--[[
	Project: LibMSP
	Author: "Etarna Moonshyne"
	Author: Morgane "Ellypse" Parize
	Author: Justin Snelgrove

	This work is licensed under the Creative Commons Zero license. While not
	required by the license, it is requested that you retain this notice and
	the list of authors with any distributions, modified or unmodified, as it
	may be required by law in some jurisdictions due to the moral rights of
	authorship.

	It would be appreciated if modified copies of the library are released
	under the same license, but this is also not required.

	- Put your character's field data in the table msp.my, e.g. msp.my["NA"] = UnitName("player")
	- When you initialise or update your character's field data, call msp:Update(); no parameters

	- To request one or more fields from someone else, call msp:Request( player, fields )
	  fields can be nil (gets you TT i.e. tooltip), or a string (one field) or a table (multiple)

	- To get a call back when we receive data (such as a request for us, or an answer), so you can
	  update your display: tinsert( msp.callback.received, YourCallbackFunctionHere )
	  You get (as sole parameter) the name of the player sending you the data

	- Player names appear as the game sends them (case sensitive!), with the realm always merged.
	- Players on different realms are referenced like this: "Name-Realm" - yes, that does work!

	- All field names must be two capital letters.

	- For more information, see documentation on the Mary Sue Protocol - http://moonshyne.org/msp/
]]

local VERSION = 32
local PROTOCOL_VERSION = 3
local CHOMP_VERSION = 20

if IsLoggedIn() then
	error(("LibMSP (embedded in: %s) cannot be loaded after login."):format((...)))
elseif msp and (msp.version or 0) >= VERSION then
	return
elseif not AddOn_Chomp or AddOn_Chomp.GetVersion() < CHOMP_VERSION then
	error(("LibMSP requires Chomp v%d or later."):format(CHOMP_VERSION))
end

local PREFIX = "MSP2"
local SEPARATOR = string.char(0x60)
local SEPARATOR_REPLACEMENT = string.char(0x27)

local PROBE_FREQUENCY = 300
local FIELD_FREQUENCY = 30

local TIME_MAX = 2 ^ 31 - 1

local TT_LIST = { "VP", "VA", "NA", "NH", "NI", "NT", "RA", "CU", "FR", "FC" }
local TT_ALL = {
	VP = true, VA = true, NA = true, NH = true,	NI = true, NT = true,
	RA = true, CU = true, FR = true, FC = true,	RC = true, CO = true,
	IC = true, PX = true, PN = true,
}
local INTERNAL_FIELDS = {
	VP = true, GC = true, GF = true, GR = true, GS = true, GU = true,
}

local PLAYER_NAME = AddOn_Chomp.NameMergedRealm(UnitFullName("player"))

local PROCESS = ("([^%s]+)%s"):format(SEPARATOR, SEPARATOR)
local PROCESS_COMPLETE = PROCESS .. "?"

local CHOMP_PREFIX_SETTINGS = {
	fullMsgOnly = false,
	broadcastPrefix = true,
	validTypes = {
		string = true,
	},
}

local CHOMP_OPTS_MATRIX = {
	SAFE = {
		REPLY = {
			priority = "LOW",
			allowBroadcast = true,
			universalBroadcast = true,
		},
		REQUEST = { -- This should never happen, but if it does...
			priority = "LOW",
			allowBroadcast = true,
		},
	},
	UNSAFE = {
		REPLY = {
			binaryBlob = true,
			priority = "LOW",
			allowBroadcast = true,
			universalBroadcast = true,
		},
		REQUEST = {
			binaryBlob = true,
			priority = "LOW",
			allowBroadcast = true,
		},
	},
}

