--[[      _ _ /~` _  _ _  _ | _ _|_ _ (~ _ _. _ _|_
         | | |\_,(_)| | ||_)|(/_ | (/__)(_| ||_) |     v21
                         |                   |
History: Mappy v1..17 2008-2009, v18 Jan 2010, v19 Dec 2012, v20 Jan 2013, v21 Aug 2013
For time/date formatting, see lua.org/pil/22.1.html
]]

-----------------------------------------------------------[ options ]

-- Configure features
bBlockInvisibleCharacters = false
bBlockIllegalSearches     = false
bEnableCatchup            = true
bEnableRegistration       = true
bEnableUserLocations      = false
bEnableImpersonate        = false
bEnableChatLogging        = true
bEnableGroupChat          = true

il         = 15   -- Number of chat log messages to keep in memory
tf = "[%H.%M]"    -- Format of chat log timestamps
AdminLevel = 0    -- Permission required for admin features (by default 0 is 'Master')
RegLevel   = 3    -- Permission given upon registration (by default 3 is 'Registered')
PLL        = 5    -- Minimum password length (must be at least one)

-- Words that flag searches;
badwords = {"clop"}

-- Settings for chat logs
chatLogPath        = Core.GetPtokaXPath().."logs/%B - %Y - 127.0.0.1.txt"
chatLogTimeFormat  = "%Y-%m-%d %H:%M:%S"

-- Settings for group chats
groupChatPruneCheckEvery = 30
groupChatTimeoutAfter    = 15*60

-- Strings
SZ_REG_CONNECTED   = "Thank you for using a registered nickname!"
SZ_UNREG_CONNECTED = "Want to secure your nickname? Register it."
SZ_REG_COMPLETED   = "Your nickname is now registered. In future, log on with your password."
SZ_INVISIBLE_CHAR  = "Sorry, remove all invisible characters from your name to reconnect."
SZ_REDIR_REASON    = "Rearranging network, please be patient..."
SZ_E_DISABLED      = "* Feature disabled."
SZ_E_SYNTAX_ERROR  = "* Syntax error."
SZ_E_UNAUTHORISED  = "* Unauthorised."
SZ_E_SCRIPT_ERROR  = "* Error performing script operation."

SZ_GCHAT_CLOSING   = "## Closing group chat..."
SZ_GCHAT_AWAYMSG   = "Away"

-----------------------------------------------------------[ data storage ]

groupchats = {}
groupChatTimer = nil
ml = {""}
mp = -1
hall = {
	-- 1-indexed,
	"Rochester and Rutherford", -- 8..15
	"Ilam Apartments",          -- 16..31
	"Ilam Apartments",
	"Bishop Julius",            -- 32..39
	"College House",            -- 40..47
	"University Hall",          -- 48..55
	"Sonada"                    -- 56..63
}
-----------------------------------------------------------[ connections ]

function OpConnected(user) SC(user) end
function RegConnected(user) SC(user) end

function UserConnected(user)
	if bBlockInvisibleCharacters then
		-- Only filters unregistered users
		if string.find(user.sNick, "­") then
			Core.SendToUser(user, "* "..SZ_INVISIBLE_CHAR)
			BanMan.TempBanNick(user.sNick, 1, "Use of invisible character", Core.GetHubSecAlias)
			Core.SendToOps("<"..Core.GetHubSecAlias.."> "..user.sNick.." tried to use an invisible character!")
		end
	end	
	SC(user)
end

function SC(user, sendMessages)
	-- CONTEXT_HUB = 0x01
	-- CONTEXT_USER = 0x02
	if sendMessages == nil then sendMessages = true end
	if not user then return end
	
	-- Clear existing
	AddUSC(user, "255 3", "", "")
	
	-- Locations
	if (bEnableUserLocations) then
		AddUSC(user, "1 2", "Get User Location", "!locate %[nick]")
	end
	
