-- ForeverUI: movable positions.
-- Every frame ForeverUI builds registers here with a default position; this table places it
-- on load and remembers where the player moves it. Everything is anchored to UIParent, never
-- to another ForeverUI frame, so moving one element never drags another.

ForeverUI = ForeverUI or {}

-- Disable a client frame. Hiding is not enough: its own code shows it again (page change,
-- vehicle exit, rune update). So we unregister its events, hide it, and hide it again on
-- OnShow.
function ForeverUI.Suppress(frame)
	if not frame or frame.foreverSuppressed then
		return
	end

	if frame.UnregisterAllEvents then
		frame:UnregisterAllEvents()
	end
	frame:Hide()

	if frame.HookScript then
		frame:HookScript("OnShow", function(self)
			self:Hide()
		end)
	end

	frame.foreverSuppressed = true
end

local Layout = {}
ForeverUI.Layout = Layout

Layout.systems = {}   -- id -> { frame, label, defaults, baseScale }
Layout.order = {}     -- ids, in registration order
Layout.editing = false
Layout.work = nil     -- working copy of the positions during a Customize UI session
Layout.onRegister = nil  -- set by Customize UI: called with an id registered while editing

local PREFIX = "|cff66ccffForeverUI|r : "
local L = ForeverUI.L

local function say(message)
	DEFAULT_CHAT_FRAME:AddMessage(PREFIX .. message)
end
Layout.Say = say

local function positions()
	ForeverUIDB = ForeverUIDB or {}
	ForeverUIDB.positions = ForeverUIDB.positions or {}
	return ForeverUIDB.positions
end

-- Positions in effect: the working copy while editing, the saved ones otherwise.
local function current()
	return Layout.work or positions()
end

-- A saved entry: an anchor (point, relativePoint, x, y), a size (scale), or both. Offsets are
-- in the frame's units at 100 %; an entry without anchor keeps the default one.
local function copy(p)
	return { point = p.point, relativePoint = p.relativePoint, x = p.x, y = p.y, scale = p.scale }
end

-- Anchor in effect: the saved one, or the default one.
function Layout.Anchor(id)
	local system = Layout.systems[id]
	local p = current()[id]
	if p and p.point then
		return p
	end
	return system and system.defaults
end

-- True while the element keeps its default anchor (the player has not moved it).
function Layout.IsDefault(id)
	local p = current()[id]
	return not (p and p.point)
end

-- Size the element has at 100 %, set by its own code (an automatic fit); the player's size
-- applies on top of it.
function Layout.SetBaseScale(id, scale)
	local system = Layout.systems[id]
	if not system then
		return false
	end
	system.baseScale = scale
	Layout.Apply(id)
	return true
end

-- Size in effect, 1 for 100 %.
function Layout.Scale(id)
	local p = current()[id]
	return p and p.scale or 1
end

-- Ratio of the frame's units at 100 % to UIParent's.
local function unit(system, scale)
	return system.frame:GetEffectiveScale() / UIParent:GetEffectiveScale() / scale
end

-- Place the frame at its saved position and size, or at the default ones. The offsets shrink
-- with the size, so the anchor stays at the same place on screen.
function Layout.Apply(id)
	local system = Layout.systems[id]
	if not system then
		return false
	end

	local p = Layout.Anchor(id)
	local scale = Layout.Scale(id)
	system.frame:SetScale(system.baseScale * scale)
	system.frame:ClearAllPoints()
	system.frame:SetPoint(p.point, UIParent, p.relativePoint, p.x / scale, p.y / scale)
	return true
end

-- Records the frame's current anchor (in the working copy while editing).
function Layout.Save(id)
	local system = Layout.systems[id]
	if not system then
		return false
	end

	local point, _, relativePoint, x, y = system.frame:GetPoint(1)
	if not point then
		return false
	end

	local scale = Layout.Scale(id)
	current()[id] = {
		point = point,
		relativePoint = relativePoint or point,
		x = (x or 0) * scale,
		y = (y or 0) * scale,
		scale = current()[id] and current()[id].scale,
	}
	return true
end

-- Moves the element. x, y: offsets in UIParent units; point: new anchor, the same point of
-- the element and of the screen (nil keeps the current anchor).
function Layout.SetPosition(id, x, y, point)
	local system = Layout.systems[id]
	if not system then
		return false
	end
	local anchor = Layout.Anchor(id)
	local k = unit(system, Layout.Scale(id))
	local p = current()[id] or {}
	p.point, p.relativePoint = point or anchor.point, point or anchor.relativePoint
	p.x, p.y = x / k, y / k
	current()[id] = p
	Layout.Apply(id)
	return true
end

-- Resizes the element around its anchor; scale: 1 for 100 %.
function Layout.SetScale(id, scale)
	if not Layout.systems[id] then
		return false
	end
	local p = current()[id] or {}
	p.scale = (scale ~= 1) and scale or nil
	current()[id] = next(p) and p or nil
	Layout.Apply(id)
	return true
end

-- Back to the default position: one element, or all of them when id is nil.
function Layout.Reset(id)
	if id then
		if not Layout.systems[id] then
			return false
		end
		current()[id] = nil
		Layout.Apply(id)
		return true
	end

	for _, systemID in ipairs(Layout.order) do
		current()[systemID] = nil
		Layout.Apply(systemID)
	end
	return true
end

-- Customize UI session: moves go to a working copy; Commit saves it, Revert drops it and
-- puts every element back where it was.
-- The working copy holds every entry, so an element registered during the session finds its
-- own; only the elements' entries go back (windows keep theirs, even moved meanwhile).
function Layout.BeginEdit()
	local work = {}
	for id, p in pairs(positions()) do
		work[id] = copy(p)
	end
	Layout.work = work
	Layout.editing = true
end

function Layout.Commit()
	local work = Layout.work
	if work then
		local saved = positions()
		for id in pairs(Layout.systems) do
			saved[id] = work[id]
		end
	end
	Layout.work = nil
	Layout.editing = false
end

function Layout.Revert()
	Layout.work = nil
	Layout.editing = false
	for _, id in ipairs(Layout.order) do
		Layout.Apply(id)
	end
end

-- Make the frame movable and place it.
-- id: saved-position key; label: edit mode label; point..y: default anchor on UIParent
function Layout.Register(frame, id, label, point, relativePoint, x, y)
	Layout.systems[id] = {
		frame = frame,
		label = label,
		defaults = { point = point, relativePoint = relativePoint, x = x, y = y },
		baseScale = frame:GetScale(),
	}
	table.insert(Layout.order, id)

	frame:SetMovable(true)
	frame:SetClampedToScreen(true)
	if frame:GetFrameStrata() ~= Layout.STRATA then frame:SetFrameStrata(Layout.STRATA) end
	Layout.Apply(id)

	if Layout.editing and Layout.onRegister then
		Layout.onRegister(id)
	end
	return frame
end

-- Change the default position of a registered element. The bottom of the screen is a chain:
-- the action bar and the bags sit on each side of the micro menu, whose width is known only
-- once its buttons are counted. An element the player has moved keeps its position.
function Layout.SetDefaults(id, point, relativePoint, x, y)
	local system = Layout.systems[id]
	if not system then
		return false
	end

	system.defaults = { point = point, relativePoint = relativePoint, x = x, y = y }
	local p = current()[id]
	if not (p and p.point) then
		Layout.Apply(id)
	end
	return true
end

