local commands = {}
local function registerCommand(cmd, handler)
	if not isstring(cmd) or not isfunction(handler) then return end
	commands[string.lower(cmd)] = handler
end

--============= UTILITY FUNCTIONS =============--
local function stop(ply)
	netstream.Start(ply, 'dbg-hack.cancel')
	if ply.hacking and IsValid(ply.hacking.target) then
		hook.Run('onKeypadHack', ply, false, ply.hacking.target)
	end
	if ply.hacking and isfunction(ply.hacking.cancel) then ply.hacking.cancel() end
	timer.Remove('dbg-hack.load' .. ply:SteamID())
	ply.hacking = nil
end

local function lock(ply, locked)
	ply.hacking.blocked = (locked == true)
	netstream.Start(ply, 'dbg-hack.updateLockStatus', locked == true)
end

local function invalidEnt(ply)
	local tgt = ply.hacking.target
	return not IsValid(tgt) or ply:GetShootPos():DistToSqr(tgt:GetPos()) > 2500
end

local function invalid(ply)
	if not IsValid(ply) or not ply.hacking then return true end
	if invalidEnt(ply) then return true, stop(ply) end
	return false
end

local function requestInput(ply, cback)
	if invalid(ply) then return end
	ply.hacking.pendingInput = cback
	netstream.Start(ply, 'dbg-hack.requestInput')
	lock(ply)
end

local function beep(ply)
	ply:EmitSound('buttons/button15.wav')
end

local function print(ply, text, append)
	if not IsValid(ply) or not ply.hacking then return false end
	beep(ply)
	netstream.Start(ply, 'dbg-hack.print', text, append == true)
	return true
end

local function input(ply, data)
	local cmd = string.lower(data[1])
	if isfunction(commands[cmd]) then
		table.remove(data, 1)
		commands[cmd](ply, data)
	else
		print(ply, cmd .. ': command not found')
		lock(ply)
	end
end

-- Player types something in terminal and presses the Enter key
netstream.Hook('dbg-hack.input', function(ply, data)

	if not isstring(data) or invalid(ply) then return end
	if ply.hacking.blocked then return lock(ply, true) end
	lock(ply, true)

	local h = ply.hacking
	if h.pendingInput then
		h.pendingInput(data)
		h.pendingInput = nil
		return
	end
	input(ply, string.Split(data, ' '))

end)

-- Player closes the terminal window (need to stop hacking process)
netstream.Hook('dbg-hack.cancel', function(ply)
	if not ply.hacking then return end
	if isfunction(ply.hacking.cancel) then ply.hacking.cancel() end
	timer.Remove('dbg-hack.load' .. ply:SteamID())
	ply.hacking = nil
end)
hook.Add('PlayerDisconnected', 'dbg-hack.cancel', function(ply)
	if ply.hacking and isfunction(ply.hacking.cancel) then ply.hacking.cancel() end
	timer.Remove('dbg-hack.load' .. ply:SteamID())
end)

--================= COMMANDS =================--
registerCommand('pwdserver', function(ply)
	hook.Run('dbg-hack.1stCommand', ply, ply.hacking.target)
	print(ply, ply.hacking.target.pwdserver)
	lock(ply)
end)

registerCommand('traceroute', function(ply, data)
	if not data[1] then
		print(ply, 'Usage: traceroute target_ip')
		return lock(ply)
	end
	if data[1] ~= ply.hacking.target.pwdserver then
		print(ply, 'Could not connect to ' .. data[1] .. ': connection was closed unexpectedly.')
		return lock(ply)
	end
	print(ply, 'traceroute to ' .. data[1] .. ', 30 hops max, 38 byte packets')

	local tm, i = 0, 0
	local function printNext()

		if invalid(ply) then return end
		i = i + 1
		if not ply.hacking.target.traceroute[i] then return lock(ply) end

		print(ply, string.format('%2d', i))

		local time = math.Rand(0.1, 0.4)
		local ip = ply.hacking.target.traceroute[i]
		timer.Simple(time, function()
			if not invalid(ply) then
				print(ply, '    ' .. ip, true)
			end
		end)

		time = time + math.Rand(0.5, 0.7)
		timer.Simple(time, function()
			if invalid(ply) then return end
			print(ply, string.rep(' ', 15 - #ip + 1), true)
			local timeStr = ''
			for j = 1, 3 do
				tm = tm + math.Rand(0.001, 0.5)
				timeStr = timeStr .. string.format('%.3f ms  ', tm)
			end
			print(ply, timeStr, true)
			printNext()
		end)

	end
	printNext()

end)

registerCommand('./inject.sh', function(ply, data)
	local ip = data[1]
	if not isstring(ip) then
		print(ply, 'Usage: ./inject.sh target_ip')
		return lock(ply)
	end
	local attNum = 0
	for i,v in ipairs(ply.hacking.target.traceroute) do
		if v == ip then
			attNum = i
			break
		end
	end
	if attNum == 0 then
		print(ply, 'Could not inject interceptor into ' .. ip .. ': connection was closed unexpectedly.')
		return lock(ply)
	end
	ply.hacking.interceptor = attNum
	print(ply, 'successfully injected interceptor on ' .. ip)
	lock(ply)
end)

local alphabet = '123456789'
local function randomPass()
	local str = ''
	for i = 1, 4 do
		str = str .. alphabet[math.random(#alphabet)]
	end
	return str
end

