williePete = {}
williePete.version = "2.1.0"
williePete.ups = 10 -- we update at 10 fps, so accuracy of a 
-- missile moving at Mach 2 is within 33 meters, 
-- with interpolation even at 3 meters

williePete.requiredLibs = {
	"dcsCommon", -- always
	"cfxZones", -- Zones, of course 
	"cfxMX",
}
--[[--
	Version History
	1.0.0 - Initial version 
	1.0.1 - update to suppress verbosity
    1.0.2 - added Gazelle WP	
	2.0.0 - dmlZones, OOP
		  - Guards for multi-unit player groups 
		  - getFirstLivingPlayerInGroupNamed()
	2.0.1 - added Harrier's FFAR M156 WP
	2.0.2 - hardened playerUpdate() 
	2.0.3 - further hardened playerUpdate()
	2.0.4 - support for the Kiowa's Hydra M259 
	2.0.5 - support for Mirage F1 WP that differ from Gazelle (?)
	2.0.6 - DCS Update 7-11 2024 weapon name bug 
	2.1.0 - DCS update 2.9.6 dynamic spawn support 
--]]--

williePete.willies = {}
williePete.wpZones = {}
williePete.playerGUIs = {} -- used for unit guis 
williePete.groupGUIs = {} -- because some people may want to install 
-- multip-unit player groups
williePete.blastedObjects = {} -- used when we detonate something 

-- recognizes WP munitions. May require regular update when new
-- models come out. 
williePete.smokeWeapons = {"HYDRA_70_M274","HYDRA_70_MK61","HYDRA_70_MK1","HYDRA_70_WTU1B","HYDRA_70_M156","HYDRA_70_M158","BDU_45B","BDU_33","BDU_45","BDU_45LGB","BDU_50HD","BDU_50LD","BDU_50LGB","C_8CM", "SNEB_TYPE254_H1_GREEN", "SNEB_TYPE254_H1_RED", "SNEB_TYPE254_H1_YELLOW",
"SNEB_TYPE254_F1B_YELLOW", "SNEB_TYPE254_F1B_GREEN", "SNEB_TYPE254_F1B_RED", "FFAR M156 WP",
"HYDRA_70_M259"}

function williePete.addWillie(theWillie)
	table.insert(williePete.willies, theWillie)
end

function williePete.addWPZone(theZone)
	table.insert(williePete.wpZones, theZone)
end

function williePete.closestCheckInTgtZoneForCoa(point, coa)
	-- returns the closest zone that point is inside. 
	-- first tries directly, then, if none found, 
	-- with added check-in radius
	local lPoint = {x=point.x, y=0, z=point.z}
	local currDelta = math.huge 
	local closestZone = nil
	-- first, we try if outright inside 
	for zName, zData in pairs(williePete.wpZones) do 
		if zData.coalition == coa then 
			-- local zPoint = cfxZones.getPoint(zData)
			local inZone, delta = cfxZones.isPointInsideZone(lPoint, zData)
			if inZone and (delta < currDelta) then 
				currDelta = delta
				closestZone = zData
			end
		end
	end
	-- if we got one, we return that zone 
	if closestZone then return closestZone, currDelta end 
	
	for zName, zData in pairs(williePete.wpZones) do 
		if zData.coalition == coa then 
			-- local zPoint = cfxZones.getPoint(zData)
			local inZone, delta = cfxZones.isPointInsideZone(lPoint, zData, zData.checkInRange)
			if inZone and (delta < currDelta) then 
				currDelta = delta
				closestZone = zData
			end
		end
	end
	if closestZone then return closestZone, currDelta end
	
	return nil, -1
	
end

function williePete.getClosestZoneForCoa(point, coa)
	local lPoint = {x=point.x, y=0, z=point.z}
	local currDelta = math.huge 
	local closestZone = nil
	for zName, zData in pairs(williePete.wpZones) do 
		if zData.coalition == coa then 
			local zPoint = cfxZones.getPoint(zData)
			local delta = dcsCommon.dist(lPoint, zPoint) -- emulate flag compare 
			if (delta < currDelta) then 
				currDelta = delta
				closestZone = zData
			end
		end
	end
	return closestZone, currDelta 
end


