mcl_throwing = {}

local arrows = {
	["mcl_throwing:arrow"] = "mcl_throwing:arrow_entity",
}

local GRAVITY = 9.81
local BOW_DURABILITY = 385

-- Charging time in microseconds
local BOW_CHARGE_TIME_HALF = 500000 -- bow level 1
local BOW_CHARGE_TIME_FULL = 1000000 -- bow level 2 (full charge)

-- TODO: Use Minecraft speed (ca. 53 m/s)
-- Currently nerfed because at full speed the arrow would easily get out of the range of the loaded map.
local BOW_MAX_SPEED = 26

--[[ Store the charging state of each player.
keys: player name
value:
false or nil = not charging or player not existing
number: currently charging, the number is the time from minetest.get_us_time
             in which the charging has started
]]
local bow_load = {}

mcl_throwing.shoot_arrow = function(arrow_item, pos, dir, yaw, shooter, power, damage)
	local obj = minetest.add_entity({x=pos.x,y=pos.y,z=pos.z}, arrows[arrow_item])
	if power == nil then
		power = 19
	end
	if damage == nil then
		damage = 3
	end
	obj:setvelocity({x=dir.x*power, y=dir.y*power, z=dir.z*power})
	obj:setacceleration({x=dir.x*-3, y=-GRAVITY, z=dir.z*-3})
	obj:setyaw(yaw-math.pi/2)
	local le = obj:get_luaentity()
	le._shooter = shooter
	le._damage = damage
	le._startpos = pos
	minetest.sound_play("mcl_throwing_bow_shoot", {pos=pos})
	if shooter ~= nil then
		if obj:get_luaentity().player == "" then
			obj:get_luaentity().player = shooter
		end
		obj:get_luaentity().node = shooter:get_inventory():get_stack("main", 1):get_name()
	end
	return obj
end

local get_arrow = function(player)
	local inv = player:get_inventory()
	local arrow_stack, arrow_stack_id
	for i=1, inv:get_size("main") do
		local it = inv:get_stack("main", i)
		if not it:is_empty() and minetest.get_item_group(it:get_name(), "ammo_bow") ~= 0 then
			arrow_stack = it
			arrow_stack_id = i
			break
		end
	end
	return arrow_stack, arrow_stack_id
end

local player_shoot_arrow = function(itemstack, player, power, damage)
	local arrow_stack, arrow_stack_id = get_arrow(player)
	local arrow_itemstring
	if not minetest.settings:get_bool("creative_mode") then
		if not arrow_stack then
			return false
		end
		arrow_itemstring = arrow_stack:get_name()
		arrow_stack:take_item()
		local inv = player:get_inventory()
		inv:set_stack("main", arrow_stack_id, arrow_stack)
	end
	local playerpos = player:getpos()
	local dir = player:get_look_dir()
	local yaw = player:get_look_horizontal()

	if not arrow_itemstring then
		arrow_itemstring = "mcl_throwing:arrow"
	end
	mcl_throwing.shoot_arrow(arrow_itemstring, {x=playerpos.x,y=playerpos.y+1.5,z=playerpos.z}, dir, yaw, player, power, damage)
	return true
end

minetest.register_tool("mcl_throwing:bow", {
	description = "Bow",
	_doc_items_longdesc = "Bows are ranged weapons to shoot arrows at your foes.",
	_doc_items_usagehelp = [[To use the bow, you first need to have at least one arrow anywhere in your inventory (unless in Creative Mode). Hold down the right mouse button to charge, release to shoot.

The arrow speed and damage increase the longer you charge. The minimum damage is 1. At full charge, the damage is 9 with a 20% chance of a critical hit dealing 10 damage instead.]],
	_doc_items_durability = BOW_DURABILITY,
	inventory_image = "mcl_throwing_bow.png",
	stack_max = 1,
	-- Trick to disable melee damage to entities.
	-- Range not set to 0 (unlike the others) so it can be placed into item frames
	range = 1,
	-- Trick to disable digging as well
	on_use = function() end,
	groups = {weapon=1,weapon_ranged=1},
})

minetest.register_tool("mcl_throwing:bow_0", {
	description = "Bow",
	_doc_items_create_entry = false,
	inventory_image = "mcl_throwing_bow_0.png",
	stack_max = 1,
	range = 0, -- Pointing range to 0 to prevent punching with bow :D
	groups = {not_in_creative_inventory=1, not_in_craft_guide=1},
})

minetest.register_tool("mcl_throwing:bow_1", {
	description = "Bow",
	_doc_items_create_entry = false,
	inventory_image = "mcl_throwing_bow_1.png",
	stack_max = 1,
	range = 0,
	groups = {not_in_creative_inventory=1, not_in_craft_guide=1},
})

minetest.register_tool("mcl_throwing:bow_2", {
	description = "Bow",
	_doc_items_create_entry = false,
	inventory_image = "mcl_throwing_bow_2.png",
	stack_max = 1,
	range = 0,
	groups = {not_in_creative_inventory=1, not_in_craft_guide=1},
})

controls.register_on_release(function(player, key, time)
	if key~="RMB" then return end
	local inv = minetest.get_inventory({type="player", name=player:get_player_name()})
	local wielditem = player:get_wielded_item()
	if (wielditem:get_name()=="mcl_throwing:bow_0" or wielditem:get_name()=="mcl_throwing:bow_1" or wielditem:get_name()=="mcl_throwing:bow_2") then
		local has_shot = false

