local DEFAULT_TEMPLATE = "ZO_GamepadItemSubEntryTemplate"
local DEFAULT_HEADER_TEMPLATE = "ZO_GamepadMenuEntryHeaderTemplate"

ZO_GamepadInventoryList = ZO_InitializingCallbackObject:Subclass()

--[[
Initializes the ZO_GamepadInventoryList. This should not be called directly, as it will be called by New().

control must be an XML control for intializing a parameteric list.
inventoryType must be one of the Bag enum values, or a table containing multiple bag enum values.
selectedDataCallback may be a function to call when the selected item has changed. May be nil.
entryEditCallback may be a function to call when initializing the ZO_GamepadEntryData for display.
    If specified, it should take a single argument which will be the ZO_GamepadEntryData, and will
    be called after entry:InitializeInventoryVisualData() and entry.itemData is set. May be nil.
categorizationFunction may be a function to call to retrieve the category string for an inventory
    item. If specified, should take a inventoryData (as returned by SHARED_INVENTORY:GenerateSingleSlotData)
    and return a string category. If nil, defaults to ZO_InventoryUtils_Gamepad_GetBestItemCategoryDescription().
sortFunction may be a function that is passed to table.sort to sort the entries for display. If nil, a default
    will be used tgat will sort alphabetically by category than by name.
useTriggers: Should the control bind the triggers to jump categories when activated? If nil, defaults to true.
]]
function ZO_GamepadInventoryList:Initialize(control, inventoryType, slotType, selectedDataCallback, entrySetupCallback, categorizationFunction, sortFunction, useTriggers, template, templateSetupFunction)
    self.control = control
    self.selectedDataCallback = selectedDataCallback
    self.entrySetupCallback = entrySetupCallback
    self.categorizationFunction = categorizationFunction
    self.sortFunction = sortFunction
    self.dataByBagAndSlotIndex = {}
    self.useTriggers = useTriggers ~= false -- nil => true
    self.template = template or DEFAULT_TEMPLATE

    self.currentSortType = ITEM_LIST_SORT_TYPE_CATEGORY

    if type(inventoryType) == "table" then
        self.inventoryTypes = inventoryType
    else
        self.inventoryTypes = { inventoryType }
    end

    for _, bagId in ipairs(self.inventoryTypes) do
        self.dataByBagAndSlotIndex[bagId] = {}
    end

    local function VendorEntryTemplateSetup(entryControl, data, selected, selectedDuringRebuild, enabled, activated)
        ZO_Inventory_BindSlot(data, slotType, data.slotIndex, data.bagId)
        ZO_SharedGamepadEntry_OnSetup(entryControl, data, selected, selectedDuringRebuild, enabled, activated)
    end

    self.list = ZO_GamepadVerticalParametricScrollList:New(self.control)
    self.list:AddDataTemplate(self.template, templateSetupFunction or VendorEntryTemplateSetup, ZO_GamepadMenuEntryTemplateParametricListFunction)
    self.list:AddDataTemplateWithHeader(self.template, templateSetupFunction or VendorEntryTemplateSetup, ZO_GamepadMenuEntryTemplateParametricListFunction, nil, DEFAULT_HEADER_TEMPLATE)

    -- generate the trigger keybinds so we can add/remove them later when necessary
    self.triggerKeybinds = {}
    ZO_Gamepad_AddListTriggerKeybindDescriptors(self.triggerKeybinds, self.list)

    local function SelectionChangedCallback(list, selectedData, oldSelectedData)
        if self.selectedDataCallback then
            self.selectedDataCallback(list, selectedData, oldSelectedData)
        end
        if selectedData then
            GAMEPAD_INVENTORY:PrepareNextClearNewStatus(selectedData)
            self:GetParametricList():RefreshVisible()
        end
    end

    local function OnEffectivelyShown()
        if self.selectedDataCallback then
            self.selectedDataCallback(self.list, self.list:GetTargetData())
        end
        -- Don't activate on show in case there is another element that is intended to be active (ie. when the list is empty and the header should be selected instead)
    end

