-- mods/default/functions.lua

--
-- Grow grass
--

minetest.register_abm({
	label = "Grass spread",
	nodenames = {"default:dirt"},
	neighbors = {"default:dirt_with_grass", "default:dirt_with_grass_footsteps"},
	interval = 2,
	chance = 200,
	catch_up = false,
	action = function(pos, node)
		local above = {x=pos.x, y=pos.y+1, z=pos.z}
		local name = minetest.get_node(above).name
		local nodedef = minetest.registered_nodes[name]
		if nodedef and (nodedef.sunlight_propagates or nodedef.paramtype == "light")
				and nodedef.liquidtype == "none"
				and (minetest.get_node_light(above) or 0) >= 11 then
			if name == "default:snow" or name == "default:snowblock" then
				minetest.set_node(pos, {name = "default:dirt_with_snow"})
			else
				minetest.set_node(pos, {name = "default:dirt_with_grass"})
			end
		end
	end
})

minetest.register_abm({
	label = "Grass spread",
	nodenames = {"default:dirt"},
	neighbors = {
		"group:spreading_dirt_type",
		"group:grass",
		"group:dry_grass",
		"default:snow",
	},
	interval = 7,
	chance = 50,
	catch_up = false,
	action = function(pos, node)
		-- Check for darkness: night, shadow or under a light-blocking node
		-- Returns if ignore above
		local above = {x = pos.x, y = pos.y + 1, z = pos.z}
		if (minetest.get_node_light(above) or 0) < 10 then
			return
		end
		if minetest.get_item_group(minetest.get_node(above).name, "liquid") > 0 then
			return
		end

		-- Look for spreading dirt-type neighbours
		local p2 = minetest.find_node_near(pos, 1, "group:spreading_dirt_type")
		if p2 then
			local n3 = minetest.get_node(p2)
			minetest.set_node(pos, {name = n3.name})
			return
		end

		-- Else, any seeding nodes on top?
		local name = minetest.get_node(above).name
		-- Snow check is cheapest, so comes first
		if name == "default:snow" then
			minetest.set_node(pos, {name = "default:dirt_with_snow"})
		elseif minetest.get_item_group(name, "dry_grass") ~= 0 then
			minetest.set_node(pos, {name = "default:dirt_with_dry_grass"})
		elseif minetest.get_item_group(name, "grass") ~= 0 then
			minetest.set_node(pos, {name = "default:dirt_with_grass"})
		end
	end
})

minetest.register_abm({
	label = "Grass covered",
	nodenames = {
		"group:spreading_dirt_type",
	},
	interval = 8,
	chance = 100,
	catch_up = false,
	action = function(pos, node)
		local above = {x = pos.x, y = pos.y + 1, z = pos.z}
		local name = minetest.get_node(above).name
		local nodedef = minetest.registered_nodes[name]
		if name ~= "ignore" and nodedef and not ((nodedef.sunlight_propagates or
				nodedef.paramtype == "light") and
				nodedef.liquidtype == "none") then
			minetest.set_node(pos, {name = "default:dirt"})
		end
	end
})


--
-- Lavacooling
--

default.cool_lava = function(pos, node)
	if node.name == "default:lava_source" then
		minetest.set_node(pos, {name = "default:obsidian"})
	else -- Lava flowing
		minetest.set_node(pos, {name = "default:molten_rock"})
	end
	minetest.sound_play("default_cool_lava",
		{pos = pos, max_hear_distance = 16, gain = 0.25})
end

minetest.register_abm({
	label = "Lava cooling",
	nodenames = {"default:lava_source", "default:lava_flowing"},
	neighbors = {"group:cools_lava", "group:water"},
	interval = 1,
	chance = 2,
	catch_up = false,
	action = function(...)
		default.cool_lava(...)
	end,
})

minetest.register_abm({
	label = "Molten rock cooling",
	nodenames = {"default:molten_rock"},
	neighbors = {"group:cools_lava", "group:water"},
	interval = 11,
	chance = 50,
	catch_up = false,
	action = function(pos, node)
		minetest.set_node(pos, {name = "default:hardened_rock"})
	end,
})