	-- Registration
	if (bEnableRegistration) then
		if user.iProfile == RegLevel then
			if sendMessages then Core.SendToUser(user, "* "..SZ_REG_CONNECTED) end
			AddUSC(user, "1 1", "Change your password...", "!reg %[line:Enter a password]")
		else
			if sendMessages then Core.SendToUser(user, "* "..SZ_UNREG_CONNECTED) end
			AddUSC(user, "1 1", "Register your nick...", "!reg %[line:Enter a password]")
		end
	end
	
	-- Catchup
	if (bEnableCatchup) then
		if sendMessages then SendCatchup(user) end
		AddUSC(user, "1 1", "Get chat history", "!catchup")		
	end
	
	-- Impersonation
	if (bEnableImpersonate or user.iProfile == AdminLevel) then
		AddUSC(user, "1 2", "Impersonate\\Say as user...", "!yuo %[nick] %[line:Enter text]")
		AddUSC(user, "1 2", "Impersonate\\Action as user [normal]...", "!yuo %[nick] /me %[line:Enter text]")
		AddUSC(user, "1 2", "Impersonate\\Action as user [system]...", "!you %[nick] %[line:Enter text]")
		AddUSC(user, "0 2", "", "")
		AddUSC(user, "1 3", "Impersonate\\Send system message...", "!you %[line:Enter text]")
	end
	
	-- Group chats
	if (bEnableGroupChat) then
		AddUSC(user, "1 1", "Group chat\\New group chat", "!groupchat_new")
		local foundAnyChats = false
		for botnick, grinfo in pairs(groupchats) do
			if grinfo["owner"] == user.sNick then
				if not foundAnyChats then
					AddUSC(user, "1 1", "Group chat\\-", "")
					foundAnyChats = true
				end
				AddUSC(user, "1 1", "Group chat\\Close chat ["..botnick.."]", "!groupchat_close "..botnick)
				AddUSC(user, "1 2", "Invite user to join ["..botnick.."]", "!groupchat_invite "..botnick.." %[nick]")
			end
		end		
	end
	
	-- Admin tasks
	if (user.iProfile == AdminLevel) then
		
		AddUSC(user, "1 1", "Admin\\Restart PtokaX", "!restart")
		AddUSC(user, "1 1", "Admin\\Redirect all users...", "!redirectallusers %[line:Redirect address]")
		AddUSC(user, "1 1", "Admin\\Set hub title...", "!sethubtitle %[line:Hub title]")
		AddUSC(user, "1 1", "Admin\\Reload MOTD from disk", "!reload-motd")
		AddUSC(user, "0 1", "Admin\\-", "")
		AddUSC(user, "1 2", "Admin\\Look up user password", "!get-password %[nick]")
		if bEnableCatchup then
			AddUSC(user, "1 1", "Admin\\Flush catchup ring buffer", "!catchup-flush")
		end
		AddUSC(user, "1 1", "Admin\\Chat as "..Core.GetHubSecAlias().."...", "!yuo "..Core.GetHubSecAlias().." %[line:Enter text]")
		AddUSC(user, "1 1", "Admin\\Get hub stats", "!get-stats")
		AddUSC(user, "1 1", "Admin\\Refresh menu", "!refreshmenu")
		
		-- Scripts menu
		
		AddUSC(user, "0 1", "Admin\\-", "")
		ScriptMan.Refresh()
		for i,v in ipairs(ScriptMan.GetScripts()) do
			local title = "Admin\\Scripts\\["..(v.bEnabled and "X" or "  ").."] "..v.sName.."\\"
			if (v.bEnabled) then
				AddUSC(user, "1 1", title.."Disable", "!stop-script "..v.sName)
			else
				AddUSC(user, "1 1", title.."Enable", "!start-script "..v.sName)
			end
			AddUSC(user, "1 1", title.."Restart", "!restart-script "..v.sName)
		end		
		
	end	
end

-----------------------------------------------------------[ main parsing ]

triggers = {

	-- Usage: !locate username
	["!locate"] = function(user, data, t)
		if not bEnableUserLocations then return Core.SendToUser(user, SZ_E_DISABLED) end
		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
			