    local function OnEffectivelyHidden()
        GAMEPAD_INVENTORY:TryClearNewStatusOnHidden()
        -- To ensure the list isn't left greyed-out once we've entered due to factors such as pending animations that would
        -- cause an effective hidden state, no longer calling self:Deactivate() here. Expecting managing classes to handle this.
    end

    local function OnInventoryUpdated(bagId)
        for _, currentInventoryType in ipairs(self.inventoryTypes) do
            if bagId == currentInventoryType then
                self:RefreshList()
                break
            end
        end
    end

    local function OnSingleSlotInventoryUpdate(bagId, slotIndex)
        if not self.control:IsHidden() then
            for _, currentInventoryType in ipairs(self.inventoryTypes) do
                if bagId == currentInventoryType then
                    local bag = self.dataByBagAndSlotIndex[bagId]
                    --we should always have a bag table to match all entries in self.inventoryTypes but this will catch any issue with that
                    internalassert(bag ~= nil)
                    if bag then
                        local entry = bag[slotIndex]
                        if entry then
                            local itemData = SHARED_INVENTORY:GenerateSingleSlotData(currentInventoryType, slotIndex)
                            if itemData then
                                itemData.bestGamepadItemCategoryName = ZO_InventoryUtils_Gamepad_GetBestItemCategoryDescription(itemData)
                                self:SetupItemEntry(entry, itemData)
                                self.list:RefreshVisible()
                            else -- The item was removed.
                                self:RefreshList()
                            end
                        else -- The item is new.
                            self:RefreshList()
                        end
                        -- don't loop over any more inventoryTypes, we've handled the slot update
                        break
                    end
                end
            end
        end
    end

    self:SetOnSelectedDataChangedCallback(SelectionChangedCallback)

    self.refresh = ZO_Refresh:New()
    self.refresh:AddRefreshGroup("list",
    {
        RefreshAll = function()
            self:OnRefreshList(self.shouldTriggerRefreshCallback)
            self.shouldTriggerRefreshCallback = nil
        end,
    })

    local function OnUpdate()
        self.list:OnUpdate()
        self.refresh:UpdateRefreshGroups()
    end
    
    self.control:SetHandler("OnUpdate", OnUpdate)
    self.control:SetHandler("OnEffectivelyShown", OnEffectivelyShown)
    self.control:SetHandler("OnEffectivelyHidden", OnEffectivelyHidden)

    SHARED_INVENTORY:RegisterCallback("FullInventoryUpdate", OnInventoryUpdated)
    SHARED_INVENTORY:RegisterCallback("SingleSlotInventoryUpdate", OnSingleSlotInventoryUpdate)
end

function ZO_GamepadInventoryList:ClearInventoryTypes()
    self.inventoryTypes = {}
    self:RefreshList()
end

function ZO_GamepadInventoryList:SetInventoryTypes(inventoryTypes)
    local newInventoryTypes
    if type(inventoryTypes) == "table" then
        newInventoryTypes = inventoryTypes
    else
        newInventoryTypes = { inventoryTypes }
    end

    if newInventoryTypes then
        local sameBags = true
        for i, newBag in ipairs(newInventoryTypes) do
             if self.inventoryTypes[i] ~= newBag then
                sameBags = false
                break
             end
        end
        if not sameBags then
            self.inventoryTypes = newInventoryTypes
            --Refresh list will also regenerate these tables for each bag, but if the inventory list is hidden it will set a dirty flag instead and do it when it is effectively shown. This is a problem
            --when a single slot update occurs because it checks self.inventoryTypes to know if we have a bag table in dataByBagAndSlotIndex to work with but we haven't rebuilt dataByBagAndSlotIndex yet
            -- so we end up with an index on a bag table that doesn't exist. So we rebuild dataByBagAndSlotIndex immediately here.
            self.dataByBagAndSlotIndex = {}
            for _, bagId in ipairs(self.inventoryTypes) do
                self.dataByBagAndSlotIndex[bagId] = {}
            end
            self:RefreshList()
            return true
        end
    end

    return false
end

function ZO_GamepadInventoryList:AddInventoryType(inventoryType)
    if self.inventoryTypes then
        table.insert(self.inventoryTypes, inventoryType)
    else
        self.inventoryTypes = {inventoryType}
    end

    self:RefreshList()
end

--[[
Add a function called when the selected item is changed.
]]--
function ZO_GamepadInventoryList:SetOnSelectedDataChangedCallback(selectedDataCallback)
    self.list:SetOnSelectedDataChangedCallback(selectedDataCallback)
end