if not msp then
	msp = {}
end
if not msp.callback then
	msp.callback = {}
end
if not msp.callback.received then
	msp.callback.received = {}
end
if not msp.callback.updated then
	msp.callback.updated = {}
end
if not msp.callback.status then
	msp.callback.status = {}
end
if not msp.callback.dataload then
	msp.callback.dataload = {}
end
if not msp.char then
	msp.char = {}
end
if not msp.my then
	msp.my = {}
end
if not msp.queuedRequests then
	msp.queuedRequests = {}
end
if not msp.ttList then
	msp.ttList = {}
end
if not msp.ttAll then
	msp.ttAll = {}
end
if msp.dummyframe and not msp.eventFrame then
	msp.dummyframe:UnregisterAllEvents()
	msp.dummyframe:SetScript("OnEvent", nil)
end
if not msp.eventFrame then
	msp.eventFrame = msp.dummyframe or CreateFrame("Frame")
end
msp.eventFrame:Hide()
msp.dummyframe = {
	RegisterEvent = function() end,
	UnregisterEvent = function() end,
}

for i, constField in ipairs(TT_LIST) do
	local needsAdding = true
	for j, field in ipairs(msp.ttList) do
		if field == constField then
			needsAdding = false
			break
		end
	end
	if needsAdding then
		msp.ttList[#msp.ttList + 1] = constField
	end
end

for constField, isField in pairs(TT_ALL) do
	if not msp.ttAll[constField] then
		msp.ttAll[constField] = true
	end
end

-- This constant is intended for public use, but not modification.
msp.INTERNAL_FIELDS = setmetatable({}, { __index = INTERNAL_FIELDS, __metatable = false, })

local function RunCallback(callbackName, ...)
	for i, func in ipairs(msp.callback[callbackName]) do
		xpcall(func, CallErrorHandler, ...)
	end
end

