function RandomPosition(latitudeMin,latitudeMax,longitudeMin,longitudeMax)
	local lat_var = math.random(1,(10^13)) --random number between 1 and 10^13
	local lon_var = math.random(1,(10^13)) --random number between 1 and 10^13
	local pos_lat = math.random(latitudeMin,latitudeMax) + (lat_var/(10^13)) --latitude; 
	local pos_lon = math.random(longitudeMin,longitudeMax) + (lon_var/(10^13)) --longitude; 
	return {latitude=pos_lat,longitude=pos_lon}
end

function CircularRandomPosition(x_latitude, x_longitude, max_radius)
	local randomisationCircle = World_GetCircleFromPoint({
		latitude=x_latitude,
		longitude=x_longitude,
		radius=math.random(0.1,max_radius),
		numpoints = 72})
	local randomisedPoint = randomisationCircle[math.random(1,#randomisationCircle)]
    return randomisedPoint
end

function ShuffleTable( t )
    local rand = math.random 
    assert( t, "ShuffleTable() expected a table, got nil" )
    local iterations = #t
    local j
    
    for i = iterations, 2, -1 do
        j = rand(i)
        t[i], t[j] = t[j], t[i]
    end
end

function ChangeScore(side,amt,reason)
	local newScore = ScenEdit_GetScore(side) + amt
	ScenEdit_SetScore(side,newScore,reason)
	print (side..' score changed to '..newScore)
	return newScore
end

function CleanUpIdleCivilianShips()
	local unitList = VP_GetSide({side='Civilian'}).units
	local numberOfCivilianUnits = #unitList
	local numberOfUnitsDeleted = 0
	for k,v in ipairs (unitList) do
		local unit = ScenEdit_GetUnit({guid=v.guid})
		if (unit.course[1] == nil or unit.speed == 0) and 
			unit.type == 'Ship' then
			ScenEdit_DeleteUnit({guid=v.guid})
			numberOfUnitsDeleted = numberOfUnitsDeleted + 1
		end
	end

	if DebugModeIsOn() and numberOfUnitsDeleted > 0 then
		ScenEdit_SpecialMessage('playerside','Civ_Cleanup fired. <BR>Initial civilian Units: '..numberOfCivilianUnits..' <BR>Civilian units cleaned up: '..numberOfUnitsDeleted)
	end
end

function OverWater (latitude, longitude)
	local pointElevation = World_GetElevation({
		latitude = latitude,
		longitude = longitude})
	if pointElevation < 0 then
		return true
	else
		return false
	end
end

function ConvertDecimalPositionToDegrees(latitude,longitude)
	local latitidePrefix, longitudePrefix
	if latitude > 0 then
		latitidePrefix = "N"
	else
		latitidePrefix = "S"
		latitude = latitude*-1
	end

	local latitudeDegrees = math.floor(latitude)
	local latitudeMinutes = math.floor((latitude - latitudeDegrees)*60)
	local latitudeSeconds = (((latitude-latitudeDegrees)*60) - latitudeMinutes)*60
	latitudeSeconds = Round(latitudeSeconds, 0)

	if longitude > 0 then
		longitudePrefix = "E"
	else
		longitudePrefix = "W"
		longitude = longitude*-1
	end

	local longitudeDegrees = math.floor(longitude)
	local longitudeMinutes = math.floor((longitude - longitudeDegrees)*60)
	local longitudeSeconds = (((longitude-longitudeDegrees)*60) - longitudeMinutes)*60
	longitudeSeconds = Round(longitudeSeconds, 0)

	local result = (latitidePrefix..latitudeDegrees .. "°" .. latitudeMinutes .. "'" .. latitudeSeconds .. '", '..
		longitudePrefix..longitudeDegrees .. "°" .. longitudeMinutes .. "'" .. longitudeSeconds .. '"')
	return result
end

------------------Comms

function DTG(TimeVar)
	if TimeVar == nil then
		TimeVar = ScenEdit_CurrentTime()
	end
	local msgtime = os.date("!%d%H%M" .. "Z" .. " " .. "%b %y", TimeVar)
	local msgtime = string.upper(msgtime)
	return msgtime
end

function GenerateRadioMessageBody(theMessage,callsign)
	local result
	if callsign == nil then callsign = 'unknown station' end
    result = '<P>'..string.upper(callsign)..'<BR> <I>"'..theMessage..'"</I></P> '
	return result
end

function RadioMessage(band,frequency,theMessage,location)
	assert(theMessage,'RadioMessage(): No message passed!')
	local DTG = DTG()
	local theMessage = "<P>"..DTG..' <BR>'..band..' <BR>'..frequency..' </P>'..theMessage
	if location ~= nil then
		ScenEdit_SpecialMessage('playerside',theMessage,{latitude=location.latitude,longitude=location.longitude})
	else
		ScenEdit_SpecialMessage('playerside',theMessage)
	end
end