--[[
Remove a function called when the selected item is changed.
]]--
function ZO_GamepadInventoryList:RemoveOnSelectedDataChangedCallback(selectedDataCallback)
    self.list:RemoveOnSelectedDataChangedCallback(selectedDataCallback)
end

--[[
Add a function called when the target data is changed.
]]--
function ZO_GamepadInventoryList:SetOnTargetDataChangedCallback(selectedDataCallback)
    self.list:SetOnTargetDataChangedCallback(selectedDataCallback)
end

--[[
Remove a function called when the target data is changed.
]]--
function ZO_GamepadInventoryList:RemoveOnTargetDataChangedCallback(selectedDataCallback)
    self.list:RemoveOnTargetDataChangedCallback(selectedDataCallback)
end

--[[
categorizationFunction function may be a function which takes a inventory data and returns
    a category string.
]]--
function ZO_GamepadInventoryList:SetCategorizationFunction(categorizationFunction)
    self.categorizationFunction = categorizationFunction
    self:RefreshList()
end

--[[
Sets the function which is passed to table.sort() when sorting the inventory inventory items.
]]--
function ZO_GamepadInventoryList:SetSortFunction(sortFunction)
    self.sortFunction = sortFunction
    self:RefreshList()
end

--[[
entryEditCallback may be a function to call when initializing the ZO_GamepadEntryData for display.
    If specified, it should take a single argument which will be the ZO_GamepadEntryData, and will
    be called after entry:InitializeInventoryVisualData() and entry.itemData is set. May be nil.
]]--
function ZO_GamepadInventoryList:SetEntrySetupCallback(entrySetupCallback)
    self.entrySetupCallback = entrySetupCallback
    self:RefreshList()
end

--[[
itemFilterFunction function may be a function which takes an inventory data and returns whether to
    include the item in the inventory list. If set to nil, all items will be included.
]]--
function ZO_GamepadInventoryList:SetItemFilterFunction(itemFilterFunction)
    self.itemFilterFunction = itemFilterFunction
    self:RefreshList()
end

--[[
    SetOnRefreshListCallback sets a function that will be called whenever the list is refreshed.
]]--
function ZO_GamepadInventoryList:SetOnRefreshListCallback(onRefreshListCallback)
    self.onRefreshListCallback = onRefreshListCallback
end

--[[
Sets whether to bind the triggers to jump categories while the list is active.

If the list is currently active, this will add/remove the bindings immediately.
]]--
function ZO_GamepadInventoryList:SetUseTriggers(useTriggers)
    if self.useTriggers == useTriggers then -- Exit out if no change, to simplify later logic.
        return
    end

    self.useTriggers = useTriggers
    if self.list:IsActive() then
        if useTriggers then
            KEYBIND_STRIP:AddKeybindButtonGroup(self.triggerKeybinds)
        else
            KEYBIND_STRIP:RemoveKeybindButtonGroup(self.triggerKeybinds)
        end
    end
end

--[[
Returns the currently selected entry's data.
]]--
function ZO_GamepadInventoryList:GetTargetData()
    return self.list:GetTargetData()
end

--[[
Returns the underlying parameteric list.
]]--
function ZO_GamepadInventoryList:GetParametricList()
    return self.list
end

--[[
Moves the selection to the next item.
]]--
function ZO_GamepadInventoryList:MoveNext()
    return self.list:MoveNext()
end

--[[
Moves the selection to the previous item.
]]--
function ZO_GamepadInventoryList:MovePrevious()
    return self.list:MovePrevious()
end

