HedgewarsScriptLoad("/Scripts/Locale.lua")

HedgewarsScriptLoad("/Scripts/Params.lua")

local gravity = 100

local mingravity

local maxgravity

local mingravity_normal

local maxgravity_normal

local mingravity_low

local maxgravity_low

local delta = 0

local period

local periodtimer = 0

local wdGameTicks = 0

local wdTTL = 0

local mln = 1000000

local lowGravityUsed = false

local script2_onNewTurn

local script2_onGameTick20

local script2_onGameInit

local script2_onHogAttack

function grav_onNewTurn()

    lowGravityUsed = false

    if maxgravity_normal == nil then

        gravity = mingravity_normal

    else

        mingravity = mingravity_normal

        maxgravity = maxgravity_normal

        if period > 0 then

           delta = div(maxgravity_normal - mingravity_normal, period)

        end

    end

    if delta ~= nil and period == nil then 

      SetGravity(gravity)

    else

      SetGravity(div(gravity, mln))

    end

    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 + 1) + 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 = tonumber(params["g"]) or gravity

    mingravity_normal = gravity

    if mingravity_normal > 0 then

        mingravity_low = div(mingravity_normal, 2)

    else

        mingravity_low = mingravity_normal * 2

    end

    mingravity = mingravity_normal

    if type(tonumber(params["g2"])) == "number" then

        maxgravity_normal = tonumber(params["g2"])

        if maxgravity_normal > 0 then

            maxgravity_low = div(maxgravity_normal, 2)

        else

            maxgravity_low = maxgravity_normal * 2

        end

        maxgravity = maxgravity_normal

    end

    period = params["period"]

    if type(mingravity) == "number" and type(maxgravity) == "number" then

        if period ~= nil then

            period = div(period, 40)

        else

            period = 125

        end

        mingravity = mingravity * mln

        mingravity_normal = mingravity_normal * mln

        mingravity_low = mingravity_low * mln

        maxgravity = maxgravity * mln

        maxgravity_normal = maxgravity_normal * mln

        maxgravity_low = maxgravity_low * mln

        if mingravity > maxgravity then

            mingravity, maxgravity = maxgravity, mingravity

            mingravity_normal, maxgravity_normal = maxgravity_normal, mingravity_normal

            mingravity_low, maxgravity_low = maxgravity_low, mingravity_low

        end

        gravity = mingravity

        if period > 0 then

            delta = div(maxgravity_normal - mingravity_normal, period)

        else

            period = -period

            delta = nil

        end

    end

    secondScript = params["script2"]

    if secondScript ~= nil then

        onParameters = nil

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

        script2_onNewTurn = onNewTurn

        script2_onGameTick20 = onGameTick20

        script2_onGameInit = onGameInit

        script2_onHogAttack = onHogAttack

        if onParameters ~= nil then

            onParameters()

        end

    end

    onNewTurn = grav_onNewTurn

    onGameTick20 = grav_onGameTick20

    onGameInit = grav_onGameInit

    onHogAttack = grav_onHogAttack

end

function grav_onGameInit()

    DisableGameFlags(gfLowGravity)

    local v, printperiod

    if period ~= nil then

        local period_ms = period * 40

        if period_ms % 1000 == 0 then

            printperiod = string.format(loc("%i s"), div(period_ms, 1000))

        else

            printperiod = string.format(loc("%i ms"), period_ms)

        end

    end

    if delta == nil then

        v = string.format(loc("Crazy Gravity: Gravity randomly changes within a range from %i%% to %i%% with a period of %s"), div(mingravity_normal, mln), div(maxgravity_normal, mln), printperiod)

    elseif period ~= nil then

        v = string.format(loc("Oscillating Gravity: Gravity periodically changes within a range from %i%% to %i%% with a period of %s"), div(mingravity_normal, mln), div(maxgravity_normal, mln), printperiod)

    elseif gravity > 100 then

        v = string.format(loc("High Gravity: Gravity is %i%%"), gravity)

    elseif gravity < 100 then

        v = string.format(loc("Low Gravity: Gravity is %i%%"), gravity)

    else

        v = loc("Gravity: 100%") .. "|" ..

            loc("Script parameter examples:") .. "|" ..

            loc("“g=150”, where 150 is 150% of normal gravity.") .. "|" ..

            loc("“g=50, g2=150, period=4000” for gravity changing|from 50 to 150 and back with period of 4000 ms.") .. "|" ..

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

    end

    Goals = v

    if script2_onGameInit ~= nil then

        script2_onGameInit()

    end

end

function grav_onHogAttack(ammoType)

    if ammoType == amLowGravity then

        lowGravityUsed = true

        if maxgravity_normal == nil then

            gravity = mingravity_low

        else

            mingravity = mingravity_low

            maxgravity = maxgravity_low

            if period > 0 then

                delta = div(maxgravity_low - mingravity_low, period)

            end

        end

    end

    if script2_onHogAttack ~= nil then

        script2_onHogAttack()

    end

end