HedgewarsScriptLoad("/Scripts/Locale.lua")

HedgewarsScriptLoad("/Scripts/Params.lua")

local gravity = 100

local mingravity

local maxgravity

local delta = 0

local period

local periodtimer = 0

local wdGameTicks = 0

local wdTTL = 0

local mln = 1000000

local script2_onNewTurn

local script2_onGameTick20

local script2_onGameStart

function grav_onNewTurn()

    SetGravity(gravity)

    wdGameTicks = GameTime

    if script2_onNewTurn ~= nil then

        script2_onNewTurn()

    end    

end

function grav_onGameTick20()

    if wdGameTicks + 15000 < GameTime then

        SetGravity(100)

    else

        if wdTTL ~= TurnTimeLeft then

            wdGameTicks = GameTime

        end

        if delta == nil then

            if periodtimer == 0 then

                periodtimer = period * 2

                SetGravity(div(GetRandom(maxgravity - mingravity) + mingravity, mln))

            else

                periodtimer = periodtimer - 1

            end

        elseif delta == 0 then

            SetGravity(gravity)

        else

            if delta > 0 and gravity + delta > maxgravity then

                gravity = maxgravity

                delta = -delta

            elseif delta < 0 and gravity + delta < mingravity then

                gravity = mingravity

                delta = -delta

            else

                gravity = gravity + delta

            end

            SetGravity(div(gravity, mln))

        end

    end

    wdTTL = TurnTimeLeft

    if script2_onGameTick20 ~= nil then

        script2_onGameTick20()

    end    

end

function onParameters()

    parseParams()

    gravity = params["g"]

    mingravity = gravity

    maxgravity = params["g2"]

    period = params["period"]

    if mingravity ~= nil and maxgravity ~= nil then

        if period ~= nil then

            period = div(period, 40)

        else

            period = 125

        end

        mingravity = mingravity * mln

        maxgravity = maxgravity * mln

        -- note: mingravity and maxgravity MUST NOT be strings at this point

        if mingravity > maxgravity then

            mingravity, maxgravity = maxgravity, mingravity

        end

        gravity = mingravity

        if period > 0 then

            delta = div(maxgravity - mingravity, period)

        else

            period = -period

            delta = nil

        end

    end

    if gravity == nil then

        gravity = 100

    end

    secondScript = params["script2"]

    if secondScript ~= nil then

        onParameters = nil

        HedgewarsScriptLoad("/Scripts/Multiplayer/" .. secondScript .. ".lua")

        script2_onNewTurn = onNewTurn

        script2_onGameTick20 = onGameTick20

        script2_onGameStart = onGameStart

        if onParameters ~= nil then

            onParameters()

        end

    end

    onNewTurn = grav_onNewTurn

    onGameTick20 = grav_onGameTick20

    onGameStart = grav_onGameStart

end

function grav_onGameStart()

    if delta == nil then

        v = string.format(loc("random in range from %i%% to %i%% with period of %i msec"), div(mingravity, mln), div(maxgravity, mln), period * 40)

    elseif period ~= nil then

        v = string.format(loc("changing range from %i%% to %i%% with period of %i msec"), div(mingravity, mln), div(maxgravity, mln), period * 40)

    else

        v = gravity .. "%"

    end

    ShowMission(loc("Gravity"),

                loc("Current setting is ") .. v,

                loc("Setup:|'g=150', where 150 is 150% of normal gravity") .. "|"

                .. loc("or 'g=50, g2=150, period=4000' for gravity changing|from 50 to 150 and back with period of 4000 msec")

                .. "||" .. loc("Set period to negative value for random gravity"),

                0, 5000)

    if script2_onGameStart ~= nil then

        script2_onGameStart()

    end

end