function ZO_Pregame_MustPlayVideos()
    return GetCVar("HasPlayedPregameVideo") == "0"
end

function ZO_Pregame_AllowVideosToPlay()
    return GetCVar("SkipPregameVideos") == "0"
end

ZO_PREGAME_CHARACTER_COUNT = 0
ZO_PREGAME_FIRED_CHARACTER_CONSTRUCTION_READY = false
ZO_PREGAME_CHARACTER_LIST_RECEIVED = false
ZO_PREGAME_HAD_GLOBAL_ERROR = false
ZO_PREGAME_IS_CHAPTER_OPENING_CINEMATIC_PLAYING = false
ZO_PREGAME_IS_CHARACTER_SELECT_CINEMATIC_PLAYING = false

local QUEUE_VIDEO = false

local currentState = nil
local previousState = nil

local loadingUpdates = false

-- We don't want to show the video or the chapter upsell when we're logging out, only when we're logging in
local shouldTryToPlayChapterOpeningCinematic = false
local shouldTryToShowChapterInterstitial = false

function Pregame_ShowScene(sceneName)
    SCENE_MANAGER:Show(sceneName)
    ZO_Dialogs_ReleaseAllDialogsExcept("HANDLE_ERROR", "HANDLE_ERROR_WITH_HELP")
end

function AttemptQuickLaunch()
    if GetCVar("QuickLaunch") == "1" then
        local acctName = GetCVar("AccountName")
        local acctPwd = GetCVar("AccountPassword")

        if acctName ~= "" and acctPwd ~= "" then
            PregameLogin(acctName, acctPwd)
        end
    end
end

function AttemptToFireCharacterConstructionReady()
    if not ZO_PREGAME_FIRED_CHARACTER_CONSTRUCTION_READY and IsPregameCharacterConstructionReady() and ZO_PREGAME_CHARACTER_LIST_RECEIVED then
        ZO_PREGAME_FIRED_CHARACTER_CONSTRUCTION_READY = true
        CALLBACK_MANAGER:FireCallbacks("OnCharacterConstructionReady")
    end
end

local AttemptToPlayIntroCinematic
do
    local OPENING_CINEMATIC =
    {
        [CHAPTER_BASE_GAME] = "Video/Opening_Cinematic_$(officialLanguage).bik",
        [CHAPTER_VOLCANO] = "Video/Morrowind_Opener_$(officialLanguage).bik",
        [CHAPTER_GLACIER] = "Video/Summerset_Opener_$(officialLanguage).bik"
    }

    function AttemptToPlayIntroCinematic()
        SetVideoCancelAllOnCancelAny(true)
        local highestUnlockedChapter = GetHighestUnlockedChapter()
        local videoPath = OPENING_CINEMATIC[highestUnlockedChapter]
        if videoPath then
            ZO_PlayVideoAndAdvance(videoPath, QUEUE_VIDEO, VIDEO_SKIP_MODE_REQUIRE_CONFIRMATION_FOR_SKIP)
        else
            ZO_PlayVideoAndAdvance("Video/Opening_Cinematic_$(officialLanguage).bik", QUEUE_VIDEO, VIDEO_SKIP_MODE_REQUIRE_CONFIRMATION_FOR_SKIP)
        end
    end
end

local PregameStates =
{
    ["CharacterSelect_FromIngame"] =
    {
        OnEnter = function()
            -- Let the character list receipt determine the state to go to.
            RequestCharacterList()
        end,

        OnExit = function()
        end
    },

    ["CharacterSelect_PlayCinematic"] =
    {
        ShouldAdvance = function()
            return false
        end,

        OnEnter = function()
            if not ZO_PREGAME_IS_CHARACTER_SELECT_CINEMATIC_PLAYING then
                AttemptToPlayIntroCinematic()
                ZO_PREGAME_IS_CHARACTER_SELECT_CINEMATIC_PLAYING = true
                if IsInGamepadPreferredMode() then
                    --Stops extra button presses from modifying the options scene, like restoring options defaults or logging out
                    GAMEPAD_OPTIONS:SetGamepadOptionsInputBlocked(true);
                end
            end
        end,