function williePete.createWPZone(aZone)
	aZone.coalition = aZone:getCoalitionFromZoneProperty("wpTarget", 0) -- side that marks it on map, and who fires arty
	aZone.shellStrength = aZone:getNumberFromZoneProperty( "shellStrength", 500) -- power of shells (strength)
	aZone.shellNum = aZone:getNumberFromZoneProperty("shellNum", 17) -- number of shells in bombardment
	aZone.transitionTime = aZone:getNumberFromZoneProperty( "transitionTime", 20) -- average time of travel for projectiles 
	aZone.coolDown = aZone:getNumberFromZoneProperty("coolDown", 180) -- cooldown after arty fire, used to set readyTime
	aZone.baseAccuracy = aZone:getNumberFromZoneProperty( "baseAccuracy", 50) 
	
	aZone.readyTime = 0 -- if readyTime > now we are not ready
	aZone.trackingPlayer = nil -- name player's unit who is being tracked for wp. may not be neccessary
	aZone.checkedIn = {} -- dict of all planes currently checked in
	
	aZone.wpMethod = aZone:getStringFromZoneProperty("wpMethod", "change")
	if aZone:hasProperty("method") then 
		aZone.wpMethod = aZone:getStringFromZoneProperty("method", "change")
	end
	
	aZone.checkInRange = aZone:getNumberFromZoneProperty( "checkInRange", williePete.checkInRange) -- default to my default
	
	aZone.ackSound = aZone:getStringFromZoneProperty("ackSound", williePete.ackSound)
	aZone.guiSound = aZone:getStringFromZoneProperty("guiSound", williePete.guiSound)
	
	if aZone:hasProperty("wpFire!") then 
		aZone.wpFire = aZone:getStringFromZoneProperty("wpFire!", "<none)")
	end
	
	if aZone.verbose then 
		trigger.action.outText("Added wpTarget zone <" .. aZone.name .. ">", 30)
	end
end

--
-- PLAYER MANAGEMENT
--
function williePete.latePlayerGUI(theUnit)
	local unitInfo = {}
	unitInfo.name = theUnit:getName() -- needed for reverse-lookup 
	local theGroup = theUnit:getGroup()
	unitInfo.gName = theGroup:getName() -- gName -- also needed for reverse lookup 
	unitInfo.coa = theGroup:getCoalition() -- coa 
	unitInfo.gID = theGroup:getID() -- gData.groupId
	unitInfo.uID = theUnit:getID() -- uData.unitId
	unitInfo.theType = theUnit:getTypeName() -- theType
	cat = theGroup:getCategory() 
	if cat == 0 then unitInfo.cat = "plane" 
	elseif cat == 1 then unitInfo.cat = "helicopter"
	else
		return -- whatever player is controlling, it's not for WP
	end 
		
	williePete.doGUIforUnitInfo(unitInfo)
end

function williePete.doGUIforUnitInfo(unitInfo)
	local pass = false 
	local uName = unitInfo.name
	local gName = unitInfo.gName	
	
	for idx, aType in pairs(williePete.facTypes) do 
		if aType == "ALL" then pass = true end 
		if aType == "ANY" then pass = true end 
		if aType == theType then pass = true end 
		if dcsCommon.stringStartsWith(aType, "HEL") and unitInfo.cat == "helicopter" then pass = true end 
		if dcsCommon.stringStartsWith(aType, "PLAN") and unitInfo.cat == "plane" then pass = true end 
	end
	
	if pass then -- we install a menu for this group 
		-- we may not want check in stuff, but it could be cool
		if williePete.playerGUIs[gName] then 
			trigger.action.outText("+++WP: Warning: we already have WP menu for unit <" .. uName .. "> in group <" .. gName .. ">. Skipped.", 30)
		elseif williePete.groupGUIs[gName] then 
			trigger.action.outText("+++WP: Warning: POSSIBLE MULTI-PLAYER UNIT GROUP DETECTED. We already have WP menu for Player Group <" .. gName .. ">. Skipped, only first unit supported. ", 30)
		else 
			unitInfo.root = missionCommands.addSubMenuForGroup(unitInfo.gID, "FAC")
			unitInfo.checkIn = missionCommands.addCommandForGroup(unitInfo.gID, "Check In", unitInfo.root, williePete.redirectCheckIn, unitInfo)
			williePete.groupGUIs[gName] = unitInfo
			williePete.playerGUIs[gName] = unitInfo
		end
	end 
end

