require "config"
require "defines"
require "util"

remote.add_interface("oxygen", {
	change_oxygen_of_player = function(player_name, amount)
		for _,v in ipairs(global.oxygen) do
			if v[1] == game.get_player(player_name) then
				v[2] = v[2] + amount
				update_gui(v)
			end
		end
	end,
	set_oxygen_of_player = function(player_name, amount)
		for _,v in ipairs(global.oxygen) do
			if v[1] == game.get_player(player_name) then
				if amount > Config.MaxOxygen then amount = Config.MaxOxygen elseif amount < 0 then amount = 0 end
				v[2] = amount
				update_gui(v)
			end
		end
	end,
	get_oxygen_of_player = function(player_name)
		for _,v in ipairs(global.oxygen) do
			if v[1] == game.get_player(player_name) then
				return v[2]
			end
		end
	end,
	has_gasmask = function(player_name)
		return has_gasmask(game.get_player(player_name))
	end
})

script.on_init(function(Initialize)
	if global.oxygen == nil then
		global.oxygen = {}
	end
	if global.oxygen_dispensers == nil then
		global.oxygen_dispensers = {}
	end
end)

script.on_event(defines.events.on_tick, function(event)
	handle_players()
	handle_dispensers()
	handle_enemy_positions()
end)

script.on_event(defines.events.on_player_created, function(event)
	if game.get_player(event.player_index).controller_type ~= defines.controllers.character then
		return
	end
	local player = game.get_player(event.player_index)
	
	table.insert(global.oxygen, {player, Config.MaxOxygen})
	
	local frame = player.gui.left.add({type="frame", name="oxygen-amount", direction="horizontal"})
	frame.add({type="label", name="caption-label", caption={"oxygen"}})
	frame.add({type="label", name="oxygen-value", caption=tostring(Config.MaxOxygen)})
	
	player_starting_inventory(player)
end)

function player_starting_inventory(player)
	if not Config.DebugMode then
		player.get_inventory(defines.inventory.player_main).insert({name="big-oxygen-bottle", count=Config.StartBottles, health=1.0})
	else
		player.get_inventory(defines.inventory.player_main).insert({name="oxygen-bottle", count=1, health=1.0})
		player.get_inventory(defines.inventory.player_main).insert({name="big-oxygen-bottle", count=1, health=1.0})
		player.get_inventory(defines.inventory.player_main).insert({name="oxygen-dispenser", count=4, health=1.0})
		player.get_inventory(defines.inventory.player_main).insert({name="offshore-pump", count=1, health=1.0})
		player.get_inventory(defines.inventory.player_main).insert({name="solar-panel", count=4, health=1.0})
		player.get_inventory(defines.inventory.player_main).insert({name="chemical-plant", count=1, health=1.0})
		player.get_inventory(defines.inventory.player_main).insert({name="small-electric-pole", count=4, health=1.0})
	end 
end

function update_gui(oxygen_player)
	oxygen_player[1].gui.left["oxygen-amount"]["oxygen-value"].caption = tostring(oxygen_player[2])
end

function remove_bottle(oxygen_player)
	local inv = oxygen_player[1].get_inventory(defines.inventory.player_main)
	local removed_bottle = remove_bottle_from_inv(oxygen_player, inv)
	if not removed_bottle then 
		inv = oxygen_player[1].get_inventory(defines.inventory.player_quickbar)
		removed_bottle = remove_bottle_from_inv(oxygen_player, inv)
	end
	return removed_bottle
end

function remove_bottle_from_inv(oxygen_player, inv)
	local removed_bottle = false
	if  inv.get_item_count("oxygen-bottle") >= 1 then
		inv.remove{name="oxygen-bottle", count=1}
		inv.insert{name="empty-oxygen-bottle", count=1}
		oxygen_player[2] = oxygen_player[2] + (Config.MaxOxygen / 2)
		oxygen_player[1].print("Small oxygen bottle is used")	-- Notify the player
		removed_bottle = true
	elseif inv.get_item_count("big-oxygen-bottle") >= 1 then
		inv.remove{name="big-oxygen-bottle", count=1}
		inv.insert{name="big-empty-oxygen-bottle", count=1}
		oxygen_player[2] = oxygen_player[2] + Config.MaxOxygen
		oxygen_player[1].print("Big oxygen bottle is used")	-- Notify the player
		removed_bottle = true
	end
	return removed_bottle
end