function ACP126(rec_station,snd_station,precedence,from,to,classification,body)
	--rec_station --4 letter code (e.g. YDCX)
	--snd_station --4 letter code +/- NR 3 number (e.g. YBDN NR 270)
	--precedence --Flash (Z), Immediate (O), Priority (P), Routine (R), Flash Override (Y)
	local dtg = DTG()
	--from --e.g. MET FLT OPS
	--to --e.g. SSN 21 SEAWOLF
	--classification --Unclass +/- SBU / FOUO / NOFORN (Restricted), Confidential, Secret, Top Secret
	--body
	_,gr = body:gsub("%S+","")
	local sig_string = string.upper('<P><FONT face=Consolas>'..rec_station..' <BR>'..
	'DE '..snd_station..' <BR>'..
	precedence..' '..dtg..' <BR>'..
	'fm '..from..' <BR>'..
	'to '..to..' <BR>'..
	'wd gr'..gr..' <BR>'..
	'bt <BR>'..
	classification..' <BR>'..
	body..' <BR>'..
	'bt <BR>'..
	'nnnn </P>')
	return sig_string
end

function TelexMessageToPlayer(rec_station, snd_station, precedence, from, to, classification, body, location)
	local theMessage = ACP126(rec_station, snd_station, precedence, from, to, classification, body)
	if location ~= nil then
		ScenEdit_SpecialMessage('playerside',theMessage,{latitude=location.latitude,longitude=location.longitude})
	else
		ScenEdit_SpecialMessage('playerside',theMessage)
	end
end

------------Weather

function GenerateRainDescriptor(rain)
	local result 
	if rain == 0 then  result = 'nil'
		elseif rain < 5 then  result = 'very light'
		elseif rain < 11 then  result = 'light'
		elseif rain < 20 then  result = 'moderate'
		elseif rain < 30 then  result = 'heavy'
		elseif rain < 40 then  result = 'very heavy'
		else  result = 'extreme'
	end
	return result
end

function GenerateCloudDescriptor(cloud)
	local result
	if cloud == 0 then  result = 'clear skies'
		elseif cloud < 0.2 then result = 'light low clouds'
		elseif cloud < 0.3 then result = 'light middle clouds'
		elseif cloud < 0.4 then result = 'light high clouds'
		elseif cloud < 0.5 then result = 'moderate low clouds'
		elseif cloud < 0.6 then result = 'moderate middle clouds'
		elseif cloud < 0.7 then result = 'moderate high clouds'
		elseif cloud < 0.8 then result = 'moderate middle clouds & light high clouds'
		elseif cloud < 0.9 then result = 'solid middle clouds & moderate high clouds'
		elseif cloud < 1.0 then result = 'thin fog & solid cloud cover'
		else result = 'thick fog & solid cloud cover'
	end
	return result
end

function ConvertTempCtoF(temp)
	local result = Round((temp*1.8) + 32,0)
	return result
end

function WeatherReport(outlook)
	if outlook == nil then outlook = 'next forecast at '..DTG(ScenEdit_CurrentTime()+21600) end

	local weather, DTG = ScenEdit_GetWeather(), DTG()
	local tempC, tempF, cloud, rain, sea = weather.temp, ConvertTempCtoF(weather.temp), GenerateCloudDescriptor(weather.undercloud), GenerateRainDescriptor(weather.rainfall), weather.seastate
		
	TelexMessageToPlayer(
		'ALL',
		'METOc',
		'r',
		'Naval Meteorology and Oceanography Command',
		'ALL STATIONS',
		'unclass',
		'WX REPORT '..DTG..' - strait of hormuz <BR>AVERAGE TEMP '..tempC..'°C / '..tempF..'°F <BR> SEA STATE '..sea..' <BR>'..rain..' PRECIPITATION <BR>'..cloud..' <BR>'..outlook,
		nil
	)
end

function WeatherDrift()
	local weatherBaseline = { seastate = 1, temp = 23, undercloud = 0.30000000, rainfall = 0 }
	local seastateVariability = math.random(0,2)
	local undercloudVariability = 0
	local tempVariability = math.random(-1,4)
	local rainfallVariability = 0

	local newTemp =  weatherBaseline.temp + tempVariability
	local newRainfall = weatherBaseline.rainfall + rainfallVariability
	local newUndercloud = weatherBaseline.undercloud + undercloudVariability
	local newSeastate = weatherBaseline.seastate + seastateVariability

	ScenEdit_SetWeather(
		newTemp, --temp
		newRainfall, --rainfall
		newUndercloud, --undercloud
		newSeastate --seastate
	)
end

function TimeIs(timeVar)
	if timeVar == nil then timeVar = ScenEdit_CurrentTime() end
	local timeStampTable = os.date("!*t",timeVar)
	local timeTable = {day = timeStampTable.day, 
		hour = timeStampTable.hour, 
		minute = timeStampTable.min}
    return timeTable
end

function WeatherReportIsDue()
	local result = false
	local hourZulu = TimeIs().hour
	local hourLocal = hourZulu + scenarioZuluOffset
	if hourLocal %6 == 0 then
			result = true
	end
	return result
end