local ScrW = ScrW
local ScrH = ScrH
local Color = Color

local STENCIL_EQUAL = STENCIL_EQUAL
local STENCIL_KEEP = STENCIL_KEEP
local STENCIL_NEVER = STENCIL_NEVER
local STENCIL_REPLACE = STENCIL_REPLACE

local draw = draw
local math = math
local render = render
local surface = surface

local draw_NoTexture = draw.NoTexture
local math_rad = math.rad
local math_sin = math.sin
local math_cos = math.cos
local render_ClearStencil = render.ClearStencil
local render_SetStencilCompareFunction = render.SetStencilCompareFunction
local render_SetStencilEnable = render.SetStencilEnable
local render_SetStencilFailOperation = render.SetStencilFailOperation
local render_SetStencilPassOperation = render.SetStencilPassOperation
local render_SetStencilReferenceValue = render.SetStencilReferenceValue
local render_SetStencilTestMask = render.SetStencilTestMask
local render_SetStencilWriteMask = render.SetStencilWriteMask
local render_SetStencilZFailOperation = render.SetStencilZFailOperation
local render_UpdateScreenEffectTexture = render.UpdateScreenEffectTexture
local surface_DrawPoly = surface.DrawPoly
local surface_DrawRect = surface.DrawRect
local surface_DrawTexturedRect = surface.DrawTexturedRect
local surface_SetDrawColor = surface.SetDrawColor
local surface_SetMaterial = surface.SetMaterial

cbox.chatbox = cbox.chatbox or {}
cbox.chatbox.tabs = cbox.chatbox.tabs or {}
cbox.chatbox.panels = cbox.chatbox.panels or {}
cbox.chatbox.modes = cbox.chatbox.modes or {}

local CHATBOX_COLOR = CreateClientConVar("cbox_chatbox_color", "160 160 160", true, false, "Chatbox background color")
local CHATBOX_ALPHA = CreateClientConVar("cbox_chatbox_alpha", "128", true, false, "Chatbox background alpha")
local CHATBOX_BLUR = CreateClientConVar("cbox_chatbox_blur", "0", true, false, "Chatbox background is blurred")
local CHATBOX_FADE = CreateClientConVar("cbox_chatbox_fade", "1", true, false, "Chatbox fades in and out")
local CHATBOX_MODE1 = CreateClientConVar("cbox_chatbox_mode1", "say", true, false, "Default mode when pressing messagemode")
local CHATBOX_MODE2 = CreateClientConVar("cbox_chatbox_mode2", "say_team", true, false, "Default mode when pressing messagemode2")

---@param height number
---@return number
local function _ScreenScaleH(height)
	return height * (ScrH() / 480)
end
local ScreenScaleH = ScreenScaleH or _ScreenScaleH

---@return number x
---@return number y
---@return number w
---@return number h
local function GetDefaultBounds()
	return ScreenScaleH(10), ScreenScaleH(275), ScreenScaleH(320), ScreenScaleH(120)
end

---Add a new chatbox tab
---@param key string Internal unique name
---@param name string Display name
---@param icon string Path to icon
---@param callback fun(): Panel What to do when the tab is created
function cbox.chatbox.AddTab(key, name, icon, callback)
	cbox.chatbox.tabs[key] = {
		name = name,
		icon = icon,
		callback = callback,
	}
end

