-- LUA Script - precede every function and global member with lowercase name of script + '_main'
g_teleporter_name_list = {}

function teleporter_name_init_name(e, name)
	-- initialise transporter within level
	g_teleporter_name_list[e] = {name = name, state = 'off', tTime = 0}
end

local function distBetween (e1, e2)
	local Dx, Dy, Dz = e1.x - e2.x, e1.y - e2.y, e1.z - e2.z
	
	return (Dx * Dx + Dy * Dy + Dz * Dz)
end

local visuals = {Amb = 0}

local function saveVisuals()
	visuals.Amb = GetAmbienceIntensity()
end

local function resetVisuals()
	SetAmbienceIntensity(visuals.Amb)
end

local function CloserThan(Ent, dist)

	local DY = Ent.y - g_PlayerPosY
	
	if math.abs(DY) < 100 then
	
		local DX = Ent.x - g_PlayerPosX
		local DZ = Ent.z - g_PlayerPosZ	
		return (DX * DX + DZ * DZ) < dist * dist
	end
	return false
end

function teleporter_name_main(e)
	local TP = g_teleporter_name_list[e]
	local Ent = g_Entity[e]
	
	if TP.state == 'off' and CloserThan(Ent, 120) and not CloserThan(Ent, 50) then
		-- transporter aware of players proximity and powers up
		if g_Time > TP.tTime then
			TP.state = 'pwup'
		end
	end
	
	if TP.state == 'pwup' and CloserThan(Ent, 20) then
		
		-- find matching or closest transporter
		local closest  = math.huge
		local otherEnd = nil
		local Ent = g_Entity[e]
		local useName = (TP.name ~= 'Transporter Green' and TP.name ~= 'Transporter Blue')
		
		for k,v in pairs(g_teleporter_name_list) do
			if k ~= e then
				if useName and v.name == TP.name then 
					otherEnd = k
					break
				else
					local dist = distBetween(g_Entity[k], Ent)
				
					if dist < closest then 
						otherEnd = k
						closest = dist
					end
				end
			end
		end
		
		if otherEnd ~= nil then
			TP.oeEnt = g_Entity[otherEnd]
			TP.state = 'tran'
			saveVisuals()
		else
			TP.oeEnt = nil
		end
	end
	
	if TP.state == 'tran' then
		SetAmbienceIntensity(255)
		TP.state = 'done'

		-- transport player here
		PlaySound(e, 0)
		
		TP.tTime = g_Time + 200
    end
	
	if TP.state == 'done' and g_Time > TP.tTime then
			local Ent = g_Entity[e]
		local OE  = TP.oeEnt
		
		SetFreezePosition(g_PlayerPosX - (Ent.x - OE.x), 
						  g_PlayerPosY - (Ent.y - OE.y), 
						  g_PlayerPosZ - (Ent.z - OE.z));
						  
		TransportToFreezePositionOnly()

		TP.state = 'over'
		resetVisuals()
	end
	
	if TP.state ~= 'off' and not CloserThan(Ent, 120) and g_Time > TP.tTime then
		-- transporter powers down and cools down
		TP.state = 'off'
		TP.tTime = g_Time + 500
	end
end