function refill_bottles(oxygen_player)
	if Config.AutoBottleRefilling and game.tick % (Config.BottleRefillingSpeed * 60) == 0 then
		local inv = oxygen_player[1].get_inventory(defines.inventory.player_main)
		local refilled_bottle = refill_bottles_by_inv(oxygen_player, inv)
		if not refilled_bottle then
			inv = oxygen_player[1].get_inventory(defines.inventory.player_quickbar)
			refilled_bottle = refill_bottles_by_inv(oxygen_player, inv)
		end
	end
	return refilled_bottle
end

function refill_bottles_by_inv(oxygen_player, inv)
	local refilled_bottle = false
	if inv.get_item_count("empty-oxygen-bottle") > 0 then
		inv.remove({name="empty-oxygen-bottle", count=1})
		inv.insert({name="oxygen-bottle", count=1})
		refilled_bottle = true
	 elseif inv.get_item_count("big-empty-oxygen-bottle") > 0 then
		inv.remove({name="big-empty-oxygen-bottle", count=1})
		inv.insert({name="big-oxygen-bottle", count=1})
		refilled_bottle = true
	end
	return refilled_bottle
end

function has_gasmask(oxygen_player)
	local armor = oxygen_player[1].get_inventory(defines.inventory.player_armor)[1]
	if armor.valid_for_read and armor.has_grid then
		for _,equip in pairs(armor.grid.equipment) do
			if equip.name == "gas-mask" then return true end
		end
	end
end

entityBuilt = function(event)
	if event.created_entity ~= nil and event.created_entity.valid and event.created_entity.name == "oxygen-dispenser" then
		table.insert(global.oxygen_dispensers, {event.created_entity, 0})
	end
end

entityRemoved = function(event)
	if event.entity ~= nil and event.entity.valid and event.entity.name == "oxygen-dispenser" then
		for i,v in ipairs(global.oxygen_dispensers) do
			if v[1] == event.entity then
				table.remove(global.oxygen_dispensers, i)
			end
		end
	end
end

function handle_dispensers()
	if global.oxygen_dispensers == nil or game.tick % 60 ~= 0 then return end
	for i,v in ipairs(global.oxygen_dispensers) do
--		game.player.print(i)
		if v[1].connected then
			if v[2] > 0 then
				local fluid = v[1].fluidbox[1]
				if fluid ~= nil and fluid.type == "oxygen" and fluid.amount >= 1 then
					fluid.amount = fluid.amount - 1
					v[1].fluidbox[1] = fluid
					v[2] = v[2] - 1
				else
					v[2] = 0
				end
			end
			if v[2] == 0 then
				local fluid = v[1].fluidbox[1]
				if fluid ~= nil and fluid.type == "oxygen" and fluid.amount >= 20 then
					v[2] = 20
					game.get_surface("nauvis").create_entity({name="oxygen-cloud", position=v[1].position})
				end
			end
		end
	end
end

function handle_players()
	if game.tick % (Config.TickCheck * 60) ~= 0 then return end
	for _,v in ipairs(global.oxygen) do
		if v[1].controller_type == defines.controllers.character and v[1].connected then
			local pos = v[1].position -- player position
			local delta = 0 - Config.DeplenishingSpeed -- amount of oxygen to be added or subtracted; here it is default subtraction when player is not near dispensers
			if has_gasmask(v) then delta = delta / 2 end -- deplenishing with mask is halved
		