--[[
Query if the inventory list is empty
]]--
do
    local function HasSlotData(inventoryType, slotIndex, filterFunction)
        local slotData = SHARED_INVENTORY:GenerateSingleSlotData(inventoryType, slotIndex)
        if slotData then
            if (not filterFunction) or filterFunction(slotData) then
                return true
            end
        end
        return false
    end

    function ZO_GamepadInventoryList:IsEmpty()
        for _, bagId in ipairs(self.inventoryTypes) do
            local filterFunction = self.itemFilterFunction
            for slotIndex in ZO_IterateBagSlots(bagId) do
                if HasSlotData(bagId, slotIndex, filterFunction) then
                    return false
                end
            end
        end

        return true
    end
end

--[[
Passthrough functions for operating on the parametric list itself
]]--
function ZO_GamepadInventoryList:SetFirstIndexSelected(...)
    self.list:SetFirstIndexSelected(...)
end

function ZO_GamepadInventoryList:SetLastIndexSelected(...)
    self.list:SetLastIndexSelected(...)
end

function ZO_GamepadInventoryList:SetPreviousSelectedDataByEval(...)
    return self.list:SetPreviousSelectedDataByEval(...)
end

function ZO_GamepadInventoryList:SetNextSelectedDataByEval(...)
    return self.list:SetNextSelectedDataByEval(...)
end

--[[
Moves the selection to the specified item.

The same arguments can be provided as ZO_ParametricScrollList.SetSelectedIndex() accepts.
]]--
function ZO_GamepadInventoryList:SetSelectedIndex(...)
    self.list:SetSelectedIndex(...)
end

--[[
Activates the inventory list.
]]--
function ZO_GamepadInventoryList:Activate()
    self.list:Activate()
    if self.useTriggers then
        KEYBIND_STRIP:AddKeybindButtonGroup(self.triggerKeybinds)
    end
end

--[[
Deactivates the inventory list.
]]--
function ZO_GamepadInventoryList:Deactivate()
    if self.useTriggers then
        KEYBIND_STRIP:RemoveKeybindButtonGroup(self.triggerKeybinds)
    end
    self.list:Deactivate()
end

--[[
GetNumItems the inventory list.
]]--
function ZO_GamepadInventoryList:GetNumItems()
    return self.list:GetNumItems()
end

--[[
GetSelectedIndex the inventory list.
]]--
function ZO_GamepadInventoryList:GetSelectedIndex()
    return self.list:GetSelectedIndex()
end

--[[
An internal helper function used to initialize or update a ZO_GamepadEntryData
 with itemData.
]]--
function ZO_GamepadInventoryList:SetupItemEntry(entry, itemData)
    entry:InitializeInventoryVisualData(itemData)
    entry.itemData = itemData
    if self.entrySetupCallback then
        self.entrySetupCallback(entry)
    end
end

local DEFAULT_GAMEPAD_ITEM_SORT =
{
    bestGamepadItemCategoryName = { tiebreaker = "name" },
    name = { tiebreaker = "requiredLevel" },
    requiredLevel = { tiebreaker = "requiredChampionPoints", isNumeric = true },
    requiredChampionPoints = { tiebreaker = "iconFile", isNumeric = true },
    iconFile = { tiebreaker = "uniqueId" },
    uniqueId = { isId64 = true },
}

local function ItemSortFunc(data1, data2)
     return ZO_TableOrderingFunction(data1, data2, "bestGamepadItemCategoryName", DEFAULT_GAMEPAD_ITEM_SORT, ZO_SORT_ORDER_UP)
end

function ZO_GamepadInventoryList:AddSlotDataToTable(slotsTable, inventoryType, slotIndex)
    local itemFilterFunction = self.itemFilterFunction
    local categorizationFunction = self.categorizationFunction or ZO_InventoryUtils_Gamepad_GetBestItemCategoryDescription
    local slotData = SHARED_INVENTORY:GenerateSingleSlotData(inventoryType, slotIndex)
    if slotData then
        if (not itemFilterFunction) or itemFilterFunction(slotData) then
            -- itemData is shared in several places and can write their own value of bestItemCategoryName.
            -- We'll use bestGamepadItemCategoryName instead so there are no conflicts.
            slotData.bestGamepadItemCategoryName = categorizationFunction(slotData)

