, y=pos.y-1, z=pos.z+1},
		rating=0.25
		}
	}

	for i=1,#neighbors do
		for j=1,#neighbors[i] do
			local neighbor = minetest.get_node(neighbors[i][j])
			local name = neighbor.name
			local water = minetest.get_item_group(name, "water")
			if(water >= 1) then
				score = score + neighbors[i].rating
			end
		end
	end

	local wetten = false
	if(wet == 0 and score >= 1) then
		wetten=true
	elseif(wet == 1 and score >= 2) then
		wetten= true
	elseif(wet == 2 and score >= 3) then
		wetten=true
	elseif(wet == 3 and score >= 5) then
		wetten=true
	elseif(wet == 4 and score >= 8) then
		wetten=true
	elseif(wet == 5 and score >= 11) then
		-- erosion: turn node into water
		-- TODO: Also drop the drops
		minetest.set_node(pos, {name="pedology:water_fresh_source"})
		return
	end

	if(wetten==true) then
		pedology.wetten(pos)
	end
end

--[[ ABM action which dries out a node when it is in direct sunlight ]]
function pedology.sun_dry(pos, node, active_object_count, active_object_wider)
	if(minetest.get_item_group(node.name, "wet") < 6) then
		-- don’t dry off if there is water nearby
		if(not minetest.find_node_near(pos, 1, {"group:water"})) then
			local light = minetest.get_node_light(pos, minetest.get_timeofday())
			if light >= pedology.DRY_LIGHT then
				pedology.dry(pos)
			end
		end
	end
end



--[[ air and vacuum]]
minetest.register_node("pedology:vacuum", {
	description = "vacuum",
	inventory_image="unknown_node.png",
	wield_image="unknown_node.png",
	paramtype="light",
	drawtype="airlike",
	damage_per_second=8,
	drowning=8,
	sunlight_propagates=true,
	walkable=false,
	pointable=false,
	diggable=false,
	buildable_to=true,
	groups={not_in_creative_inventory=1}
})

minetest.register_node("pedology:thinair2", {
	description = "very thin air",
	inventory_image="unknown_node.png",
	wield_image="unknown_node.png",
	paramtype="light",
	drawtype="airlike",
	sunlight_propagates=true,
	walkable=false,
	pointable=false,
	diggable=false,
	buildable_to=true,
	groups={not_in_creative_inventory=1}
})

minetest.register_node("pedology:thinair1", {
	description = "thin air",
	inventory_image="unknown_node.png",
	wield_image="unknown_node.png",
	paramtype="light",
	drawtype="airlike",
	sunlight_propagates=true,
	walkable=false,
	pointable=false,
	diggable=false,
	buildable_to=true,
	groups={not_in_creative_inventory=1}
})

--[[ liquids ]]

function pedology.register_liquid(basename, description, alpha, viscosity, drowning, damage_per_second, post_effect_color, additional_groups)
	flowing_groups = {wet=6,not_in_creative_inventory=1}
	source_groups = {wet=6}
	for k,v in pairs(additional_groups) do
		flowing_groups[k] = v
		source_groups[k] = v
	end

	local tile = "pedology_"..basename..".png"
	local nodedef_source = {
	description = description.." source",
	inventory_image = minetest.inventorycube(tile),
	tiles = {tile},
	alpha = alpha,
	paramtype = "light",
	walkable = false,
	pointable = false,
	diggable = false,
	buildable_to = true,
	drop = "",
	liquid_alternative_flowing = "pedology:"..basename.."_flowing",
	liquid_alternative_source = "pedology:"..basename.."_source",
	liquid_viscosity = viscosity,
	post_effect_color = post_effect_color,
	drowning = drowning,
	damage_per_second = damage_per_second,

	drawtype = "liquid",
	liquidtype = "source",
	groups = source_groups,
	}
	minetest.register_node("pedology:"..basename.."_source", nodedef_source)

	local nodedef_flowing = {
	description = description.." flowing",
	inventory_image = minetest.inventorycube(tile),
	tiles = {tile},
	alpha = alpha,
	paramtype = "light",
	walkable = false,
	pointable = false,
	diggable = false,
	buildable_to = true,
	drop = "",
	liquid_alternative_flowing = "pedology:"..basename.."_flowing",
	liquid_alternative_source = "pedology:"..basename.."_source",
	liquid_viscosity = viscosity,
	post_effect_color = post_effect_color,
	drowning = drowning,
	damage_per_second = damage_per_second,