		Core.SendToUser(user, GetHallFromIP(t[2]))
	end,
	
	-- Usage: !reg password
	["!reg"] = function(user, data, t)
		if not bEnableRegistration then return Core.SendToUser(user, SZ_E_DISABLED) end		
		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
		
		if string.len(t[2])>=PLL then
			if RegMan.GetReg(user.sNick)==nil then
				RegMan.AddReg(user.sNick, t[2], RegLevel)
				Core.SendToUser(user, "* "..SZ_REG_COMPLETED)
			else
				RegMan.ChangeReg(user.sNick, t[2], RegLevel)
				Core.SendToUser(user, "* Password changed.")
			end
			RegMan.Save()
		else
			Core.SendToUser(user, "* Passwords must be at least "..PLL.." characters long.")
		end
	end,
	
	-- Usage: !catchup
	["!catchup"] = function(user, data, t)
		if not bEnableCatchup then return Core.SendToUser(user, SZ_E_DISABLED) end
		
		SendCatchup(user)
	end,	
	
	-- Action as user
	-- Usage: !you their-nick message goes here
	["!you"] = function(user, data, t)
		if bEnableImpersonate or user.iProfile == AdminLevel then
			local m
			_,m=s2(data)
			_,m=s2(m)
			Core.SendToAll("* "..m)
			logCatchup("* "..m)
		else
			Core.SendToUser(user, SZ_E_DISABLED)
		end				
	end,
	
	-- Say as user
	-- Usage: !yuo their-nick message goes here
	["!yuo"] = function(user, data, t)
		if bEnableImpersonate or user.iProfile == AdminLevel then
			local m, u, mg
			_,m=s2(data)
			_,m=s2(m)
			u,mg=s2(m)
			Core.SendToAll("<"..u.."> "..mg)
			logCatchup("<"..u.."> "..mg)
		else
			Core.SendToUser(user, Z_E_DISABLED)
		end
	end,
	
	-- Initiate a group chat
	-- Usage: !groupchat_new
	["!groupchat_new"] = function(user, data, t)
		if bEnableGroupChat or user.iProfile == AdminLevel then
			if #t ~= 1 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
			groupchat_init(user.sNick)
		else
			Core.SendToUser(user, Z_E_DISABLED)
		end
	end,
	
	-- Invite a user to a group chat under your control
	-- Usage: !groupchat_invite botnick friendnick
	["!groupchat_invite"] = function(user, data, t)
		if bEnableGroupChat or user.iProfile == AdminLevel then
			if #t ~= 3 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
			groupchat_invite(user, t[2], t[3])
		else
			Core.SendToUser(user, Z_E_DISABLED)
		end
	end,
	
	-- Close a group chat under your control
	-- Usage: !groupchat_close botnick
	["!groupchat_close"] = function(user, data, t)
		if bEnableGroupChat or user.iProfile == AdminLevel then
			if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
			groupchat_end(user, t[2])
		else
			Core.SendToUser(user, Z_E_DISABLED)
		end
	end
	
}
adminTriggers = {

	-- Usage: !get-password their-nick
	["!get-password"] = function(user, data, t)
		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
		
		local reguser = RegMan.GetReg(t[2])
		if reguser then
			Core.SendToUser(user, "User "..reguser.sNick.." has password '"..reguser.sPassword.."'")
		else
			Core.SendToUser(user, "User "..t[2].." not registered.")
		end
	end,

	-- Usage: !reload-motd
	["!reload-motd"] = function(user, data, t)
		local motd = readFile(Core.GetPtokaXPath().."cfg/Motd.txt", "rb")
		if motd then
			SetMan.SetMOTD(motd)
			SetMan.Save()
			Core.SendToUser(user, "<"..Core.GetHubSecAlias().."> "..SetMan.GetMOTD())
		else
			Core.SendToUser(user, "* Error opening '"..Core.GetPtokaXPath().."cfg/Motd.txt'")
		end		
	end,
	
	-- Usage: !redirectallusers target-address
	["!redirectallusers"] = function(user, data, t)
		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
		
		local allUsers = Core.GetOnlineUsers()
		for _, u in pairs(allUsers) do
			Core.SendToUser(user, "* Redirecting ".. u.sNick .." to "..t[2])
			Core.Redirect(u, t[2], SZ_REDIR_REASON)
		end
	end,
	