--
-- Optimized helper to put all items in an inventory into a drops list
--

function default.get_inventory_drops(pos, inventory, drops)
	local inv = minetest.get_meta(pos):get_inventory()
	local n = #drops
	for i = 1, inv:get_size(inventory) do
		local stack = inv:get_stack(inventory, i)
		if stack:get_count() > 0 then
			drops[n+1] = stack:to_table()
			n = n + 1
		end
	end
end


--
-- Papyrus and cactus growing
--

function default.grow_cactus(pos, node)
	pos.y = pos.y - 1
	local node = minetest.get_node(pos)
	if minetest.get_item_group(node.name, "sand") == 0 then
		return
	end
	pos.y = pos.y + 1
	local height = 0
	node = minetest.get_node(pos)
	while node.name == "default:cactus" and height < 5 do
		height = height + 1
		pos.y = pos.y + 1
		node = minetest.get_node(pos)
	end
	if node.name ~= "air" then return end
	-- Increased chance for figs to grow the taller the cactus is.
	if height < math.random(2, 5) then
		minetest.set_node(pos, {name="default:cactus"})
	else
		minetest.set_node(pos, {name="default:cactus_fig"})
	end
	return true
end

function default.grow_papyrus(pos, node)
	pos.y = pos.y - 1
	local node = minetest.get_node(pos)
	if minetest.get_item_group(node.name, "soil") == 0 then
		return
	end
	if not minetest.find_node_near(pos, 3, {"group:water"}) then
		return
	end
	pos.y = pos.y + 1
	node = minetest.get_node(pos)
	local height = 0
	while node.name == "default:papyrus" and height < 5 do
		height = height + 1
		pos.y = pos.y + 1
		node = minetest.get_node(pos)
	end
	if height < math.random(0, 5) and node.name == "air" then
		minetest.set_node(pos, {name="default:papyrus"})
		return true
	end
end

minetest.register_abm({
	nodenames = {"default:coral_brown", "default:coral_orange", "default:coral_purple"},
	neighbors = {"air"},
	interval = 17,
	chance = 5,
	catch_up = false,
	action = function(pos, node)
		if not minetest.find_node_near(pos, 1, "group:water") then
			minetest.set_node(pos, {name = "default:coral_skeleton"})
		end
	end,
})

-- Wrapping the functions in abm action is necessary to make overriding them possible.
minetest.register_abm({
	label = "Grow cactus",
	nodenames = {"default:cactus"},
	neighbors = {"group:sand"},
	interval = 70,
	chance = 30,
	action = function(...)
		default.grow_cactus(...)
	end,
})

minetest.register_abm({
	label = "Grow cactus from fig",
	nodenames = {"default:cactus_fig"},
	neighbors = {"group:sand"},
	interval = 7,
	chance = 3,
	action = function(pos, node)
		local node_under = minetest.get_node_or_nil({x = pos.x, y = pos.y - 1, z = pos.z})
		if minetest.get_item_group(node_under.name, "sand") ~= 0 then
			minetest.set_node(pos, {name="default:cactus"})
		end
	end,
})

minetest.register_abm({
	label = "Grow papyrus",
	nodenames = {"default:papyrus"},
	neighbors = {"default:dirt", "default:dirt_with_grass", "default:papyrus_roots"},
	interval = 40,
	chance = 30,
	action = function(...)
		default.grow_papyrus(...)
	end,
})

function default.place_kelp(itemstack, placer, pos)
	if minetest.get_node(pos).name ~= "default:sand" then
		return itemstack
	end

	local height = math.random(4, 6)
	local pos_top = {x = pos.x, y = pos.y + height, z = pos.z}
	local node_top = minetest.get_node(pos_top)
	local def_top = minetest.registered_nodes[node_top.name]
	
	if placer then
		local player_name = placer:get_player_name()
		if minetest.is_protected(pos, player_name)
			and minetest.is_protected(pos_top, player_name) then
			minetest.chat_send_player(player_name, "Node is protected")
			minetest.record_protection_violation(pos, player_name)
			return itemstack
		end
	end