function williePete.startPlayerGUI()
	-- scan all mx players 
	-- note: currently assumes single-player groups
	-- in preparation of single-player 'commandForUnit'
	for uName, uData in pairs(cfxMX.playerUnitByName) do 
		local unitInfo = {}
		-- try and access each unit even if we know that the 
		-- unit does not exist in-game right now 
		local gData = cfxMX.playerUnit2Group[uName]
		local gName = gData.name 
		local coa = cfxMX.groupCoalitionByName[gName]
		local theType = uData.type

		if williePete.verbose then 
			trigger.action.outText("unit <" .. uName .. ">: type <" .. theType .. "> coa <" .. coa .. ">, group <" .. gName .. ">", 30)
		end 
		
		unitInfo.name = uName -- needed for reverse-lookup 
		unitInfo.gName = gName -- also needed for reverse lookup 
		unitInfo.coa = coa 
		unitInfo.gID = gData.groupId
		unitInfo.uID = uData.unitId
		unitInfo.theType = theType
		unitInfo.cat = cfxMX.groupTypeByName[gName]
		-- now check type against willie pete config for allowable types 
--[[--		local pass = false 
		for idx, aType in pairs(williePete.facTypes) do 
			if aType == "ALL" then pass = true end 
			if aType == "ANY" then pass = true end 
			if aType == theType then pass = true end 
			if dcsCommon.stringStartsWith(aType, "HEL") and unitInfo.cat == "helicopter" then pass = true end 
			if dcsCommon.stringStartsWith(aType, "PLAN") and unitInfo.cat == "plane" then pass = true end 
		end
		
		if pass then -- we install a menu for this group 
			-- we may not want check in stuff, but it could be cool
			if williePete.playerGUIs[gName] then 
				trigger.action.outText("+++WP: Warning: we already have WP menu for unit <" .. uName .. "> in group <" .. gName .. ">. Skipped.", 30)
			elseif williePete.groupGUIs[gName] then 
				trigger.action.outText("+++WP: Warning: POSSIBLE MULTI-PLAYER UNIT GROUP DETECTED. We already have WP menu for Player Group <" .. gName .. ">. Skipped, only first unit supported. ", 30)
			else 
				unitInfo.root = missionCommands.addSubMenuForGroup(unitInfo.gID, "FAC")
				unitInfo.checkIn = missionCommands.addCommandForGroup(unitInfo.gID, "Check In", unitInfo.root, williePete.redirectCheckIn, unitInfo)
				williePete.groupGUIs[gName] = unitInfo
				williePete.playerGUIs[gName] = unitInfo
			end
		end 
--]]--
		williePete.doGUIforUnitInfo(unitInfo)
		-- store it - WARNING: ASSUMES SINGLE-UNIT Player Groups 
		--williePete.playerGUIs[uName] = unitInfo
	end
end

--
-- BOOM command
--
function williePete.doBoom(args)
	local unitInfo = args.unitInfo
	if unitInfo then 
		-- note that unit who commânded fire may no longer be alive 
		-- so check it every time. unit must be alive 
		-- to receive credits later
		local uName = unitInfo.gName
		local blastRad = math.floor(math.sqrt(args.strength)) * 2
		if blastRad < 10 then blastRad = 10 end 
		
		local affectedUnits = dcsCommon.getObjectsForCatAtPointWithRadius(nil, args.point, blastRad)
		for idx, aUnit in pairs(affectedUnits) do 
			local aName = aUnit:getName()
			if williePete.verbose then 
				trigger.action.outText("<" .. aName .. "> is in blast Radius (" .. blastRad .. "m) of shells for <" .. uName .. ">'s target coords", 30)
			end
			williePete.blastedObjects[aName] = unitInfo.name -- last one gets the kill
		end 
	end
	trigger.action.explosion(args.point, args.strength)

end

function williePete.doParametricFireAt(aPoint, accuracy, shellNum, shellBaseStrength, shellVariance, transitionTime, unitInfo)
	if williePete.verbose then 
		trigger.action.outText("fire with accuracy <" .. accuracy .. "> shellNum <" .. shellNum .. "> baseStren <" .. shellBaseStrength .. "> variance <" .. shellVariance .. ">, ttime <" .. transitionTime .. ">", 30)
	end 
	
