local BlackHoleCore = {}

-- Hi, welcome to the main works of Blackhole v5 Alpha! I guess you know these stuff, so feel free to break it!

-- Logger for one-time messages
local logger = {
    bodyForce = false,
    velocity = false,
    sizeProp = false,
    zeroGrav = false,
    consuming = false,
    gravEngine = false
}

function BlackHoleCore.Setup(config)
    local self = {}

    -- Store configuration values
    self.hole = config.hole
    self.gravitationalConstant = config.gravitationalConstant
    self.updateInterval = config.updateInterval
    self.damping = config.damping
    self.rangeFactor = config.rangeFactor
    self.transparencySteps = config.transparencySteps
    self.dematerializeDuration = config.dematerializeDuration
    self.sizeProportion = config.sizeProportion
    self.rangeProportion = config.rangeProportion
    self.partColor = config.partColor
    self.partMaterialTransform = config.partMaterialTransform
    self.absorption = config.absorption
    self.growth = config.growth
    self.killPlayers = config.killPlayers
    self.collision = config.collision
    self.fixedPosition = config.fixedPosition
    self.toggleMicroGravity = config.toggleMicroGravity
    self.infinityHandler = config.infinityHandler
    self.paradoxHandler = config.paradoxHandler
    self.mergeBlackholes = config.mergeBlackholes
    self.gravityEngine = config.gravityEngine
    self.glint = config.glint
    self.glintProportion = config.glintProportion
    self.rocheLimitFactor = config.rocheLimitFactor
    self.gravitySync = config.gravitySync

    -- Internal variables
    self.lastUpdateTime = 0
    self.logger = logger
    self.CollectionService = game:GetService("CollectionService")
    self.previousSize = self.hole.Size.X
    self.glintProportions = self.previousSize * self.glintProportion

    ---------------------------------------------------------------------
    -- CORE FUNCTIONS
    ---------------------------------------------------------------------
    -- Destroy joints within the Roche limit
    function self.DestroyJointsWithinRocheLimit(object)
        local distance = (self.hole.Position - object.Position).Magnitude
        local rocheLimit = (self.hole.Size.Magnitude / 2) * self.rocheLimitFactor
        if distance <= rocheLimit then
            for _, descendant in pairs(object:GetDescendants()) do
                if descendant:IsA("JointInstance") then descendant:Destroy() end
            end
        end
    end

    -- Apply gravity to a given object
    function self.ApplyGravity(object)
        local currentTime = tick()
        if currentTime - self.lastUpdateTime < self.updateInterval then return end
        self.lastUpdateTime = currentTime

        local direction = self.hole.Position - object.Position
        local distance = direction.Magnitude
        local holeRadius = self.hole.Size.Magnitude / 2
        local distanceSquared = (distance / ((self.rangeFactor / 100) + ((self.rangeFactor / 100) * (1 / 64))))^2
        local magnitude = self.gravitationalConstant / distanceSquared

        -- Dampening for velocity-based gravity when gravitySync is enabled
        local engineType = string.lower(self.gravityEngine)
        if (engineType == "velocity" or engineType == "speed" or engineType == "2") and self.gravitySync then
            magnitude = magnitude / (self.gravitationalConstant * 0.1)
        end

        local force = direction.Unit * magnitude * object:GetMass()

        -- Infinity handler: neutralize force inside inner radius
        if self.infinityHandler and distance < holeRadius then
            force = Vector3.zero
            direction = Vector3.zero
        end

        -- Apply force/velocity based on gravity engine
        if engineType == "bodyforce" or engineType == "force" or engineType == "1" then
            local bodyForce = object:FindFirstChild("BlackHoleBodyForce") or Instance.new("BodyForce", object)
            bodyForce.Name = "BlackHoleBodyForce"
            bodyForce.Force = (bodyForce.Force + force) * self.damping
            if not self.logger.bodyForce then
                print("{BHv5A} Using FORCE-based gravity (+Stability, -Accuracy) MODEL SUPPORTED")
                self.logger.bodyForce = true
            end

        elseif engineType == "velocity" or engineType == "speed" or engineType == "2" then
            local blackHoleRadius = self.hole.Size.X / 2
            if distance < blackHoleRadius then return end
            object.Velocity = object.Velocity + force * self.damping
            if not self.logger.velocity then
                print("{BHv5A} Using VELOCITY-based gravity (-Stability, +Accuracy) DOES NOT SUPPORT MODELS!!!")
                self.logger.velocity = true
            end

        else
            print("{BHv5A} Invalid Gravity Engine request! Switching to default (Force-based Gravity)")
            self.logger.gravEngine = true
            self.gravityEngine = "1"
        end
    end

    -- Check and apply gravity to an object if appropriate
    function self.CheckAndApplyGravity(obj)
        if not obj:IsDescendantOf(game.Workspace) or not obj:IsA("BasePart") then return end
        if obj == self.hole or obj.Parent:IsA("Player") or obj.Anchored then return end
        self.DestroyJointsWithinRocheLimit(obj)
        self.ApplyGravity(obj)
    end