registerCommand('./unhash.sh', function(ply, data)
	if not isstring(data[1]) then
		print(ply, 'Usage: ./unhash.sh target_hash')
		return lock(ply)
	end
	local ans = {}
	if data[1] ~= ply.hacking.target.problem then
		local seed = tonumber(tostring(data[1]), 16)
		if not seed then
			print(ply, 'Incorrect hash')
			return lock(ply)
		end
		math.randomseed(tonumber(tostring(data[1]), 16))
		for i = 1, 5 do
			ans[#ans + 1] = randomPass()
		end
		math.randomseed(CurTime())
	else ans = ply.hacking.target.passs end

	local i = 0
	local function printNext()
		if invalid(ply) then return end
		i = i + 1
		if not ans[i] then return lock(ply) end
		print(ply, string.format('%2d.  %s', i, ans[i]))
		timer.Simple(math.Rand(0.1, 3), printNext)
	end
	print(ply, 'Possible combinations:')
	timer.Simple(math.Rand(0.1, 3), printNext)

end)

registerCommand('sudo', function(ply, data)

	if not isstring(data[1]) then
		print(ply, 'Usage: sudo command command_args')
		return lock(ply)
	end
	local cmd = string.lower(data[1])
	if cmd ~= 'unlock' then
		return input(ply, data)
	end

	local hashPart
	if ply.hacking.interceptor then
		local h, ind = ply.hacking.target.problem, ply.hacking.target.hashpts[ply.hacking.interceptor]
		hashPart = ''
		for i = 1, ind-1 do
			hashPart = hashPart .. '**'
		end
		hashPart = hashPart .. h[ind * 2 - 1] .. h[ind * 2]
		for i = ind + 1, 4 do
			hashPart = hashPart .. '**'
		end
		hashPart = hashPart
	end

	print(ply, '[sudo] password for kpad: ')
	requestInput(ply, function(pwd)
		if hashPart then
			print(ply, 'Received pwd hash part: ' .. hashPart)
		end
		if pwd == ply.hacking.target:GetPassword() then
			print(ply, 'Unlocked.')
			ply.hacking.target:Process(true)
			hook.Run('onKeypadHack', ply, true, ply.hacking.target)
			if isfunction(ply.hacking.succeed) then ply.hacking.succeed() end
		else
			print(ply, 'Sorry, try again.')
			ply.hacking.target:Process(false)
			if isfunction(ply.hacking.fail) then ply.hacking.fail() end
		end
		lock(ply)
	end)

end)

--================ EASTER EGGS ================--
local files = {
	{'-rwxrwx--x', '1176', 'Feb', '16', '00:19', 'inject.sh'},
	{'-rwxrwxr--', '484', 'Mar', '29', '22:18', 'README.TXT'},
	{'-rwxrwx--x', '9008', 'May', '10', '22:54', 'unhash.sh'},
}

registerCommand('ls', function(ply)
	print(ply, 'total ' .. #files)
	for _,v in ipairs(files) do
		print(ply, string.format('%10s 1 crackr crackr %4s %3s %2s %5s %s', unpack(v)))
	end
	lock(ply)
end)

registerCommand('cat', function(ply, args)
	if not isstring(args[1]) then
		print(ply, 'Usage: cat file_name')
		return lock(ply)
	end
	if string.lower(args[1]) ~= 'readme.txt' then
		print(ply, '[cat] file ' .. args[1] .. ' not found or permission denied for user kpad')
		return lock(ply)
	end

	print(ply, [[    HOW TO USE THIS PIECE OF SHIT:
1. Detect keypad's current upsource IP using "pwdserver" command:
  > pwdserver
  37.212.16.22
2. Check it's packet path using "traceroute" command:
  > traceroute 37.212.16.22
  traceroute to 37.212.16.22, 30 hops max, 38 byte packets
  ...
3. Set interceptors on one of IPs from traceroute:
  > ./inject.sh 37.212.16.22
  Successfully injected interceptor on 37.212.16.22
4. Try to unlock keypad:
  > sudo unlock
  [sudo] password for kpad: 1111
  Received pwd hash part: ******2f**
  Sorry, try again.
5. Collect all hash parts and run unhash.sh:
  > ./unhash.sh 16bd7c2fd0
  Possible combinations:
   1.  1234
   2.  8888
   3.  1984
6. Try to unlock keypad with all passwords prompted:
  > sudo unlock
  [sudo] password for kpad: 1234
  Sorry, try again.
  > sudo unlock
  [sudo] password for kpad: 8888
  Unlocked.
Feel free contact me if you have any questions: giwamam817@jmail7.com
]])
	lock(ply)
end)

local pmeta = FindMetaTable('Player')
function pmeta:Hack(ent, succ, fail, cancel)
	if self:GetShootPos():DistToSqr(ent:GetPos()) > 2500 then
		return self:addExploitAttempt()
	end
	ent:GenerateProblem()
	self.hacking = {
		target = ent,
		succeed = succ,
		fail = fail,
		cancel = cancel,
		blocked = true,
	}
	netstream.Start(self, 'dbg-hack.start')
	timer.Create('dbg-hack.load' .. self:SteamID(), 6, 1, function()
		netstream.Start(self, 'dbg-hack.loaded')
		lock(self)
	end)
end