	-- accuracy is meters from center 
	if not aPoint then return end 
	if not accuracy then accuracy = 100 end 
	if not shellNum then shellNum = 17 end 
	if not shellBaseStrength then shellBaseStrength = 500 end 
	if not shellVariance then shellVariance = 0.2 end 
	if not transitionTime then transitionTime = 17 end 
	
	local alt = land.getHeight({x=aPoint.x, y=aPoint.z})
	local center = {x=aPoint.x, y=alt, z=aPoint.z}
	
	for i=1, shellNum do
		local thePoint = dcsCommon.randomPointInCircle(accuracy, 0, center.x, center.z)
		thePoint.y = land.getHeight({x=thePoint.x, y=thePoint.z})
		local boomArgs = {}
		local strVar = shellBaseStrength * shellVariance
		strVar = strVar * (2 * dcsCommon.randomPercent() - 1.0) -- go from -1 to 1
		
		boomArgs.strength = shellBaseStrength + strVar
		thePoint.y = land.getHeight({x = thePoint.x, y = thePoint.z}) + 1  -- elevate to ground height + 1
		boomArgs.point = thePoint
		boomArgs.zone = aZone
		boomArgs.unitInfo = unitInfo
		local timeVar = 5 * (2 * dcsCommon.randomPercent() - 1.0) -- +/- 1.5 seconds
		if timeVar < 0 then timeVar = -timeVar end 

		timer.scheduleFunction(williePete.doBoom, boomArgs, timer.getTime() + transitionTime + timeVar)
	end
end

--
-- COMMS
--

function williePete.redirectCheckIn(unitInfo)
	timer.scheduleFunction(williePete.doCheckIn, unitInfo, timer.getTime() + 0.1)
end

-- fix for multi-unit player groups where only one of them is 
-- alive: get first living player in group. Will be added to 
-- dcsCommon soon 
function williePete.getFirstLivingPlayerInGroupNamed(gName)
	local theGroup = Group.getByName(gName)
	if not theGroup then return nil end 
	local theUnits = theGroup:getUnits()
	for idx, aUnit in pairs(theUnits) do 
		if Unit.isExist(aUnit) and aUnit.getPlayerName and 
		aUnit:getPlayerName() then 
			return aUnit -- return first living player unit 
		end
	end
	return nil 
end

function williePete.doCheckIn(unitInfo)
	-- WARNING: unitInfo points to first processed player in 
	-- group. May not work fully with multi-unit player groups 
	local gName = unitInfo.gName
	local theUnit = williePete.getFirstLivingPlayerInGroupNamed(gName) --Unit.getByName(unitInfo.name)
	if not theUnit then 
		-- dead man calling. Pilot dead but unit still alive 
		-- OR second unit in multiplayer group, but unit 1 
		-- does not / no longer exists 
		trigger.action.outText("Calling station, say again, can't read you.", 30)
		return 
	end
	
	local p = theUnit:getPoint() -- only react to first player unit
	local theZone, dist = williePete.closestCheckInTgtZoneForCoa(p, unitInfo.coa)

	if not theZone then 
		theZone, dist = williePete.getClosestZoneForCoa(p, unitInfo.coa)
		if not theZone then 
			trigger.action.outTextForGroup(unitInfo.gID, "No target zone in range.", 30)
			trigger.action.outSoundForGroup(unitInfo.gID, williePete.guiSound)
			return 
		end
		dist = math.floor(dist /100) / 10 
		bearing = dcsCommon.bearingInDegreesFromAtoB(p, theZone:getPoint())
		trigger.action.outTextForGroup(unitInfo.gID, unitInfo.gName .. ", you are too far from target zone, closest target zone is " .. theZone.name .. ", " .. dist .. "km at bearing " .. bearing .. "°", 30)
		trigger.action.outSoundForGroup(unitInfo.gID, theZone.guiSound)
		return 
	end
	
	-- we are now checked in to zone -- unless we are already checked in
	-- NOTE: we use group name, not unit name!
	if theZone.checkedIn[unitInfo.gName] then 
		trigger.action.outTextForGroup(unitInfo.gID, unitInfo.gName .. ", " .. theZone.name .. ", we heard you the first time, proceed.", 30)
		trigger.action.outSoundForGroup(unitInfo.gID, theZone.guiSound)
		return 
	end
	
