-- CVT Transmission Type-A v0.8 by Vegetable Studio
-- Please visit "https://www.patreon.com/vegetable_studio" for instructions

-- Essentials
local raw = ac.accessCarPhysics()
local car = ac.getCar(0)
local engine = ac.INIConfig.carData(0, 'engine.ini')
local drivetrain = ac.INIConfig.carData(0, 'drivetrain.ini')
local tyre = ac.INIConfig.carData(0, 'tyre.ini')

local gearCount = car.gearCount
local limiter = car.rpmLimiter
local torque = ac.DataLUT11.load(engine:get('HEADER', 'POWER_CURVE', 'power.lut'))
local idleRpm = engine:get('ENGINE_DATA', 'MINIMUM', 800)
local clutchMaxTorque = drivetrain:get('CLUTCH', 'MAX_TORQUE', 600)
local gearsFinalRatio = drivetrain:get('GEARS', 'FINAL', 4.4)
local circumference = tyre:get('REAR', 'RADIUS', 0.32) * 2 * math.pi
local rpmToKmh = circumference / 1000 * 60

local gearRatios = {}

for i = 1, gearCount do
    gearRatios[i] = drivetrain:get('GEARS', 'GEAR_' .. tostring(i), 0)
end

local gear, speed, rpmEngine, throttle = 1, 0, 0, 0

-- Values for torque converter simulation
local stallRpm = 2000 * math.round(idleRpm / 1000)
local stallTorque = torque:get(stallRpm)
local stallPower = stallRpm * stallTorque / 5250
local kFactor = math.round(stallRpm / math.sqrt(stallTorque), -1)
local lockUpMap = ac.DataLUT11.parse('(|' .. tostring(stallRpm * 1 / gearRatios[1] / gearsFinalRatio * rpmToKmh) .. '=0|'.. tostring(stallRpm * 1.25 / gearRatios[1] / gearsFinalRatio * rpmToKmh) ..'=1|)')
local speedLag = 0
local rpmWheel, rpmDiff = 0, 0
local tcPressure = 0
local tcLoad = 0
local torqueMult = 1
local torqueEngine = 0
local targetFinal = gearsFinalRatio
local torqueConverter, lockUp = 0, 0

-- Values for gear ratio target calculation
local maxPower, maxPowerRpm = 0, 0

for i = math.ceil(idleRpm / 100) * 100, math.floor(limiter / 100) * 100, 100 do
    if torque:get(i) * i > maxPower then
        maxPower = torque:get(i) * i
        maxPowerRpm = i
    end
end

local rpmMap = ac.DataLUT11.parse('(|0=' .. tostring(math.ceil(idleRpm / 500) * 500) .. '|0.9=' .. tostring(math.min(maxPowerRpm, limiter * 0.94)) .. '|)')
local targetRpm, targetRatio = 0, 0


function script.update(dt)
    -- Disable H-shifter to stop overriding engaged gear
    if raw.isShifterSupported == true then
        raw.isShifterSupported = false
    end

    -- -- Update final ratio & top speeds when setup is changed, Not working at the moment
    -- if math.abs(raw.gearsFinalRatio - targetFinal) > 0.1 then
    --     gearsFinalRatio = raw.gearsFinalRatio
    --     for i = 1, gearCount do
    --         topSpeeds[i] = limiter * 0.99 / gearRatios[i] / gearsFinalRatio * rpmToKmh
    --     end
    -- end

    -- Essentials
    gear = math.max(1, car.gear)
    speed = math.round(car.poweredWheelsSpeed, 2)
    rpmEngine = math.max(raw.rpm, 1)
    throttle = raw.gas
    torqueEngine = math.max(car.drivetrainTorque, 0)

    -- Torque converter simulation
    speedLag = math.applyLag(speedLag, speed, 0.95, dt)
    rpmWheel = math.max(speed / rpmToKmh * gearsFinalRatio * gearRatios[gear], 1)
    rpmDiff = math.max(rpmEngine - rpmWheel, 0)

    tcPressure = math.pow(rpmDiff / kFactor, 2)
    tcLoad = math.min(car.drivetrainPower / stallPower, 1)

    torqueMult = 1 + (rpmDiff / stallRpm) * (1 - math.min(rpmWheel / stallRpm, 1))
    targetFinal = gearsFinalRatio * torqueMult
    torqueConverter = math.clamp((tcPressure / clutchMaxTorque * (1 - tcLoad) + math.sqrt(torqueEngine / clutchMaxTorque) * tcLoad), 0, 1)

    -- Clutch lock-up feature
    lockUp = lockUpMap:get(speedLag)

    -- Calculates gear ratio target
    targetRpm = math.applyLag(targetRpm, rpmMap:get(throttle), 0.98, dt)

    if car.gear > 0 then
        targetRatio = math.clampN(targetRpm / (speed / rpmToKmh * gearsFinalRatio), gearRatios[gearCount], gearRatios[1])
        targetFinal = targetFinal / gearRatios[gear] * targetRatio
    end

    -- Actual physics override
    ac.setGearsFinalRatio(targetFinal)
    raw.clutch = torqueConverter + (1 - torqueConverter) * lockUp

     --Debug
    ac.debug("Shift Mode", 'D')
    -- ac.debug("Original Final Ratio", gearsFinalRatio)
    -- ac.debug("Target RPM", targetRpm)
    -- ac.debug("Target Ratio",  targetRatio)
    -- ac.debug("Current Final Ratio", raw.gearsFinalRatio)
    -- ac.debug("K Factor", kFactor)
    -- ac.debug("Stator Pressure", math.round(tcPressure) .. ' Nm')
    -- ac.debug("Torque Multiplication", math.round(torqueMult, 2))
    -- ac.debug("Clutch Lock-Up", math.round(lockUp * 100) .. '%')
    -- ac.debug("Torque Converter", math.round(torqueConverter, 2))
    -- ac.debug("Slippage", math.round(((rpmEngine / rpmWheel) - 1) * 100) .. '%')
    -- ac.debug("Torque Output", math.round(torqueEngine * torqueMult) .. ' Nm')
end