-- Auras2: Preview + Edit Mode helper (split from MSUF_A2_Render.lua)
-- Goal: isolate preview/ticker/cleanup logic to reduce Render bloat, with zero feature regression.

local addonName, ns = ...

local type, tostring = type, tostring
local pairs, ipairs = pairs, ipairs
local GetTime = GetTime
local C_Timer = C_Timer

local API = ns and ns.MSUF_Auras2
if type(API) ~= "table" then  return end

API.Preview = (type(API.Preview) == "table") and API.Preview or {}
local Preview = API.Preview

-- ------------------------------------------------------------
-- Helpers
-- ------------------------------------------------------------

local function IsEditModeActive()
    local fn = API.IsEditModeActive
    if type(fn) == "function" then return fn() == true end
    local st = rawget(_G, "MSUF_EditState")
    if type(st) == "table" and st.active == true then return true end
    if rawget(_G, "MSUF_UnitEditModeActive") == true then return true end
    return false
end

-- API.IsEditModeActive is owned by Render (cached). Preview must not override it.

local function EnsureDB()
    local DB = API.DB
    if DB and DB.Ensure then return DB.Ensure() end
    return nil, nil
end

local function GetAurasByUnit()
    local st = API.state
    if type(st) ~= "table" then  return nil end
    return st.aurasByUnit
end

local function GetCooldownTextMgr()
    -- Prefer split module API, but keep legacy global aliases.
    local CT = API.CooldownText
    local reg = CT and CT.RegisterIcon
    local unreg = CT and CT.UnregisterIcon

    if type(reg) ~= "function" then
        reg = rawget(_G, "MSUF_A2_CooldownTextMgr_RegisterIcon")
    end
    if type(unreg) ~= "function" then
        unreg = rawget(_G, "MSUF_A2_CooldownTextMgr_UnregisterIcon")
    end

     return reg, unreg
end

-- Phase F: Preview no longer depends on Render helpers.
-- It calls Apply directly so Render can stay orchestration-only.
local function GetApply()
    return (type(API.Apply) == "table") and API.Apply or nil
end

-- ------------------------------------------------------------
-- Preview cleanup (safety): ensure preview icons never block real auras
-- ------------------------------------------------------------

-- Forward-declared here because ClearPreviewIconsInContainer needs it,
-- but the full preview CD text block is defined later with the other helpers.
local function ClearPreviewCDText(icon, cd)
    if not icon then return end
    local fs = icon._msufA2_previewCDText
    if fs then
        fs:Hide()
        fs:SetText("")
    end
    if cd then
        cd._msufA2_pvCDSize = nil
        cd._msufA2_pvCDOffX = nil
        cd._msufA2_pvCDOffY = nil
        cd._msufA2_pvCDFont = nil
    end
    icon._msufA2_pvCDSize = nil
    icon._msufA2_pvCDOffX = nil
    icon._msufA2_pvCDOffY = nil
    icon._msufA2_pvCDFont = nil
end

local function ClearPreviewIconsInContainer(container)
    if not container or not container._msufIcons then  return end

    local _, unreg = GetCooldownTextMgr()

    for _, icon in ipairs(container._msufIcons) do
        if icon and icon._msufA2_isPreview == true then
            -- Ensure preview cooldown text/ticker stops tracking this icon.
            if type(unreg) == "function" then
                unreg(icon)
            end

            icon._msufA2_isPreview = nil
            icon._msufA2_previewMeta = nil
            icon._msufA2_previewDurationObj = nil
            icon._msufA2_previewStackT = nil
            icon._msufA2_previewCooldownT = nil
            icon._msufA2_previewCDCounter = nil
            -- Clear render-side caches so preview textures never 'stick' on reused icon frames.
            icon._msufA2_lastVisualAuraInstanceID = nil
            icon._msufA2_lastCooldownAuraInstanceID = nil
            icon._msufA2_lastDurationObject = nil
            icon._msufA2_lastCooldownUsesDurationObject = nil
            icon._msufA2_lastCooldownUsesExpiration = nil
            icon._msufA2_lastCooldownType = nil
            -- Bug 1 fix: Also clear texture diff cache so real auras always
            -- get their texture set after preview exit.
            icon._msufA2_lastTexAid = nil
            -- Force CommitIcon to do a full apply (bypass diff-gate).
            icon._msufA2_lastCommit = nil

            if icon.cooldown then
                -- Clean up preview-only cooldown text FontString.
                ClearPreviewCDText(icon, icon.cooldown)

