import Semantics.FixedPoint
import Semantics.Bind

namespace Semantics.Autobalance

open Semantics

/--
NodeState: Represents the health of a research node.
-/
structure NodeState where
  ip          : String
  recordCount : Nat
  isOnline    : Bool
  load        : Q16_16
  deriving Repr, BEq

/--
BalanceInvariant: A network is 'Grounded' if the variance in record counts 
is within the prescribed tolerance (10% delta).
-/
def isGrounded (nodes : List NodeState) : Bool :=
  let onlineNodes := nodes.filter (·.isOnline)
  if onlineNodes.length < 2 then true
  else
    -- Simple heuristic: if any online node has 0 records while others have many, not grounded.
    let hasEmpty := onlineNodes.any (·.recordCount == 0)
    let hasLoaded := onlineNodes.any (·.recordCount > 100)
    !(hasEmpty && hasLoaded)

/--
EquilibriumCost: The cost of an autobalance event (Q16.16).
Cross-node broadcast is expensive but necessary for full view.
-/
def balanceCost (n : NodeState) (g : Metric) : UInt32 :=
  if n.isOnline then 0x00008000 -- 0.5 cost
  else 0x00050000 -- 5.0 cost (penalty for attempting sync to offline node)

/--
The Autobalance Bind: Connects the local substrate to the network equilibrium.
-/
def balanceBind (localNode : NodeState) (remoteNode : NodeState) (g : Metric) : Bind NodeState NodeState :=
  controlBind localNode remoteNode g (fun n _ _ => balanceCost n g) 
    (fun _ => if isGrounded [localNode, remoteNode] then "equilibrium_attained" else "rebalance_required")
    (fun _ => "lawful_sync_witness")

end Semantics.Autobalance