local historyWindow
 
-- Update the History Window by using the slider position to figure out which offset in the data table 
-- in this case a simple text list for the label controls used.
local function UpdateHistoryWindow(...)
    local tlw = historyWindow
    tlw.DataOffset = tlw.DataOffset or 0
    if tlw.DataOffset < 0 then tlw.DataOffset = 0 end
    if #tlw.DataLines == 0 then return end
    tlw.Slider:SetMinMax(0,#tlw.DataLines - tlw.MaxLines)
    for i = 1,tlw.MaxLines do
        local curLine = tlw.Lines[i]
        local curData = tlw.DataLines[tlw.DataOffset + i]
        curLine.Text:SetText(curData)
    end 
end

-- Initialise the History Window
-- 30 label controls seemed adequate for a screen full of information, 
-- the scroll bar would simply move the starting point in the data list 
-- to decide which one goes on which label
local function InitHistoryWindow(...)
    local tlw = WINDOW_MANAGER:CreateTopLevelWindow(nil)    
 
    tlw.DataOffset = 0
    tlw.MaxLines = 30
    tlw.DataLines = {}
    tlw.Lines = {}
 
    tlw:SetHeight(625)
    tlw:SetWidth(575)
    tlw:SetAnchor(CENTER,GuiRoot,CENTER,0,0)
    tlw:SetDrawLayer(DL_BACKGROUND)
    tlw:SetMouseEnabled(true)
    tlw:SetMovable(false)
    tlw:SetClampedToScreen(true)
    tlw:SetHidden(true)
    tlw:SetHandler("OnMouseWheel",function(self,delta)
        local value = tlw.DataOffset - delta
        if value < 0 then 
            value = 0
        elseif value > #tlw.DataLines - tlw.MaxLines then 
            value = #tlw.DataLines - tlw.MaxLines 
        end
        tlw.DataOffset = value
        tlw.Slider:SetValue(tlw.DataOffset)
        UpdateHistoryWindow()
    end)
    tlw:SetHandler("OnShow",function(self)
        local index = 0
 
        -- Make sure we are looking at the latest data  
                -- I create a quick access table for traversing easily 
                -- for reading purposes only
        UpdateHarvestHistory()
 
        -- Update what the window lines are going to show.
                -- This is reading through my table of data generated with the function above.
                -- And generating a text line of information to display on the label
        tlw.DataLines = {}
        for historyIndex,historyData in pairs(harvestHistory) do
            for zoneIndex,zoneData in pairs(historyData) do
                if zoneIndex ~= "version" then
                    for itemIndex,itemData in pairs(zoneData) do
                        for indexIndex,indexData in pairs(itemData) do
                            index = index + 1
                            tlw.DataLines[index] = string.format("[%d]: %s %s in %s at %0.3f,%0.3f",index,itemIndex,tostring(indexData["Action"]),zoneIndex,indexData["X"],indexData["Y"])
                        end
                    end
                end
            end
        end
        tlw.Caption.Text:SetText(addonName .. " ["..addonVersion.."] - " .. #tlw.DataLines or 0 .. " Total")
        UpdateHistoryWindow()
    end)
 
    tlw.BackGround = WINDOW_MANAGER:CreateControl(nil,tlw,CT_BACKDROP)
    tlw.BackGround:SetAnchorFill(tlw)
    tlw.BackGround:SetCenterColor(0.0, 0.0, 0.0, 0.5)   
    tlw.BackGround:SetEdgeColor(1.0, 1.0, 0.0, 0.5)
    tlw.BackGround:SetEdgeTexture(nil, 2, 2, 2.0, 2.0)  
 
        -- This is what turns a simple slider into a scrollbar
    local tex = "/esoui/art/miscellaneous/scrollbox_elevator.dds"
    tlw.Slider = WINDOW_MANAGER:CreateControl(nil,tlw,CT_SLIDER)
    tlw.Slider:SetDimensions(30,tlw:GetHeight())
    tlw.Slider:SetMouseEnabled(true)
    tlw.Slider:SetThumbTexture(tex,tex,tex,30,50,0,0,1,1)
    tlw.Slider:SetValue(0)
    tlw.Slider:SetValueStep(1)
    tlw.Slider:SetAnchor(LEFT,tlw,RIGHT,0,0)
 
