local gfx <const> = playdate.graphics
local controlY = 0
local controlX = 0

local index = 0

local menuitems = {}
local menu = null
local page = 0

local imgCursor = gfx.image.new("gfx/cursor")
local imgBytes = gfx.image.new("gfx/bytes")
assert(imgCursor)
assert(imgBytes)

mainmenu = {}
function mainMenuCreation()
    mainmenu = {}
    mainmenu[4],mainmenu[3],mainmenu[2], mainmenu[1], mainmenu[0] = "START NEW GAME", "USER LEVELS", "LEVEL EDITOR", "ABOUT THE CREATOR", "mainNoPlay"
    
    if playdate.datastore.read("savegame") then
        map = playdate.datastore.read("savegame").savedLevel
        mainmenu[5], mainmenu[0] = "CONTINUE", "mainPlay"  
    end
end

function createMenu(items)
    killBlades()
    killPlayer()
    mode = "menu"
    controlX = -80
    index = 0
    menuitems = {}
    local _y =220 
    menu = items[0]
    for i=1, #items, 1 do
        menuitems[i] = {name=items[i],y=_y}
        _y -= 20
    end
end

function updateMenu()
    gfx.clear(gfx.kColorBlack)
    -- input 
    local change, aChange = playdate.getCrankChange()

    if playdate.buttonJustPressed(playdate.kButtonUp) then
        index -= 1
    elseif playdate.buttonJustPressed(playdate.kButtonDown) then
        index += 1
    end

    index += change * 0.01

    if math.floor(index) < 0 then index = #menuitems -0.01 end
    if math.floor(index) > #menuitems - 1 then index = 0 end

    controlX = playdate.math.lerp(controlX, 20, 0.3)
    controlY = playdate.math.lerp(controlY, (20 * math.floor(index)) - 1, 0.5)
    for i = 1, #menuitems, 1 do
        local item = menuitems[i]
        gfx.drawText(item.name,controlX,item.y)
    end
    imgCursor:draw(controlX - 17,controlY + (243 - (20 * #menuitems)))

    if playdate.buttonJustPressed(playdate.kButtonA) then
        menuButtonPress(menuitems[#menuitems - math.floor(index)].name)
    end

    imgBytes:draw(0,0)
end

local function customLoad()
    local lvls = playdate.file.listFiles("levels")
    local m = {}
    m[0], m[1] = "customs", "BACK"
    if #lvls - ((7*page)) <= 0 then page = 0 end
    if #lvls < 7 then
        for i = 1, #lvls, 1 do
            m[i+1] = lvls[i]:upper()
        end
    elseif lvls[1 + (7*page)] then
        m[2] = "NEXT PAGE"
        for i = 1, 7, 1 do
            if lvls[i+(7*page)] then
                m[i+2] = lvls[i+(7*page)]:upper()
            end
        end
    end
    
    createMenu(m)

    index = #lvls
end

function menuButtonPress(name)
    if name == "START NEW GAME" and menu == "mainPlay" then
        local m = {}
        m[0], m[1], m[2] = "newgame", "CANCEL", "CONFIRM"
        createMenu(m)
    
    elseif name == "START NEW GAME" or name == "CONFIRM" then
        addMapSave("levels/level.json")
    
    elseif name == "CONTINUE" then
        addMap(map)

    elseif name == "ABOUT THE CREATOR" then
        local m = {}
        m[0],m[1] = "about", "BACK"
        createMenu(m)
    
    elseif name == "USER LEVELS" then
        page = 0
        customLoad()
    elseif name == "NEXT PAGE" then
        page += 1
        if menu == "customs" then
            customLoad()
        else
            editLoad()
        end
    
    elseif name == "BACK" or name == "CANCEL" then
        createMenu(mainmenu)
    
    elseif menu == "customs" then
        addMap("levels/"..name)
    end
end