local version = '0.3'
function widget:GetInfo()
    return {
        name      = "Marker On Click",
        desc      = "Place marker on single click while using hotkey for drawing, ver "..version,
        author    = "Helwor",
        date      = "October 2022", 
        license   = "GNU GPL v2",
        layer     = 0,
        enabled   = true,
        handler   = true,
    }
end
-- Config
local MOVE_THRESHOLD = 4 -- can place a marker until the mouse moved this many pixel from the click position
local DOUBLECLICK_TIME = 0.30 -- how long shall we wait for a double click to happen before authorizing to place a marker
                              -- , value try to be as close as possible of the text label trigger
--
-- NOTE: since we use Update CallIn, the delay may vary depending on lag, the catching of click is not reliable, so user have to press until the next Update round
-- the widget is disabled at start of game if no hotkey is found for drawing on map

local spMarkerAddPoint = Spring.MarkerAddPoint
local spTraceScreenRay = Spring.TraceScreenRay
local spGetMouseState = Spring.GetMouseState
local spIsUserWriting = Spring.IsUserWriting
local Echo = Spring.Echo

local hotkey = {}

local catchDrawing, dontCatchThisOne, drawing, _, pos
local doubleClickDelay, waitDblClick, waitRelease


-- debugging
local debugging = true
local DebugUp
local last_doubleClickTime
local textLabel
local secondClick
local f = debugging and VFS.Include("LuaUI\\Widgets\\UtilsFunc.lua")
--

function widget:KeyPress(key,mods,isRepeat)
    if isRepeat then
        return
    end
    catchDrawing = hotkey[key]
end
function widget:KeyRelease(key)
    if hotkey[key] then
        catchDrawing = false
        doubleClickDelay = false
        drawing = false
        waitRelease = false
        waitDblClick = false
        if debugging then
            measureSecondClick = false
            secondClick = 0
        end
        

    end
end

function widget:Update(dt)
    if debugging then
        DebugUp("catchDrawing", catchDrawing)
        DebugUp("dontCatchThisOne", dontCatchThisOne)
        DebugUp("drawing", drawing)
        DebugUp("pos", pos)
        DebugUp("doubleClickDelay", doubleClickDelay)
        DebugUp("waitDblClick", waitDblClick)
        DebugUp("waitRelease", waitRelease)
        DebugUp("last_doubleClickTime", last_doubleClickTime)
        DebugUp("textLabel", textLabel)
    end
    if not catchDrawing then
        return
    end
    if spIsUserWriting() then
        doubleClickDelay = false
        waitDblClick = false
        drawing = false
        catchDrawing = false
        dontCatchThisOne = false
        if debugging then
            textLabel = true
            measureSecondClick = false
        end
        return
    end

    textLabel = false
    if doubleClickDelay then
        doubleClickDelay = doubleClickDelay - dt
        if doubleClickDelay <= -dt then
            doubleClickDelay = false
        end
    end
    local mx,my,lmb = spGetMouseState()
    if debugging then
        if measureSecondClick then 
            secondClick = secondClick+dt
            DebugUp("secondClick", secondClick)
            DebugUp('lastDT',dt)
        end
    end
    if waitRelease then
        if lmb then 
            return
        end
        waitRelease = false
    end
    if waitDblClick then
        if lmb and spIsUserWriting() then -- text label should have been triggered there
        else
            waitDblClick = not lmb and doubleClickDelay
            if not waitDblClick then
                spMarkerAddPoint(pos[1],pos[2],pos[3])
                if debugging then
                    measureSecondClick = false
                end
            else
                return
            end
        end
    end
    if not drawing then
        if lmb  then
            last_mx,last_my = mx,my
            drawing = true
            doubleClickDelay = DOUBLECLICK_TIME
            dontCatchThisOne = false
            if debugging then
                measureSecondClick = true
                secondClick = 0
                last_doubleClickTime = doubleClickDelay
            end
        end
    else
        if not lmb then
            drawing = false
        end
        if dontCatchThisOne then
            return
        end
        local delta = ((last_mx-mx)^2 + (last_my-my)^2)^0.5
        if delta>MOVE_THRESHOLD then
            dontCatchThisOne = true
            return
        end
        if not (drawing or dontCatchThisOne) then
            -- we're half way there, get the pos for our marker
            _,pos = spTraceScreenRay(mx, my, true, true, false,false)
            if not pos then
                return
            end
            waitDblClick = true
            waitRelease = true
        end
    end
end

function widget:Initialize()
    if debugging then
        DebugUp = f.DebugWinInit(widget)
    end
    for _,key in pairs(WG.crude.GetHotkeys("drawinmap") or {}) do
        hotkey[key:byte(-1)] = true
    end
    if not next(hotkey) then
        Echo(widget:GetInfo().name .. ' disabled, no hotkey for drawing on map')
        widgetHandler:RemoveWidget(widget)
    end
end