		local speed, damage
		local p_load = bow_load[player:get_player_name()]
		local charge
		-- Type sanity check
		if type(p_load) == "number" then
			charge = minetest.get_us_time() - p_load
		else
			-- In case something goes wrong ...
			-- Just assume minimum charge.
			charge = 0
			minetest.log("warning", "[mcl_throwing] Player "..player:get_player_name().." fires arrow with non-numeric bow_load!")
		end
		charge = math.max(math.min(charge, BOW_CHARGE_TIME_FULL), 0)

		local charge_ratio = charge / BOW_CHARGE_TIME_FULL
		charge_ratio = math.max(math.min(charge_ratio, 1), 0)

		-- Calculate damage and speed
		-- Fully charged
		if charge >= BOW_CHARGE_TIME_FULL then
			speed = BOW_MAX_SPEED
			local r = math.random(1,5)
			if r == 1 then
				-- 20% chance for critical hit
				damage = 10
			else
				damage = 9
			end
		-- Partially charged
		else
			-- Linear speed and damage increase
			speed = math.max(4, BOW_MAX_SPEED * charge_ratio)
			damage = math.max(1, math.floor(9 * charge_ratio))
		end

		has_shot = player_shoot_arrow(wielditem, player, speed, damage)

		wielditem:set_name("mcl_throwing:bow")
		if has_shot and minetest.settings:get_bool("creative_mode") == false then
			wielditem:add_wear(65535/BOW_DURABILITY)
		end
		player:set_wielded_item(wielditem)
		bow_load[player:get_player_name()] = false
	end
end)

controls.register_on_hold(function(player, key, time)
	if key ~= "RMB" then
		return
	end
	local name = player:get_player_name()
	local inv = minetest.get_inventory({type="player", name=name})
	local wielditem = player:get_wielded_item()
	if wielditem:get_name()=="mcl_throwing:bow" and (minetest.settings:get_bool("creative_mode") or inv:contains_item("main", "mcl_throwing:arrow")) then
		wielditem:set_name("mcl_throwing:bow_0")
		bow_load[name] = minetest.get_us_time()
	else
		if type(bow_load[name]) == "number" then
			if wielditem:get_name() == "mcl_throwing:bow_0" and minetest.get_us_time() - bow_load[name] >= BOW_CHARGE_TIME_HALF then
				wielditem:set_name("mcl_throwing:bow_1")
			elseif wielditem:get_name() == "mcl_throwing:bow_1" and minetest.get_us_time() - bow_load[name] >= BOW_CHARGE_TIME_FULL then
				wielditem:set_name("mcl_throwing:bow_2")
			end
		else
			wielditem:set_name("mcl_throwing:bow")
		end
	end
	player:set_wielded_item(wielditem)
end)

minetest.register_globalstep(function(dtime)
	for _, player in pairs(minetest.get_connected_players()) do
		local wielditem = player:get_wielded_item()
		local controls = player:get_player_control()
		local inv = minetest.get_inventory({type="player", name = player:get_player_name()})
		if bow_load[player:get_player_name()] and (wielditem:get_name()~="mcl_throwing:bow_0" and wielditem:get_name()~="mcl_throwing:bow_1" and wielditem:get_name()~="mcl_throwing:bow_2") then
			local list = inv:get_list("main")
			for place, stack in pairs(list) do
				if stack:get_name()=="mcl_throwing:bow_0" or stack:get_name()=="mcl_throwing:bow_1" or stack:get_name()=="mcl_throwing:bow_2" then
					stack:set_name("mcl_throwing:bow")
					list[place] = stack
					break
				end
			end
			inv:set_list("main", list)
			bow_load[player:get_player_name()] = false
		end
	end
end)

minetest.register_on_leaveplayer(function(player)
	bow_load[player:get_player_name()] = nil
end)

if minetest.get_modpath("mcl_core") and minetest.get_modpath("mcl_mobitems") then
	minetest.register_craft({
		output = 'mcl_throwing:bow',
		recipe = {
			{'', 'mcl_core:stick', 'mcl_mobitems:string'},
			{'mcl_core:stick', '', 'mcl_mobitems:string'},
			{'', 'mcl_core:stick', 'mcl_mobitems:string'},
		}
	})
	minetest.register_craft({
		output = 'mcl_throwing:bow',
		recipe = {
			{'mcl_mobitems:string', 'mcl_core:stick', ''},
			{'mcl_mobitems:string', '', 'mcl_core:stick'},
			{'mcl_mobitems:string', 'mcl_core:stick', ''},
		}
	})
end

minetest.register_craft({
	type = "fuel",
	recipe = "mcl_throwing:bow",
	burntime = 15,
})

-- Add entry aliases for the Help
if minetest.get_modpath("doc") then
	doc.add_entry_alias("tools", "mcl_throwing:bow", "tools", "mcl_throwing:bow_0")
	doc.add_entry_alias("tools", "mcl_throwing:bow", "tools", "mcl_throwing:bow_1")
	doc.add_entry_alias("tools", "mcl_throwing:bow", "tools", "mcl_throwing:bow_2")
end