local CRC32C = {
	0x00000000, 0xF26B8303, 0xE13B70F7, 0x1350F3F4,
	0xC79A971F, 0x35F1141C, 0x26A1E7E8, 0xD4CA64EB,
	0x8AD958CF, 0x78B2DBCC, 0x6BE22838, 0x9989AB3B,
	0x4D43CFD0, 0xBF284CD3, 0xAC78BF27, 0x5E133C24,
	0x105EC76F, 0xE235446C, 0xF165B798, 0x030E349B,
	0xD7C45070, 0x25AFD373, 0x36FF2087, 0xC494A384,
	0x9A879FA0, 0x68EC1CA3, 0x7BBCEF57, 0x89D76C54,
	0x5D1D08BF, 0xAF768BBC, 0xBC267848, 0x4E4DFB4B,
	0x20BD8EDE, 0xD2D60DDD, 0xC186FE29, 0x33ED7D2A,
	0xE72719C1, 0x154C9AC2, 0x061C6936, 0xF477EA35,
	0xAA64D611, 0x580F5512, 0x4B5FA6E6, 0xB93425E5,
	0x6DFE410E, 0x9F95C20D, 0x8CC531F9, 0x7EAEB2FA,
	0x30E349B1, 0xC288CAB2, 0xD1D83946, 0x23B3BA45,
	0xF779DEAE, 0x05125DAD, 0x1642AE59, 0xE4292D5A,
	0xBA3A117E, 0x4851927D, 0x5B016189, 0xA96AE28A,
	0x7DA08661, 0x8FCB0562, 0x9C9BF696, 0x6EF07595,
	0x417B1DBC, 0xB3109EBF, 0xA0406D4B, 0x522BEE48,
	0x86E18AA3, 0x748A09A0, 0x67DAFA54, 0x95B17957,
	0xCBA24573, 0x39C9C670, 0x2A993584, 0xD8F2B687,
	0x0C38D26C, 0xFE53516F, 0xED03A29B, 0x1F682198,
	0x5125DAD3, 0xA34E59D0, 0xB01EAA24, 0x42752927,
	0x96BF4DCC, 0x64D4CECF, 0x77843D3B, 0x85EFBE38,
	0xDBFC821C, 0x2997011F, 0x3AC7F2EB, 0xC8AC71E8,
	0x1C661503, 0xEE0D9600, 0xFD5D65F4, 0x0F36E6F7,
	0x61C69362, 0x93AD1061, 0x80FDE395, 0x72966096,
	0xA65C047D, 0x5437877E, 0x4767748A, 0xB50CF789,
	0xEB1FCBAD, 0x197448AE, 0x0A24BB5A, 0xF84F3859,
	0x2C855CB2, 0xDEEEDFB1, 0xCDBE2C45, 0x3FD5AF46,
	0x7198540D, 0x83F3D70E, 0x90A324FA, 0x62C8A7F9,
	0xB602C312, 0x44694011, 0x5739B3E5, 0xA55230E6,
	0xFB410CC2, 0x092A8FC1, 0x1A7A7C35, 0xE811FF36,
	0x3CDB9BDD, 0xCEB018DE, 0xDDE0EB2A, 0x2F8B6829,
	0x82F63B78, 0x709DB87B, 0x63CD4B8F, 0x91A6C88C,
	0x456CAC67, 0xB7072F64, 0xA457DC90, 0x563C5F93,
	0x082F63B7, 0xFA44E0B4, 0xE9141340, 0x1B7F9043,
	0xCFB5F4A8, 0x3DDE77AB, 0x2E8E845F, 0xDCE5075C,
	0x92A8FC17, 0x60C37F14, 0x73938CE0, 0x81F80FE3,
	0x55326B08, 0xA759E80B, 0xB4091BFF, 0x466298FC,
	0x1871A4D8, 0xEA1A27DB, 0xF94AD42F, 0x0B21572C,
	0xDFEB33C7, 0x2D80B0C4, 0x3ED04330, 0xCCBBC033,
	0xA24BB5A6, 0x502036A5, 0x4370C551, 0xB11B4652,
	0x65D122B9, 0x97BAA1BA, 0x84EA524E, 0x7681D14D,
	0x2892ED69, 0xDAF96E6A, 0xC9A99D9E, 0x3BC21E9D,
	0xEF087A76, 0x1D63F975, 0x0E330A81, 0xFC588982,
	0xB21572C9, 0x407EF1CA, 0x532E023E, 0xA145813D,
	0x758FE5D6, 0x87E466D5, 0x94B49521, 0x66DF1622,
	0x38CC2A06, 0xCAA7A905, 0xD9F75AF1, 0x2B9CD9F2,
	0xFF56BD19, 0x0D3D3E1A, 0x1E6DCDEE, 0xEC064EED,
	0xC38D26C4, 0x31E6A5C7, 0x22B65633, 0xD0DDD530,
	0x0417B1DB, 0xF67C32D8, 0xE52CC12C, 0x1747422F,
	0x49547E0B, 0xBB3FFD08, 0xA86F0EFC, 0x5A048DFF,
	0x8ECEE914, 0x7CA56A17, 0x6FF599E3, 0x9D9E1AE0,
	0xD3D3E1AB, 0x21B862A8, 0x32E8915C, 0xC083125F,
	0x144976B4, 0xE622F5B7, 0xF5720643, 0x07198540,
	0x590AB964, 0xAB613A67, 0xB831C993, 0x4A5A4A90,
	0x9E902E7B, 0x6CFBAD78, 0x7FAB5E8C, 0x8DC0DD8F,
	0xE330A81A, 0x115B2B19, 0x020BD8ED, 0xF0605BEE,
	0x24AA3F05, 0xD6C1BC06, 0xC5914FF2, 0x37FACCF1,
	0x69E9F0D5, 0x9B8273D6, 0x88D28022, 0x7AB90321,
	0xAE7367CA, 0x5C18E4C9, 0x4F48173D, 0xBD23943E,
	0xF36E6F75, 0x0105EC76, 0x12551F82, 0xE03E9C81,
	0x34F4F86A, 0xC69F7B69, 0xD5CF889D, 0x27A40B9E,
	0x79B737BA, 0x8BDCB4B9, 0x988C474D, 0x6AE7C44E,
	0xBE2DA0A5, 0x4C4623A6, 0x5F16D052, 0xAD7D5351,
}

