ACM Slim modified

-- declare addon ------------------------------------------------------------
local ACM, private = ...
local LibStub = LibStub

-- local variables ----------------------------------------------------------
local allManaValues = {} -- stores all values during combat
local span = 1100 -- this is the left and right limit of manaburn or managain in absolute MPS value (user setting?)
local numsegments = 10 -- negative/positive half-bar number of segments (center segment excluded)
local segment_span = span/numsegments -- how much MPS per segment?

-- declare the database
local db
function ACM:OnInitialize()
    self:CreateManaBar()
end

function ACM:OnEnable()
    self:RegisterEvent("PLAYER_REGEN_ENABLED")
    self:RegisterEvent("PLAYER_REGEN_DISABLED")
end

function ACM:CreateManaBar()
    -- build and set frame
    private.manaDisplay = CreateFrame("Frame", "manaDisplay", UIParent)
    private.manaDisplay:SetHeight(20)
    private.manaDisplay:SetWidth(210)
    BackDrop:EnhanceBackdrop(private.manaDisplay)
    local TEXTURE = "Interface\\BUTTONS\\WHITE8X8"

    private.manaDisplay:SetBackdrop({
        bgFile = TEXTURE, tile = false, tileSize = 16,
        edgeFile = self.db.profile.barBorder, edgeSize = 16,
        insets = { left = 4, right = 4, top = 4, bottom = 4 },
    })

    private.manaDisplay:SetBackdropGradient("HORIZONTAL", 1, 0, 0, 0, 1, 0)
    -- private.manaDisplay:SetBackdropBorderColor(0.6, 0.6, 0.6, 1)

    private.manaDisplay:SetAlpha(1)

    -- create the segments that the pointer is attached to
    for i = 1, 21 do
        local t = private.manaDisplay.segments[i] or private.manaDisplay:CreateTexture(nil, "ARTWORK")
        t:SetPoint("LEFT", private.manaDisplay.segments[i - 1], "RIGHT", 0, 0)
        t:SetWidth(private.manaDisplay:GetWidth() / 21)
        t:SetHeight(private.manaDisplay:GetHeight() - 10)
        t:SetTexture(TEXTURE)
        t:SetAlpha(0.8)
        private.manaDisplay.segments[i] = t
    end
end

local function round(input, idp)
    local mult = 10^(idp or 0)
    if input >= 0 then return math.floor(input * mult + 0.5) / mult
    else return math.ceil(input * mult - 0.5) / mult end
end

local in_combat
function ACM:PLAYER_REGEN_ENABLED()
    in_combat = false
    private.manaDisplay:SetScript("OnUpdate", nil)

    -- reset indicator to posistion 0, which is 11, or centre
    private.manaDisplay.indicator:SetPoint("CENTER", private.manaDisplay.segments[11], "RIGHT")

    -- calculate overall average gain or loss of Mana
    local allManaSum = 0

    local t = allManaValues
    for k = 1, #t do
        local v = t[k]
        allManaSum = allManaSum + v
    end

    local combatAverage = round((allManaSum / #t))

    combatAverage = nil
    allManaValues = {}
end

function ACM:PLAYER_REGEN_DISABLED()
    if #self.db.char.logs > 20 then
        table.remove(self.db.char.logs, 1) -- keep log file to a max of 20 entries, removing oldest
    end
    in_combat = true
    local firstManaValue = UnitPower("player", SPELL_POWER_MANA)

    -- must show the display in combat, or nothing happens, including calculating/printing overall average
    if not private.manaDisplay:IsShown() then
        private.manaDisplay:Show()
    end
    private.manaDisplay.leftSide:SetText("")
    private.manaDisplay.rightSide:SetText("")

    local counter = 0
    private.manaDisplay:SetScript("OnUpdate", function(self, elapsed)
        counter = counter + elapsed
        if counter < 1 then return end
        counter = 0

        local currentMana = UnitPower("player", SPELL_POWER_MANA)

        local deltaMana = currentMana - firstManaValue or currentMana
        firstManaValue = currentMana

        local numManaValues = #allManaValues + 1
        allManaValues[numManaValues] = deltaMana

        -- get 10 (or less, if there are less) recent values
        local count = numManaValues >= 10 and 10 or numManaValues
        for index = numManaValues - count + 1, numManaValues - 1 do
            deltaMana = deltaMana + allManaValues[index]
        end

        local average = deltaMana / count
        local average_normalized = floor(min(min(abs(average)/segment_span,numsegments),numsegments)+0.5)-- normalized to absolute 'segment units'
        local pointer = 11 -- 1-21 means 11 = center spot, 1-10 segments left, 12-21 segments right
        if average < 0 then
            pointer = (mumsegments + 1) - average_normalized
        elseif average > 0 then
            pointer = average_normalized + (numsegments + 1)
        end

        private.manaDisplay.indicator:SetPoint("CENTER", private.manaDisplay.segments[pointer], "RIGHT")

        -- losing mana
        if average < 0 then
            -- respect user's display settings
            if self.db.profile.showLeft then
                private.manaDisplay.leftSide:SetFormattedText(L["Full Burn!"] .."\n%d", average)
                private.manaDisplay.rightSide:SetText("")
            else
                private.manaDisplay.leftSide:SetFormattedText(average)
                private.manaDisplay.rightSide:SetText("")
            end

        -- gaining mana
        elseif average > 1 then
            -- more respecting
            if self.db.profile.showRight then
                private.manaDisplay.rightSide:SetFormattedText(L["Gaining Mana!"] .."\n%d", average)
                private.manaDisplay.leftSide:SetText("")
            else
                private.manaDisplay.rightSide:SetFormattedText(average)
                private.manaDisplay.leftSide:SetText("")
            end

        -- breaking even
        else
            private.manaDisplay.leftSide:SetText("")
            private.manaDisplay.rightSide:SetText("")
        end
    end)
end