addon/Quests/Quests.lua

function CzechQuestsAddon:ShowTranslationFrame(primaryHeader, primaryText, secondaryHeader, secondaryText, parentFrame, yOffset, xOffset)
    -- replace placeholders with current values
    primaryText = CzechQuestsAddon:replacePlaceholders(primaryText);
    secondaryText = CzechQuestsAddon:replacePlaceholders(secondaryText);

    -- when user change own setting, does not require reload, just apply it
    CzechQuestsAddon:SetTextureFromSettings(CzechQuestsAddon.translationFrame)

    -- reset all texts
    CzechQuestsAddon:ResetTranslationText(CzechQuestsAddon.translationFrame)

    -- set text to labels
    CzechQuestsAddon.translationFrame.primaryHeader:SetText(primaryHeader:upper())
    CzechQuestsAddon.translationFrame.primaryText:SetText(primaryText)
    CzechQuestsAddon.translationFrame.secondaryHeader:SetText(secondaryHeader:upper())
    CzechQuestsAddon.translationFrame.secondaryText:SetText(secondaryText)

    local primaryTextTopMargin = -CzechQuestsAddon.translationFrame.primaryHeader:GetHeight() - 15
    local secondaryHeaderTopMargin = primaryTextTopMargin - CzechQuestsAddon.translationFrame.primaryText:GetHeight() - 20
    local secondaryTextTopMargin = secondaryHeaderTopMargin - CzechQuestsAddon.translationFrame.secondaryHeader:GetHeight() - 5

    -- apply gap between headers and texts
    local gap = 10
    local function addPadding(text, value)
        if text ~= "" then
            gap = gap + value
        end
    end

    addPadding(primaryHeader, 10)
    addPadding(primaryText, 5)
    addPadding(secondaryHeader, 25)
    addPadding(secondaryText, 5)

    -- apply positions
    CzechQuestsAddon.translationFrame.primaryHeader:SetPoint("TOPLEFT", 10, -10)
    CzechQuestsAddon.translationFrame.primaryText:SetPoint("TOPLEFT", 10, primaryTextTopMargin)
    CzechQuestsAddon.translationFrame.secondaryHeader:SetPoint("TOPLEFT", 10, secondaryHeaderTopMargin)
    CzechQuestsAddon.translationFrame.secondaryText:SetPoint("TOPLEFT", 10, secondaryTextTopMargin)

    -- apply changes per wow
    if (WOW_PROJECT_ID == WOW_PROJECT_CLASSIC) then
        CzechQuestsAddon.translationFrame:SetPoint("TOPLEFT", parentFrame, "TOPRIGHT", -8 + xOffset, yOffset)
    else
        CzechQuestsAddon.translationFrame:SetPoint("TOPLEFT", parentFrame, "TOPRIGHT", 8 + xOffset, yOffset)
    end

    -- calculate height
    local height = 0;
    local heights = {
        CzechQuestsAddon.translationFrame.primaryHeader:GetHeight(),
        CzechQuestsAddon.translationFrame.primaryText:GetHeight(),
        CzechQuestsAddon.translationFrame.secondaryHeader:GetHeight(),
        CzechQuestsAddon.translationFrame.secondaryText:GetHeight(),
        gap,
        10
    }
    for _, value in ipairs(heights) do
        height = height + value
    end

    CzechQuestsAddon.translationFrame:SetParent(parentFrame)
    CzechQuestsAddon.translationFrame:SetHeight(height < 200 and 200 or height)
end

function CzechQuestsAddon:ShowQuestTranslation(event)
    -- Hide frame, may contain old texts
    CzechQuestsAddon.translationFrame:Hide()

    -- Classic Era has QuestLogFrame
    if QuestLogFrame then
        if QuestLogFrame:IsShown() then
            local questIndex = GetQuestLogSelection()
            if questIndex > 0 then
                local questId = select(8, GetQuestLogTitle(questIndex))
                local questData = CzechQuestsAddon:GetData("quest", questId)
                if questData then
                    local suffix = CzechQuestsAddon.options.DEBUG_MODE and " (" .. questId .. ")" or ""
                    local questTitle = questData.title .. suffix
                    CzechQuestsAddon:ShowTranslationFrame(
                            questTitle,
                        questData.objective,
                        "Popis",
                        questData.description,
                        QuestLogFrame,
                        -14,
                        0
                    )
                    CzechQuestsAddon.translationFrame:Show()
                end
            end
        end
    end

    -- Retail has QuestMapDetailsScrollFrame
    if QuestMapDetailsScrollFrame then
        if QuestMapDetailsScrollFrame:IsShown() then
            -- get quest ID
            local questId = C_QuestLog.GetSelectedQuest()
            -- detect if quest frame does not include npc preview
            local hasModel = QuestModelScene:IsShown()
            -- show translation frame
            local questData = CzechQuestsAddon:GetData("quest", questId)
            if questData then
                local suffix = CzechQuestsAddon.options.DEBUG_MODE and " (" .. questId .. ")" or ""
                local questTitle = questData.title .. suffix
                local xOffset = hasModel and 210 or 0
                CzechQuestsAddon:ShowTranslationFrame(
                    questTitle,
                    questData.objective,
                    "Popis",
                    questData.description,
                    QuestMapFrame,
                    0,
                    xOffset
                )
                CzechQuestsAddon.translationFrame:Show()
            else
                CzechQuestsAddon.translationFrame:Hide()
            end
        end
    end