                -- Clear cooldown visuals so preview never leaves "dark" state.
                if icon.cooldown.Clear then icon.cooldown:Clear() end
                if icon.cooldown.SetCooldown then icon.cooldown:SetCooldown(0, 0) end
                if icon.cooldown.SetCooldownDuration then icon.cooldown:SetCooldownDuration(0) end

                -- Restore Blizzard native countdown for real auras.
                if icon.cooldown.SetHideCountdownNumbers then
                    icon.cooldown:SetHideCountdownNumbers(false)
                end
            end

            icon:Hide()
        end
    end
 end

local function ClearPreviewsForEntry(entry)
    if not entry then  return end
    ClearPreviewIconsInContainer(entry.buffs)
    ClearPreviewIconsInContainer(entry.debuffs)
    ClearPreviewIconsInContainer(entry.mixed)
    ClearPreviewIconsInContainer(entry.private)
    entry._msufA2_previewActive = nil
 end

local function ClearAllPreviews()
    local AurasByUnit = GetAurasByUnit()
    if type(AurasByUnit) ~= "table" then  return end

    for _, entry in pairs(AurasByUnit) do
        if entry and entry._msufA2_previewActive == true then
            ClearPreviewsForEntry(entry)
        end
    end
 end

Preview.ClearPreviewsForEntry = ClearPreviewsForEntry
Preview.ClearAllPreviews = ClearAllPreviews

-- Keep existing public exports stable for Options + other modules.
API.ClearPreviewsForEntry = API.ClearPreviewsForEntry or ClearPreviewsForEntry
API.ClearAllPreviews = API.ClearAllPreviews or ClearAllPreviews

if _G and type(_G.MSUF_Auras2_ClearAllPreviews) ~= "function" then
    _G.MSUF_Auras2_ClearAllPreviews = function()  return API.ClearAllPreviews() end
end

-- ------------------------------------------------------------
-- Preview tickers (Edit Mode): cycle stacks + cooldowns
-- ------------------------------------------------------------

local PreviewTickers = {
    stacks = nil,
    cooldown = nil,
}

local function ShouldRunPreviewTicker(kind, a2, shared)
    if not a2 or not a2.enabled then  return false end
    local DB = API and API.DB
    if DB and DB.AnyUnitEnabledCached and DB.AnyUnitEnabledCached() ~= true then  return false end
    if not shared or shared.showInEditMode ~= true then  return false end
    if not API.IsEditModeActive or API.IsEditModeActive() ~= true then  return false end
    if kind == "stacks" and shared.showStackCount == false then  return false end
     return true
end

local function ForEachPreviewIcon(fn)
    local AurasByUnit = GetAurasByUnit()
    if type(AurasByUnit) ~= "table" then  return end

    for _, entry in pairs(AurasByUnit) do
        if entry and entry._msufA2_previewActive == true then
            -- Inline container iteration (no temp table allocation)
            local container = entry.buffs
            if container and container._msufIcons then
                for _, icon in ipairs(container._msufIcons) do
                    if icon and icon:IsShown() and icon._msufA2_isPreview == true then
                        fn(icon)
                    end
                end
            end
            container = entry.debuffs
            if container and container._msufIcons then
                for _, icon in ipairs(container._msufIcons) do
                    if icon and icon:IsShown() and icon._msufA2_isPreview == true then
                        fn(icon)
                    end
                end
            end
            container = entry.mixed
            if container and container._msufIcons then
                for _, icon in ipairs(container._msufIcons) do
                    if icon and icon:IsShown() and icon._msufA2_isPreview == true then
                        fn(icon)
                    end
                end
            end
            container = entry.private
            if container and container._msufIcons then
                for _, icon in ipairs(container._msufIcons) do
                    if icon and icon:IsShown() and icon._msufA2_isPreview == true then
                        fn(icon)
                    end
                end
            end
        end
    end
 end

-- File-scope state for preview tick callbacks (avoid closure per tick)
local _tickShared = nil
local _tickA2db = nil
local _tickStackCountAnchor = nil
local _tickApplyAnchorStyle = nil
local _tickApplyOffsets = nil
local _tickApplyCDOffsets = nil
local _tickReg = nil