	drawtype = "flowingliquid",
	liquidtype = "flowing",
	groups = flowing_groups,
	paramtype2 = "flowingliquid",
	}

	minetest.register_node("pedology:"..basename.."_flowing", nodedef_flowing)

end

pedology.register_liquid("water_fresh", "freshwater", 100, 1,   2, 0, {a=60, r=100, b=200, g=100}, {water=1})
--pedology.register_liquid("water_salt", "salt water",  180, 2,   4, 0, {a=80, r=120, b=200, g=120}, {water=1})
pedology.register_liquid("water_ponding", "ponding water", 234, 4, 3, 0, {a=128, r=85, g=85, g=60}, {water=1})

--[[
TODO: Decide wheather to keep or to remove lava
pedology.register_liquid("lava_1", "very hot lava",	230, 2, 10, 8, {a=230, r=255, g=0, b=0}, {hot=6000, lava=1})
pedology.register_liquid("lava_2", "hot lava",		230, 3,  9, 7, {a=230, r=255, g=0, b=0}, {hot=5000, lava=1})
pedology.register_liquid("lava_3", "lava",		230, 4,  8, 6, {a=230, r=255, g=0, b=0}, {hot=4000, lava=1})
pedology.register_liquid("lava_4", "cold lava",		230, 5,  7, 6, {a=230, r=255, g=0, b=0}, {hot=3000, lava=1})
]]
 
--[[ register a sucky/oozing node to this mod ]]
function pedology.register_sucky(basename, description, wetness, oozing, sucky, melting_point, sounds, additional_groups)
	local wetname = basename.."_"..tostring(wetness)
	local noncreative
	local groups = { sucky=sucky, oozing=oozing, wet=wetness, melting_point=melting_point, not_in_creative_inventory = noncreative, [basename]=1 }
	if additional_groups ~= nil then
		for k,v in pairs(additional_groups) do
			groups[k] = v
		end
	end
	-- If the node is not dry, do not add it into the creative inventory
	if wetness == 0 then noncreative = 0 else noncreative = 1 end
	local nodedef = {
		description = description,
		inventory_image = minetest.inventorycube("pedology_"..wetname..".png"),
		tiles = {"pedology_"..wetname..".png"},
		paramtype = "light",
--		drop = "pedology:"..basename.."_lump 4",
		groups = groups,
		sounds = sounds,
	}
	local name = "pedology:"..wetname

	minetest.register_node(name, nodedef)
end


--[[
	This function registers a couple of sucky/oozing nodes, including all their “wet” variants.
	It also registers an ABM.

	parameters:
	basename: The internal name piece from which the concrete basenames will be build. The wetness level will be appended.
	basedescription. The description of the nodes. A proper wetness adjective (“dry”, “wet”, …) will be prepended.
	maxwet: The maximum wetness level of this node group (minimum: 0, maximum: 5)
	oozeinterval: The interval in seconds in which it the node may ooze. the Minimal value: 1
	oozechance: The inverted chance (1/x) to ooze
	melttable: Table of melting_point values for each wetness level
	sounds: Sound specification for all nodes
	additional_groups: table of additional groups of all the nodes. May be empty or nil (meaning no additional groups).
]]
function pedology.register_sucky_group(basename, basedescription, maxwet, oozeinterval, oozechance, melttable, sounds, additional_groups)
	local oozing, dripinterval
	local m -- melting_point
	for w=0, maxwet do
		if(w==0) then oozing=0 else oozing=1 end
		if (w==maxwet and w ~= 5) then sucky=0 else sucky=1 end
		if melttable == nil then m = 0 else m = melttable[w] end
		pedology.register_sucky(basename, (pedology.wetnames[w]).." "..basedescription, w, oozing, sucky, m, sounds, additional_groups)
		-- register dripping
		if(w>0 and pedology.USE_DRIPS == true) then
			minetest.register_abm({
				nodenames = {"pedology:"..basename.."_"..tostring(w)},
				neighbors = {"air"},
				interval = math.max(oozeinterval/4,2),
				chance = math.max(oozechance,22),
				action = pedology.create_drip,
			})
		end
	end
	if(maxwet > 0) then
		minetest.register_abm({
			nodenames = {"group:"..basename},
			neighbors = {"group:sucky"},
			interval = oozeinterval,
			chance = oozechance,
			action = pedology.ooze,
		})