	-- Usage: !refreshmenu
	["!refreshmenu"] = function(user, data, t)
		SC(user, false)
	end,
	
	-- Usage: !start-script filename.lua
	["!start-script"] = function(user, data, t)
		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end		
		if (ScriptMan.StartScript(t[2]) == nil) then Core.SendToUser(user, SZ_E_SCRIPT_ERROR) end
		
		Core.SendToUser(user, "* Script "..t[2].." started.");
		SetMan.Save()
		SC(user, false)
	end,
	
	-- Usage: !stop-script filename.lua
	["!stop-script"] = function(user, data, t)
		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end		
		if (ScriptMan.StopScript(t[2]) == nil) then Core.SendToUser(user, SZ_E_SCRIPT_ERROR) end
		
		Core.SendToUser(user, "* Script "..t[2].." stopped.");
		SetMan.Save()
		SC(user, false)
	end,
		
	-- Usage: !restart-script filename.lua
	["!restart-script"] = function(user, data, t)
		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end		
		if (ScriptMan.RestartScript(t[2]) == nil) then Core.SendToUser(user, SZ_E_SCRIPT_ERROR) end
		
		Core.SendToUser(user, "* Script "..t[2].." restarted.");
		SetMan.Save()
		SC(user, false)
	end,
	
	-- Usage: !get-stats
	["!get-stats"] = function(user, data, t)
		Core.SendToUser(user, "* Peak users this boot: "..Core.GetActualUsersPeak())
		Core.SendToUser(user, "* Peak users all time: "..Core.GetMaxUsersPeak())
		Core.SendToUser(user, "* Current share: "..Core.GetCurrentSharedSize())
		Core.SendToUser(user, "* Uptime: "..Core.GetUpTime().." seconds")
	end,
	
	-- Usage: !catchup-flush
	["!catchup-flush"] = function(user, data, t)
		flushCatchup()
		Core.SendToUser(user, "* Catchup flushed.")
	end,
	
	-- Usage: !sethubtitle title goes here
	["!sethubtitle"] = function(user, data, t)
		SetMan.SetString(0, table.concat(t, " ", 2))
		SetMan.Save()
	end,
	
}

function ChatArrival(user, data)
	local validcommand=false

	if (string.sub(data, 1, 1) == "<" ) then
		data=string.sub(data, 1, string.len(data) -1)
		t = {}
		for k in string.gmatch(data, "%s+([^%s]+)") do
			table.insert(t, k)
		end
		
		if (#t>=1 and triggers[t[1]]) then
			triggers[t[1]](user, data, t)
			return true
			
		elseif (#t>=1 and user.iProfile == AdminLevel and adminTriggers[t[1]]) then
			adminTriggers[t[1]](user, data, t)
			return true
		
		elseif t[1] and string.sub(t[1], 1, 1) == "!" then
			-- Don't add potential system commands to catchup/logs
			
		else
			logCatchup(data:sub(1)) --, -2)) --string.len(data)))
			logChat(nmdc_unescape(data:sub(1))) --, -2)))
		end
		
	end
	
end

function ToArrival(user, data)
	-- Parse data and determine whether it's intended for any groupchat bots
	local recipient = data:gsub("%$To: ([^%s]+) From: [^%s]+ %$<[^>]+> (.*)|", "%1")
	local body      = data:gsub("%$To: ([^%s]+) From: [^%s]+ %$<[^>]+> (.*)|", "%2")
	
	-- Core.SendToUser(user, nmdc_escape(data))
	
	-- Core.SendToUser(user, "got recipient ["..recipient.."] and body ["..body.."]")
	
	if groupchats[recipient] then
		groupchat_sayas(recipient, user.sNick, body)
		return true -- abort
	else	
		return false -- process normally
	end
end

function OnStartup()
	-- Create groupchat pruner
	groupChatTimer = TmrMan.AddTimer(groupChatPruneCheckEvery * 1000, "groupchat_prune")
end

-----------------------------------------------------------[ impersonation ]

function s2(inp)
	sp = string.find(inp, " ")
	if sp==nil then sp=0 end
	return string.sub(inp, 1, sp-1), string.sub(inp, sp+1)
end

-----------------------------------------------------------[ group chat ]

function groupchat_init(ownernick)
	-- Generate a nick for the bot by adding numbers to the user's nick until
	--  one is not currently in use
	local suffix = 1
	while true do
		-- Core.GetUser doesn't include script bots
		if Core.GetUser(ownernick .. suffix) == nil and not groupchats[ownernick..suffix] then
			break
		end
	
		suffix = suffix + 1
		if suffix > 100 then
			Core.SendToNick(ownernick, "Error: Couldn't pick a group chat username")
			return
		end
	end
	local botnick = ownernick..suffix
	
	-- Register bot
	if not Core.RegBot(botnick, "", "", false) then
		Core.SendToNick(ownernick, "Error: Couldn't start group chat")
		return
	end
	
	-- Save all data
	groupchats[botnick] = {
		["owner"] = ownernick,
		["last"] = os.time(),
		["users"] = {
			[ownernick] = true
		}
	}
	
	-- Refresh usercommands
	SC( Core.GetUser(ownernick), false )
	
	groupchat_say(botnick, "## Joins: "..ownernick)
end

-- Owner invites a user into an existing group chat
function groupchat_invite(user, botnick, friendnick)
	if groupchats[botnick] and  groupchats[botnick]["owner"] == user.sNick then -- only owner can invite
		if Core.GetUser(friendnick) then -- Check if user's online
		
			-- Add user and notify participants
			groupchats[botnick]["users"][friendnick] = true
			
			-- Notify self of existing participants
			for peer,_ in pairs(groupchats[botnick]["users"]) do
				local isHost = ""
				if (groupchats[botnick]["owner"] == peer) then
					isHost = " (host)"
				end
				if peer ~= friendnick then
					-- we go last
					Core.SendPmToNick(friendnick, botnick, "## Joins: "..peer..isHost)
				end
			end
			
			-- Notify existing participants (and self) of joining
			groupchat_say(botnick, "## Joins: "..friendnick) -- updates mtime
			
		else
			Core.SendToUser(user, "Error: User not online")
		end			
	else
		Core.SendToUser(user, SZ_E_UNAUTHORISED) -- nonexistent or not yours
	end
end

-- Pass user as well, so that administrators can prune groupchat bots.
function groupchat_end(user, botnick)
	if groupchats[botnick] then
		if groupchats[botnick]["owner"] == user.sNick or user.iProfile == AdminLevel then
			-- End chat
			groupchat_remove(botnick)
		else
			-- Not allowed
			Core.SendToUser(user, SZ_E_UNAUTHORISED)
		end
	end
end

-- Every minute or so, prune group chats that havn't had any replies in a while. 
function groupchat_prune()
	if #groupchats then
		for botnick, gcdata in pairs(groupchats) do
			if (os.time() - gcdata["last"]) > groupChatTimeoutAfter then
				groupchat_remove(botnick)
			end
		end
	end
end

-- Explicitly remove a group chat. Only called by other groupchat_ helper
--  functions
function groupchat_remove(botnick)
	if groupchats[botnick] then
		-- Send leaving message to any still-connected users
		groupchat_say(botnick, SZ_GCHAT_CLOSING)
		
		-- Part the bot
		Core.UnregBot(botnick)
	
		local owner = groupchats[botnick]["owner"]
	
		-- Remove from groupchat registry
		groupchats[botnick] = nil
		
		-- Refresh usercommands for the host
		SC( Core.GetUser(owner), false )
	end
end

-- Explicitly say a message into a group chat. Only called by other groupchat_
--  helper functions
function groupchat_say(botnick, message)
	if groupchats[botnick] then
		for destnick, _ in pairs(groupchats[botnick]["users"]) do
			Core.SendPmToNick( destnick, botnick, message )
		end
		groupchats[botnick]["last"] = os.time()
	end
end