local function crc32c_hash(s)
	local bxor, band, brshift, strbyte = bit.bxor, bit.band, bit.rshift, string.byte

	local crc = 0xffffffff
	local len = #s

	for i = 1, len - 7, 8 do
		local b1, b2, b3, b4, b5, b6, b7, b8 = strbyte(s, i, i + 7)

		crc = bxor(brshift(crc, 8), CRC32C[band(bxor(crc, b1), 0xFF) + 1])
		crc = bxor(brshift(crc, 8), CRC32C[band(bxor(crc, b2), 0xFF) + 1])
		crc = bxor(brshift(crc, 8), CRC32C[band(bxor(crc, b3), 0xFF) + 1])
		crc = bxor(brshift(crc, 8), CRC32C[band(bxor(crc, b4), 0xFF) + 1])
		crc = bxor(brshift(crc, 8), CRC32C[band(bxor(crc, b5), 0xFF) + 1])
		crc = bxor(brshift(crc, 8), CRC32C[band(bxor(crc, b6), 0xFF) + 1])
		crc = bxor(brshift(crc, 8), CRC32C[band(bxor(crc, b7), 0xFF) + 1])
		crc = bxor(brshift(crc, 8), CRC32C[band(bxor(crc, b8), 0xFF) + 1])
	end

	for i = (len - (len % 8)) + 1, len do
		local b = strbyte(s, i)
		crc = bxor(brshift(crc, 8), CRC32C[band(bxor(crc, b), 0xFF) + 1])
	end

	return bxor(crc, 0xffffffff)
end

local function tohex(n)
	return string.format("%.X", bit.arshift(n, 0))
end

local function crc32c_tostring(s)
	return tohex(crc32c_hash(s))
end

local CRC32CCache = setmetatable({}, {
	__index = function(self, s)
		if not s or s == "" then
			return ""
		end
		local crc = crc32c_tostring(s)
		self[s] = crc
		return crc
	end,
})

function msp:CRC32(s)
	return tonumber(CRC32CCache[s], 16)
end

-- Benchmarking function.
function msp:DebugHashTest(text, silent)
	local startTime = debugprofilestop()
	local currentTime = startTime
	local count = 0
	while currentTime < startTime + 1000 do
		crc32c_hash(text)
		count = count + 1
		currentTime = debugprofilestop()
	end
	if silent then
		return count, currentTime - startTime, (currentTime - startTime) / count
	end
	print(("%d iterations of crc32c in %d milliseconds, %f milliseconds per CRC32C."):format(count, currentTime - startTime, (currentTime - startTime) / count))
end

local emptyMeta = {
	__index = function(self, field)
		return ""
	end,
}

local charMeta = {
	__index = function(self, key)
		if key == "field" then
			self[key] = setmetatable({}, emptyMeta)
			return self[key]
		elseif key == "ver" or key == "time" or key == "buffer" or key == "req" then
			self[key] = {}
			return self[key]
		else
			return nil
		end
	end,
}

local mspCharMeta = {
	__index = function(self, name)
		-- Account for unmaintained code using names without realms.
		name = AddOn_Chomp.NameMergedRealm(name)
		if not rawget(self, name) then
			rawset(self, name, setmetatable({}, charMeta))
			RunCallback("dataload", name, self[name])

			local fields = rawget(self, name).field
			local ver = rawget(self, name).ver

			for field, value in pairs(fields) do
				if not ver[field] and not msp.ttAll[field] then
					ver[field] = ver[field] or tonumber(CRC32CCache[value], 16)
				end
			end

			-- Calculate TT version separately from the assigned data.