	end
end

do

local sound_clay = {footstep = {name="pedology_clay_footstep", gain=0.5}}
local sound_silt_fine = {footstep = {name="pedology_silt_footstep", gain=0.3}}
local sound_silt_medium = {footstep = {name="pedology_silt_footstep", gain=0.35}}
local sound_silt_coarse = {footstep = {name="pedology_silt_footstep", gain=0.4}}
local sound_sand_fine = {footstep = {name="pedology_sand_footstep", gain=0.2}}
local sound_sand_medium = {footstep = {name="pedology_sand_footstep", gain=0.25}}
local sound_sand_coarse = {footstep = {name="pedology_sand_footstep", gain=0.3}}
local sound_gravel_fine = {footstep = {name="pedology_gravel_footstep", gain=1}}
local sound_gravel_medium = {footstep = {name="pedology_gravel_footstep", gain=1}}
local sound_gravel_coarse = {footstep = {name="pedology_gravel_footstep", gain=1}}

--[[ register sucky and oozing nodes ]]
--[[ ground nodes ]]
pedology.register_sucky_group("clay", "clay",
	5, 60, 1.25, {3000, 3100, 3200, 3500, 3550, 3600}, sound_clay, { crumbly = 3, sun_dry = 1})
pedology.register_sucky_group("silt_fine", "fine silt",
	5, 45, 1.25, {2800, 2900, 3000, 3100, 3200, 3300}, sound_silt_fine, { crumbly = 3, sun_dry = 1 })
pedology.register_sucky_group("silt_medium", "medium silt",
	4, 30, 1.25, {2600, 2800, 3200, 3800, 4200}, sound_silt_medium, { crumbly = 3, sun_dry = 1 })
pedology.register_sucky_group("silt_coarse", "coarse silt",
	3, 20, 1.25, {2000, 2200, 2400, 2800}, sound_silt_coarse, { crumbly = 3, sun_dry = 1 })
pedology.register_sucky_group("sand_fine", "fine sand",
	2, 10, 1.111111, {1100, 1200, 1300}, sound_sand_fine, { crumbly = 3, sand = 1, sun_dry = 1 })
pedology.register_sucky_group("sand_medium", "medium sand",
	1, 5, 1.111111, {990, 1100}, sound_sand_medium, { crumbly = 3, sand = 1, sun_dry = 1 })
pedology.register_sucky_group("sand_coarse", "coarse sand",
	0, nil, nil, {900}, sound_sand_coarse, { crumbly = 3, sand = 1, sun_dry = 1 })
pedology.register_sucky_group("gravel_fine", "fine gravel",
	1, 2, 1, {670, 770}, sound_gravel_fine, { crumbly = 2, sun_dry = 1 })
pedology.register_sucky_group("gravel_medium", "medium gravel",
	2, 1.5, 1, {600, 800, 1250}, sound_gravel_medium, { crumbly = 2, sun_dry = 1})
pedology.register_sucky_group("gravel_coarse", "coarse gravel", 
	2, 1, 1, {500, 750, 1000}, sound_gravel_coarse, { crumbly = 1, sun_dry = 1 })


--[[ TODO: clay mud
pedology.register_liquid("clay_3", "sludgy clay", 192, 6, 5, 0, {a=192, r=104, g=23, b=0}, {oozing=1})
pedology.register_liquid("clay_4", "muddy clay", 156, 4, 5, 0, {a=156, r=123, g=57, b=6}, {oozing=1})
pedology.register_liquid("clay_5", "slurry clay", 128, 2, 5, 0, {a=128, r=146, g=85, b=73}, {oozing=1})
]]