        -- When we change the slider's value we need to change the data offset and redraw the display
    tlw.Slider:SetHandler("OnValueChanged",function(self,value,eventReason)
        tlw.DataOffset = math.min(value,#tlw.DataLines - tlw.MaxLines)
        UpdateHistoryWindow()
    end)
 
    tlw.Caption = WINDOW_MANAGER:CreateControl(nil,tlw,CT_CONTROL)
    tlw.Caption:SetDimensions(tlw:GetWidth(),30)
    tlw.Caption:SetAnchor(BOTTOMLEFT,tlw,TOPLEFT,0,0)
    tlw.Caption:SetHidden(false)
 
    tlw.Caption.Text = WINDOW_MANAGER:CreateControl(nil,tlw.Caption,CT_LABEL)
    tlw.Caption.Text:SetAnchorFill(tlw.Caption)
    tlw.Caption.Text:SetFont("ZoFontGameLargeBoldShadow")
    tlw.Caption.Text:SetDimensions(tlw.Caption:GetWidth(),tlw.Caption:GetHeight())
    tlw.Caption.Text:SetText(addonName .. " ["..addonVersion.."] - " .. #harvestHistory or 0 .. " Total")
    tlw.Caption.Text:SetHorizontalAlignment(TEXT_ALIGN_LEFT) 
    tlw.Caption.Text:SetHidden(false)
 
    tlw.Close = WINDOW_MANAGER:CreateControl(nil,tlw,CT_BUTTON)
    tlw.Close:SetDimensions(tlw.Caption:GetHeight(),tlw.Caption:GetHeight())
    tlw.Close:SetAnchor(BOTTOMRIGHT,tlw.Slider,TOPRIGHT,0,0)
    tlw.Close:SetHidden(false)
    tlw.Close:SetFont("ZoFontGameLargeBoldShadow")
    tlw.Close:SetText("X")
    tlw.Close:SetHandler("OnClicked",function(self) 
        tlw:SetHidden(true) 
    end)
 
        -- And this is the block of code that generates the group of controls that make up the scrollable area.
        -- As well as labels you could add buttons and other controls and attach them to the lines control.
    for i=1,tlw.MaxLines do
        tlw.Lines[i] = WINDOW_MANAGER:CreateControl(nil,tlw,CT_CONTROL)
        tlw.Lines[i]:SetDimensions(tlw:GetWidth(),20)
        if i == 1 then
            tlw.Lines[i]:SetAnchor(TOPLEFT,tlw,TOPLEFT,5,5)
        else
            tlw.Lines[i]:SetAnchor(TOPLEFT,tlw.Lines[i-1],BOTTOMLEFT,0,0)
        end
 
        tlw.Lines[i].Text = WINDOW_MANAGER:CreateControl(nil,tlw.Lines[i],CT_LABEL)
        tlw.Lines[i].Text:SetFont("ZoFontGame")
        tlw.Lines[i].Text:SetDimensions(tlw.Lines[i]:GetWidth(),30)
        tlw.Lines[i].Text:SetAnchor(LEFT,tlw.Lines[i],LEFT,5,5)
        tlw.Lines[i].Text:SetText(string.format("Line %d Data %s",i,"Line " .. i))
        tlw.Lines[i]:SetHidden(false)
    end
 
        -- transfer simply named control to a more user friendly file wide control name
    historyWindow = tlw
end

-- Our Addon is loaded so we can start work
local function AddOnLoaded(eventID,addon)
    if addon ~= addonName then return end
    EVENT_MANAGER:UnregisterForEvent(addonName,eventID)
    -- Initialise your saved variables here so it's ready when you need it
    InitHistoryWindow()
    EVENT_MANAGER:RegisterForEvent( addonName ,EVENT_PLAYER_ACTIVATED , PlayerActivated )
end

-- Track addons loading
EVENT_MANAGER:RegisterForEvent( addonName ,EVENT_ADD_ON_LOADED , AddOnLoaded )