	-- we now check in 
	theZone.checkedIn[unitInfo.gName] = unitInfo
	
	-- add the 'Target marked' menu 
	unitInfo.targetMarked = missionCommands.addCommandForGroup(unitInfo.gID, "Target Marked, commence firing", unitInfo.root, williePete.redirectTargetMarked, unitInfo)
	-- remove 'check in'
	missionCommands.removeItemForGroup(unitInfo.gID, unitInfo.checkIn)
	unitInfo.checkIn = nil 
	-- add 'check out'
	unitInfo.checkOut = missionCommands.addCommandForGroup(unitInfo.gID, "Check Out of " .. theZone.name, unitInfo.root, williePete.redirectCheckOut, unitInfo)
	
	trigger.action.outTextForGroup(unitInfo.gID, "Roger " .. unitInfo.gName .. ", " .. theZone.name .. " tracks you, standing by for target data.", 30)
	trigger.action.outSoundForGroup(unitInfo.gID, theZone.guiSound)
end

function williePete.redirectCheckOut(unitInfo)
	timer.scheduleFunction(williePete.doCheckOut, unitInfo, timer.getTime() + 0.1)
end

function williePete.doCheckOut(unitInfo)
	-- check out of all zones 
	local wasCheckedIn = false 
	local fromZone = ""
	for idx, theZone in pairs(williePete.wpZones) do 
		if theZone.checkedIn[unitInfo.gName] then 
			wasCheckedIn = true 
			fromZone = theZone.name
		end 
		theZone.checkedIn[unitInfo.gName] = nil 
	end
	if not wasCheckedIn then 
		trigger.action.outTextForGroup(unitInfo.gID, unitInfo.gName .. ", roger cecked-out. Good hunting!", 30)
		trigger.action.outSoundForGroup(unitInfo.gID, williePete.guiSound)
	else 
		trigger.action.outTextForGroup(unitInfo.gID, unitInfo.gName .. " has checked out of " .. fromZone ..".", 30)
		trigger.action.outSoundForGroup(unitInfo.gID, williePete.guiSound)
	end
	
	-- remove checkOut and targetMarked 
	missionCommands.removeItemForGroup(unitInfo.gID, unitInfo.checkOut)
	unitInfo.checkOut = nil
	missionCommands.removeItemForGroup(unitInfo.gID, unitInfo.targetMarked)
	unitInfo.targetMarked = nil
	
	-- add check in 
	unitInfo.checkIn = missionCommands.addCommandForGroup(unitInfo.gID, "Check In", unitInfo.root, williePete.redirectCheckIn, unitInfo)
end


function williePete.redirectTargetMarked(unitInfo)
	timer.scheduleFunction(williePete.doTargetMarked, unitInfo, timer.getTime() + 0.1)
end

function williePete.rogerDodger(args)
	local unitInfo = args[1]
	local theZone = args[2]
	
	trigger.action.outTextForCoalition(unitInfo.coa, "Roger " .. unitInfo.gName .. ", good copy, firing.", 30)
	trigger.action.outSoundForCoalition(unitInfo.coa, theZone.ackSound)
end

function williePete.doTargetMarked(unitInfo)
	-- first, check if we are past the time-out
	local now = timer.getTime()
	
	if not unitInfo.wpInZone then 
		trigger.action.outTextForGroup(unitInfo.gID, "No target mark visible, please mark again", 30)
		trigger.action.outSoundForGroup(unitInfo.gID, williePete.guiSound)
		return
	end
	
	-- now check if zone matches check-in 
	if not unitInfo.expiryTime or unitInfo.expiryTime < now then 
		trigger.action.outTextForGroup(unitInfo.gID, "Target mark stale or ambiguous, set fresh mark", 30)
		trigger.action.outSoundForGroup(unitInfo.gID, williePete.guiSound)
		return
	end
	