---Add a new chatbox send mode
---@param key string Internal unique name
---@param name string Display name
---@param callback fun(text) What to do when enter is pressed on this mode
function cbox.chatbox.AddMode(key, name, callback)
	cbox.chatbox.modes[key] = {
		name = name,
		callback = callback,
	}
end

local MATERIAL_BLUR = Material("pp/blurscreen")

local function add_rounded_poly(poly, x, y, rad, seg, offset)
	offset = offset or 0

	for i = 0, seg do
		local r = math_rad(((i + offset) / seg) * -90)
		poly[#poly + 1] = {
			x = x + math_sin(r) * rad,
			y = y + math_cos(r) * rad,
			u = math_sin(r) / 2 + 0.5,
			v = math_cos(r) / 2 + 0.5,
		}
	end
end

local function RoundedBoxPoly(w, h, rad, seg)
	local poly = {}

	local x, y = 0, 0

	add_rounded_poly(poly, x + rad, y + rad, rad, seg, seg)

	poly[#poly + 1] = {
		x = x + (w - rad),
		y = y,
		u = 0.5,
		v = 0.5,
	}

	add_rounded_poly(poly, x + (w - rad), y + rad, rad, seg, seg * 2)

	poly[#poly + 1] = {
		x = x + w,
		y = y + (h - rad),
		u = 0.5,
		v = 0.5,
	}

	add_rounded_poly(poly, x + (w - rad), y + (h - rad), rad, seg, seg * 3)

	poly[#poly + 1] = {
		x = x + rad,
		y = y + h,
		u = 0.5,
		v = 0.5,
	}

	add_rounded_poly(poly, x + rad, y + (h - rad), rad, seg)

	return poly
end

local PREV_W, PREV_H, BACKGROUND_POLY

local function CreateChatbox()
	if IsValid(cbox.chatbox.panels.frame) then
		cbox.chatbox.panels.frame:Remove()
	end

	local frame = vgui.Create("DFrame", nil, "cbox.chatbox")
	frame:SetCookieName("cbox_chatbox")
	frame:SetDeleteOnClose(false)
	frame:SetSizable(true)
	frame:SetScreenLock(true)
	frame:DockPadding(8, 8, 8, 8)

	local dx, dy, dw, dh = GetDefaultBounds()

	-- TODO: make this configurable
	frame:SetMinWidth(dw)
	frame:SetMinHeight(dh)

	local x = frame:GetCookie("pos_x", dx)
	local y = frame:GetCookie("pos_y", dy)
	local w = frame:GetCookie("width", dw)
	local h = frame:GetCookie("height", dh)
	frame:SetPos(x, y)
	frame:SetSize(w, h)
	PREV_W = w
	PREV_H = h
	BACKGROUND_POLY = RoundedBoxPoly(w, h, 8, 24)

	frame:SetVisible(false)

	function frame:PerformLayout() end

	frame.btnClose:Remove()
	frame.btnMinim:Remove()
	frame.btnMaxim:Remove()
	frame.lblTitle:Remove()

	function frame:CrossFade(anim, delta, out)
		if anim.Finished then
			if out then
				self:Close()
				self:SetVisible(false)
			else
				self:MakePopup()
			end
		end

		if anim.Started then
			if out then
				self:SetAlpha(255)
			else
				self:SetAlpha(0)
			end
		end

		self:SetAlpha(out and 255 * (1 - delta) or 255 * delta)
	end

	frame.animFade = Derma_Anim("Fade", frame, frame.CrossFade)

	frame.oldThink = frame.Think

	function frame:Think()
		self:oldThink()

		self.animFade:Run()

		local w, h = self:GetSize()
		if w ~= PREV_W or h ~= PREV_H then
			PREV_W = w
			PREV_H = h
			BACKGROUND_POLY = RoundedBoxPoly(w, h, 8, 24)
		end
	end

	function frame:Paint(w, h)
		local alpha = CHATBOX_ALPHA:GetInt()

		-- Reset everything to known good
		render_SetStencilWriteMask(0xFF)
		render_SetStencilTestMask(0xFF)
		render_SetStencilReferenceValue(0)
		render_SetStencilPassOperation(STENCIL_KEEP)
		render_SetStencilZFailOperation(STENCIL_KEEP)
		render_ClearStencil()

