--@name apply force suspension
--@author Koptilnya1337
--@shared

    local _restLength = 26.0
    local _springTravel = 20.0
    local _springStiffness = 35000
    local _compressionDamper = 140000 -- 45000
    local _reboundDamper = 35000 -- 196000
    local _maxForce = 500000

    local _minLength = 0
    local _maxLength = 0
    local _lastLength = 0
    local _springLength = 0
    local _springVelocity = 0
    local _springForce = 0
    local _damperForce = 0

if SERVER then
    wire.adjustInputs(
        {
            'Wheel1',
            'Wheel2',
            'Wheel3',
            'Wheel4',
            'Strut1',
            'Strut2',
            'Strut3',
            'Strut4',
            'Base'
        },
        {
            'entity',
            'entity',
            'entity',
            'entity',
            'entity',
            'entity',
            'entity',
            'entity',
            'entity'
        }
    )

    local wheel1 = wire.ports.Wheel1
    local wheel2 = wire.ports.Wheel2
    local wheel3 = wire.ports.Wheel3
    local wheel4 = wire.ports.Wheel4

    local strut1 = wire.ports.Strut1
    local strut2 = wire.ports.Strut2
    local strut3 = wire.ports.Strut3
    local strut4 = wire.ports.Strut4

    local wheels = { wheel1, wheel2, wheel3, wheel4 }
    local struts = { strut1, strut2, strut3, strut4 }

    local base = wire.ports.Base

    function handleWheel(base, wheel, strut)
        local lastLength = 0

        return function ()
            if not base:isValid() then return end
            if not wheel:isValid() then return end
            if not strut:isValid() then return end

            local distance = strut:getPos():getDistance(wheel:getPos()) - _restLength
            local strutToWheelDirection = (strut:getPos() - wheel:getPos()):setX(0):setY(0):getNormalized()
            local springVelocity = (distance - lastLength)

            local usedDamper = springVelocity > 0 and _compressionDamper or _reboundDamper
            local spring = distance * _springStiffness
            local dampener = springVelocity * usedDamper

            local force = math.clamp((spring + dampener) * game.getTickInterval(), -_maxForce, _maxForce)
            local direction = (strut:getPos() - wheel:getPos()):getNormalized() --base:getUp()

            lastLength = distance

            base:applyForceOffset(-force * direction, wheel:getPos())
            wheel:applyForceCenter(force * direction * strutToWheelDirection)
        end
    end

    local wheelHandlers = {}

    for idx, wheel in ipairs(wheels) do
        table.insert(wheelHandlers, handleWheel(base, wheel, struts[idx]))
    end

    hook.add('tick', 'runtime', function()
        for _, handler in ipairs(wheelHandlers) do
            handler()
        end
    end)

end