--LUA Lag Compensation
--by FlooD
--thx to Jermuk for his custom server
--and lasthope and def3ct for initial testing.

BUFFER_SIZE = 25

buffer = {}
for i = 0, (BUFFER_SIZE - 1) do
	buffer[i] = {}
	for j = 1, 32 do
		buffer[i][j] = {0, 0}
	end
end

weapons = {}
weapons[30] = {range = 300, damage = 22, name = "AK-47"}
weapons[32] = {range = 300, damage = 22, name = "M4A1"}
weapons[50] = {range = 8, damage = 50, name = "Knife"}
weapons[3] = {range = 300, damage = 34, name = "Deagle"}

for i = 1, 100 do
	if weapons[i] then
		parse("mp_wpndmg "..weapons[i]["name"].." 0")
	end
end

addhook("always", "updatebuffer")
function updatebuffer()
	for i = 0, (BUFFER_SIZE - 2) do
		buffer[BUFFER_SIZE - 1 - i] = deepcopy(buffer[BUFFER_SIZE - 2 - i])
	end
	for i = 1, 32 do
		buffer[0][i][1], buffer[0][i][2] = player(i,"x"), player(i,"y")
	end
end

addhook("leave", "clearbuffer")
addhook("die", "clearbuffer")
function clearbuffer(id)
	for i = 0, (BUFFER_SIZE - 1) do
		buffer[i][id] = {0, 0}
	end
end

addhook("attack", "onattack")
function onattack(id)
	local wpn = player(id, "weapon")
	local frames = math.floor(player(id, "ping") / 20)
	if frames > (BUFFER_SIZE - 1) then
		frames = (BUFFER_SIZE -1)
	end

	local rot = player(id, "rot")
	local increment_x = math.sin(math.pi * rot / 180)
	local increment_y = math.cos(math.pi * rot / 180)

	local current_x = player(id, "x")
	local current_y = player(id, "y")

	local targets = player(0, "tableliving")

	local hit = {}
	for i = 1, 32 do
		hit[i] = 0
	end

	for i = 1, (3 * weapons[wpn]["range"]) do
		current_x = current_x + increment_x
		current_y = current_y - increment_y

		local tile_x = math.floor(current_x / 32)
		local tile_y = math.floor(current_y / 32)
		if tile(tile_x, tile_y, "wall") then
			return
		end

		for j = 1, #targets do
			local tid=targets[j]
			if ((game("sv_friendlyfire") == 1) or (player(tid, "team") ~= player(id, "team"))) and (tid ~= id) and (hit[tid] == 0) and (math.abs(buffer[frames][tid][1] - current_x) <= 12) and (math.abs(buffer[frames][tid][2] - current_y) <= 12) then
				hit[tid] = 1
				local newarmor = player(tid, "armor") - weapons[wpn]["damage"]
				if newarmor < 0 then
					newarmor = 0
				end
				local newhealth = player(tid, "health") - (weapons[wpn]["damage"] - math.floor(game("mp_kevlar") * (player(tid, "armor") - newarmor)))
				if newhealth > 0 then
					parse("sethealth "..tid.." "..newhealth)
					parse("setarmor "..tid.." "..newarmor)
				else
					parse("customkill "..id.." "..weapons[wpn]["name"].." "..tid)
				end
			end
		end
	end
end

function deepcopy(object)
    local lookup_table = {}
    local function _copy(object)
        if type(object) ~= "table" then
            return object
        elseif lookup_table[object] then
            return lookup_table[object]
        end
        local new_table = {}
        lookup_table[object] = new_table
        for index, value in pairs(object) do
            new_table[_copy(index)] = _copy(value)
        end
        return setmetatable(new_table, getmetatable(object))
    end
    return _copy(object)
end