--the amazing dropship factory by knorke
local testing = false
local pad = piece "bauplattform"
local nano = piece "flare2"
local geruest = piece "geruest"
local radar = piece "radart2"

local transporter = piece "transporter"
local antrieb = piece "antrieb"
local turm = piece "turm"
local waffe = piece "waffe"

local storedUnits = {}
--storedUnits[1] = "dgheavytank"
--storedUnits[2] = "dgbike"
--storedUnits[3] = "dgheavytank"

local maxUnits = 8
local unloadRadius = 90
local busy = false

function script.Create(unitID)
    if (testing) then Spring.Echo ("spaceport here!") end
    Hide (geruest)
    Move (transporter, y_axis, 1000)
    Move (pad, y_axis, -50) --move build pad underground but hovercrafts ignore it so that is useless
    hideTransporter()
    if (testing) then StartThread (loop) end
end

function script.QueryBuildInfo() return pad end

--no nano bubbling
--function script.QueryNanoPiece() return nano end

function script.Activate()
    SetUnitValue(COB.YARD_OPEN, 1)
    SetUnitValue(COB.INBUILDSTANCE, 1)
    SetUnitValue(COB.BUGGER_OFF, 1)
    return 1
end

function script.Deactivate()
    SetUnitValue(COB.YARD_OPEN, 0)
    SetUnitValue(COB.INBUILDSTANCE, 0)
    SetUnitValue(COB.BUGGER_OFF, 0)
    return 0
end

function loop () --for testing
    while (true) do
        Spring.Echo ("que:" .. #Spring.GetFullBuildQueue(unitID) .. "  #storedUnits:" .. #storedUnits)
        Sleep (1000)
    end
end

function script.StartBuilding()
    bID = Spring.GetUnitIsBuilding (unitID)
    hideUnitPieces (bID)
    Spring.SetUnitNoSelect (bID, true)
    --local x,y,z = Spring.GetUnitPosition (unitID)
    --Spring.SetUnitPosition (bID, x,100,z)
end

function script.StopBuilding()
    local _,  _,  _, _,  buildprogress = Spring.GetUnitHealth (bID)
    if (buildprogress==1) then
        storeUnit (unitName (bID))
        Spring.DestroyUnit (bID,false,true)
    end
    if (not busy) then StartThread (shouldWeDeliver) end    --seems not to work without this. maybe buildque only gets cleared once StopBuilding returns?
end

function shouldWeDeliver ()
    Sleep (500)
    if (#storedUnits >= maxUnits or (#Spring.GetFullBuildQueue(unitID)==0 and #storedUnits >0)) then deliverUnits () end
end

function unitName (uID)
    if (not Spring.ValidUnitID (uID)) then return "invalid unitID in unitName()" end
    local udID =Spring.GetUnitDefID(uID)
    local uDef = UnitDefs [udID]
    return uDef.name
end

function deliverUnits ()
    busy = true
    while (#storedUnits >= maxUnits or (#Spring.GetFullBuildQueue(unitID)==0 and #storedUnits >0)) do
        if (#storedUnits == 0) then return end
        showTransporter()
        Move (transporter, y_axis, 0, 100)
        Spin (radar, y_axis, 2)
        WaitForMove (transporter, y_axis)
        local x,y,z = Spring.GetUnitPosition (unitID)
        local teamID = Spring.GetUnitTeam (unitID)
        if (testing) then Spring.Echo ("#storedUnits:" .. #storedUnits) end
        local n = #storedUnits
        if (n > maxUnits) then n = maxUnits end
        local step = (math.pi*2)/n
        for i=1, n do
            dx = x + math.sin (step*i)*unloadRadius
            dz = z + math.cos (step*i)*unloadRadius
            local newUnit = Spring.CreateUnit (storedUnits[i], dx,y,dz, 0, teamID)
            copyMoveOrders (unitID, newUnit)
            if (testing) then Spring.Echo (i .. " deliver:" .. storedUnits[i]) end
        end
        local sUold = #storedUnits
        for i=sUold,1,-1  do
            if (i <= n) then
                storedUnits[i] = storedUnits[i+n]
                storedUnits[i+n] = nil
            end
        end
        --storedUnits = {}
        Move (transporter, y_axis, 1000, 100)
        WaitForMove (transporter, y_axis)
        hideTransporter()
        StopSpin (radar, y_axis,1)
    end
    busy = false
end

function storeUnit (unitname)
    storedUnits[#storedUnits+1] = unitname
end

---------------------------------
function script.Killed(recentDamage, maxHealth)
    if (busy) then explodeTransporter() end
    return 0
end

function explodeTransporter ()
    Explode (transporter, SFX.FIRE)
    Explode (waffe, SFX.FIRE)
    Explode (turm, SFX.FIRE)
    Explode (antrieb, SFX.SHATTER)
end

function hideTransporter()
    Hide (transporter)
    Hide (antrieb)
    Hide (turm)
    Hide (waffe)
end

function showTransporter()
    Show (transporter)
    Show (antrieb)
    Show (turm)
    Show (waffe)
end

--make a unit invisible by hiding all its pieces...lol
function hideUnitPieces (uID)
    local allpieces = Spring.GetUnitPieceList (uID)
    local piece_n = table.getn (allpieces)
    --Spring.Echo ("unit has " .. piece_n  .. " pieces")
    for pID=1, piece_n,1  do
        --Spring.Echo ("pID:" .. pID)
        Spring.UnitScript.CallAsUnit(uID, Spring.UnitScript.Hide, pID)
    end
end

function copyMoveOrders (unitA, unitB)
  local commands = Spring.GetUnitCommands(unitA)
  for i = 1, #commands do
    local cmd = commands[i]
    if (cmd.id == CMD.MOVE  or cmd.id == CMD.FIGHT or cmd.id == CMD.PATROL) then    --only copy some commands
        Spring.GiveOrderToUnit(unitB, cmd.id, cmd.params, cmd.options.coded)
    end
  end
end