local UINavigator = {}

local INPUT_TYPE = {
    REMOTE          = "REMOTE",       -- 遥控
    MOUSE           = "MOUSE",        -- 鼠标
    GESTURE         = "GESTURE"       -- 手势
}

local nGestureScale = 1.2
local nFrameCount = 10
local nRemoteInputTime = 5
local nGestureInputTime = 0.2

local lastMousePos
local nLastGestureInputTime
local nLastRemoteInputTime
local lastSelectedObj
local originalScale
local currentInputType

local function ChangeInputType(INPUT_TYPE)
    currentInputType = INPUT_TYPE
end

local function UpdateLastRemoteTime()
    nLastRemoteInputTime = CS.UnityEngine.Time.unscaledTime
end

local function UpdateLastGestureTime()
    nLastGestureInputTime = CS.UnityEngine.Time.unscaledTime
end

local function SelectButton(selectable)
    if nil == selectable then
        CS.UnityEngine.EventSystems.EventSystem.current:SetSelectedGameObject(nil)
        return
    end

    selectable.gameObject:SetActive(true)
    selectable.transform:GetComponent("Selectable"):Select()
end

local function SetEntryButton(button)
    ChangeInputType(INPUT_TYPE.REMOTE)
    UpdateLastRemoteTime()
    SelectButton(button)
end

local function SetGestureInputType()
    UpdateLastGestureTime()
    if currentInputType == INPUT_TYPE.GESTURE then return end

    ChangeInputType(INPUT_TYPE.GESTURE)

    -- 手势输入时  ui从缩放动画变成放大效果
    if lastSelectedObj
        and not lastSelectedObj:IsDestroyed()
        and not lastSelectedObj.transform:CompareTag("CommonUtilsMenu") then
        lastSelectedObj.transform:DOKill()
        lastSelectedObj.transform.localScale = nGestureScale * originalScale
    end
end

local function CheckInput()
    local Input = CS.UnityEngine.Input
    local KeyCode = CS.UnityEngine.KeyCode
    if Input.GetKeyDown(KeyCode.Escape) then
        local eventManager = require('Base/ZEventDispatchCenter.lua')
        eventManager:DispatchEvent(eventManager.EventType.COMMON_REMOTE_RETURN)
    end
end

local function GetSelected()
    local selected = CS.UnityEngine.EventSystems.EventSystem.current.currentSelectedGameObject
    if selected and not selected:Equals(nil) and selected.activeInHierarchy then
        return selected:GetComponent("Selectable")
    end

    return nil
end

local function ResetLastSelectedTransform()
    if lastSelectedObj and not lastSelectedObj:IsDestroyed() then
        lastSelectedObj.transform:DOKill()
        lastSelectedObj.transform.localScale = originalScale
    end
end

local function DispatchEventSelectBtn(selected)
    local eventManager = require('Base/ZEventDispatchCenter.lua')
    eventManager:DispatchEvent(eventManager.EventType.COMMON_SELECT_BUTTON, lastSelectedObj, selected)
end

local function MakeButtonFlash(selected)
    selected.transform:DOKill()
    selected.transform.localScale = originalScale
    selected.transform:DOScale(1.2, 1):SetLoops(-1, CS.DG.Tweening.LoopType.Yoyo)
end

local function SetSelectData(selected)
    if not selected then return end

    originalScale = selected.transform.localScale

    if selected.transform:CompareTag("CommonUtilsMenu") then
        local eventManager = require('Base/ZEventDispatchCenter.lua')
        eventManager:DispatchEvent(eventManager.EventType.COMMON_UI_NAVIGATOR_SELECT_MENU, selected)
        return
    end