        GetStateTransitionData = function()
            return "CharacterSelect_FromCinematic"
        end,

        OnExit = function()
        end,
    },

    ["CharacterSelect_FromCinematic"] =
    {
        OnEnter = function(allowAnimation)
            ZO_PREGAME_IS_CHARACTER_SELECT_CINEMATIC_PLAYING = false
            if IsInGamepadPreferredMode() then
                GAMEPAD_OPTIONS:SetGamepadOptionsInputBlocked(false)
            end
        end,
        
        OnExit = function()
        end
    },

    ["PlayChapterOpeningCinematic"] =
    {
        ShouldAdvance = function()
            return false
        end,

        OnEnter = function()
            AttemptToPlayIntroCinematic()
            ZO_PREGAME_IS_CHAPTER_OPENING_CINEMATIC_PLAYING = true
            SCENE_MANAGER:ShowBaseScene()
        end,

        GetStateTransitionData = function()
            return "WaitForGameDataLoaded"
        end,

        OnExit = function()
        end,
    },

    ["WaitForGameDataLoaded"] =
    {
        ShouldAdvance = function()
            local loaded, total = GetDataLoadStatus()
            return loaded == total
        end,

        OnEnter = function()
            SuppressWorldList()
            RegisterForLoadingUpdates()
            -- Make sure we aren't showing a scene here if we
            -- didn't show the cinematic before switching to this scene
            SCENE_MANAGER:ShowBaseScene()
        end,
        
        OnExit = function()
        end,

        GetStateTransitionData = function()
            return "ChapterUpgradeInterstitial"
        end
    },

    ["CharacterCreateFadeIn"] = 
    {
        ShouldAdvance = function()
            return false
        end,

        OnEnter = function()
            ZO_CharacterCreate_FadeIn()
        end,

        GetStateTransitionData = function()
            return "CharacterCreate"
        end,

        OnExit = function()
        end,
    },

    ["CharacterCreate"] =
    {
        OnEnter = function(allowAnimation)
            ZO_CHARACTERCREATE_MANAGER:SetCharacterMode(CHARACTER_MODE_CREATION)
            local characterCreate = SYSTEMS:GetObject(ZO_CHARACTER_CREATE_SYSTEM_NAME)
            characterCreate:Reset()
            characterCreate:InitializeForCharacterCreate()

            if IsInGamepadPreferredMode() then
                Pregame_ShowScene("gamepadCharacterCreate")
            else
                Pregame_ShowScene("gameMenuCharacterCreate")
                -- PEGI update currently only needs to be shown on PC
                if DoesPlatformRequirePregamePEGI() and not HasAgreedToPEGI() then
                    ZO_Dialogs_ShowDialog("PEGI_COUNTRY_SELECT")
                end
            end
        end,

        OnExit = function()
            ZO_Dialogs_ReleaseDialog("CHARACTER_CREATE_CREATING")
            SetCharacterCameraZoomAmount(-1) -- zoom all the way out when leaving this state
        end
    },

    ["CharacterCreate_Barbershop"] =
    {
        OnEnter = function(allowAnimation)
            if IsInGamepadPreferredMode() then
                Pregame_ShowScene("gamepadCharacterCreate")
            else
                Pregame_ShowScene("gameMenuCharacterCreate")
            end
        end,

        OnExit = function()
            ZO_Dialogs_ReleaseDialog("CHARACTER_CREATE_CREATING")
            SetCharacterCameraZoomAmount(-1) -- zoom all the way out when leaving this state
        end
    },

    ["ChapterUpgrade"] =
    {
        ShouldAdvance = function()
            return false
        end,

        OnEnter = function()
            if IsConsoleUI() then
                Pregame_ShowScene("chapterUpgradeGamepad")
            else
                Pregame_ShowScene("chapterUpgradeKeyboard")
            end
        end,
        
        GetStateTransitionData = function()
            return "CharacterSelect"
        end,