            table.insert(slotsTable, slotData)
        end
    end
end

function ZO_GamepadInventoryList:GenerateSlotTable()
    local slots = {}

    for _, bagId in ipairs(self.inventoryTypes) do
        for slotIndex in ZO_IterateBagSlots(bagId) do
            self:AddSlotDataToTable(slots, bagId, slotIndex)
        end
    end

    table.sort(slots, self.sortFunction or ItemSortFunc)
    return slots
end

do
    local function IsInFilteredCategories(filterCategories, itemData)
        -- No category selected, don't filter out anything.
        if ZO_IsTableEmpty(filterCategories) then
            return true
        end

        for _, filterData in ipairs(itemData.filterData) do
            if filterCategories[filterData] then
                return true
            end
        end

        return false
    end
    --[[
    If the list is hidden, queues a refresh for the next time the list is shown.
     Otherwise, clears and fully refreshes the list.
    ]]--
    function ZO_GamepadInventoryList:RefreshList(shouldTriggerRefreshListCallback)
        self.shouldTriggerRefreshCallback = self.shouldTriggerRefreshCallback or shouldTriggerRefreshListCallback
        self.refresh:RefreshAll("list")
    end

    function ZO_GamepadInventoryList:OnRefreshList(shouldTriggerRefreshListCallback)
        self.list:Clear()

        for _, bagId in ipairs(self.inventoryTypes) do
            self.dataByBagAndSlotIndex[bagId] = {}
        end

        local slots = self:GenerateSlotTable()
        local currentBestCategoryName = nil
        for _, itemData in ipairs(slots) do
            local passesTextFilter = TEXT_SEARCH_MANAGER:IsItemInSearchTextResults(self.searchContext, BACKGROUND_LIST_FILTER_TARGET_BAG_SLOT, itemData.bagId, itemData.slotIndex)
            local passesCategoryFilter = IsInFilteredCategories(self.filterCategories, itemData)
            if passesTextFilter and passesCategoryFilter then
                local entry = ZO_GamepadEntryData:New(itemData.name, itemData.iconFile)
                self:SetupItemEntry(entry, itemData)

                if self.currentSortType == ITEM_LIST_SORT_TYPE_CATEGORY and itemData.bestGamepadItemCategoryName ~= currentBestCategoryName then
                    currentBestCategoryName = itemData.bestGamepadItemCategoryName
                    entry:SetHeader(currentBestCategoryName)

                    self.list:AddEntryWithHeader(self.template, entry)
                else
                    self.list:AddEntry(self.template, entry)
                end
                self.dataByBagAndSlotIndex[itemData.bagId][itemData.slotIndex] = entry
            end
        end

        self.list:Commit()

        if shouldTriggerRefreshListCallback and self.onRefreshListCallback then
            self.onRefreshListCallback(self.list)
        end
    end
end

function ZO_GamepadInventoryList:SetSearchContext(context)
    self.searchContext = context
end

function ZO_GamepadInventoryList:GetSearchContext()
    return self.searchContext
end

--[[
Refreshes the appearance of the list without clearing and fully refreshing the list
]]--
function ZO_GamepadInventoryList:RefreshVisible()
    self.list:RefreshVisible()
end

--[[
Enables or disables direcitonal input to the list.

enable must be a boolean.
]]--
function ZO_GamepadInventoryList:SetDirectionalInputEnabled(enable)
    self.list:SetDirectionalInputEnabled(enable)
end

--[[
Sets if the inventory list is aligned to the screen center.
Does not need an expectedEntryHeight
]]--
function ZO_GamepadInventoryList:SetAlignToScreenCenter(alignToScreenCenter, expectedEntryHeight)
    self.list:SetAlignToScreenCenter(alignToScreenCenter, expectedEntryHeight)
end

--[[
Gets the control of the list
]]--
function ZO_GamepadInventoryList:GetControl()
    return self.list:GetControl()
end

--[[
Returns true if the list is active
]]--
function ZO_GamepadInventoryList:IsActive()
    return self.list:IsActive()
end

function ZO_GamepadInventoryList:SetNoItemText(noItemText)
    self.list:SetNoItemText(noItemText)
end

function ZO_GamepadInventoryList:ClearList()
    self.list:Clear()
end