    MakeButtonFlash(selected)
end

local function IsRemoteKeyDown()
    local Input = CS.UnityEngine.Input
    local KeyCode = CS.UnityEngine.KeyCode

    return Input.GetKeyDown(KeyCode.LeftArrow)
            or Input.GetKeyDown(KeyCode.RightArrow)
            or Input.GetKeyDown(KeyCode.UpArrow)
            or Input.GetKeyDown(KeyCode.DownArrow)
            or Input.GetKeyDown(KeyCode.Return)
            or Input.GetKeyDown(KeyCode.Joystick1Button0)
end

local function UpdateSelectableBehaviour()
    local selected = GetSelected()

    if selected ~= lastSelectedObj then
        ResetLastSelectedTransform()
        DispatchEventSelectBtn(selected)
        SetSelectData(selected)

        lastSelectedObj = selected
        return
    end
end

local function CheckRemoteKeyDown()
    if IsRemoteKeyDown() then
        ChangeInputType(INPUT_TYPE.REMOTE)
        return
    end

    local Time = CS.UnityEngine.Time
    local Input = CS.UnityEngine.Input
    local mouseMove = CS.UnityEngine.Vector3.SqrMagnitude(Input.mousePosition - lastMousePos)
    if Time.frameCount > nFrameCount
        and (mouseMove > 0.1 or Input.GetMouseButtonDown(0)) then
            ChangeInputType(INPUT_TYPE.MOUSE)
    end

    lastMousePos = Input.mousePosition
end

local function Select(selected)
    if selected then
        selected.gameObject:SetActive(true)
        selected:Select()
        return
    end

    CS.UnityEngine.EventSystems.EventSystem.current:SetSelectedGameObject(nil)
end

local function GetKeyCode()
    local KeyCode        = CS.UnityEngine.KeyCode
    local Input          = CS.UnityEngine.Input

    if Input.GetKeyDown(KeyCode.LeftArrow) then
        return KeyCode.LeftArrow
    end

    if Input.GetKeyDown(KeyCode.RightArrow) then
        return KeyCode.RightArrow
    end

    if Input.GetKeyDown(KeyCode.UpArrow) then
        return KeyCode.UpArrow
    end

    if Input.GetKeyDown(KeyCode.DownArrow) then
        return KeyCode.DownArrow
    end

    return KeyCode.None
end

local function SetKeyboardSelected(selected)
    -- 没有选中的UI 寻找第一个
    if nil == selected
        or not selected.isActiveAndEnabled
    then
        local Navigation = CS.UnityEngine.UI.Navigation

        local allSelectablesArray = CS.UnityEngine.UI.Selectable.allSelectablesArray
        local nLen = allSelectablesArray.Length
        for nIndex = 0, nLen - 1, 1 do
            if nil ~= allSelectablesArray[nIndex]:IsDestroyed()
                and Navigation.Mode.None ~= allSelectablesArray[nIndex].navigation.mode
            then
                Select(allSelectablesArray[nIndex])
                break
            end
        end

        return
    end

    if 1 == CS.UnityEngine.Selectable.allSelectableCount
        and CS.UnityEngine.EventSystems.EventSystem.current.currentSelectedGameObject
    then
        Select(nil)
    end
end

local function UpdateKeyboardSelection()
    local selected = GetSelected()

    local Navigation = CS.UnityEngine.UI.Navigation
    if selected and selected.navigation.mode == Navigation.Mode.None then
        Select(nil)
        return
    end

    local KeyCode = CS.UnityEngine.KeyCode
    local currentKeyCode = GetKeyCode()

    if KeyCode.None ~= currentKeyCode then
        SetKeyboardSelected(selected)
        UpdateLastRemoteTime()
        return
    end

    if 1 == CS.UnityEngine.Selectable.allSelectableCount
        and CS.UnityEngine.EventSystems.EventSystem.current.currentSelectedGameObject
        and CS.UnityEngine.Time.unscaledTime - nLastRemoteInputTime > nRemoteInputTime
    then
        Select(nil)
    end
end

local function UpdateMouseSelection()
    local EventSystems = CS.UnityEngine.EventSystems
    if not EventSystems.EventSystem.current:IsPointerOverGameObject() then
        Select(nil)
        return
    end