	if def_top and def_top.liquidtype == "source" and
			minetest.get_item_group(node_top.name, "water") > 0 then
		minetest.set_node(pos, {name = "default:sand_with_kelp",
			param2 = height * 16})
		if itemstack and not minetest.is_creative_enabled(placer) then
			itemstack:take_item()
		end
	end

	return itemstack
end

minetest.register_abm({
	label = "Grow Kelp",
	nodenames = {"default:sand_with_small_kelp"},
	interval = 11,
	chance = 50,
	action = function(pos, node)
		minetest.set_node(pos, {name = "default:sand"})
		default.place_kelp(nil, nil, pos)
	end,
})

-- Dig upwards
function default.dig_up(pos, node, digger)
	if digger == nil then return end
	local np = {x = pos.x, y = pos.y + 1, z = pos.z}
	local nn = minetest.get_node(np)
	if nn.name == node.name then
		minetest.node_dig(np, nn, digger)
	end
end

-- Rotate symmetric nodes 
function default.rotate_horizontal(pos)
	local node = minetest.get_node(pos)
	if node.param2 == 2 then
		node.param2 = 0
	elseif node.param2 == 3 then
		node.param2 = 1
	else
		return
	end
	minetest.set_node(pos, node)
end

--
-- Register a craft to copy the metadata of items
--

function default.register_craft_metadata_copy(ingredient, result)
	minetest.register_craft({
		type = "shapeless",
		output = result,
		recipe = {ingredient, result}
	})

	minetest.register_on_craft(function(itemstack, player, old_craft_grid, craft_inv)
		if itemstack:get_name() ~= result then
			return
		end

		local original
		local index
		for i = 1, #old_craft_grid do
			if old_craft_grid[i]:get_name() == result then
				original = old_craft_grid[i]
				index = i
			end
		end
		if not original then
			return
		end
		local copymeta = original:get_meta():to_table()
		itemstack:get_meta():from_table(copymeta)
		-- put the book with metadata back in the craft grid
		craft_inv:set_stack("craft", index, original)
	end)
end

--
-- Log API / helpers
--

local log_non_player_actions = minetest.settings:get_bool("log_non_player_actions", false)

local is_pos = function(v)
	return type(v) == "table" and
		type(v.x) == "number" and type(v.y) == "number" and type(v.z) == "number"
end

function default.log_player_action(player, ...)
	local msg = player:get_player_name()
	if player.is_fake_player or not player:is_player() then
		if not log_non_player_actions then
			return
		end
		msg = msg .. "(" .. (type(player.is_fake_player) == "string"
			and player.is_fake_player or "*") .. ")"
	end
	for _, v in ipairs({...}) do
		-- translate pos
		local part = is_pos(v) and minetest.pos_to_string(v) or v
		-- no leading spaces before punctuation marks
		msg = msg .. (string.match(part, "^[;,.]") and "" or " ") .. part
	end
	minetest.log("action",  msg)
end

local nop = function() end
function default.set_inventory_action_loggers(def, name)
	local on_move = def.on_metadata_inventory_move or nop
	def.on_metadata_inventory_move = function(pos, from_list, from_index,
			to_list, to_index, count, player)
		default.log_player_action(player, "moves stuff in", name, "at", pos)
		return on_move(pos, from_list, from_index, to_list, to_index, count, player)
	end
	local on_put = def.on_metadata_inventory_put or nop
	def.on_metadata_inventory_put = function(pos, listname, index, stack, player)
		default.log_player_action(player, "moves", stack:get_name(), stack:get_count(), "to", name, "at", pos)
		return on_put(pos, listname, index, stack, player)
	end
	local on_take = def.on_metadata_inventory_take or nop
	def.on_metadata_inventory_take = function(pos, listname, index, stack, player)
		default.log_player_action(player, "takes", stack:get_name(), stack:get_count(), "from", name, "at", pos)
		return on_take(pos, listname, index, stack, player)
	end
end

