-- Settings
-- Possible values: 
--    "LTR"     - Left to Right,
--    "RTL"     - Right to Left,
--    "TTB"    - Top to Bottom,
--    "BTT"    - Bottom to top
local FILL_DIRECTION = "BTT"

local ATTENUATE_DEAD_BARS = true

local function reanchorOutlets(P, outlet, healthBar)
    P.ClearPoints(outlet)
    P.Point(outlet, "TOPLEFT", healthBar:GetStatusBarTexture(), "TOPRIGHT")
    P.Point(outlet, "BOTTOMLEFT", healthBar:GetStatusBarTexture(), "BOTTOMRIGHT")
end

local function reanchorInlets(P, inlet, healthBar)
    P.ClearPoints(inlet)
    P.Point(inlet, "TOPLEFT", healthBar:GetStatusBarTexture())
    P.Point(inlet, "BOTTOMLEFT", healthBar:GetStatusBarTexture())
end

local function reanchorVerticalOutlets(P, outlet, healthBar)
    P.ClearPoints(outlet)
    P.Point(outlet, "TOPLEFT", healthBar:GetStatusBarTexture(), "BOTTOMLEFT")
    P.Point(outlet, "TOPRIGHT", healthBar:GetStatusBarTexture(), "BOTTOMRIGHT")
end

local function reanchorVerticalInlets(P, inlet, healthBar)
    P.ClearPoints(inlet)
    P.Point(inlet, "TOPLEFT", healthBar:GetStatusBarTexture())
    P.Point(inlet, "TOPRIGHT", healthBar:GetStatusBarTexture())
end

local function applyFillDirection()
    Cell.funcs.IterateAllUnitButtons(function(b)
            local P = Cell.pixelPerfectFuncs
            local healthBar = b.widgets.healthBar
            local healthBarLoss = b.widgets.healthBarLoss
            
            if FILL_DIRECTION == "LTR" then
                healthBar:SetOrientation("HORIZONTAL")
                healthBar:SetReverseFill(true)
                
                P.ClearPoints(healthBarLoss)
                P.Point(healthBarLoss, "TOPLEFT", healthBar:GetStatusBarTexture(), "TOPRIGHT")
                P.Point(healthBarLoss, "BOTTOMRIGHT", healthBar, "BOTTOMRIGHT")
                
                reanchorOutlets(P, b.widgets.damageFlashTex, healthBar)
                reanchorOutlets(P, b.widgets.incomingHeal, healthBar)
                reanchorOutlets(P, b.widgets.shieldBar, healthBar)
                
                reanchorInlets(P, b.widgets.shieldBarR, healthBar)
                reanchorInlets(P, b.widgets.absorbsBar, healthBar)
                
            elseif FILL_DIRECTION == "RTL" then
                healthBar:SetOrientation("HORIZONTAL")
                healthBar:SetReverseFill(false)
                
                P.ClearPoints(healthBarLoss)
                P.Point(healthBarLoss, "TOPLEFT", healthBar, "TOPLEFT")
                P.Point(healthBarLoss, "BOTTOMRIGHT", healthBar:GetStatusBarTexture(), "BOTTOMLEFT")
                
                reanchorOutlets(P, b.widgets.damageFlashTex, healthBar)
                reanchorOutlets(P, b.widgets.incomingHeal, healthBar)
                reanchorOutlets(P, b.widgets.shieldBar, healthBar)
                
                reanchorInlets(P, b.widgets.shieldBarR, healthBar)
                reanchorInlets(P, b.widgets.absorbsBar, healthBar)
                
            elseif FILL_DIRECTION == "TTB" then
                healthBar:SetOrientation("VERTICAL")
                healthBar:SetReverseFill(false)
                
                P.ClearPoints(healthBarLoss)
                P.Point(healthBarLoss, "TOPLEFT", healthBar, "TOPLEFT")
                P.Point(healthBarLoss, "BOTTOMRIGHT", healthBar:GetStatusBarTexture(), "TOPRIGHT")
                
                reanchorVerticalOutlets(P, b.widgets.damageFlashTex, healthBar)
                reanchorVerticalOutlets(P, b.widgets.incomingHeal, healthBar)
                reanchorVerticalOutlets(P, b.widgets.shieldBar, healthBar)
                
                reanchorVerticalInlets(P, b.widgets.shieldBarR, healthBar)
                reanchorVerticalInlets(P, b.widgets.absorbsBar, healthBar)
                
            elseif FILL_DIRECTION == "BTT" then
                healthBar:SetOrientation("VERTICAL")
                healthBar:SetReverseFill(true)
                
                P.ClearPoints(healthBarLoss)
                P.Point(healthBarLoss, "TOPLEFT", healthBar:GetStatusBarTexture(), "BOTTOMLEFT")
                P.Point(healthBarLoss, "BOTTOMRIGHT", healthBar, "BOTTOMRIGHT")
                
                reanchorVerticalOutlets(P, b.widgets.damageFlashTex, healthBar)
                reanchorVerticalOutlets(P, b.widgets.incomingHeal, healthBar)
                reanchorVerticalOutlets(P, b.widgets.shieldBar, healthBar)
                
                reanchorVerticalInlets(P, b.widgets.shieldBarR, healthBar)
                reanchorVerticalInlets(P, b.widgets.absorbsBar, healthBar)
            end
            
            -- Special cases
            local overAbsorbGlow = b.widgets.overAbsorbGlow
            local overShieldGlow = b.widgets.overShieldGlow
            P.ClearPoints(overAbsorbGlow)
            P.ClearPoints(overShieldGlow)
            
            if FILL_DIRECTION == "LEFT_TO_RIGHT" or FILL_DIRECTION == "RIGHT_TO_LEFT" then
                P.Point(overAbsorbGlow, "TOPRIGHT")
                P.Point(overAbsorbGlow, "BOTTOMRIGHT")
                P.Point(overShieldGlow, "TOPLEFT")
                P.Point(overShieldGlow, "BOTTOMLEFT")
            else
                P.Point(overAbsorbGlow, "TOP")
                P.Point(overShieldGlow, "TOP")
            end
    end)
end

function hookCell()
    if Cell.__fill_direction_hook_installed then return end
    
    if ATTENUATE_DEAD_BARS then
        local F = Cell.funcs
        local oldGetHealthBarColor = F.GetHealthBarColor
        F.GetHealthBarColor = function(...)
            local colors = {oldGetHealthBarColor(...)}
            if not isDeadOrGhost then
                return unpack(colors)
            end
            return colors[4], colors[5], colors[6], colors[1], colors[2], colors[3]
        end
        
        Cell.funcs.IterateAllUnitButtons(function(button)
                local originalSetVertexColor = button.widgets.healthBarLoss.SetVertexColor
                button.widgets.healthBarLoss.SetVertexColor = function(self, r, g, b, a)
                    local dead = button.states.isDeadOrGhost or button.states.isDead
                    if dead then
                        r, g, b, a = button.widgets.healthBar:GetStatusBarColor()
                    end
                    originalSetVertexColor(self, r, g, b, a)
                end
        end)
    end
    
    local B = Cell.bFuncs
    hooksecurefunc(B, "SetOrientation", function()
            applyFillDirection()
    end)
    
    applyFillDirection()
    Cell.__fill_direction_hook_installed = true
end

hookCell()
Cell.RegisterCallback("AddonLoaded", "FillDirectionHook", hookCell)