			if not ver.TT then
				local tt = {}

				for _, field in ipairs(msp.ttList) do
					local contents = fields[field]

					if contents == "" then
						tt[#tt + 1] = field
					else
						tt[#tt + 1] = string.format("%s:%s", field, contents)
					end
				end

				local ttContents = table.concat(tt, SEPARATOR)
				ver.TT = tonumber(CRC32CCache[ttContents], 16)
			end
		end

		return rawget(self, name)
	end,
	__newindex = function(self, name, value)
		-- No legitimate reason for anything except us (using rawset above)
		-- to create anything here.
		return
	end,
}

setmetatable(msp.char, mspCharMeta)

for charName, charTable in pairs(msp.char) do
	setmetatable(charTable, charMeta)
	if rawget(charTable, "field") then
		setmetatable(charTable.field, emptyMeta)
	end
end

msp.protocolversion = PROTOCOL_VERSION
msp.my.VP = tostring(msp.protocolversion)

-- This is only used internally as a shortcut to skip version info on tooltip
-- fields.
msp.myver = setmetatable({}, {
	__index = function(self, field)
		if msp.ttAll[field] then
			return nil
		elseif field == "TT" then
			return tonumber(CRC32CCache[msp.ttContents], 16)
		end
		return tonumber(CRC32CCache[msp.my[field]], 16)
	end,
	__newindex = function() end,
	__metatable = false,
})

local function AddTTField(field)
	if type(field) ~= "string" or not field:find("^%u%u$") then
		error("msp:AddFieldsToTooltip(): All fields must be strings matching Lua pattern \"%u%u\".", 3)
	end
	if not tContains(msp.ttList, field) then
		msp.ttList[#msp.ttList + 1] = field
	end
	if not msp.ttAll[field] then
		msp.ttAll[field] = true
	end
end

function msp:AddFieldsToTooltip(fields)
	if type(fields) == "table" then
		for i, field in ipairs(fields) do
			AddTTField(field)
		end
	else
		AddTTField(fields)
	end
end

local function Send(name, chunks, msgSafety, msgType)
	local payload
	if type(chunks) == "string" then
		payload = chunks
	elseif type(chunks) == "table" then
		payload = table.concat(chunks, SEPARATOR)
	else
		return 0
	end
	AddOn_Chomp.SmartAddonMessage(PREFIX, payload, "WHISPER", name, CHOMP_OPTS_MATRIX[msgSafety][msgType])
	return math.ceil(#payload / 255)
end

local Process
function Process(name, command, isSafe)
	local action, field, crc, contents = command:match("(%p?)(%u%u)(%x*)%:?(.*)")
	if not field then return end
	if crc == "0" then
		crc = ""
	end
	if contents == "" then
		contents = nil
	end
	local crcNum = tonumber(crc, 16)
	local now = GetTime()
	if action == "?" then
		if not msp.ttCache then
			-- If an update hasn't successfully run, don't respond to requests.
			return
		end
		if msp.ttAll[field] then
			field = "TT"
		end
		if (msp.char[name].req[field] or 0) > now then
			msp.char[name].req[field] = now + 5
			return
		end
		msp.char[name].req[field] = now + 5
		if field == "TT" then
			-- This all has to be duplicated for TT since the original header
			-- documentation lied.
			if crc ~= CRC32CCache[msp.ttContents] then
				if not msp.char[name].safeReply then
					msp.char[name].safeReply = {}
				end
				local reply = msp.char[name].safeReply
				reply[#reply + 1] = msp.ttCache
			else
				if not msp.char[name].unsafeReply then
					msp.char[name].unsafeReply = {}
				end
				local reply = msp.char[name].unsafeReply
				reply[#reply + 1] = ("!%s%s"):format(field, CRC32CCache[msp.ttContents] or "")
			end
		elseif crc ~= CRC32CCache[msp.my[field]] then
			if not msp.char[name].safeReply then
				msp.char[name].safeReply = {}
			end
			local reply = msp.char[name].safeReply
			if not msp.my[field] or msp.my[field] == "" then
				reply[#reply + 1] = field
			else
				reply[#reply + 1] = ("%s%s:%s"):format(field, CRC32CCache[msp.my[field]], msp.my[field])
			end
		else
			if not msp.char[name].unsafeReply then
				msp.char[name].unsafeReply = {}
			end
			local reply = msp.char[name].unsafeReply
			reply[#reply + 1] = ("!%s%s"):format(field, CRC32CCache[msp.my[field]] or "")
		end
	elseif action == "!" and crcNum == msp.char[name].ver[field] then
		msp.char[name].time[field] = now
	elseif action == "" and isSafe then
		msp.char[name].field[field] = contents
		msp.char[name].ver[field] = crcNum
		msp.char[name].time[field] = now
		if field == "TT" then
			for ttField in pairs(msp.ttAll) do
				-- Clear fields that haven't been updated in PROBE_FREQUENCY,
				-- but should have been sent with a tooltip (if they're used by
				-- the opposing addon).
				if msp.char[name].field[ttField] and (msp.char[name].time[ttField] or 0) < now - PROBE_FREQUENCY then
					Process(name, ttField, isSafe)
				end
			end
		end
		if field then
			RunCallback("updated", name, field, contents, crcNum)
		end
	end
end

