local CoreGui = game:GetService("CoreGui")
local GuiService = game:GetService("GuiService")
local TweenService = game:GetService("TweenService")
local UserInputService = game:GetService("UserInputService")

local Modules = CoreGui.RobloxGui.Modules
local Common = Modules.Common
local LuaApp = Modules.LuaApp
local LuaChat = Modules.LuaChat

local Constants = require(LuaChat.Constants)
local Create = require(LuaChat.Create)
local DialogInfo = require(LuaChat.DialogInfo)
local Signal = require(Common.Signal)
local NotificationType = require(LuaApp.Enum.NotificationType)

local Components = LuaChat.Components
local ChatDisabledIndicator = require(Components.ChatDisabledIndicator)
local ChatLoadingIndicator = require(Components.ChatLoadingIndicator)
local ConversationList = require(Components.ConversationList)
local ConversationSearchBox = require(Components.ConversationSearchBox)
local ConversationEntry = require(Components.ConversationEntry)
local HeaderLoader = require(Components.HeaderLoader)
local NoFriendsIndicator = require(Components.NoFriendsIndicator)
local PaddedImageButton = require(Components.PaddedImageButton)

local ConversationActions = require(LuaChat.Actions.ConversationActions)
local FetchChatEnabled = require(LuaChat.Actions.FetchChatEnabled)
local GetFriendCount = require(LuaChat.Actions.GetFriendCount)
local SetActiveConversationId = require(LuaChat.Actions.SetActiveConversationId)
local SetAppLoaded = require(LuaChat.Actions.SetAppLoaded)

local appStageLoaded = require(LuaApp.Analytics.Events.appStageLoaded)

local CREATE_CHAT_IMAGE = "rbxasset://textures/ui/LuaChat/icons/ic-createchat1-24x24.png"
local CREATE_GROUP_CHAT_IMAGE = "rbxasset://textures/ui/LuaChat/icons/ic-create-group.png"

local Intent = DialogInfo.Intent

local ConversationHub = {}

ConversationHub.__index = ConversationHub

local LuaChatNotificationButtonEnabled = settings():GetFFlag("LuaChatNotificationButtonEnabled")
local LuaChatCreateChatEnabled = settings():GetFFlag("LuaChatCreateChatEnabled")

local function requestOlderConversations(appState)
	-- Don't fetch older conversations if the oldest conversation has already been fetched.
	if appState.store:getState().ChatAppReducer.ConversationsAsync.oldestConversationIsFetched then
		return
	end

	-- Don't fetch older conversations if the oldest conversation is  fetched.
	if appState.store:getState().ChatAppReducer.ConversationsAsync.pageConversationsIsFetching then
		return
	end

	-- Ask for new conversations
	local convoCount = 0
	for _, _ in pairs(appState.store:getState().ChatAppReducer.Conversations) do
		convoCount = convoCount + 1
	end
	local pageSize = Constants.PageSize.GET_CONVERSATIONS
	local currentPage = math.floor(convoCount / pageSize)
	spawn(function()
		appState.store:dispatch(ConversationActions.GetLocalUserConversationsAsync(currentPage + 1, pageSize))
	end)
end

function ConversationHub.new(appState)
	local self = {}
	self.connections = {}

	setmetatable(self, ConversationHub)

	spawn(function()
		appState.store:dispatch(FetchChatEnabled())
		appState.store:dispatch(ConversationActions.GetUnreadConversationCountAsync())
		appState.store:dispatch(GetFriendCount())
		appState.store:dispatch(
			ConversationActions.GetLocalUserConversationsAsync(1, Constants.PageSize.GET_CONVERSATIONS)
		):andThen(function()
			appState.store:dispatch(SetAppLoaded(true))
		end)
	end)

	self.appState = appState
	self._analytics = appState.analytics

	self.rbx = Create.new "Frame" {
		Name = "ConversationHub",
		Size = UDim2.new(1, 0, 1, 0),
		BackgroundColor3 = Constants.Color.WHITE,
		BorderSizePixel = 0,