-- ------------------------------------------------------------
-- Preview cooldown text: own FontString that responds to user's
-- cooldownTextSize / cooldownTextOffsetX / cooldownTextOffsetY
-- in real-time while the Edit Mode popup is open.
-- ------------------------------------------------------------

local PREVIEW_CD_FONT = "Fonts\\FRIZQT__.TTF"

local function ResolvePreviewCDConfig(icon, shared, a2db)
    local size = (shared and shared.cooldownTextSize) or 14
    local offX = (shared and shared.cooldownTextOffsetX) or 0
    local offY = (shared and shared.cooldownTextOffsetY) or 0

    local unit = icon._msufUnit
    if unit and a2db and a2db.perUnit then
        local pu = a2db.perUnit[unit]
        if pu and pu.overrideLayout == true and type(pu.layout) == "table" then
            local lay = pu.layout
            if type(lay.cooldownTextSize) == "number" then size = lay.cooldownTextSize end
            if type(lay.cooldownTextOffsetX) == "number" then offX = lay.cooldownTextOffsetX end
            if type(lay.cooldownTextOffsetY) == "number" then offY = lay.cooldownTextOffsetY end
        end
    end

    if type(size) ~= "number" or size <= 0 then size = 14 end
    if type(offX) ~= "number" then offX = 0 end
    if type(offY) ~= "number" then offY = 0 end
    return size, offX, offY
end

local function EnsurePreviewCDText(icon)
    if not icon then return nil end
    local fs = icon._msufA2_previewCDText
    if fs then return fs end

    -- Parent to the icon frame (not the Cooldown widget which may reject CreateFontString).
    local ok, result = pcall(function()
        return icon:CreateFontString(nil, "OVERLAY")
    end)
    if not ok or not result then return nil end
    fs = result

    -- Resolve global MSUF font if available; otherwise use default
    local fontPath = PREVIEW_CD_FONT
    local fontFlags = "OUTLINE"
    local gfs = _G.MSUF_GetGlobalFontSettings
    if type(gfs) == "function" then
        local p, fl = gfs()
        if type(p) == "string" and p ~= "" then fontPath = p end
        if type(fl) == "string" then fontFlags = fl end
    end
    fs:SetFont(fontPath, 14, fontFlags)
    -- Anchor to the cooldown frame center so it visually overlays the swirl.
    local cd = icon.cooldown
    local anchor = (cd and cd.GetObjectType) and cd or icon
    fs:SetPoint("CENTER", anchor, "CENTER", 0, 0)
    fs:SetJustifyH("CENTER")
    fs:SetJustifyV("MIDDLE")
    fs:SetTextColor(1, 1, 1, 1)
    fs:SetShadowOffset(1, -1)
    fs:SetShadowColor(0, 0, 0, 1)
    icon._msufA2_previewCDText = fs
    return fs
end

local function _PreviewStackIconFn(icon)
    if not icon or not icon.count then return end

    if _tickApplyAnchorStyle then
        _tickApplyAnchorStyle(icon, _tickStackCountAnchor)
    end
    if _tickApplyOffsets then
        _tickApplyOffsets(icon, icon._msufUnit, _tickShared, _tickStackCountAnchor)
    end

    icon._msufA2_previewStackT = (icon._msufA2_previewStackT or 0) + 1

    local num = icon._msufA2_previewStackT
    if num > 9 then
        num = 1
        icon._msufA2_previewStackT = 1
    end

    icon.count:SetText(num)

    if _tickShared and _tickShared.showStackCount == false then
        icon.count:Hide()
    else
        icon.count:Show()
    end
end

local function PreviewTickStacks()
    local a2, shared = EnsureDB()
    if not ShouldRunPreviewTicker("stacks", a2, shared) then  return end

    local A = GetApply()

    -- Set file-scope upvalues for callback
    _tickShared = shared
    _tickStackCountAnchor = shared and shared.stackCountAnchor
    _tickApplyAnchorStyle = A and A.ApplyStackCountAnchorStyle
    _tickApplyOffsets = A and A.ApplyStackTextOffsets

    ForEachPreviewIcon(_PreviewStackIconFn)
 end

local function _PreviewCooldownIconFn(icon)
    if not icon or not icon.cooldown then return end
    local cd = icon.cooldown

    -- Hide Blizzard's native countdown; we render our own preview text.
    if cd.SetHideCountdownNumbers then
        cd:SetHideCountdownNumbers(true)
    end

    -- Apply cooldown offsets from Icons module (invalidates caches, applies font family)
    if _tickApplyCDOffsets then
        pcall(_tickApplyCDOffsets, icon, icon._msufUnit, _tickShared)
    end

    -- Update cooldown swirl visuals (duration object preferred; fallback to SetCooldown).
    if icon._msufA2_previewDurationObj and cd.SetCooldownFromDurationObject then
        cd:SetCooldownFromDurationObject(icon._msufA2_previewDurationObj)
    elseif cd.SetCooldown then
        local now = GetTime()
        local start = (icon._msufA2_previewCooldownT or 0) + (now - 10)
        cd:SetCooldown(start, 10)
    end

    if _tickReg then
        pcall(_tickReg, icon)
    end

    -- Preview-only cooldown text: create FontString and keep it synced
    -- with the user's cooldownTextSize / cooldownTextOffsetX / Y settings.
    local fs = EnsurePreviewCDText(icon)
    if not fs then return end

    local size, offX, offY = ResolvePreviewCDConfig(icon, _tickShared, _tickA2db)