        OnExit = function()
        end,
    },

    ["ChapterUpgradeInterstitial"] =
    {
        ShouldAdvance = function()
            if not shouldTryToShowChapterInterstitial then
                return true
            end

            return not CHAPTER_UPGRADE_MANAGER:ShouldShow()
        end,

        OnEnter = function()
            if IsConsoleUI() then
                Pregame_ShowScene("chapterUpgradeGamepad")
            else
                Pregame_ShowScene("chapterUpgradeKeyboard")
            end
        end,
        
        GetStateTransitionData = function()
            return "WaitForCharacterDataLoaded"
        end,

        OnExit = function()
        end,
    },

    ["WaitForCharacterDataLoaded"] =
    {
        ShouldAdvance = function()
            return IsPregameCharacterConstructionReady()
        end,

        OnEnter = function()
        end,

        GetStateTransitionData = function()
            if ZO_PREGAME_CHARACTER_COUNT > 0 then
                return "CharacterSelect"
            else
                return "CharacterCreateFadeIn"
            end
        end,

        OnExit = function()
        end,
    },

    ["BeginLoadingIntoWorld"] =
    {
        OnEnter = function()
            if (IsInGamepadPreferredMode() or IsConsoleUI()) then  -- TODO integrate this with PC gamepad
                ZO_CharacterSelect_Gamepad_ShowLoginScreen()
            else
                SCENE_MANAGER:ShowBaseScene()
                ZO_Dialogs_ShowDialog("REQUESTING_CHARACTER_LOAD")
            end
        end,

        OnExit = function()
        end
    },

    ["ScreenAdjust"] =
    {
        ShouldAdvance = function()
            return not IsConsoleUI()
        end,

        OnEnter = function()
            SCENE_MANAGER:Show("screenAdjust")
        end,

        OnExit = function()
        end,

        GetStateTransitionData = function()
            return "GammaAdjust"
        end,
    },

    ["ScreenAdjustIntro"] =
    {
        ShouldAdvance = function()
            return not IsConsoleUI() or GetCVar("PregameScreenAdjustEnabled") ~= "1"
        end,

        OnEnter = function()
            SCENE_MANAGER:Show("screenAdjustIntro")
            SetCVar("PregameScreenAdjustEnabled", "false")
        end,

        OnExit = function()
        end,

        GetStateTransitionData = function()
            return "GammaAdjust"
        end,
    },

    ["GammaAdjust"] =
    {
        ShouldAdvance = function()
            return not ZO_GammaAdjust_NeedsFirstSetup()
        end,

        OnEnter = function()
            SCENE_MANAGER:Show("gammaAdjust")
        end,

        OnExit = function()
            SetCVar("PregameGammaCheckEnabled", "false")
        end,

        GetStateTransitionData = function()
            if IsConsoleUI() or not DoesPlatformSelectServer() then
                return "ShowEULA"
            else
                return "ServerSelectIntro"
            end
        end,
    },

    ["PlayIntroMovies"] =
    {
        ShouldAdvance = function()
            return not(ZO_Pregame_MustPlayVideos() or ZO_Pregame_AllowVideosToPlay())
        end,

        OnEnter = function()
            -- If you haven't played the videos, you can't skip them until they finish...
            local skipMode
            if IsConsoleUI() then
                skipMode = VIDEO_SKIP_MODE_ALLOW_SKIP
            else
                skipMode = ZO_Pregame_MustPlayVideos() and VIDEO_SKIP_MODE_NO_SKIP or VIDEO_SKIP_MODE_ALLOW_SKIP
            end

            -- TODO: Determine if these videos need localization or subtitles...
            SetVideoCancelAllOnCancelAny(false)

            PlayVideo("Video/Bethesda_logo.bik", QUEUE_VIDEO, skipMode)

            ZO_PlayVideoAndAdvance("Video/ZOS_logo.bik", QUEUE_VIDEO, skipMode)
        end,

        GetStateTransitionData = function()
            return "ShowHavokSplashScreen"
        end,

        OnExit = function()
        end,
    },

    ["ShowLegalSplashScreen"] =
    {
        ShouldAdvance = function()
            return not(ZO_Pregame_MustPlayVideos() or ZO_Pregame_AllowVideosToPlay())
        end,

        OnEnter = function()
            SCENE_MANAGER:Show("logoSplash")
        end,

        GetStateTransitionData = function()
            return "ScreenAdjustIntro"
        end,

        OnExit = function()
        end,
    },

    ["ShowHavokSplashScreen"] =
    {
        ShouldAdvance = function()
            return not(ZO_Pregame_MustPlayVideos() or ZO_Pregame_AllowVideosToPlay())
        end,

        OnEnter = function()
            SCENE_MANAGER:Show("havokSplash")
        end,

        GetStateTransitionData = function()
            return "ShowDMMVideo"
        end,

        OnExit = function()
        end,
    },

    ["ShowDMMVideo"] =
    {
        ShouldAdvance = function()
            local serviceType = GetPlatformServiceType()
            return not(serviceType == PLATFORM_SERVICE_TYPE_DMM and (ZO_Pregame_MustPlayVideos() or ZO_Pregame_AllowVideosToPlay()))
        end,

        OnEnter = function()
            local skipMode = ZO_Pregame_MustPlayVideos() and VIDEO_SKIP_MODE_NO_SKIP or VIDEO_SKIP_MODE_ALLOW_SKIP
            ZO_PlayVideoAndAdvance("Video/jp_DMM_logo.bik", QUEUE_VIDEO, skipMode)
        end,

        GetStateTransitionData = function()
            return "ShowLegalSplashScreen"
        end,

        OnExit = function()
        end,
    },

    ["Disconnect"] =
    {
        OnEnter = function()
            SetCVar("QuickLaunch", "0")
            PregameDisconnect()
        end,

        OnExit = function ()
        end,
    }
}

function PregameStateManager_AddStates(externalStates)
    for key, value in pairs(externalStates) do
        PregameStates[key] = value
    end
end

function PregameStateManager_SetState(stateName, ...)
    local newPregameState = PregameStates[stateName]
    local stateArgs = { ... }

    -- Because GetTransitionData returns the next state as the first argument, insert state name into this table.
    -- The actual arguments passed to OnEnter will be adjusted to account for it.
    table.insert(stateArgs, 1, stateName)

    if(newPregameState) then
        if(currentState) then
            PregameStates[currentState].OnExit()
        end

        previousState = currentState

        local foundState = false
        while(not foundState) do
            currentState = stateName
            local shouldAdvance = (newPregameState.ShouldAdvance == nil) or newPregameState.ShouldAdvance()
            if(shouldAdvance) then
                if(newPregameState and newPregameState.GetStateTransitionData) then
                    stateArgs = { newPregameState.GetStateTransitionData() }
                    stateName = stateArgs[1]
                    newPregameState = PregameStates[stateName]
                else
                    foundState = true
                end
            else
                foundState = true
            end
        end

        newPregameState.OnEnter(select(2, unpack(stateArgs)))
        CALLBACK_MANAGER:FireCallbacks("OnPregameEnterState", currentState)
    end
end

function PregameStateManager_ReenterLoginState()
    if(PregameStateManager_GetCurrentState() == "AccountLogin") then
        CALLBACK_MANAGER:FireCallbacks("OnPregameEnterState", "AccountLogin")
    else
        PregameStateManager_SetState("AccountLogin")
    end
end

function PregameStateManager_AdvanceState()
    local currentStateData = PregameStates[currentState]
    if(currentStateData and currentStateData.GetStateTransitionData) then
        PregameStateManager_SetState(currentStateData.GetStateTransitionData())
    else
        -- If there are no transition data, then we're not going anywhere...we'll be locked in the current state.
        -- Do not call this if you're not on a state with transition data
        assert(false)
    end
end