		Create.new "UIListLayout" {
			SortOrder = "LayoutOrder",
		}
	}

	self.ConversationTapped = Signal.new()
	self.CreateChatButtonPressed = Signal.new()
	self.isSearchOpen = false

	local header = HeaderLoader.GetHeader(appState, Intent.ConversationHub)
	header:SetTitle(appState.localization:Format("CommonUI.Features.Label.Chat"))
	header:SetDefaultSubtitle()

	header.rbx.Parent = self.rbx
	header.rbx.LayoutOrder = 0
	self.header = header

	local createChatButton
	if LuaChatCreateChatEnabled then
		createChatButton = PaddedImageButton.new(self.appState, "CreateChat", CREATE_CHAT_IMAGE)
	else
		createChatButton = PaddedImageButton.new(self.appState, "CreateGroup", CREATE_GROUP_CHAT_IMAGE)
	end

	createChatButton:SetVisible(false)
	createChatButton.Pressed:Connect(function()
		self.CreateChatButtonPressed:Fire()
	end)

	self.createChatButton = createChatButton

	local searchConversationsButton = PaddedImageButton.new(self.appState,
		"SearchConversations", "rbxasset://textures/ui/LuaChat/icons/ic-search.png")

	if LuaChatCreateChatEnabled then
		header:AddButton(searchConversationsButton)
		header:AddButton(createChatButton)
	else
		header:AddButton(createChatButton)
		header:AddButton(searchConversationsButton)
	end

	if LuaChatNotificationButtonEnabled then
		local notificationButton = PaddedImageButton.new(self.appState, "Notification",
			"rbxasset://textures/Icon_Stream_Off.png")
		notificationButton.Pressed:Connect(function()
			GuiService:BroadcastNotification("", NotificationType.VIEW_NOTIFICATIONS)
		end)
		header:AddButton(notificationButton)
	end

	local searchHeader = HeaderLoader.GetHeader(appState, Intent.ConversationHub)
	searchHeader:SetTitle("")
	searchHeader:SetSubtitle("")
	searchHeader.rbx.LayoutOrder = 0

	local conversationSearchBox = ConversationSearchBox.new(self.appState)
	searchHeader:AddContent(conversationSearchBox)

	local noFriendsIndicator = NoFriendsIndicator.new(appState)
	self.noFriendsIndicator = noFriendsIndicator
	noFriendsIndicator.rbx.Size = UDim2.new(1, 0, 1, -header.rbx.Size.Y.Offset)
	noFriendsIndicator.rbx.Parent = self.rbx
	noFriendsIndicator.rbx.LayoutOrder = 1

	local chatDisabledIndicator = ChatDisabledIndicator.new(appState)
	self.chatDisabledIndicator = chatDisabledIndicator
	chatDisabledIndicator.rbx.Size = UDim2.new(1, 0, 1, -header.rbx.Size.Y.Offset)
	chatDisabledIndicator.rbx.Parent = self.rbx
	chatDisabledIndicator.rbx.LayoutOrder = 1

	local chatLoadingIndicator = ChatLoadingIndicator.new(appState)
	self.chatLoadingIndicator = chatLoadingIndicator
	chatLoadingIndicator.rbx.Size = UDim2.new(1, 0, 1, -header.rbx.Size.Y.Offset)
	chatLoadingIndicator.rbx.Parent = self.rbx
	chatLoadingIndicator.rbx.LayoutOrder = 1

	chatDisabledIndicator.openPrivacySettings:Connect(function()
		GuiService:BroadcastNotification("", NotificationType.PRIVACY_SETTINGS)
	end)

	local list = ConversationList.new(appState, appState.store:getState().ChatAppReducer.Conversations, ConversationEntry)
	self.list = list
	list.rbx.Size = UDim2.new(1, 0, 1, -header.rbx.Size.Y.Offset)
	list.rbx.Parent = self.rbx
	list.rbx.LayoutOrder = 1

	list.ConversationTapped:Connect(function(convoId)
		conversationSearchBox:Cancel()
		appState.store:dispatch(SetActiveConversationId(convoId))
		self.ConversationTapped:Fire(convoId)
	end)

	list.RequestOlderConversations:Connect(function()
		requestOlderConversations(appState)
	end)

	searchConversationsButton.Pressed:Connect(function()
		header.rbx.Parent = nil
		searchHeader.rbx.Parent = self.rbx
		self.rbx.BackgroundColor3 = Constants.Color.GRAY5
		list:SetFilterPredicate(conversationSearchBox.SearchFilterPredicate)
		conversationSearchBox.rbx.SearchBoxContainer.SearchBoxBackground.Search:CaptureFocus()
		self.isSearchOpen = true
	end)

	conversationSearchBox.SearchChanged:Connect(function()
		list:SetFilterPredicate(conversationSearchBox.SearchFilterPredicate)
		self:getOlderConversationsForSearchIfNecessary()
	end)

	conversationSearchBox.Closed:Connect(function()
		searchHeader.rbx.Parent = nil
		header.rbx.Parent = self.rbx
		self.rbx.BackgroundColor3 = Constants.Color.WHITE
		list:SetFilterPredicate(nil)
		self.isSearchOpen = false
	end)

	appState.store.Changed:Connect(function(state, oldState)

		self:Update(state, oldState)