--
-- NOTICE: This method is not an official part of the API yet.
-- This method may change in future.
--

function default.can_interact_with_node(player, pos)
	if player and player:is_player() then
		if minetest.check_player_privs(player, "protection_bypass") then
			return true
		end
	else
		return false
	end

	local meta = minetest.get_meta(pos)
	local owner = meta:get_string("owner")

	if not owner or owner == "" or owner == player:get_player_name() then
		return true
	end

	-- Is player wielding the right key?
	local item = player:get_wielded_item()
	if minetest.get_item_group(item:get_name(), "key") == 1 then
		local key_meta = item:get_meta()

		if key_meta:get_string("secret") == "" then
			local key_oldmeta = item:get_meta():get_string("")
			if key_oldmeta == "" or not minetest.parse_json(key_oldmeta) then
				return false
			end

			key_meta:set_string("secret", minetest.parse_json(key_oldmeta).secret)
			item:set_metadata("")
		end

		return meta:get_string("key_lock_secret") == key_meta:get_string("secret")
	end

	return false
end


--
-- Fence registration helper
--
local fence_collision_extra = minetest.settings:get_bool("enable_fence_tall") and 3/8 or 0

function default.register_fence(name, def)
	minetest.register_craft({
		output = name .. " 4",
		recipe = {
			{ def.material, 'group:stick', def.material },
			{ def.material, 'group:stick', def.material },
		}
	})

	local fence_texture = "default_fence_overlay.png^" .. def.texture ..
			"^default_fence_overlay.png^[makealpha:255,126,126"
	-- Allow almost everything to be overridden
	local default_fields = {
		paramtype = "light",
		drawtype = "nodebox",
		node_box = {
			type = "connected",
			fixed = {-1/8, -1/2, -1/8, 1/8, 1/2, 1/8},
			-- connect_top =
			-- connect_bottom =
			connect_front = {{-1/16,  3/16, -1/2,   1/16,  5/16, -1/8 },
				         {-1/16, -5/16, -1/2,   1/16, -3/16, -1/8 }},
			connect_left =  {{-1/2,   3/16, -1/16, -1/8,   5/16,  1/16},
				         {-1/2,  -5/16, -1/16, -1/8,  -3/16,  1/16}},
			connect_back =  {{-1/16,  3/16,  1/8,   1/16,  5/16,  1/2 },
				         {-1/16, -5/16,  1/8,   1/16, -3/16,  1/2 }},
			connect_right = {{ 1/8,   3/16, -1/16,  1/2,   5/16,  1/16},
				         { 1/8,  -5/16, -1/16,  1/2,  -3/16,  1/16}}
		},
		collision_box = {
			type = "connected",
			fixed = {-1/8, -1/2, -1/8, 1/8, 1/2 + fence_collision_extra, 1/8},
			-- connect_top =
			-- connect_bottom =
			connect_front = {-1/8, -1/2, -1/2,  1/8, 1/2 + fence_collision_extra, -1/8},
			connect_left =  {-1/2, -1/2, -1/8, -1/8, 1/2 + fence_collision_extra,  1/8},
			connect_back =  {-1/8, -1/2,  1/8,  1/8, 1/2 + fence_collision_extra,  1/2},
			connect_right = { 1/8, -1/2, -1/8,  1/2, 1/2 + fence_collision_extra,  1/8}
		},
		connects_to = {"group:fence", "group:wood", "group:tree", "group:wall"},
		inventory_image = fence_texture,
		wield_image = fence_texture,
		tiles = {def.texture},
		sunlight_propagates = true,
		is_ground_content = false,
		groups = {},
	}
	for k, v in pairs(default_fields) do
		if def[k] == nil then
			def[k] = v
		end
	end