-- this will only advance the state if we are currently in the state passed in
function PregameStateManager_AdvanceStateFromState(state)
    if currentState == state then
        PregameStateManager_AdvanceState()
    end
end

function PregameStateManager_GetCurrentState()
    return currentState
end

function PregameStateManager_GetPreviousState()
    return previousState
end

local function OnCharacterListReceived(eventCode, characterCount, maxCharacters, mostRecentlyPlayedCharacterId)
    ZO_PREGAME_CHARACTER_LIST_RECEIVED = true
    ZO_PREGAME_CHARACTER_COUNT = characterCount

    local isPlayingVideo = false

    if shouldTryToPlayChapterOpeningCinematic then
        local highestUnlockedChapter = GetHighestUnlockedChapter()
        local highestSeenOpening = tonumber(GetCVar("HighestChapterOpeningCinematicSeen"))

        if highestUnlockedChapter > highestSeenOpening then
            SetCVar("HighestChapterOpeningCinematicSeen", highestUnlockedChapter)
            ZO_SavePlayerConsoleProfile()
            -- Play intro movie
            PregameStateManager_SetState("PlayChapterOpeningCinematic")
            isPlayingVideo = true
        end
    end

    if not isPlayingVideo then
        -- Go to character create/select as necessary after we have our data
        -- If we are already at CharacterSelect when we get the character list, then we don't need to move
        -- This could happen when we rename or delete a character
        if PregameStateManager_GetCurrentState() ~= "CharacterSelect" then
            PregameStateManager_SetState("WaitForGameDataLoaded")
        elseif characterCount == 0 then
            -- However, if we delete our last character then we need to switch to CharacterCreate
            -- so we can create a new character. We also want to avoid CharacterCreateFadeIn since
            -- that won't transition very nicely between CharacterSelect and CharacterCreate
            -- We are also assuming here that we already have character data since we were at character select
            PregameStateManager_SetState("CharacterCreate")
        end
    end

    -- if this hasn't been fired yet, then fire it (could have been a reload or coming from in-game)
    AttemptToFireCharacterConstructionReady()
end

-- Debugging utility...you must be at character select already to use this.
local function SetupUIReloadAfterLogin()
    g_careAboutLoading = false
    RequestCharacterList()

    return "CharacterSelect"
    -- Return an invalid state, allow the character list receipt to figure out what state to advance to
end

local initialStateOverrideFn --= SetupUIReloadAfterLogin -- normally this is nil, it can be set to a custom function to allow the reload to drop into a desired state

function UnregisterForLoadingUpdates()
    if loadingUpdates then
        EVENT_MANAGER:UnregisterForEvent("PregameStateManager", EVENT_AREA_LOAD_STARTED)
        EVENT_MANAGER:UnregisterForEvent("PregameStateManager", EVENT_SUBSYSTEM_LOAD_COMPLETE)
        loadingUpdates = false
    end
end

local function OnAreaLoadStarted()
    ZO_Dialogs_ReleaseAllDialogs(true)
end

function IsPlayingChapterOpeningCinematic()
    return PregameStateManager_GetCurrentState() == "PlayChapterOpeningCinematic"
end

function IsInCharacterSelectCinematicState()
    return PregameStateManager_GetCurrentState() == "CharacterSelect_PlayCinematic"
end

function IsInCharacterCreateState()
    return PregameStateManager_GetCurrentState() == "CharacterCreate"
end

local function OnCharacterSelected(eventCode, characterId)
    PregameStateManager_SetState("BeginLoadingIntoWorld")
end

function PregameIsFullyLoaded()
    return GetNumLoadedSubsystems() == GetNumTotalSubsystemsToLoad()
end

function AttemptToAdvancePastChapterOpeningCinematic()
    if IsPlayingChapterOpeningCinematic() then
        if PregameIsFullyLoaded() and ZO_PREGAME_IS_CHAPTER_OPENING_CINEMATIC_PLAYING == false then
            PregameStateManager_AdvanceState()
        end
    end
end

function AttemptToAdvancePastCharacterSelectCinematic()
    if (IsInCharacterSelectCinematicState()) then
        if (PregameIsFullyLoaded() and ZO_PREGAME_IS_CHARACTER_SELECT_CINEMATIC_PLAYING == false) then
            PregameStateManager_AdvanceState()
        end
    end
end