    -- Resolve global font (may change between ticks if user switches fonts)
    local fontPath = PREVIEW_CD_FONT
    local fontFlags = "OUTLINE"
    local gfs = _G.MSUF_GetGlobalFontSettings
    if type(gfs) == "function" then
        local p, fl = gfs()
        if type(p) == "string" and p ~= "" then fontPath = p end
        if type(fl) == "string" then fontFlags = fl end
    end

    -- Apply font family + size (diff-gated)
    if icon._msufA2_pvCDSize ~= size or icon._msufA2_pvCDFont ~= fontPath then
        fs:SetFont(fontPath, size, fontFlags)
        icon._msufA2_pvCDSize = size
        icon._msufA2_pvCDFont = fontPath
    end

    -- Apply offsets (diff-gated); anchor to cooldown center
    if icon._msufA2_pvCDOffX ~= offX or icon._msufA2_pvCDOffY ~= offY then
        local anchor = (cd and cd.GetObjectType) and cd or icon
        fs:ClearAllPoints()
        fs:SetPoint("CENTER", anchor, "CENTER", offX, offY)
        icon._msufA2_pvCDOffX = offX
        icon._msufA2_pvCDOffY = offY
    end

    -- Cycle a fake countdown value (1-9, updates each tick ~0.5s)
    local counter = (icon._msufA2_previewCDCounter or 0) + 1
    if counter > 9 then counter = 1 end
    icon._msufA2_previewCDCounter = counter
    fs:SetText(tostring(counter))
    fs:Show()
end

local function PreviewTickCooldown()
    local a2, shared = EnsureDB()
    if not ShouldRunPreviewTicker("cooldown", a2, shared) then  return end

    local A = GetApply()

    -- Set file-scope upvalues for callback
    _tickShared = shared
    _tickA2db = a2
    _tickApplyCDOffsets = A and A.ApplyCooldownTextOffsets
    _tickReg, _ = GetCooldownTextMgr()

    pcall(ForEachPreviewIcon, _PreviewCooldownIconFn)
 end

local function EnsureTicker(kind, need, interval, fn)
    local t = PreviewTickers[kind]
    if need then
        if not t then
            PreviewTickers[kind] = C_Timer.NewTicker(interval, fn)
        end
    else
        if t then
            t:Cancel()
            PreviewTickers[kind] = nil
        end
    end
 end

local function UpdatePreviewStackTicker()
    local a2, shared = EnsureDB()

    -- If the user disables Edit Mode previews, hard-clear any existing preview icons immediately.
    if shared and shared.showInEditMode ~= true then
        if API.ClearAllPreviews then
            API.ClearAllPreviews()
        end
    end

    local need = ShouldRunPreviewTicker("stacks", a2, shared)
    EnsureTicker("stacks", need, 0.50, PreviewTickStacks)
 end

local function UpdatePreviewCooldownTicker()
    local a2, shared = EnsureDB()

    -- If the user disables Edit Mode previews, hard-clear any existing preview icons immediately.
    if shared and shared.showInEditMode ~= true then
        if API.ClearAllPreviews then
            API.ClearAllPreviews()
        end
    end

    local need = ShouldRunPreviewTicker("cooldown", a2, shared)
    EnsureTicker("cooldown", need, 0.50, PreviewTickCooldown)
 end

Preview.UpdatePreviewStackTicker = UpdatePreviewStackTicker
Preview.UpdatePreviewCooldownTicker = UpdatePreviewCooldownTicker

API.UpdatePreviewStackTicker = API.UpdatePreviewStackTicker or UpdatePreviewStackTicker
API.UpdatePreviewCooldownTicker = API.UpdatePreviewCooldownTicker or UpdatePreviewCooldownTicker

if _G and type(_G.MSUF_Auras2_UpdatePreviewStackTicker) ~= "function" then
    _G.MSUF_Auras2_UpdatePreviewStackTicker = function()
        if API and API.UpdatePreviewStackTicker then
            return API.UpdatePreviewStackTicker()
        end
     end
end

if _G and type(_G.MSUF_Auras2_UpdatePreviewCooldownTicker) ~= "function" then
    _G.MSUF_Auras2_UpdatePreviewCooldownTicker = function()
        if API and API.UpdatePreviewCooldownTicker then
            return API.UpdatePreviewCooldownTicker()
        end
     end
end

