Follow_And_Shove

function widget:GetInfo()
  return {
    name      = "Follow And Shove (v1.1)",
    desc      = "giving a guard order while holding the alt key causes the selected units to constantly path to the selected unit",
    author    = "AutoWar",
    date      = "2015",
    license   = "GNU GPL, v2 or later",
    layer     = 9999,
    enabled   = true
  }
end

-----------------------------------------------------------------

local spGetUnitNearestEnemy = Spring.GetUnitNearestEnemy
local spGetAllUnits         = Spring.GetAllUnits    --( ) -> nil | unitTable = { [1] = number unitID, ... }
local spMarkerAddPoint      = Spring.MarkerAddPoint
local spEcho                = Spring.Echo
local spInsertUnitCmdDesc   = Spring.InsertUnitCmdDesc
local spGetUnitAllyTeam     = Spring.GetUnitAllyTeam
local spValidUnitID         = Spring.ValidUnitID
local spGetUnitPosition     = Spring.GetUnitPosition
local spGetUnitDefID        = Spring.GetUnitDefID
local spGiveOrderToUnit     = Spring.GiveOrderToUnit
local spGetUnitStates       = Spring.GetUnitStates
local spGiveOrderToUnitArray= Spring.GiveOrderToUnitArray
local spGetUnitIsDead       = Spring.GetUnitIsDead
local spValidUnitID         = Spring.ValidUnitID
local spGetTeamUnits        = Spring.GetTeamUnits  --( number teamID ) -> nil | unitTable = { [1] = number unitID, etc... }
local spGetMyTeamID         = Spring.GetMyTeamID
local spGetMyAllyTeamID     = Spring.GetMyAllyTeamID
local spIsUnitIcon          = Spring.IsUnitIcon
local myAllyID = Spring.GetMyAllyTeamID()
local myTeamID = Spring.GetMyTeamID()
local CMD_ATTACK = CMD.ATTACK
local CMD_MOVE = CMD.MOVE
local CMD_UNIT_SET_TARGET = 34923
local spGetAllyTeamList         = Spring.GetAllyTeamList    --( ) -> { [1] = number allyTeamID, etc... }
local spGetTeamList             = Spring.GetTeamList        --( [number allyTeamID = -1] ) -> nil | { [1] = number teamID, etc... }
local spGetUnitTeam             = Spring.GetUnitTeam        --( number unitID ) -> nil | number teamID
local CMD_LOAD_UNITS            = CMD.LOAD_UNITS            -- expect 1 parameter in return (unitid) or 4 parameters in return (mappos+radius)
local spGetUnitTransporter      = Spring.GetUnitTransporter --( number unitID ) -> nil | number unitID
local spGetUnitIsTransporting   = Spring.GetUnitIsTransporting --( number unitID ) -> nil | { [1] = number unitID, etc... }
local spGetUnitHealth           = Spring.GetUnitHealth      --( number unitID ) -> nil | number health, number maxHealth, number paralyzeDamage, number captureProgress, number buildProgress
local spGetUnitIsStunned        = Spring.GetUnitIsStunned   --( number unitID ) -> nil | boolean stunned_or_inbuild, boolean stunned, boolean inbuild
local spGetUnitRulesParam       = Spring.GetUnitRulesParam  --( number unitID, number index | string ruleName ) -> nil | number value | string value
local CMD_OPT_SHIFT             = CMD.OPT_SHIFT             --If the unit is working down a shift queue, add it seemless into it
local CMD_INSERT                = CMD.INSERT
local spGetCommandQueue         = Spring.GetCommandQueue    --( number unitID, number count = 0 ) -> nil | number commandQueueSize,  ( number unitID [, number count = -1] ) -> nil | table commandQueueTable = {[1] = {("id"=number),("params"={ [1]=number, ...}),("options"={"coded"=number,"alt"=boolean,"ctrl"=boolean,"shift"=boolean,"right"=boolean,"internal"=boolean,"meta"=boolean}}), ...}
local spGetSelectedUnits        = Spring.GetSelectedUnits   --( ) -> { [1] = unitID, ... }
local spGetGroundHeight         = Spring.GetGroundHeight    --(x,z)
local CMD_CAPTURE               = CMD.CAPTURE               --expect 1 parameter in return (unitid) or 4 parameters in return (mappos+radius)
local spGetUnitRulesParam       = Spring.GetUnitRulesParam  --( number unitID, number index | string ruleName ) -> nil | number value | string value
local CMD_GUARD                 = CMD.GUARD                 --expect 1 parameters in return (unitid)

-----------------------------------------------------------------



-----------------------------------------------------------------

local function Distance(x1,z1,x2,z2)
    return math.sqrt((x1-x2)^2 + (z1-z2)^2)
end

local function GetUnitName(unitID)
    if spValidUnitID(unitID)==true and spGetUnitDefID(unitID) then
        return UnitDefs[spGetUnitDefID(unitID)].name
    end
end

-----------------------------------------------------------------

local ActivelyFollowingUnitsTable = {}

function widget:UnitCommand(unitID, unitDefID, unitTeam, cmdId, cmdOpts, cmdParams,cmdTag)
--spEcho(cmdId,cmdOpts,cmdParams[1])
    if cmdId==CMD_GUARD and cmdOpts==CMD.OPT_ALT then
        --spEcho(cmdId,cmdOpts)
        local targetID = cmdParams[1] --the target unit to follow
        local followerID = unitID --the unit following the target
        ActivelyFollowingUnitsTable[followerID]=targetID
    end
    if cmdId==0 and cmdParams[1]==nil then --give a stop order
        ActivelyFollowingUnitsTable[unitID]=nil --remove selected followers from widget's control
    end
end


function widget:GameFrame(frameNum)
    if frameNum%15==0 then
        for followerID,targetID in pairs(ActivelyFollowingUnitsTable) do
        --spEcho(followerID, targetID, spValidUnitID(followerID), spValidUnitID(targetID))
            if spValidUnitID(followerID)==true and spValidUnitID(targetID)==true then
            local x,y,z = spGetUnitPosition(targetID)
                --spEcho(followerID, targetID)
                spGiveOrderToUnit(followerID, CMD_MOVE, {x,y,z}, {"alt"})
            end
        end
    end
end




--[[

Follow And Shove Command

hotkey plus guard command will set the guarded unit as the mappos data source for move orders every second.

uses altkey+gaurd

v1.1 changelog
update speed increased to twice per second

]]