		if state.ChatAppReducer.Conversations ~= oldState.ChatAppReducer.Conversations
			or state.ChatAppReducer.Location.current ~= oldState.ChatAppReducer.Location.current then
			list:Update(state, oldState)
		end
	end)

	local state = appState.store:getState()
	self:Update(state, state)

	local appRoutes = state.Navigation.history
	local currentRoute = appRoutes[#appRoutes]
	local currentSection = currentRoute[1]
	appStageLoaded(self._analytics.EventStream, currentSection.name, "chatRender")

	return self
end

function ConversationHub:Start()
	local inputServiceConnection = UserInputService:GetPropertyChangedSignal('OnScreenKeyboardVisible'):Connect(function()
		self:TweenRescale()
	end)
	table.insert(self.connections, inputServiceConnection)

	local statusBarTappedConnection = UserInputService.StatusBarTapped:Connect(function()
		if self.appState.store:getState().ChatAppReducer.Location.current.intent ~= Intent.ConversationHub then
			return
		end
		self.list.rbx:ScrollToTop()
	end)
	table.insert(self.connections, statusBarTappedConnection)
end

function ConversationHub:Stop()
	for _, connection in ipairs(self.connections) do
		connection:Disconnect()
	end

	self.connections = {}
end

function ConversationHub:Update(state, oldState)
	self.header:SetConnectionState(state.ConnectionState)

	local conversations = state.ChatAppReducer.Conversations
	local appLoaded = state.ChatAppReducer.AppLoaded

	local haveConversations = next(conversations) ~= nil

	if state.ChatAppReducer.ChatEnabled then
		self.chatDisabledIndicator.rbx.Visible = false

		if state.ChatAppReducer.ChatEnabled ~= oldState.ChatAppReducer.ChatEnabled then
			spawn(function()
				self.appState.store:dispatch(
					ConversationActions.GetLocalUserConversationsAsync(1, Constants.PageSize.GET_CONVERSATIONS)
				)
			end)
		end
	else
		self.chatDisabledIndicator.rbx.Visible = true
		self.list.rbx.Visible = false
		self.noFriendsIndicator.rbx.Visible = false
		self.chatLoadingIndicator:SetVisible(false)

		return
	end

	if appLoaded then
		self.chatLoadingIndicator:SetVisible(false)
	else
		self.chatLoadingIndicator:SetVisible(true)
		self.list.rbx.Visible = false
		self.noFriendsIndicator.rbx.Visible = false

		return
	end

	if haveConversations then
		self.list.rbx.Visible = true
		self.noFriendsIndicator.rbx.Visible = false
	else
		self.list.rbx.Visible = false
		self.noFriendsIndicator.rbx.Visible = true
	end

	if state.FriendCount < Constants.MIN_PARTICIPANT_COUNT then
		self.createChatButton:SetVisible(false)
	else
		self.createChatButton:SetVisible(true)
	end

	if state.ChatAppReducer.ConversationsAsync.pageConversationsIsFetching
		~= oldState.ChatAppReducer.ConversationsAsync.pageConversationsIsFetching then
		self.list:Update(state, oldState)
		self:getOlderConversationsForSearchIfNecessary()
	end
end

function ConversationHub:getOlderConversationsForSearchIfNecessary(appState)
	-- To Check:
	-- 1) Search is open
	-- 2) Not have loaded all oldest conversations
	-- 3) Not currently getting conversations
	-- 4) Has enough items to show
	-- Note that we already try to load more conversations if we scroll down to the bottom of the list
	local state = self.appState.store:getState()
	if not self.isSearchOpen
		or state.ChatAppReducer.ConversationsAsync.oldestConversationIsFetched
		or state.ChatAppReducer.ConversationsAsync.pageConversationsIsFetching then
		return
	end

	if self.list.rbx.CanvasSize.Y.Offset > self.list.rbx.AbsoluteSize.Y then
		return
	end

	requestOlderConversations(self.appState)
end

function ConversationHub:TweenRescale()
	local keyboardSize = 0
	if UserInputService.OnScreenKeyboardVisible then
		keyboardSize = self.rbx.AbsoluteSize.Y - UserInputService.OnScreenKeyboardPosition.Y
	end
	local newSize = UDim2.new(1, 0, 1, -(self.header.rbx.Size.Y.Offset + keyboardSize))

	local duration = UserInputService.OnScreenKeyboardAnimationDuration
	local tweenInfo = TweenInfo.new(duration)

	local propertyGoals =
	{
		Size = newSize
	}
	local tween = TweenService:Create(self.list.rbx, tweenInfo, propertyGoals)

	tween:Play()
end

return ConversationHub