	-- now, check if the zone is ready to receive 
	if not unitInfo.wpInZone or not unitInfo.pos then 
		-- should not happen, but better safe than sorry
		trigger.action.outTextForGroup(unitInfo.gID, "Lost sight of target location, set new mark", 30)
		trigger.action.outSoundForGroup(unitInfo.gID, williePete.guiSound)
		return 
	end
	
	local tgtZone = unitInfo.wpInZone 
	-- see if we are checked into that zone 
	if not tgtZone.checkedIn[unitInfo.gName] then 
		-- zones don't match
		trigger.action.outTextForGroup(unitInfo.gID, "Say again " .. unitInfo.gName .. ", we have crosstalk. Try and reset coms", 30)
		trigger.action.outSoundForGroup(unitInfo.gID, williePete.guiSound)
		return
	end
	
	-- see if zone is ready to receive 
	local timeRemaining = math.floor(tgtZone.readyTime - now)
	if timeRemaining > 0 then 
		-- zone not ready
		trigger.action.outTextForGroup(unitInfo.gID, "Stand by " .. unitInfo.gName .. ", artillery not ready. Expect " .. timeRemaining + math.random(1, 5) .. " seconds.", 30)
		trigger.action.outSoundForGroup(unitInfo.gID, tgtZone.guiSound)
		return
	end
	
	-- if we get here, we are fire at mark 
	local alt = math.floor(land.getHeight({x = unitInfo.pos.x, y = unitInfo.pos.z}))
	local grid = coord.LLtoMGRS(coord.LOtoLL(unitInfo.pos))
	local mgrs = grid.UTMZone .. ' ' .. grid.MGRSDigraph .. ' ' .. grid.Easting .. ' ' .. grid.Northing
	local theLoc = mgrs 
	trigger.action.outTextForCoalition(unitInfo.coa, tgtZone.name ..", " .. unitInfo.gName .." is transmitting target location. Fire at " .. theLoc .. ", elevation " .. alt .. " meters, target marked.", 30)
	trigger.action.outSoundForCoalition(unitInfo.coa, tgtZone.guiSound)
	timer.scheduleFunction(williePete.rogerDodger, {unitInfo, tgtZone},timer.getTime() + math.random(2, 5))
	
	-- collect zone's fire params & fire
	local shellStrength = tgtZone.shellStrength
	local shellNum = tgtZone.shellNum 
	local transitionTime = tgtZone.transitionTime
	local accuracy = tgtZone.baseAccuracy 
	
	williePete.doParametricFireAt(unitInfo.pos, accuracy, shellNum, shellStrength, 0.2, transitionTime, unitInfo)
	
	-- set zone's cooldown
	tgtZone.readyTime = now + tgtZone.coolDown

	-- if we have an output, trigger it now 
	if tgtZone.wpFire then 
		cfxZones.pollFlag(tgtZone.wpFire, tgtZone.wpMethod, tgtZone)
	end
end
-- return true if a zone is actively tracking theUnit to place 
-- a wp 

function williePete.zoneIsTracking(theUnit) -- group level!
	local uName = theUnit:getName()
	local uGroup = theUnit:getGroup()
	local gName = uGroup:getName() 
	
	for idx, theZone in pairs(williePete.wpZones) do
		if theZone.checkedIn[gName] then return true end
	end	
	return false
end

function williePete.isWP(theWeapon) 
	local theDesc = theWeapon:getTypeName()
	for idx, wpw in pairs(williePete.smokeWeapons) do 
		if theDesc == wpw then return true end 
	end
	if williePete.verbose then 
		trigger.action.outText(theDesc .. " is no wp, ignoring.", 30)
	end
		
	return false 
end

function williePete.zedsDead(theObject) 
	if not theObject then return end 
	if not theObject.getName then return end -- DCS July-11 oddity. 
	local theName = theObject:getName()
	-- now check if it's a registered blasted object:getSampleRate()
	-- in multi-unit player groups, this can can lead to 
	-- mis-attribution, beware!
	local blaster = williePete.blastedObjects[theName]
	if blaster then 
		local theUnit = Unit.getByName(blaster)
		if theUnit then 
			-- interface to playerscore 
			if cfxPlayerScore then
				local fakeEvent = {}
				fakeEvent.initiator = theUnit -- killer
				fakeEvent.target = theObject -- vic 
				cfxPlayerScore.killDetected(fakeEvent)
			end
		end
		williePete.blastedObjects[theName] = nil 
	end
end

function williePete:onEvent(event)
	if not event.initiator then 
		return 
	end 
	
	-- see if a dynamic spawn 
	if event.id == 15 then 
		local theUnit = event.initiator
		if not cfxMX.isDynamicPlayer(theUnit) then return end 
		williePete.latePlayerGUI(theUnit)
		return 
	end 
	