local function HandleMessage(name, message, isSafe, sessionID, isComplete)
	if isComplete or message:find(SEPARATOR, nil, true) then
		local buffer = msp.char[name].buffer[sessionID or 0]
		if buffer then
			if type(buffer) == "string" then
				message = buffer .. message
			else
				buffer[#buffer + 1] = message
				message = table.concat(buffer)
			end
			msp.char[name].buffer[sessionID] = nil
		end
		for command in message:gmatch(isComplete and PROCESS_COMPLETE or PROCESS) do
			Process(name, command, isSafe)
			if not isComplete then
				message = message:gsub(command:gsub("(%W)","%%%1") .. SEPARATOR, "")
			end
		end
	end
	local buffer = msp.char[name].buffer[sessionID or 0]
	if isComplete then
		local safeReply = msp.char[name].safeReply
		if safeReply then
			msp.char[name].safeReply = nil
			Send(name, safeReply, "SAFE", "REPLY")
		end
		local unsafeReply = msp.char[name].unsafeReply
		if unsafeReply then
			msp.char[name].unsafeReply = nil
			Send(name, unsafeReply, "UNSAFE", "REPLY")
		end
		RunCallback("received", name)
	elseif buffer then
		if type(buffer) == "string" then
			msp.char[name].buffer[sessionID] = { buffer, message }
		else
			buffer[#buffer + 1] = message
		end
	else
		msp.char[name].buffer[sessionID] = message
	end
end

local function Chomp_Callback(...)
	local _, message, channel, name = ...
	local sessionID, msgID, msgTotal = select(13, ...)
	if sessionID == -1 then
		-- Chomp metadata wasn't present, meaning it's a legacy MSP client and
		-- we should ignore it.
		return
	end
	msp.char[name].supported = true
	msp.char[name].scantime = nil
	local method = channel:match("%:(.+)$")
	local isSafe = method == "BATTLENET" or method == "LOGGED"
	HandleMessage(name, message, isSafe, sessionID, msgID == msgTotal)

	-- Inform status handlers of the message.
	RunCallback("status", name, "MESSAGE", msgID, msgTotal)
end