    -- If quest is right from NPC, this work for both wow version
    if QuestFrame:IsShown() then
        -- get quest ID
        local questId = GetQuestID()
        -- detect if quest frame does not include npc preview
        local hasModel = QuestModelScene and QuestModelScene:IsShown() or false
        -- show translation frame
        if questId then
            local questData = CzechQuestsAddon:GetData("quest", questId)
            if questData then
                CzechQuestsAddon.translationFrame:Show()
                local suffix = CzechQuestsAddon.options.DEBUG_MODE and " (" .. questId .. ")" or ""
                local questTitle = questData.title .. suffix
                local xOffset = hasModel and 210 or 0
                if event == "QUEST_PROGRESS" then
                    CzechQuestsAddon:ShowTranslationFrame(
                        questTitle,
                        questData.progress,
                        "",
                        "",
                        QuestFrame,
                        -20,
                        xOffset
                    )
                elseif event == "QUEST_COMPLETE" then
                    CzechQuestsAddon:ShowTranslationFrame(
                        questTitle,
                        questData.completion,
                        "",
                        "",
                        QuestFrame,
                        -20,
                        xOffset
                    )
                elseif event == "QUEST_DETAIL" then
                    CzechQuestsAddon:ShowTranslationFrame(
                        questTitle,
                        questData.description,
                        "Cíl úkolu",
                        questData.objective,
                        QuestFrame,
                        -20,
                        xOffset
                    )
                else
                    CzechQuestsAddon.translationFrame:Hide()
                end
            else
                CzechQuestsAddon.translationFrame:Hide()
            end
        end
    end
end

function CzechQuestsAddon:ShowQuestItemTranslation()
    -- Hide frame, may contain old texts
    CzechQuestsAddon.translationFrame:Hide()

    -- should work for both wow version
    if ItemTextFrame:IsShown() then
        itemName = ItemTextGetItem();
        local itemText = CzechQuestsAddon.GetData("item", itemName)
        if itemText ~= "" and itemText ~= nil then
            CzechQuestsAddon:ShowTranslationFrame(
                    "",
                    itemText,
                    "",
                    "",
                    ItemTextFrame,
                    -20,
                    0
            )
        end
        CzechQuestsAddon.translationFrame:Show()
    end
end

-- Hover is enabled only for QuestLogFrame and QuestMapDetailsScrollFrame
local function SetHoverScripts(frame)
    local frameName = frame:GetName()

    if not string.find(frameName, "QuestLogItem") and not string.find(frameName, "QuestProgressItem") then
        frame:SetScript("OnEnter", function()
            CzechQuestsAddon:ShowQuestTranslation()
        end)

        frame:SetScript("OnLeave", function()
            CzechQuestsAddon.translationFrame:Hide()
        end)
    end
end

-- create translation frame
CzechQuestsAddon.translationFrame = CzechQuestsAddon:CreateTranslationFrame()

-- Register events with the main frame
CzechQuestsAddon.translationFrame:RegisterEvent("PLAYER_LOGIN")
CzechQuestsAddon.translationFrame:RegisterEvent("QUEST_PROGRESS")
CzechQuestsAddon.translationFrame:RegisterEvent("QUEST_COMPLETE")
CzechQuestsAddon.translationFrame:RegisterEvent("QUEST_FINISHED")
CzechQuestsAddon.translationFrame:RegisterEvent("QUEST_DETAIL")
CzechQuestsAddon.translationFrame:RegisterEvent("ITEM_TEXT_READY")

-- Preparation for eventually show translation when hover quest in quest tracker for retail
--if (WOW_PROJECT_ID == WOW_PROJECT_MAINLINE) then
--    _G.EventRegistry:RegisterCallback("OnQuestBlockHeader.OnEnter", function(sender, self, questID, isGroup)
--        print(questID)
--    end)
--end

-- Define event handler for the main frame
CzechQuestsAddon.translationFrame:SetScript("OnEvent", function(self, event, ...)
    if event == "PLAYER_LOGIN" then
        -- classic
        if QuestLogFrame then
            SetHoverScripts(QuestLogFrame)
        end
         -- retail
        if QuestMapDetailsScrollFrame then
            SetHoverScripts(QuestMapDetailsScrollFrame)
        end
    end

    if event == "QUEST_PROGRESS" or event == "QUEST_COMPLETE" or event == "QUEST_DETAIL" or event == "QUEST_FINISHED" then
        CzechQuestsAddon:ShowQuestTranslation(event)
    end

    if (event == "ITEM_TEXT_READY") then
        CzechQuestsAddon:ShowQuestItemTranslation()
    end
end)