	-- check if it's a dead event
	if event.id == 8 then 
		-- death event
		williePete.zedsDead(event.initiator)
	end
	
	if not event.weapon then 
		return 
	end 
	
	local theUnit = event.initiator
	local pType = "(AI)"
	if theUnit.getPlayerName and theUnit:getPlayerName() then pType = "(" .. theUnit:getName() .. ")" end
		
	if event.id == 1 then -- S_EVENT_SHOT
		-- initiator is who fired. maybe want to test if player  
		
		if not williePete.isWP(event.weapon) then 
			-- we only trigger on WP weapons 
			return  
		end
		
		-- make sure that whoever fired it is being tracked by 
		-- a zone. zoneIsTracking checks on GROUP level!
		if not williePete.zoneIsTracking(theUnit) then 
			return  
		end
		
		-- it's a willie, fired by player who is checked in: let's track it 
		local theWillie = {}
		theWillie.firedBy = theUnit:getName()
		theWillie.theUnit = theUnit 
		theWillie.theGroup = theUnit:getGroup() 
		theWillie.gName = theWillie.theGroup:getName()
		theWillie.weapon = event.weapon
		theWillie.wt = theWillie.weapon:getTypeName()
		theWillie.pos = theWillie.weapon:getPoint()
		theWillie.v = theWillie.weapon:getVelocity()
		
		williePete.addWillie(theWillie)
	end
	
end 

-- test if a projectile has hit the ground inside a wp zone 
function williePete.isInside(theWillie)
	local thePoint = theWillie.pos 
	local theUnitName = theWillie.firedBy -- may be dead already, but who cares
	local theUnit = Unit.getByName(theUnitName) 
	if not theUnit then return false end -- unit dead 
	if not Unit.isExist(theUnit) then return false end -- dito 
	local theGroup = theUnit:getGroup()
	local gName = theGroup:getName() 
	local unitInfo = williePete.groupGUIs[gName] -- returns unitInfo struct, contains group info 
	if not unitInfo then return nil end 
	for idx, theZone in pairs(williePete.wpZones) do
		if cfxZones.pointInZone(thePoint, theZone) then 
			-- we are inside. but is this the right coalition?
			if unitInfo.coa == theZone.coalition then 
				return theZone
			end
			-- if we want to allow neutral zones (doens't make sense)
			-- add another guard below 
		end
	end
	return nil
end


-- update 

function williePete.projectileHit(theWillie) 
	-- interpolate pos: half time between updates times last velocity 
	local vmod = dcsCommon.vMultScalar(theWillie.v, 0.5 / williePete.ups)
	theWillie.pos = dcsCommon.vAdd(theWillie.pos, vmod) 
	
	-- reset last mark for player's group 
	-- access unitInfo 
	local thePlayer = williePete.playerGUIs[theWillie.gName]
	thePlayer.pos = nil
	thePlayer.wpInZone = nil 
	
	-- check if this is within a wpZones 
	local theZone = williePete.isInside(theWillie)
	if not theZone then 
		if williePete.verbose then 
			trigger.action.outText("+++wp: wp expired outside zone", 30)
		end
		return 
	end 
	
	-- if we receive a zone, we know that the player's 
	-- coalition matches the one of the zone 
	thePlayer.expiryTime = timer.getTime() + williePete.wpMaxTime -- set timeout in which player can give fire command 
	thePlayer.pos = theWillie.pos -- remember the loc
	thePlayer.wpInZone = theZone -- remember the zone 
	
end

function williePete.updateWP()
	timer.scheduleFunction(williePete.updateWP, {}, timer.getTime() + 1/williePete.ups)
	
	local nextPete = {}
	for idx, theWillie in pairs(williePete.willies) do 
		-- check if it still exists
		if Weapon.isExist(theWillie.weapon) then 
			-- update loc, proceed to next round 
			theWillie.pos = theWillie.weapon:getPoint()
			theWillie.v = theWillie.weapon:getVelocity()
			table.insert(nextPete, theWillie)
		else 
			-- weapon disappeared: it has hit something
			-- but unguided rockets do not create an event for that 
			williePete.projectileHit(theWillie)
			-- no longer propagates to next round
		end
	end
	williePete.willies = nextPete
end