local function Chomp_Error(name)
	RunCallback("status", name, "ERROR")
end

local function EventFrame_Handler(self, event, ...)
	if event == "GROUP_ROSTER_UPDATE" then
		if not IsInGroup() then
			return
		end
		local unitFormat, maxMembers
		if IsInRaid() then
			unitFormat = "raid%d"
			maxMembers = MAX_RAID_MEMBERS
		else
			unitFormat = "party%d"
			maxMembers = MAX_PARTY_MEMBERS
		end
		for i = 1, maxMembers do
			local unit = unitFormat:format(i)
			local relationship = UnitRealmRelationship(unit)
			if relationship == LE_REALM_RELATION_COALESCED then
				local name = AddOn_Chomp.NameMergedRealm(UnitFullName(unit))
				local charTable = msp.char[name]
				if not charTable.seenInGroup then
					charTable.seenInGroup = true
					charTable.scantime = nil
					charTable.supported = nil
					charTable.time = nil
				end
			elseif not relationship then
				-- Only returns nil if the unit doesn't exist, and only doesn't
				-- exist if we've passed the maximum present party/raid index.
				break
			end
		end
		-- Return to not trigger msp:Update() below.
		return
	elseif event == "PLAYER_LOGIN" then
		AddOn_Chomp.RegisterAddonPrefix(PREFIX, Chomp_Callback, CHOMP_PREFIX_SETTINGS)
		AddOn_Chomp.RegisterErrorCallback(Chomp_Error)
		local GU = UnitGUID("player")
		local GC = select(2, UnitClass("player"))
		local GR = select(2, UnitRace("player"))
		local GS = UnitSex("player")
		local GF = UnitFactionGroup("player")
		msp.my.GU = tostring(GU)
		msp.my.GC = tostring(GC)
		msp.my.GR = tostring(GR)
		msp.my.GS = tostring(GS)
		msp.my.GF = tostring(GF)

		if IsTrialAccount() then
			msp.my.TR = "1"
		elseif IsVeteranTrialAccount() then
			msp.my.TR = "2"
		else
			msp.my.TR = "0"
		end

		if GF == "Neutral" then
			self:RegisterEvent("NEUTRAL_FACTION_SELECT_RESULT")
		end
		emptyMeta.__metatable = false
		charMeta.__metatable = false
		mspCharMeta.__metatable = false
	elseif event == "NEUTRAL_FACTION_SELECT_RESULT" then
		local GF = UnitFactionGroup("player")
		msp.my.GF = tostring(GF)
	end
	if msp.ttCache then
		msp:Update()
	end
end
msp.eventFrame:SetScript("OnEvent", EventFrame_Handler)
msp.eventFrame:RegisterEvent("PLAYER_LOGIN")

function msp:Update()
	if not msp.my.VA or msp.my.VA == "" then
		error("msp:Update(): msp.my.VA is absent, assuming profile is not set. Update aborted.")
	end
	local updated = false
	-- Remember, charTable.field will return "" for empty fields.
	local charTable = self.char[PLAYER_NAME]
	charTable.supported = true
	for field, contents in pairs(charTable.field) do
		if not self.my[field] then
			updated = true
			charTable.field[field] = nil
			charTable.ver[field] = nil
			RunCallback("updated", PLAYER_NAME, field, nil, nil)
		end
	end
	for field, contents in pairs(self.my) do
		if contents == "" then
			contents = nil
			self.my[field] = nil
		end
		if field ~= "TT" then
			if contents and contents:find(SEPARATOR, nil, true) then
				-- Hopefully nobody notices.
				contents = contents:gsub(SEPARATOR, SEPARATOR_REPLACEMENT)
				self.my[field] = contents
			end
			if contents and not AddOn_Chomp.CheckLoggedContents(contents) then
				self.my[field] = charTable.field[field] ~= "" and charTable.field[field] or nil
				CallErrorHandler(("msp:Update(): Found illegal byte or sequence in field %s, contents reverted to last known-good value."):format(field))
			elseif charTable.field[field] ~= (contents or "") then
				updated = true
				charTable.field[field] = contents
				local version = self.myver[field]
				charTable.ver[field] = version
				charTable.time[field] = TIME_MAX
				RunCallback("updated", PLAYER_NAME, field, contents, version)
			end
		end
	end
	if updated or not self.ttCache then
		local tt = {}
		for i, field in ipairs(self.ttList) do
			if not self.my[field] then
				tt[#tt + 1] = field
			else
				tt[#tt + 1] = ("%s:%s"):format(field, self.my[field])
			end
		end
		self.ttContents = table.concat(tt, SEPARATOR) or ""
		self.ttCache = ("%s%sTT%s"):format(self.ttContents, SEPARATOR, CRC32CCache[self.ttContents])
		local version = self.myver.TT
		charTable.ver.TT = version
		charTable.time.TT = TIME_MAX
		RunCallback("updated", PLAYER_NAME, "TT", nil, version)
		RunCallback("received", PLAYER_NAME)
	end
	return updated
end