    local pointerEventData = EventSystems.PointerEventData(EventSystems.EventSystem.current)
    local mousePosition = CS.UnityEngine.Input.mousePosition
    local mousePos      = CS.UnityEngine.Vector2(mousePosition.x, mousePosition.y)
    pointerEventData.position = mousePos

    local listRaycast = CS.System.Collections.Generic.List(CS.UnityEngine.EventSystems.RaycastResult)()
    EventSystems.EventSystem.current:RaycastAll(pointerEventData, listRaycast)

    local tPointSelect = {}
    for _, tRaycast in pairs(listRaycast) do
        local selectable = tRaycast.gameObject:GetComponent("Selectable")
        if selectable and selectable.navigation.mode ~= CS.UnityEngine.UI.Navigation.Mode.None then
            table.insert(tPointSelect, selectable)
        end
    end

    if 0 == #tPointSelect then
        Select(nil)
        return
    end

    local firstSeleted = tPointSelect[1]
    if EventSystems.EventSystem.current.currentSelectedGameObject == firstSeleted.gameObject then
        return
    end

    Select(firstSeleted)
end

local function UpdateGestureSelection()
    if CS.UnityEngine.Time.unscaledTime - nLastGestureInputTime > nGestureInputTime then
        ChangeInputType(INPUT_TYPE.GESTURE)

        if lastSelectedObj
            and not lastSelectedObj:IsDestroyed()
            and not lastSelectedObj.transform:CompareTag("CommonUtilsMenu") then
            MakeButtonFlash(lastSelectedObj)
        end
    end
end

local function SwitchInputType()
    if INPUT_TYPE.REMOTE == currentInputType then
        UpdateKeyboardSelection()
        return
    end

    if INPUT_TYPE.MOUSE == currentInputType then
        UpdateMouseSelection()
        return
    end

    if INPUT_TYPE.GESTURE == currentInputType then
        UpdateGestureSelection()
        return
    end
end

local function RegisterEvent()
    local eventManager = require('Base/ZEventDispatchCenter.lua')

    eventManager:RegisterEvent(eventManager.EventType.COMMON_SET_ENTRY_BUTTON, SetEntryButton)
    eventManager:RegisterEvent(eventManager.EventType.COMMON_SET_GESTUREINPUT, SetGestureInputType)
    eventManager:RegisterEvent(eventManager.EventType.COMMON_UI_NAVIGATOR_ANIM, MakeButtonFlash)
    eventManager:RegisterEvent(eventManager.EventType.COMMON_UI_NAVIGATOR_SELECT, Select)
end

local function UnregisterEvent()
    local eventManager = require('Base/ZEventDispatchCenter.lua')

    eventManager:UnregisterEvent(eventManager.EventType.COMMON_UI_NAVIGATOR_SELECT, Select)
    eventManager:UnregisterEvent(eventManager.EventType.COMMON_UI_NAVIGATOR_ANIM, MakeButtonFlash)
    eventManager:UnregisterEvent(eventManager.EventType.COMMON_SET_GESTUREINPUT, SetGestureInputType)
    eventManager:UnregisterEvent(eventManager.EventType.COMMON_SET_ENTRY_BUTTON, SetEntryButton)
end

function UINavigator.Awake(luaRoot)
    UINavigator.luaRoot = luaRoot

    local canvas = CS.UnityEngine.GameObject.Find('Canvas')
    UINavigator._rootCanvas = canvas

    lastMousePos = CS.UnityEngine.Input.mousePosition
end

function UINavigator.Start()
    RegisterEvent()
end

function UINavigator.Update()
    CheckInput()
    UpdateSelectableBehaviour()
    CheckRemoteKeyDown()

    SwitchInputType()
end

function UINavigator.OnDestroy()
    UnregisterEvent()

    CS.UnityEngine.GameObject.Destroy(UINavigator.rootPanel)
end

return UINavigator