-- ---------- Draw order
-- camelot keeps the playing screen in LOW (unit frames, minimap, objectives) and MEDIUM (action
-- bars, menu, bags bar) and raises each window above the whole MEDIUM strata (toplevel, Raise).
-- 3.3.5 does not raise our windows above the bars, so every element of the playing screen
-- goes to LOW, keeping its levels, and MEDIUM holds only the windows and bags: any of them is
-- drawn over any element of the playing screen. The client's buttons we anchor elsewhere (main
-- bar, micro-menu, bag slots, bonus, stance, pet, totem and possess bars) are children of
-- MainMenuBar; the vehicle bar and the durability figure belong to the playing screen too.
-- The pet buttons carry their own MEDIUM and do not follow their bar.
Layout.STRATA = "LOW"
local CLIENT_FRAMES = { "MainMenuBar", "VehicleMenuBar", "DurabilityFrame" }
for i = 1, NUM_PET_ACTION_SLOTS or 10 do
	CLIENT_FRAMES[#CLIENT_FRAMES + 1] = "PetActionButton" .. i
end

-- MainMenuBar holds secure buttons: out of combat only
local function lowerClientFrames()
	if InCombatLockdown() then
		return false
	end
	for _, name in ipairs(CLIENT_FRAMES) do
		local f = _G[name]
		if f and f:GetFrameStrata() ~= Layout.STRATA then f:SetFrameStrata(Layout.STRATA) end
	end
	return true
end
local lowered = lowerClientFrames()

-- Places every element once saved variables are loaded.
local watcher = CreateFrame("Frame")
watcher:RegisterEvent("PLAYER_LOGIN")
watcher:RegisterEvent("PLAYER_REGEN_ENABLED")
watcher:SetScript("OnEvent", function(_, event)
	if not lowered then lowered = lowerClientFrames() end
	if event ~= "PLAYER_LOGIN" then return end
	for _, id in ipairs(Layout.order) do
		Layout.Apply(id)
	end
end)

-- /fui mouse: while active, each click prints the frame under the mouse (GetMouseFocus), its
-- parents and its regions, to find where a screen element comes from.
local spy = CreateFrame("Frame")
spy:Hide()
local function describe(frame)
	if not frame then return L.LAYOUT_SPY_NOTHING end
	local name = frame.GetName and frame:GetName() or nil
	local type_ = frame.GetObjectType and frame:GetObjectType() or "?"
	return (name or L.LAYOUT_SPY_UNNAMED) .. " [" .. type_ .. "]"
end
spy:SetScript("OnUpdate", function(self)
	local down = IsMouseButtonDown("LeftButton") or IsMouseButtonDown("RightButton")
	if down and not self.pressed then
		local f = GetMouseFocus and GetMouseFocus()
		say(L.LAYOUT_SPY_UNDER_MOUSE .. describe(f))
		local p, path = f and f:GetParent(), {}
		while p and #path < 8 do
			table.insert(path, describe(p))
			p = p:GetParent()
		end
		DEFAULT_CHAT_FRAME:AddMessage("   " .. L.LAYOUT_SPY_PARENTS .. table.concat(path, " < "))
		if f and f.GetRegions then
			for _, r in ipairs({ f:GetRegions() }) do
				if r.GetTexture and r:GetTexture() then
					DEFAULT_CHAT_FRAME:AddMessage("   " .. L.LAYOUT_SPY_TEXTURE .. tostring(r:GetTexture()))
				elseif r.GetText and r:GetText() then
					DEFAULT_CHAT_FRAME:AddMessage("   " .. L.LAYOUT_SPY_TEXT .. tostring(r:GetText()))
				end
			end
		end
		for _, k in ipairs({ "name", "mapLinkID", "description", "poiID", "instanceID", "mapID" }) do
			if f and f[k] ~= nil then
				DEFAULT_CHAT_FRAME:AddMessage("   ." .. k .. " = " .. tostring(f[k]))
			end
		end
	end
	self.pressed = down and true or false
end)
ForeverUI.MouseSpy = spy
ForeverUI.MouseDebug = function()
	if spy:IsShown() then
		spy:Hide()
		say(L.LAYOUT_SPY_STOPPED)
	else
		spy.pressed = true
		spy:Show()
		say(L.LAYOUT_SPY_STARTED)
	end
end

SLASH_FOREVERUI1 = "/fui"
SLASH_FOREVERUI2 = "/foreverui"