local function RunRequestQueue()
	for name, fields in pairs(msp.queuedRequests) do
		msp:Request(name, fields)
		msp.queuedRequests[name] = nil
	end
end

function msp:QueueRequest(name, field)
	if type(field) ~= "string" or not field:find("^%u%u$") then
		error("msp:QueueRequest(): field: invalid field")
	end
	name = AddOn_Chomp.NameMergedRealm(name)
	if name == PLAYER_NAME or name:match("^([^%-]+)") == UNKNOWNOBJECT then
		return false
	end
	local now = GetTime()
	if self.char[name].supported == false and now < self.char[name].scantime + PROBE_FREQUENCY then
		return false
	elseif now <= (self.char[name].time[field] or 0) + FIELD_FREQUENCY then
		return false
	end
	local pendingRequests = next(msp.queuedRequests) ~= nil
	if not self.queuedRequests[name] then
		self.queuedRequests[name] = {}
	end
	local queue = self.queuedRequests[name]
	queue[#queue + 1] = field
	if not pendingRequests then
		C_Timer.After(0, RunRequestQueue)
	end
end

function msp:Request(name, fields)
	name = AddOn_Chomp.NameMergedRealm(name)
	if name == PLAYER_NAME or name:match("^([^%-]+)") == UNKNOWNOBJECT then
		return false
	end
	local now = GetTime()
	if self.char[name].supported == false and now < self.char[name].scantime + PROBE_FREQUENCY then
		return false
	elseif not self.char[name].supported then
		self.char[name].supported = false
		self.char[name].scantime = now
	end
	local fieldsType = type(fields)
	if fieldsType == "string" then
		fields = { fields }
	elseif fieldsType == "nil" then
		fields = { "TT" }
	end
	local toSend = {}
	for i, field in ipairs(fields) do
		if type(field) == "string" and field:find("^%u%u$") then
			if self.ttAll[field] then
				-- Will only get requested once, due to time marking/checking.
				field = "TT"
			end
			if now > (self.char[name].time[field] or 0) + FIELD_FREQUENCY then
				if not self.char[name].ver[field] then
					toSend[#toSend + 1] = "?" .. field
				else
					toSend[#toSend + 1] = ("?%s%s"):format(field, tohex(self.char[name].ver[field]))
				end
				-- Marking time here prevents rapid re-requesting. Also done in
				-- receive.
				self.char[name].time[field] = now
			end
		end
	end
	if #toSend > 0 then
		Send(name, toSend, "UNSAFE", "REQUEST")
		return true
	end
	return false
end

function msp:Send(name, chunks)
	name = AddOn_Chomp.NameMergedRealm(name)
	if name == PLAYER_NAME then
		return 0
	end
	return Send(name, chunks, "SAFE", "REQUEST")
end

-- GHI makes use of this. Even if not used for filtering, keep it.
function msp:PlayerKnownAbout(name)
	if not name or name == "" then
		return false
	end
	-- AddOn_Chomp.NameMergedRealm() is called on this in the msp.char metatable.
	return self.char[name].supported ~= nil
end

-- Strips TRP3 markup tags from a given string. The contents of the tags will be entirely
-- removed.
function msp:StripTRP3MarkupTags(input)
	return string.gsub(input, "%{.-%}", "")
end

msp.version = VERSION

if msp.ttCache then
	msp:Update()
end
