local body = piece "body"
local main = piece "main"

local head = piece "head"
local pipesL = piece "pipesL"
local pipesR = piece "pipesR"

local pistons = piece "pistons"
local arms = piece "arms"

local platform = piece "platform"
local turret = piece "turret"
local guns = piece "guns"
local flair1 = piece "flair1"
local flair2 = piece "flair2"

local back = piece "back"
local rocket1 = piece "rocket1"
local rocket2 = piece "rocket2"
local rocket3 = piece "rocket3"
local rocket4 = piece "rocket4"

local armBR = piece "armBR"
local wheelBR = piece "wheelBR"
local trackBR1 = piece "trackBR1"
local trackBR2 = piece "trackBR2"
local BR = piece "BR"

local armFR = piece "armFR"
local wheelFR = piece "wheelFR"
local trackFR1 = piece "trackFR1"
local trackFR2 = piece "trackFR2"
local FR = piece "FR"

local armBL = piece "armBL"
local wheelBL = piece "wheelBL"
local trackBL1 = piece "trackBL1"
local trackBL2 = piece "trackBL2"
local BL = piece "BL"

local armFL = piece "armFL"
local wheelFL = piece "wheelFL"
local trackFL1 = piece "trackFL1"
local trackFL2 = piece "trackFL2"
local FL = piece "FL"

local SIG_MOVE = 1  --signal for the move animation thread
local SIG_SUSP = 2  --signal for the suspension animation thread

local BRA = 0
local FRA = 0
local BLA = 0
local FLA = 0
local bodyA = 0

local function susp()

    Signal(SIG_SUSP)
    SetSignalMask(SIG_SUSP)
    while (true) do
            --if ground_height_old == null then
            --ground_height_old = 0
            --end

        unitposx,unitposy,unitposz = Spring.GetUnitPosition(unitID)
        ground_height = Spring.GetGroundHeight(unitposx,unitposz)
        BRx,BRy,BRz = Spring.GetUnitPiecePosDir(unitID,BR)
        BR_height = ground_height-(Spring.GetGroundHeight(BRx,BRz))
        FRx,FRy,FRz = Spring.GetUnitPiecePosDir(unitID,FR)
        FR_height = ground_height-(Spring.GetGroundHeight(FRx,FRz))
        BLx,BLy,BLz = Spring.GetUnitPiecePosDir(unitID,BL)
        BL_height = ground_height-(Spring.GetGroundHeight(BLx,BLz))
        FLx,FLy,FLz = Spring.GetUnitPiecePosDir(unitID,FL)
        FL_height = ground_height-(Spring.GetGroundHeight(FLx,FLz))

        --Spring.Echo (BR_height)
        --Spring.Echo (FR_height)
        --Spring.Echo (BL_height)
        --Spring.Echo (FL_height)



        bodyLRHeight = ((BR_height+FR_height)/4)-((BL_height+FL_height)/4)

        Spring.Echo (bodyLRHeight)

        bodyTilt = math.asin(bodyLRHeight/25)

        Spring.Echo (bodyTilt)

        BRA = math.asin((BR_height-bodyLRHeight)/47)
        FRA = math.asin((FR_height-bodyLRHeight)/47)
        BLA = math.asin((BL_height+bodyLRHeight)/47)
        FLA = math.asin((FL_height+bodyLRHeight)/47)



        bodyA = (FRA+FLA)/2

        Turn (main, 3, bodyTilt, math.rad(20))
        Turn (platform, 3, -bodyTilt, math.rad(20))
        Move (armBR, 2, -bodyLRHeight, 10)
        Move (armFR, 2, -bodyLRHeight, 10)
        Move (armBL, 2, bodyLRHeight, 10)
        Move (armFL, 2, bodyLRHeight, 10)

        --height_dif = math.sqrt(math.abs(ground_height - ground_height_old) * 10)
        --Spring.Echo (height_dif)
        --Move (main, 2, -height_dif, 5)