SlashCmdList["FOREVERUI"] = function(message)
	local command, argument = string.match(message or "", "^(%S*)%s*(.*)$")
	argument = argument or ""
	command = string.lower(command or "")

	if command == "" or command == "edit" then
		ForeverUI.CustomizeUI.Toggle()
	elseif command == "reset" then
		if InCombatLockdown() then
			-- secure frames (unit frames, action bars) cannot move in combat: the saved positions
			-- would be erased and the frames left where they are
			say(ERR_NOT_IN_COMBAT)
		elseif argument ~= "" then
			if Layout.Reset(argument) then
				say(L.LAYOUT_RESET_ONE .. argument)
			else
				say(L.LAYOUT_UNKNOWN_ELEMENT .. argument)
			end
		else
			Layout.Reset()
			say(L.LAYOUT_RESET_ALL)
		end
	elseif command == "bar" then
		if ForeverUI.ActionBarDebug then
			ForeverUI.ActionBarDebug()
		else
			say(L.LAYOUT_NO_DIAG_ACTIONBAR)
		end
	elseif command == "bottom" then
		if ForeverUI.BottomBarDebug then
			ForeverUI.BottomBarDebug()
		else
			say(L.LAYOUT_NO_DIAG_BOTTOM)
		end
	elseif command == "statusbars" then
		if ForeverUI.StatusBarsDebug then
			ForeverUI.StatusBarsDebug()
		else
			say(L.LAYOUT_NO_DIAG_STATUSBARS)
		end
	elseif command == "bags" then
		local key, value = string.match(argument, "^(%S+)%s+(%S+)$")
		if key and ForeverUI.BagsSet then
			ForeverUI.BagsSet(key, value)
		elseif ForeverUI.BagsDebug then
			ForeverUI.BagsDebug()
		else
			say(L.LAYOUT_NO_DIAG_BAGS)
		end
	elseif command == "model" then
		if ForeverUI.CharacterModelTune then
			ForeverUI.CharacterModelTune(argument)
		else
			say(L.LAYOUT_NO_MODEL_TUNE)
		end
	elseif command == "tabs" then
		if ForeverUI.CharacterTabsDebug then
			ForeverUI.CharacterTabsDebug()
		else
			say(L.LAYOUT_NO_DIAG_TABS)
		end
	elseif command == "character" then
		if ForeverUI.CharacterSheetDebug then
			ForeverUI.CharacterSheetDebug()
		else
			say(L.LAYOUT_NO_DIAG_SHEET)
		end
	elseif command == "close" then
		if ForeverUI.CharacterCloseDebug then
			ForeverUI.CharacterCloseDebug()
		else
			say(L.LAYOUT_NO_DIAG_SHEET)
		end
	elseif command == "minimap" then
		if ForeverUI.MinimapDebug then
			ForeverUI.MinimapDebug(argument)
		else
			say(L.LAYOUT_NO_DIAG_MINIMAP)
		end
	elseif command == "mouse" then
		ForeverUI.MouseDebug()
	elseif command == "map" then
		if ForeverUI.WorldMapDebug then
			ForeverUI.WorldMapDebug()
		else
			say(L.LAYOUT_NO_DIAG_WORLDMAP)
		end
	elseif command == "questlog" then
		if ForeverUI.QuestLogDebug then
			ForeverUI.QuestLogDebug()
		else
			say(L.LAYOUT_NO_DIAG_QUESTLOG)
		end
	elseif command == "tracking" then
		if ForeverUI.ObjectiveTrackerDebug then
			ForeverUI.ObjectiveTrackerDebug()
		else
			say(L.LAYOUT_NO_DIAG_TRACKER)
		end
	elseif command == "spellbook" then
		if ForeverUI.SpellBookDebug then
			ForeverUI.SpellBookDebug()
		else
			say(L.LAYOUT_NO_DIAG_SPELLBOOK)
		end
	elseif command == "micro" then
