-- Triumvirate Kernel — Builder / Judge / Warden Consensus
--
-- Three parallel kernel instances on same hardware.
-- 2/3 consensus required for any state transition.
--
-- If one kernel gets "pulled into dimension 822yTe~" (crashes/corrupts/diverges),
-- the other two preserve the boundary law. System continues.
--
-- Consensus rule:
--   accept_transition := at least 2/3 agree AND Warden does not veto
--
-- This is the fault model for "machine loss" — one agent can fail,
-- but the quorum preserves lawful behavior.
--
-- Truth Seal: [ SSS-ENE-TRIUMVIRATE-2026-05-03 ]

module TriumvirateKernel where

import BaseTypes
import Memory
import SyscallInterface
import Semantics.LawfulLoss (BindResult, lawfulLoss, mkLawful, mkUnlawful, BindClass)
import LawfulHardware (HardwareEvent, eventToBindResult)
import GCLSelfHost (ChildKernel, ChildState)

-- ═══════════════════════════════════════════════════════════════════════════
-- §1  Triumvirate Roles
-- ═══════════════════════════════════════════════════════════════════════════

/-- The three roles of the triumvirate:
--
-- Builder: Proposes new structures, generates candidates, builds forward
--   ADD clock action
--   manifold_reg: Topological state registry
--   
-- Judge: Adjudicates disputes, validates proofs, decides conflicts
--   PAUSE clock action  
--   heatsink_halt: Energy guard, prevents runaway
--   
-- Warden: Validates integrity, checks proofs, enforces rollback
--   SUBTRACT clock action
--   stark_trace: Integrity chain
--   warden_valid: Proof validation
--
-- Each role runs as separate kernel instance with isolated memory.
-- They communicate via shared memory ring buffer (lawful channel).
-- -/]

inductive TriumvirateRole where
  | Builder   -- Proposes, builds, progresses
  | Judge     -- Adjudicates, decides, pauses
  | Warden    -- Validates, verifies, enforces
  deriving Repr, BEq, Inhabited

/-- Clock actions for each role. -/]
inductive ClockAction where
  | Add       -- Builder: forward progress
  | Subtract  -- Warden: validation/rollback
  | Pause     -- Judge: hold for decision
  deriving Repr, BEq

def roleToAction : TriumvirateRole → ClockAction
  | .Builder => .Add
  | .Warden  => .Subtract
  | .Judge   => .Pause

-- ═══════════════════════════════════════════════════════════════════════════
-- §2  Triumvirate Kernel Instance
-- ═══════════════════════════════════════════════════════════════════════════

/-- Each kernel instance knows its role and communicates with others. -/]

structure TriumvirateInstance where
  role          : TriumvirateRole
  instanceId    : InstanceID              -- 0=Builder, 1=Judge, 2=Warden
  clock         : TriumvirateClock
  hardware      : HardwareInterface       -- Access to actual hardware (via shim)
  commChannel   : TriumvirateChannel      -- Shared memory with other instances
  state         : TriumvirateState
  
structure TriumvirateClock where
  builderTicks  : Nat                     -- ADD actions taken
  wardenTicks   : Nat                     -- SUBTRACT actions taken
  judgeTicks    : Nat                     -- PAUSE actions taken
  lastSync      : Timestamp               -- Last consensus point
  
structure TriumvirateState where
  active        : Bool                    -- Is this instance running?
  healthy       : Bool                    -- Passed health checks?
  lastProposal  : Option Proposal         -- What we last proposed/voted on
  voteHistory   : Array Vote              -- Record of all votes

/-- Shared communication channel between instances.
    Implemented as lock-free ring buffer in shared memory. -/]

structure TriumvirateChannel where
  proposals     : RingBuffer Proposal     -- Builder proposals
  votes         : RingBuffer Vote         -- All instance votes
  decisions     : RingBuffer Decision   -- Final consensus
  healthBeats   : Array Timestamp         -- Last heartbeat from each instance
  
structure Proposal where
  id            : ProposalID
  proposer      : TriumvirateRole
  action        : ProposedAction
  timestamp     : Timestamp
  evidence      : Array BindResult        -- Supporting witnesses
  
inductive ProposedAction where
  | AcceptChildKernel child  -- From GCLSelfHost
  | MigrateProcess pid dst   -- Process migration
  | UpdateTopology change    -- ENE topology change
  | CheckpointSystem         -- