function widget:GetInfo() return {
    name    = "Missile Pinger",
    desc    = "Battlefield Awareness: Pings allied nukes, tacnukes, emps, and napalm strikes.",
    author  = "_Shaman",
    date    = "2020-04-16",
    license = "CC-0",
    layer   = -1,
    enabled = true,
} end

local online = true
local points = {}
local circlehandler = {}
local drawinglimit = 25 -- Spring has a limit on how many lines a widget can draw per ~15 (10? 12?) frames it seems.
local recentallied = 0
local watcheddefs = {}
local silos = {}
local lastsay = 0
watcheddefs[UnitDefNames["staticnuke"].id] = {points = 60, radius = 910, type = "nuclear strike", life = 45}
watcheddefs[UnitDefNames["tacnuke"].id] = {points = 16, radius = 192/2, type = "tactical nuke", life = 10}
watcheddefs[UnitDefNames["napalmmissile"].id] = {points = 16, radius = 512/2, type = "napalm strike",life = 10}
watcheddefs[UnitDefNames["empmissile"].id] = {points = 16, radius = 280/2, type = "EMP",life = 13}
watcheddefs[UnitDefNames["subtacmissile"].id] = {points = 16, radius = 256/2, type = "tactical nuke",life = 13}
local empty = {}

local function EraseRadius(x,z,radius,points,stepnum,ending)
    local x2,y2 = 0
    local x1,y1 = 0
    local step = 360/points
    for i=stepnum, ending do
        x1 = radius * math.sin(math.rad(i*step)) + x
        y1 = radius * math.cos(math.rad(i*step)) + z
        Spring.MarkerErasePosition(x1,Spring.GetGroundHeight(x1,y1),y1)
    end
end



local function CreateRadius(x,z,radius,points,stepnum,ending)
    local x2,y2 = 0
    local x1,y1 = 0
    local step = 360/points
    local ox,oy = 0
    for i=stepnum, ending do
        if i == stepnum then
            x1 = radius * math.sin(math.rad(i*step)) + x
            y1 = radius * math.cos(math.rad(i*step)) + z
            if i > 1 then
                x2 = radius * math.sin(math.rad((i-1)*step)) + x
                y2 = radius * math.cos(math.rad((i-1)*step)) + z
            end
        else
            x2 = x1
            y2 = y1
            x1 = radius * math.sin(math.rad(i*step)) + x
            y1 = radius * math.cos(math.rad(i*step)) + z
        end
        if i>1 then
            Spring.MarkerAddLine(x1,Spring.GetGroundHeight(x1,y1)+700,y1,x2,Spring.GetGroundHeight(x1,y1)+700,y2)
        end
        if i == points then
            ox = radius * math.sin(math.rad(1*step)) + x
            oy = radius * math.cos(math.rad(1*step)) + z
            Spring.MarkerAddLine(x1,Spring.GetGroundHeight(x1,y1)+700,y1,ox,Spring.GetGroundHeight(x1,y1)+700,oy)
        end
    end
end

local function GetName(teamID)
    local name = "Unknown"
    if #Spring.GetPlayerList(teamID) > 1 then
        name = select(1,Spring.GetPlayerInfo(select(2,Spring.GetTeamInfo(teamID)))) .. "'s squad"
    else
        name = select(1,Spring.GetPlayerInfo(select(2,Spring.GetTeamInfo(teamID))))
    end
    return name
end

local function GetID(x,z) -- Assigns an ID to a missile strike.
    local id = x + z + Spring.GetGameFrame()
    if circlehandler[id] ~= nil then
        repeat
            id = id + 1
        until circlehandler[id] == nil
    end
    return id
end

function widget:UnitDestroyed(unitID)
    silos[unitID] = nil
end

function widget:UnitCommand(unitID, unitDefID, unitTeam, cmdID, cmdParams, cmdOpts, cmdTag, bypass)
    --Spring.Echo("Got " .. unitDefID .. "\nOnList: " .. tostring(watcheddefs[unitDefID] ~= nil))
    if watcheddefs[unitDefID] and cmdID == CMD.ATTACK then
        if ((unitDefID == UnitDefNames["staticnuke"].id or unitDefID == UnitDefNames["subtacmissile"].id) and (select(1,Spring.GetUnitStockpile(unitID)) == 0 and type(bypass) ~= "boolean")) or select(5,Spring.GetUnitHealth(unitID)) < 1.0 then
            --Spring.Echo("added " .. unitID)
            silos[unitID] = {cmdParams[1], cmdParams[2], cmdParams[3]}
            return
        end

        local p = watcheddefs[unitDefID].points
        local type = watcheddefs[unitDefID].type
        local radius = watcheddefs[unitDefID].radius
        local life = watcheddefs[unitDefID].life
        local x,y,z = 0
        if #cmdParams == 1 then
            x,y,z = Spring.GetUnitPosition(cmdParams[1])
        else
            x = cmdParams[1]
            y = cmdParams[2]
            z = cmdParams[3]
        end
        local name = GetName(unitTeam)
        points[GetID(x,z)] = {x = x,y=y, z = z, timer = life,radius=radius,points=p}
        Spring.MarkerAddPoint(x,y,z,"Incoming allied " .. type .. "( " .. name .. ")",false)
        circlehandler[GetID(x,z)] = {x=x,z=z,points=p,current=0,radius=radius,erase=false}
        --Spring.Echo("It's a " .. UnitDefs[unitDefID].name)
        if unitDefID == UnitDefNames["staticnuke"].id then recentallied = Spring.GetGameFrame() end
    end
end

function widget:GameFrame(f)
    if Spring.GetGameRulesParam("recentNukeLaunch") == 1 and f < recentallied - 30 then
        Spring.SendCommands("say a:[info] WARNING: Possible enemy nuke launch detected.")
    end
    for id,_ in pairs(silos) do
        --Spring.Echo("NumCommands: " .. tostring(#Spring.GetUnitCommands(id,2)))
        if ((UnitDefNames["staticnuke"].id == Spring.GetUnitDefID(id) or UnitDefNames["subtacmissile"].id) and #Spring.GetUnitCommands(id,1) == 0) or (UnitDefNames["staticnuke"].id ~=  Spring.GetUnitDefID(id) and select(5,Spring.GetUnitHealth(id))) == 1.0 then
            --Spring.Echo("Calling UnitCommand")
            widget:UnitCommand (id, Spring.GetUnitDefID(id), Spring.GetUnitTeam(id), CMD.ATTACK, silos[id], empty, empty, true)
            silos[id] = nil
        end
    end
    drawinglimit = 25
    if f%30 == 0 then
        for id, data in pairs(points) do
            data.timer = data.timer - 1
            if data.timer == 0 then
                Spring.MarkerErasePosition(data.x,data.y,data.z)
                drawinglimit = drawinglimit - 1
                circlehandler[GetID(data.x,data.z)] = {x = data.x, z = data.z,points = data.points,radius=data.radius,current=0,erase=true}
                points[id] = nil
            end
        end
    end
    if f%10 == 0 then
        local result = 0
        for id,data in pairs(circlehandler) do
            if data.current ~= data.points then
                result = math.min(10,drawinglimit)
                result = math.min(result, data.points - data.current)
                drawinglimit = drawinglimit - result
                if not data.erase and drawinglimit > 0 then
                    CreateRadius(data.x,data.z,data.radius,data.points,data.current,data.current+result)
                    data.current = data.current + result
                elseif drawinglimit > 0 then
                    EraseRadius(data.x,data.z,data.radius,data.points,data.current,data.current+result)
                    data.current = data.current + result
                end
            else
                circlehandler[id] = nil
            end
        end
    end
end