		if ForeverUI.MicroDebug then
			ForeverUI.MicroDebug()
		else
			say(L.LAYOUT_NO_DIAG_MICROMENU)
		end
	elseif command == "titles" then
		if ForeverUI.TitlesDebug then
			ForeverUI.TitlesDebug()
		else
			say(L.LAYOUT_NO_DIAG_TITLES)
		end
	elseif command == "pvp" then
		if ForeverUI.PvPDebug then
			-- /fui pvp 0.35: sets the circular gauge to 35 % without earning honor.
			ForeverUI.PvPDebug(tonumber(argument))
		else
			say(L.LAYOUT_NO_DIAG_PVP)
		end
	elseif command == "arena" then
		if ForeverUI.PvPArenaDebug then
			ForeverUI.PvPArenaDebug()
		else
			say(L.LAYOUT_NO_DIAG_ARENA)
		end
	elseif command == "tabard" then
		if ForeverUI.TabardModelTune then
			ForeverUI.TabardModelTune(argument)
		end
	elseif command == "chat" then
		if ForeverUI.ChatDebug then
			ForeverUI.ChatDebug()
		else
			say(L.LAYOUT_NO_DIAG_CHAT)
		end
	elseif command == "chatlines" then
		if ForeverUI.ChatRecordLines then
			ForeverUI.ChatRecordLines()
		else
			say(L.LAYOUT_NO_CHAT_LINES)
		end
	elseif command == "buffs" then
		if ForeverUI.BuffsDebug then
			ForeverUI.BuffsDebug()
		else
			say(L.LAYOUT_NO_DIAG_BUFFS)
		end
	elseif command == "finder" then
		if ForeverUI.GroupFinderDebug then
			ForeverUI.GroupFinderDebug()
		else
			say(L.LAYOUT_NO_DIAG_GROUPFINDER)
		end
	elseif command == "social" then
		if ForeverUI.SocialDebug then
			ForeverUI.SocialDebug()
		else
			say(L.LAYOUT_NO_DIAG_SOCIAL)
		end
	elseif command == "bg" then
		if ForeverUI.PvPBattlegroundsDebug then
			ForeverUI.PvPBattlegroundsDebug()
		else
			say(L.LAYOUT_NO_DIAG_BATTLEGROUNDS)
		end
	elseif command == "pet" then
		if ForeverUI.PetDebug then
			ForeverUI.PetDebug()
		else
			say(L.LAYOUT_NO_DIAG_PET)
		end
	elseif command == "currency" or command == "currencies" then
		if ForeverUI.TokensDebug then
			ForeverUI.TokensDebug()
		else
			say(L.LAYOUT_NO_DIAG_CURRENCY)
		end
	elseif command == "skills" then
		if ForeverUI.SkillsDebug then
			ForeverUI.SkillsDebug()
		else
			say(L.LAYOUT_NO_DIAG_SKILLS)
		end
	elseif command == "rep" then
		if ForeverUI.ReputationDebug then
			-- /fui rep Alliance: keeps only that faction.
			ForeverUI.ReputationDebug(argument ~= "" and argument or nil)
		else
			say(L.LAYOUT_NO_DIAG_REPUTATION)
		end
	elseif command == "sets" then
		if ForeverUI.EquipmentSetsDebug then
			ForeverUI.EquipmentSetsDebug()
		else
			say(L.LAYOUT_NO_DIAG_SETS)
		end
	elseif command == "debug" then
		if ForeverUI.PlayerFrameDebug then
			ForeverUI.PlayerFrameDebug()
		else
			say(L.LAYOUT_NO_DIAG)
		end
	elseif command == "list" then
		say(L.LAYOUT_LIST_HEADER)
		for _, id in ipairs(Layout.order) do
			local system = Layout.systems[id]
			local saved = positions()[id]
			DEFAULT_CHAT_FRAME:AddMessage(string.format("   %s (%s)%s", id, system.label,
				saved and L.LAYOUT_LIST_MOVED or ""))
		end
	else
		say(L.LAYOUT_HELP)
	end
end