        Turn (armBR, 1, -BRA, math.rad(20))
        Turn (armFR, 1, FRA, math.rad(20))
        Turn (armBL, 1, -BLA, math.rad(20))
        Turn (armFL, 1, FLA, math.rad(20))
        Turn (main, 1, bodyA, math.rad(20))
        Turn (platform, 1, -bodyA)
        Move (platform, 2, -bodyA*10)

        --ground_height_old = ground_height

        Sleep(40)
    --Sleep(200)

    end
end

function script.Create()
    Show(trackFL1)
        Show(trackFR1)
        Show(trackBL1)
        Show(trackBR1)
    Hide(trackFL2)
        Hide(trackFR2)
        Hide(trackBL2)
        Hide(trackBR2)
        Turn (armBR, 1, 0)
        Turn (armFR, 1, 0)
        Turn (armBL, 1, 0)
        Turn (armFL, 1, 0)
end


local function move()
    Signal(SIG_MOVE)
    SetSignalMask(SIG_MOVE)
    while (true) do
    Show(trackFL1)
        Show(trackFR1)
        Show(trackBL1)
        Show(trackBR1)
    Hide(trackFL2)
        Hide(trackFR2)
        Hide(trackBL2)
        Hide(trackBR2)

        Sleep(70)

        Show(trackFL2)
        Show(trackFR2)
        Show(trackBL2)
        Show(trackBR2)
    Hide(trackFL1)
        Hide(trackFR1)
        Hide(trackBL1)
        Hide(trackBR1)

        Sleep(70)

    end
end


function script.Killed()

end

local function open()
    StartThread (move)
    Turn (head, 1, -(math.rad(30)+bodyA), math.rad(40))
    Turn (pipesL, 1, (math.rad(30)+bodyA), math.rad(40))
    Turn (pipesR, 1, (math.rad(30)+bodyA), math.rad(40))
    Turn (platform, 1, -(math.rad(30)+bodyA), math.rad(40))
    Move (platform, 3, 7, 10)
    Move (platform, 2, 2, 4)
    Turn (main, 1, (math.rad(30)+bodyA), math.rad(40))
    Turn (back, 1, -math.rad(50), math.rad(50))
    Turn (pistons, 1, -math.rad(15), math.rad(15))
    Move (arms, 3, -5, 5)
    Move (arms, 2, 5, 5)
    Move (body, 2, 12, 12)
    Turn (armBR, 1, -(math.rad(20)+BRA), math.rad(20))
    Turn (armFR, 1, (math.rad(20)+FRA), math.rad(20))
    Turn (armBL, 1, -(math.rad(20)+BLA), math.rad(20))
    Turn (armFL, 1, (math.rad(20)+FLA), math.rad(20))
    Sleep(1000)
    Signal(SIG_MOVE)
end

local function close()
    StartThread (move)
    Turn (head, 1, 0, math.rad(40))
    Turn (pipesL, 1, 0, math.rad(40))
    Turn (pipesR, 1, 0, math.rad(40))
    Turn (platform, 1, 0, math.rad(40))
    Move (platform, 3, 0, 10)
    Move (platform, 2, 0, 1)
    Turn (main, 1, bodyA, math.rad(30))
    Turn (back, 1, 0, math.rad(50))
    Turn (pistons, 1, 0, math.rad(15))
    Move (arms, 3, 0, 5)
    Move (arms, 2, 0, 5)
    Move (body, 2, 0, 12)
    Turn (armBR, 1, -BRA, math.rad(20))
    Turn (armFR, 1, FRA, math.rad(20))
    Turn (armBL, 1, -BLA, math.rad(20))
    Turn (armFL, 1, FLA, math.rad(20))
    Sleep(1000)
    Signal(SIG_MOVE)
end

function script.Activate()
    StartThread (open)
    return 1
end

function script.Deactivate()
    StartThread (close)
    return 0
end



function script.StartMoving()
    StartThread (move)
    StartThread (susp)
end

function script.StopMoving()
    Signal(SIG_MOVE)
    Signal(SIG_SUSP)
end