-- Say a message from a user (i.e. don't echo it back to them)
function groupchat_sayas(botnick, selfnick, message)
	if groupchats[botnick] then
		local valid = false;
		for destnick, _ in pairs(groupchats[botnick]["users"]) do
			if destnick == selfnick then
				valid = true
				break
			end
		end
		if valid then
			for destnick, _ in pairs(groupchats[botnick]["users"]) do
				if destnick ~= selfnick then
					Core.SendPmToNick(destnick, botnick, "<"..selfnick.."> "..message)
				end
			end
		else
			Core.SendPmToNick(selfnick, botnick, SZ_GCHAT_AWAYMSG) -- pretend we're not here
		end
	end
end

-----------------------------------------------------------[ search parsing ]

function SearchArrival(user, data)
	if bBlockIllegalSearches then
		sstr=data
		while string.find(sstr, "?") do
			sstr=string.sub(sstr, string.find(sstr,"?")+1)
		end
		sstr="$"..string.lower( string.sub(sstr,1,string.len(sstr)-1) )
		
		t = {}
		for k in string.gmatch(sstr, "%$([^%$]+)") do
			table.insert(t, k)
		end
		sstr=table.concat(t, " ")

		if string.sub(sstr, 1, 4) ~= "tth:" then 
			local showbanner=false
			for cnt=1,#badwords do
				if string.find(sstr, badwords[cnt]) then 
					showbanner=true
					break
				end
			end
			if showbanner then
				Core.SendToAll("<"..Core.GetHubSecAlias().."> "..user.sNick.." just searched for '"..sstr.."'!")
				return true		-- disable the search
			end
		end
	end
end

-----------------------------------------------------------[ location ]

function GetHallFromIP(userNick)
	if Core.GetUser(userNick) == nil then
		return "* User "..userNick.." doesn't have a location."
	else
		-- Dumb check of third digit in IP
		subnet = string.gsub(Core.GetUser(userNick).sIP, "%d+%D%d+%D(%d+)%D%d+", "%1")
		subnet = math.floor(subnet / 8)
		if hall[subnet]==nil then
			return "* User "..userNick.." is located somewhere unknown"
		else
			return "* User "..userNick.." is located at "..hall[subnet]
		end
	end
end

-----------------------------------------------------------[ catchup ]

function SendCatchup(user)
	local sz = getRange(ml, isz(mp), il)..getRange(ml, 0, isz(mp))
	Core.SendToNick(user.sNick, "* Showing up to "..il.." messages.."..sz)
	Core.SendToNick(user.sNick, "* Catchup completed.\n")
end

function isz(n) return (n + 1 + il) % il end

function logCatchup(text)
	mp = isz(mp)
	ml[mp] = os.date(tf).." "..text
end

function flushCatchup()
	ml = {""}
	mp = -1
end

-----------------------------------------------------------[ chatlogs ]

function logChat(text)
	local logfile = os.date(chatLogPath)
	local f = io.open(logfile, "a+")
	f:write("["..os.date(chatLogTimeFormat).."] "..text.."\n")
	f:close()
end

-----------------------------------------------------------[ general ]

function onError(sErrMsg)
	Core.SendPmToOps(Core.GetHubSecAlias, "The hub script has broken down!\n"..sErrMsg)	
end

function AddUSC(user, mode, menu, cstr)
	Core.SendToUser(user, "$UserCommand "..mode.." "..menu.."$<%[mynick]> "..cstr.."&#124;")
end

-- @return nil|string
function readFile(path)
	local f = io.open(path, "rb")
	if (f) then
		f:close()
		
		lines = {}
		for line in io.lines(path) do
			lines[#lines + 1] = line
		end
		return table.concat(lines, "\n")
	end
	return nil
end

-- @return string
function getRange(array, first, last) 
	local c = first
	local s = ""
	while not (c >= last or array[c] == nil) do
		s = s.."\n"..array[c]
		c = c + 1
	end
	return s
end

function nmdc_escape(message)
	local r = message:gsub("&", "&amp;"):gsub("|", "&#124;"):gsub("%$", "&#36;") -- escape $ sign
	return r -- otherwise there are two arguments
end

function nmdc_unescape(message)
	local r = message:gsub("&#36;", "$"):gsub("&#124;", "|"):gsub("&amp;", "&")
	return r
end