function williePete.playerUpdate() 
	timer.scheduleFunction(williePete.playerUpdate, {}, timer.getTime() + 2) -- check 30 times a minute
	-- zone still checked in updates for zones 
	for idx, theZone in pairs(williePete.wpZones) do 
		-- make sure any unit checked in is still inside 
		-- the zone that they checked in, or they are checked out 
		--local zp = cfxZones.getPoint(theZone)
		for idy, unitInfo in pairs(theZone.checkedIn) do 
			-- make sure at least one unit still exists
			local dropUnit = true 
			local theGroup = Group.getByName(unitInfo.gName)
			if theGroup then 
				local allUnits = theGroup:getUnits()
				for idx, theUnit in pairs(allUnits) do 
				--local theUnit = Unit.getByName(unitInfo.name)
					if theUnit and Unit.isExist(theUnit) and 
					theUnit.getPlayerName and theUnit:getPlayerName() then 
						local up = theUnit:getPoint()
						up.y = 0
						local isInside, dist = cfxZones.isPointInsideZone(up, theZone, theZone.checkInRange)
						 
						if isInside then 
							dropUnit = false
						end
					end
				end
			else 
				trigger.action.outText("+++wp: strange issues with group <" .. unitInfo.gName .. ">, does not exist. Skipped in playerUpdate()", 30)
			end
			if dropUnit then 
				-- all outside, remove from zone check-in 
				-- williePete.doCheckOut(unitInfo)
				timer.scheduleFunction(williePete.doCheckOut, unitInfo, timer.getTime() + 0.1) -- to not muck up iteration
			end
		end
	end
	
	-- menu updates for all players 
end

--
-- Config & Start
--
function williePete.readConfigZone()
	local theZone = cfxZones.getZoneByName("wpConfig") 
	if not theZone then 
		theZone = cfxZones.createSimpleZone("wpConfig") 
	end 
	
	local facTypes = theZone:getStringFromZoneProperty("facTypes", "all")
	facTypes = string.upper(facTypes)
	
	-- make this an array 
	local allTypes = {}
	if dcsCommon.containsString(facTypes, ",") then 
		allTypes = dcsCommon.splitString(facTypes, ",")
	else 
		table.insert(allTypes, facTypes) 
	end
	williePete.facTypes = dcsCommon.trimArray(allTypes)
	
	-- how long a wp is active. must not be more than 5 minutes
	williePete.wpMaxTime = theZone:getNumberFromZoneProperty( "wpMaxTime", 3 * 60)
	
	-- default check-in range, added to target zone's range and used 
	-- for auto-check-out 
	williePete.checkInRange = theZone:getNumberFromZoneProperty("checkInRange", 10000) -- 10 km outside
	
	williePete.ackSound = theZone:getStringFromZoneProperty( "ackSound", "some")
	williePete.guiSound = theZone:getStringFromZoneProperty( "guiSound", "some")
	
	williePete.verbose = theZone.verbose
	
	if williePete.verbose then 
		trigger.action.outText("+++wp: read config", 30)
	end 
end

function williePete.start()
	if not dcsCommon.libCheck("cfx williePete", 
		williePete.requiredLibs) then
		return false 
	end
	
	-- read config 
	williePete.readConfigZone()
	
	-- collect all wp target zones 
	local attrZones = cfxZones.getZonesWithAttributeNamed("wpTarget")
	
	for k, aZone in pairs(attrZones) do 
		williePete.createWPZone(aZone) -- process attribute and add to zone
		williePete.addWPZone(aZone) -- remember it so we can smoke it
	end
	
	-- add event handler
	world.addEventHandler(williePete)

	-- initialize all players from MX
	williePete.startPlayerGUI()

	-- start updates 
	williePete.updateWP() -- for tracking wp, at ups
	williePete.playerUpdate() -- for tracking players, at 1/s 

	
	trigger.action.outText("williePete v" .. williePete.version .. " loaded.", 30)

	return true
end

-- let's go 
if not williePete.start() then 
	trigger.action.outText("cf/x Willie Pete aborted: missing libraries", 30)
	williePete = nil 
end