local function OnSubsystemLoadComplete(eventId, subSystem)
    if subSystem == LOADING_SYSTEM_GAME_DATA or subSystem == LOADING_SYSTEM_SHARED_CHARACTER_OBJECT then
        AttemptToFireCharacterConstructionReady()
        -- LOADING_SYSTEM_GAME_DATA loads before LOADING_SYSTEM_SHARED_CHARACTER_OBJECT so if we hit either
        -- of those then the game data is loaded
        if subSystem == LOADING_SYSTEM_GAME_DATA then
            PregameStateManager_AdvanceStateFromState("WaitForGameDataLoaded")
        elseif subSystem == LOADING_SYSTEM_SHARED_CHARACTER_OBJECT then
            PregameStateManager_AdvanceStateFromState("WaitForCharacterDataLoaded")
        end
    end

    if PregameIsFullyLoaded() then
        if IsPlayingChapterOpeningCinematic() then
            AttemptToAdvancePastChapterOpeningCinematic()
        end

        CALLBACK_MANAGER:FireCallbacks("PregameFullyLoaded")
        UnregisterForLoadingUpdates()
    end
end

function RegisterForLoadingUpdates()
    if not loadingUpdates then
        EVENT_MANAGER:RegisterForEvent("PregameStateManager", EVENT_AREA_LOAD_STARTED, OnAreaLoadStarted)
        EVENT_MANAGER:RegisterForEvent("PregameStateManager", EVENT_SUBSYSTEM_LOAD_COMPLETE, OnSubsystemLoadComplete)
        loadingUpdates = true
    end
end

local function OnShowPregameGuiInState(eventCode, desiredState)
    SetGuiHidden("pregame", false)

    if initialStateOverrideFn then
        desiredState = initialStateOverrideFn()
    end

    if desiredState and desiredState ~= "" then
        PregameStateManager_SetState(desiredState, true)
    end
end

function PregameStateManager_PlayCharacter(charId, loadOption)
    if(type(loadOption) == "string") then
        PregameStateManager_SetState(loadOption)
    else --We will need to revisit this once the tutorial gate is integrated into the build
        CALLBACK_MANAGER:FireCallbacks("OnCharacterLoadRequested")
        SelectCharacterForPlay(charId, loadOption)
    end
end

function PregameStateManager_ClearError()
    ZO_PREGAME_HAD_GLOBAL_ERROR = false
end

local function OnDisplayNameReady()
    shouldTryToPlayChapterOpeningCinematic = true
    shouldTryToShowChapterInterstitial = true
end

function ZO_RegisterForSavedVars(systemName, version, defaults, callback)
    local function OnReady()
        local savedVars = ZO_SavedVars:NewAccountWide("ZO_Pregame_SavedVariables", version, systemName, defaults)
        callback(savedVars)
    end

    local function OnAddonLoaded(eventId, name)
        if name == "ZO_Pregame" then
            EVENT_MANAGER:UnregisterForEvent(systemName, EVENT_ADD_ON_LOADED)

            -- Wait for login
            if GetDisplayName() ~= "" then
                OnReady()
            end
        end
    end

    EVENT_MANAGER:RegisterForEvent(systemName, EVENT_ADD_ON_LOADED, OnAddonLoaded)
    -- Every time we log in, we need a new saved vars for that account
    EVENT_MANAGER:RegisterForEvent(systemName, EVENT_DISPLAY_NAME_READY, OnReady)
end

EVENT_MANAGER:RegisterForEvent("PregameStateManager", EVENT_DISPLAY_NAME_READY, OnDisplayNameReady)
EVENT_MANAGER:RegisterForEvent("PregameStateManager", EVENT_CHARACTER_LIST_RECEIVED, OnCharacterListReceived)
EVENT_MANAGER:RegisterForEvent("PregameStateManager", EVENT_SHOW_PREGAME_GUI_IN_STATE, OnShowPregameGuiInState)
EVENT_MANAGER:RegisterForEvent("PregameStateManager", EVENT_CHARACTER_SELECTED_FOR_PLAY, OnCharacterSelected)