		-- Enable stencils
		render_SetStencilEnable(true)
		-- Set everything up everything draws to the stencil buffer instead of the screen
		render_SetStencilReferenceValue(1)
		render_SetStencilCompareFunction(STENCIL_NEVER)
		render_SetStencilFailOperation(STENCIL_REPLACE)

		draw_NoTexture()
		surface_SetDrawColor(255, 255, 255)
		surface_DrawPoly(BACKGROUND_POLY)

		-- Only draw things that are in the stencil buffer
		render_SetStencilCompareFunction(STENCIL_EQUAL)
		render_SetStencilFailOperation(STENCIL_KEEP)

		if CHATBOX_BLUR:GetBool() and alpha ~= 255 then
			local x, y = self:LocalToScreen(0, 0)

			surface_SetMaterial(MATERIAL_BLUR)
			surface_SetDrawColor(255, 255, 255, 255)

			for i = 0.33, 1, 0.33 do
				MATERIAL_BLUR:SetFloat("$blur", 5 * i)
				MATERIAL_BLUR:Recompute()
				render_UpdateScreenEffectTexture()
				surface_DrawTexturedRect(x * -1, y * -1, ScrW(), ScrH())
			end
		end

		local r, g, b = cbox.utils.ParseColorString(CHATBOX_COLOR:GetString())
		surface_SetDrawColor(r, g, b, alpha)
		surface_DrawRect(0, 0, w, h)

		-- Let everything render normally again
		render_SetStencilEnable(false)
	end

	function frame:OnClose()
		local x, y = frame:GetPos()
		local w, h = frame:GetSize()
		frame:SetCookie("pos_x", x)
		frame:SetCookie("pos_y", y)
		frame:SetCookie("width", w)
		frame:SetCookie("height", h)
	end

	function frame:OnKeyCodeTyped(key)
		if key == KEY_ESCAPE then
			cbox.chatbox.Close()
			gui.HideGameUI()
		end
	end

	cbox.chatbox.panels.frame = frame

	local tabs = vgui.Create("DPropertySheet", frame, "cbox.chatbox.tabs")
	tabs:Dock(FILL)
	tabs:SetPadding(0)

	function tabs:Paint(w, h) end

	function tabs:OnActiveTabChanged( old, new )
		if new:GetPanel().cbox_id == "\1chat" then
			cbox.chatbox.panels.input:RequestFocus()
		end
	end

	cbox.chatbox.panels.tabs = tabs

	for id, tab in next, cbox.chatbox.tabs do
		local function catch(err)
			cbox.utils.RealmError(("Failed to create tab %q:"):format(id), err)
		end

		local ok, ret = xpcall(tab.callback, catch)
		if not ok then continue end
		if not ispanel(ret) then
			cbox.utils.RealmError(("Got non-panel for tab %q!"):format(id))
			continue
		end

		local sheet = tabs:AddSheet(tab.name, ret, tab.icon)
		sheet.Panel.cbox_id = id

		function sheet.Tab:ApplySchemeSettings()
			local ExtraInset = 8

			if self.Image then
				ExtraInset = ExtraInset + self.Image:GetWide()
			end

			self:SetTextInset(ExtraInset, 2)
			local w, h = self:GetContentSize()
			h = self:GetTabHeight()

			self:SetSize(w + 8, h)

			DLabel.ApplySchemeSettings( self )
		end
		-- TODO: configurable font
		sheet.Tab:SetFont("ChatFont")

		function sheet.Tab:Paint(w, h)
			if self:IsActive() then
				surface_SetDrawColor(0, 0, 0, 128)
				surface_DrawRect(0, 0, w, 20)
			else
				surface_SetDrawColor(0, 0, 0, 64)
				surface_DrawRect(0, 2, w, 18)
			end
		end
	end
end

local function Init()
	include("cbox/cl_modes.lua")

	local tab_files = file.Find("cbox/tabs/*", "LUA")
	for _, name in ipairs(tab_files) do
		cbox.utils.RealmPrint("Loading chatbox tab:", name)
		include("cbox/tabs/" .. name)
	end