			local total_dispensers = game.get_surface("nauvis").count_entities_filtered{
				area = {{pos.x - Config.OxygenRadiusEnemies, pos.y - Config.OxygenRadiusEnemies}, {pos.x + Config.OxygenRadiusEnemies, pos.y + Config.OxygenRadiusEnemies}},
				name="oxygen-dispenser"
			}
			if total_dispensers > 0 then
				delta = delta + player_near_dispenser(v)
			end
 			v[2] = v[2] + delta
			if v[2] >= Config.MaxOxygen then
				v[2] = Config.MaxOxygen
				if Config.AutoBottleRefilling then refill_bottles(v) end
			elseif v[2] <= 0 then
				local removed_bottle = remove_bottle(v)
				if not removed_bottle then
					v[1].character.damage(Config.ChokingDamage, v[1].force, "oxygen")
					v[2] = 0
					if game.tick % (Config.PlayerChokingNoteSpeed  * 60) then
						v[1].print("Player is choking")
					end
				end
			end
			v[2] = tonumber(string.format("%." .. (2) .. "f", v[2]))
			update_gui(v)
		end
	end
end

function player_near_dispenser(oxygen_player)
	local pos = oxygen_player[1].position -- player position
	local dispenser = game.get_surface("nauvis").find_entities_filtered{
		area = {{pos.x - Config.OxygenRadiusEnemies, pos.y - Config.OxygenRadiusEnemies}, {pos.x + Config.OxygenRadiusEnemies, pos.y + Config.OxygenRadiusEnemies}},
		name="oxygen-dispenser"
	}
	local delta = 0
	for _,d in ipairs(dispenser) do
		local fluid = d.fluidbox[1]
		if fluid ~= nil and fluid.type == "oxygen" and fluid.amount >= 20 then
			local distance = distance(oxygen_player[1], d)
			delta = delta + Config.ReplenishingSpeed - (Config.ReplenishingSpeed / Config.OxygenRadiusEnemies * distance)
			if delta > Config.OxygenMultiplicator then delta = Config.OxygenMultiplicator end
		end
	end
	return delta
end

function handle_enemy_positions()
	if global.oxygen_dispensers == nil or game.tick % (Config.TickCheck * 60) ~= 0 then return end
	for _,v in ipairs(global.oxygen_dispensers) do
		if v[2] > 0 then
			local pos = v[1].position -- item position
			local enemies = game.get_surface("nauvis").find_enemy_units(pos, Config.OxygenRadiusEnemies)
			if #enemies > 0 then
				for _,e in ipairs(enemies) do
					e.damage(Config.DamageToEnemies, e.force, "oxygen")
				end
			end
			local total_spawners = game.get_surface("nauvis").count_entities_filtered{
				area = {{pos.x - Config.OxygenRadiusSpawners, pos.y - Config.OxygenRadiusSpawners}, {pos.x + Config.OxygenRadiusSpawners, pos.y + Config.OxygenRadiusSpawners}}, type="unit-spawner"
			}
			if total_spawners > 0 then
				local spawners = game.get_surface("nauvis").find_entities_filtered{
					area = {{pos.x - Config.OxygenRadiusSpawners, pos.y - Config.OxygenRadiusSpawners}, {pos.x + Config.OxygenRadiusSpawners, pos.y + Config.OxygenRadiusSpawners}}, type="unit-spawner"
				}
				for _,s in ipairs(spawners) do
					s.damage(Config.DamageToSpawners, s.force, "oxygen")
				end
			end
		end
	end
end

function distance(entity1, entity2)
	local distance_x = 0
	local distance_y = 0
	local distance = 0
	if entity1.position.x > entity2.position.x then
		distance_x = entity1.position.x - entity2.position.x
	else
		distance_x = entity2.position.x - entity1.position.x
	end
	if entity1.position.y > entity2.position.y then
		distance_y = entity1.position.y - entity2.position.y
	else
		distance_y = entity2.position.y - entity1.position.y
	end
	distance = (distance_x ^ 2 + distance_y ^ 2) ^ (1/2)
	return tonumber(string.format("%." .. (2) .. "f", distance))
end

script.on_event(defines.events.on_built_entity, entityBuilt)
script.on_event(defines.events.on_robot_built_entity, entityBuilt)

script.on_event(defines.events.on_preplayer_mined_item, entityRemoved)
script.on_event(defines.events.on_robot_pre_mined, entityRemoved)
script.on_event(defines.events.on_entity_died, entityRemoved)