--[[ turf ]]
--[[pedology.register_sucky_group("turf_fibric", "fibric turf",
	2, 120, 1.25, {1000, 1100, 1200}, sound_silt_coarse, { crumbly = 3, flammable = 1 } )
pedology.register_sucky_group("turf_hemic", "hemic turf",
	2, 180, 1.225, {1100, 1200, 1300}, sound_silt_coarse, { crumbly = 3, flammable = 1 } )
pedology.register_sucky_group("turf_sapric", "sapric turf",
	2, 240, 1.2, {1200, 1300, 1400}, sound_silt_coarse, { crumbly = 3, flammable = 1 } )]]

pedology.register_sucky("turf_fibric", "dry fibric turf", 0, 0, 1, 1000, sound_silt_coarse, { crumbly = 3, flammable = 1 } )
pedology.register_sucky("turf_fibric", "wet fibric turf", 1, 1, 1, 1100, sound_silt_coarse, { crumbly = 3 } )
pedology.register_sucky("turf_fibric", "watery fibric turf", 2, 1, 0, 1200, sound_silt_coarse, { crumbly = 3 } )

pedology.register_sucky("turf_hemic", "dry hemic turf", 0, 0, 1, 1100, sound_silt_coarse, { crumbly = 3, flammable = 1 } )
pedology.register_sucky("turf_hemic", "wet hemic turf", 1, 1, 1, 1200, sound_silt_coarse, { crumbly = 3 } )
pedology.register_sucky("turf_hemic", "watery hemic turf", 2, 1, 0, 1300, sound_silt_coarse, { crumbly = 3 } )

pedology.register_sucky("turf_sapric", "dry sapric turf", 0, 0, 1, 1200, sound_silt_coarse, { crumbly = 3, flammable = 1 } )
pedology.register_sucky("turf_sapric", "wet sapric turf", 1, 1, 1, 1300, sound_silt_coarse, { crumbly = 3 } )
pedology.register_sucky("turf_sapric", "watery sapric turf", 2, 1, 0, 1400, sound_silt_coarse, { crumbly = 3 } )

minetest.register_abm({
nodenames = {"group:turf_fibric"}, neighbors = {"group:sucky"}, interval = 120, chance = 1.25, action = pedology.ooze
})
minetest.register_abm({
nodenames = {"group:turf_hemic"}, neighbors = {"group:sucky"}, interval = 180, chance = 1.225, action = pedology.ooze
})
minetest.register_abm({
nodenames = {"group:turf_sapric"}, neighbors = {"group:sucky"}, interval = 240, chance = 1.5, action = pedology.ooze
})


end

pedology.maxwet = {}
pedology.maxwet.clay =		5
pedology.maxwet.silt_fine =	5
pedology.maxwet.silt_medium =	4
pedology.maxwet.silt_coarse =	3
pedology.maxwet.sand_fine =	2
pedology.maxwet.sand_medium =	1
pedology.maxwet.sand_coarse =	0
pedology.maxwet.gravel_fine =	1
pedology.maxwet.gravel_medium =	2
pedology.maxwet.gravel_coarse =	2

pedology.maxwet.turf_fibric =    2
pedology.maxwet.turf_hemic =     2
pedology.maxwet.turf_sapric =    2

--[[ “API” functions ]]
--[[ Replace the node at <pos> with a node with a “drier” version of it, if available ]]
function pedology.dry(pos)
	local node = minetest.get_node(pos)
	local wet = minetest.get_item_group(node.name, "wet")
	local dried = tostring(wet - 1)
	if wet <= 0 then
		return
	end
	local newbasename = string.sub(node.name,1,#node.name-1)
	newbasename = newbasename .. dried
	minetest.set_node(pos, {name=newbasename, param1=0, param2=0})
end

--[[ Replace the node at <pos> with a “wetter” version of it, if available ]]
function pedology.wetten(pos)
	local node = minetest.get_node(pos)
	local wet = minetest.get_item_group(node.name, "wet")
	local cutbasename = string.sub(node.name,9,#node.name-2)
	if pedology.maxwet[cutbasename] == nil then
		return
	elseif wet > pedology.maxwet[cutbasename] then
		return
	end
	
	local newbasename = string.sub(node.name,1,#node.name-1) .. tostring(wet+1)
	minetest.set_node(pos, {name=newbasename, param1=0, param2=0})
end

--[[ register ABMs ]]
minetest.register_abm({
	nodenames = {"group:sun_dry"},
	neighbors = {"air"},
	interval = 30,
	chance = 10,
	action = pedology.sun_dry,
})

minetest.register_abm({
	nodenames = {"group:sucky"},
	neighbors = {"group:water"},
	interval = 30,
	chance = 1,
	action = pedology.suck,
})

minetest.register_abm({
	nodenames = {"group:melting_point"},
	neighbors = {"group:hot"},
	interval = 1,
	chance = 1,
	action = function(pos,node,...)
		minetest.set_node(pos,node)
	end,
})