	if not IsValid(cbox.chatbox.panels.frame) then
		CreateChatbox()
	end

	hook.Add("PlayerBindPress", "cbox.chatbox", function(ply, bind, pressed)
		local lply = LocalPlayer()
		if IsValid(lply) and ply ~= lply then
			cbox.utils.RealmError("Got mismatched player. How???", ply)
			return
		end
		if bind ~= "messagemode" and bind ~= "messagemode2" then return end
		if not pressed then return end

		cbox.chatbox.Open(bind == "messagemode2")

		return true
	end)

	hook.Add("Think", "cbox.chatbox", function()
		if cbox.chatbox.IsOpen() and input.IsKeyDown(KEY_ESCAPE) then
			cbox.chatbox.Close()
			gui.HideGameUI()
		end
	end)

	hook.Run("cbox.chatbox.Initialize")
end

---Opens the chatbox
---@param alt? boolean Was this request to open made by messagemode2 (team chat)
function cbox.chatbox.Open(alt)
	alt = alt ~= nil and alt or false

	local frame = cbox.chatbox.panels.frame

	if not IsValid(frame) then
		CreateChatbox()
	end

	frame:SetVisible(true)

	if frame.animFade ~= nil and CHATBOX_FADE:GetBool() then
		frame.animFade:Start(0.1, false)
	else
		frame:SetAlpha(255)
		frame:MakePopup()
	end

	if not IsValid(cbox.chatbox.panels.input) or not IsValid(cbox.chatbox.panels.tabs) then
		-- attempt to reinit
		if IsValid(frame) then
			frame:Remove()
		end
		Init()
	end

	if not IsValid(cbox.chatbox.panels.input) or not IsValid(cbox.chatbox.panels.tabs) then
		cbox.utils.RealmError("Input or tabs aren't valid, chat tab failed to load, bailing!")
		if IsValid(frame) then
			frame:Remove()
		end
		hook.Remove("PlayerBindPress", "cbox.chatbox")
		return
	end

	for _, tab in ipairs(cbox.chatbox.panels.tabs:GetItems()) do
		if tab.Panel.cbox_id == "\1chat" and cbox.chatbox.panels.tabs:GetActiveTab() ~= tab.Tab then
			cbox.chatbox.panels.tabs:SetActiveTab(tab.Tab)
		end
	end

	cbox.chatbox.panels.input:RequestFocus()

	if IsValid(cbox.chatbox.panels.mode_switch) then
		if alt then
			cbox.chatbox.panels.mode_switch:UpdateMode(CHATBOX_MODE2:GetString())
		else
			cbox.chatbox.panels.mode_switch:UpdateMode(CHATBOX_MODE1:GetString())
		end
	end

	hook.Run("StartChat")
end

---Closes the chatbox
function cbox.chatbox.Close()
	local frame = cbox.chatbox.panels.frame

	if frame.animFade ~= nil and CHATBOX_FADE:GetBool() then
		frame.animFade:Start(0.1, true)
	else
		frame:Close()
		frame:SetVisible(false)
	end

	hook.Run("FinishChat")

	cbox.chatbox.panels.input:SetText("")
	hook.Run("ChatTextChanged", "")
end

---Gets if the chatbox is open
---@return boolean
function cbox.chatbox.IsOpen()
	local frame = cbox.chatbox.panels.frame
	return IsValid(frame) and frame:IsVisible() == true and frame:GetAlpha() == 255
end

hook.Add("Initialize", "cbox.chatbox", Init)

concommand.Add("cbox_chatbox_reload", function()
	CreateChatbox()
end, nil, "Reloads the chatbox")

concommand.Add("_cbox_chatbox_fullreload", function()
	if IsValid(cbox.chatbox.panels.frame) then
		cbox.chatbox.panels.frame:Remove()
	end
	Init()
end, nil, "Fully reinitializes the chatbox, use only in extreme breakage.")