	-- Always add to the fence group, even if no group provided
	def.groups.fence = 1

	def.texture = nil
	def.material = nil

	minetest.register_node(name, def)
end

--
-- Fence rail registration helper
--

function default.register_fence_rail(name, def)
	minetest.register_craft({
		output = name .. " 16",
		recipe = {
			{ def.material, def.material },
			{ "", ""},
			{ def.material, def.material },
		}
	})

	local fence_rail_texture = "default_fence_rail_overlay.png^" .. def.texture ..
			"^default_fence_rail_overlay.png^[makealpha:255,126,126"
	-- Allow almost everything to be overridden
	local default_fields = {
		paramtype = "light",
		drawtype = "nodebox",
		node_box = {
			type = "connected",
			fixed = {{-1/16,  3/16, -1/16, 1/16,  5/16, 1/16},
				 {-1/16, -3/16, -1/16, 1/16, -5/16, 1/16}},
			-- connect_top =
			-- connect_bottom =
			connect_front = {{-1/16,  3/16, -1/2,   1/16,  5/16, -1/16},
				         {-1/16, -5/16, -1/2,   1/16, -3/16, -1/16}},
			connect_left =  {{-1/2,   3/16, -1/16, -1/16,  5/16,  1/16},
				         {-1/2,  -5/16, -1/16, -1/16, -3/16,  1/16}},
			connect_back =  {{-1/16,  3/16,  1/16,  1/16,  5/16,  1/2 },
				         {-1/16, -5/16,  1/16,  1/16, -3/16,  1/2 }},
			connect_right = {{ 1/16,  3/16, -1/16,  1/2,   5/16,  1/16},
		                         { 1/16, -5/16, -1/16,  1/2,  -3/16,  1/16}}
		},
		collision_box = {
			type = "connected",
			fixed = {-1/8, -1/2, -1/8, 1/8, 1/2 + fence_collision_extra, 1/8},
			-- connect_top =
			-- connect_bottom =
			connect_front = {-1/8, -1/2, -1/2,  1/8, 1/2 + fence_collision_extra, -1/8},
			connect_left =  {-1/2, -1/2, -1/8, -1/8, 1/2 + fence_collision_extra,  1/8},
			connect_back =  {-1/8, -1/2,  1/8,  1/8, 1/2 + fence_collision_extra,  1/2},
			connect_right = { 1/8, -1/2, -1/8,  1/2, 1/2 + fence_collision_extra,  1/8}
		},
		connects_to = {"group:fence", "group:wall"},
		inventory_image = fence_rail_texture,
		wield_image = fence_rail_texture,
		tiles = {def.texture},
		sunlight_propagates = true,
		is_ground_content = false,
		groups = {},
	}
	for k, v in pairs(default_fields) do
		if def[k] == nil then
			def[k] = v
		end
	end

	-- Always add to the fence group, even if no group provided
	def.groups.fence = 1

	def.texture = nil
	def.material = nil

	minetest.register_node(name, def)
end

--
-- Mese post registration helper
--

function default.register_mesepost(name, def)
	minetest.register_craft({
		output = name .. " 4",
		recipe = {
			{'', 'default:glass', ''},
			{'default:mese_crystal', 'default:mese_crystal', 'default:mese_crystal'},
			{'', def.material, ''},
		}
	})

	local post_texture = def.texture .. "^default_mese_post_light_side.png^[makealpha:0,0,0"
	local post_texture_dark = def.texture .. "^default_mese_post_light_side_dark.png^[makealpha:0,0,0"
	-- Allow almost everything to be overridden
	local default_fields = {
		wield_image = post_texture,
		drawtype = "nodebox",
		node_box = {
			type = "fixed",
			fixed = {
				{-2 / 16, -8 / 16, -2 / 16, 2 / 16, 8 / 16, 2 / 16},
			},
		},
		paramtype = "light",
		tiles = {def.texture, def.texture, post_texture_dark, post_texture_dark, post_texture, post_texture},
		use_texture_alpha = "opaque",
		light_source = default.LIGHT_MAX,
		sunlight_propagates = true,
		is_ground_content = false,
		groups = {choppy = 2, oddly_breakable_by_hand = 2, flammable = 2},
		sounds = default.node_sound_wood_defaults(),
	}
	for k, v in pairs(default_fields) do
		if def[k] == nil then
			def[k] = v
		end
	end

	def.texture = nil
	def.material = nil

	minetest.register_node(name, def)
end