    -- Absorb smaller black holes
    function self.AbsorbSmallerBlackHole(otherBlackHole)
        local function AverageSize(part)
            return (part.Size.X + part.Size.Y + part.Size.Z) / 3
        end
        local thisSize = AverageSize(self.hole)
        local otherSize = AverageSize(otherBlackHole)
        local sizeDifference = math.floor((thisSize - otherSize) * 1000 + 0.5) / 1000

        local function resetForces(blackHole)
            local bf = blackHole:FindFirstChild("BlackHoleBodyForce")
            if bf then bf.Force = Vector3.new(0, 0, 0) end
        end
        local function applyNewForce(blackHole)
            local newBF = Instance.new("BodyForce", blackHole)
            newBF.Force = Vector3.new(0, blackHole.Size.Magnitude * 2, 0)
        end

        if sizeDifference > 0.001 then
            self.CollectionService:RemoveTag(otherBlackHole, "Blackholev5")
            task.wait(0.01)
            resetForces(otherBlackHole)
            self.hole.Size = otherBlackHole.Size * 0.5
            self.rangeFactor = (self.hole.Size.Magnitude * 0.5) * (self.rangeProportion / self.sizeProportion)
            otherBlackHole:Destroy()
            resetForces(self.hole)
            applyNewForce(self.hole)
        elseif sizeDifference < -0.001 then
            task.wait(0.1)
            resetForces(otherBlackHole)
            applyNewForce(otherBlackHole)
            self.hole:Destroy()
        else
            local unifiedSize = self.hole.Size * 2
            local newBlackHole = self.hole:Clone()
            newBlackHole.Size = unifiedSize
            newBlackHole.Position = self.hole.Position
            newBlackHole.Parent = self.hole.Parent
            self.CollectionService:AddTag(newBlackHole, "Blackholev5")
            local newGlintSize = self.glint.Size.Keypoints[1].Value * 2
            newBlackHole.VFX.Glint.Size = NumberSequence.new(newGlintSize)
            self.hole:Destroy()
            otherBlackHole:Destroy()
            resetForces(newBlackHole)
            applyNewForce(newBlackHole)
            self.hole = newBlackHole
        end
    end

    -- Damage players when they touch the black hole
    function self.onTouch(part)
        local humanoid = part.Parent:FindFirstChild("Humanoid")
        if humanoid then humanoid.Health = 0 end
    end

    -- Update Glint's size based on the black hole's size
    function self.updateGlintSize()
        local currentSize = self.hole.Size.X
        if currentSize ~= self.previousSize then
            local scaleFactor = currentSize / self.previousSize
            local newSize = self.glint.Size.Keypoints[1].Value * scaleFactor
            self.glint.Size = NumberSequence.new(newSize)
            self.previousSize = currentSize
        end
    end

    ---------------------------------------------------------------------
    -- RUN FUNCTION: SET UP LOOP & EVENT CONNECTIONS (INCLUDING ABSORPTION)
    ---------------------------------------------------------------------
    function self.Run()
        local RunService = game:GetService("RunService")

        -- Set up absorption events if enabled
        if self.absorption then
            self.hole.Touched:Connect(function(part)
                if self.CollectionService:HasTag(part, "Blackholev5") and self.mergeBlackholes then
                    self.AbsorbSmallerBlackHole(part)
                    return
                end
                if part.Anchored or (self.CollectionService:HasTag(part, "Blackholev5") and self.paradoxHandler) then
                    return
                end

                local function CalculateAverageSize(part)
                    return (part.Size.X + part.Size.Y + part.Size.Z) / 3
                end

                local objectAverageSize = CalculateAverageSize(part)
                local blackHoleSize = self.hole.Size.X
                local sizeIncrement = objectAverageSize / (blackHoleSize * self.sizeProportion)

                part.BrickColor = self.partColor
                part.Material = self.partMaterialTransform
                part.CanCollide = self.collision
                part.Anchored = self.fixedPosition

                for _, transparency in ipairs(self.transparencySteps) do
                    part.Transparency = transparency
                    wait(self.dematerializeDuration)
                end

                part:Destroy()

                if self.growth then
                    self.hole.Size = self.hole.Size + Vector3.new(sizeIncrement, sizeIncrement, sizeIncrement)
                    self.rangeFactor = self.rangeFactor + sizeIncrement * self.rangeProportion
                end
            end)
            print("{BHv5A} Absorption is ENABLED")
        else
            print("{BHv5A} Absorption is DISABLED")
        end

        -- Main gravitational loop
        RunService.Heartbeat:Connect(function()
            for _, obj in pairs(workspace:GetDescendants()) do
                self.CheckAndApplyGravity(obj)
            end
            self.updateGlintSize()
        end)

        -- Connect kill-player logic if enabled
        if self.killPlayers then
            self.hole.Touched:Connect(self.onTouch)
        end

        -- Toggle micro gravity
        workspace.Gravity = self.toggleMicroGravity and 0 or workspace.Gravity
        print("{BHv5A} Gravity is " .. (self.toggleMicroGravity and "DISABLED" or "ENABLED"))
    end

    return self
end

return BlackHoleCore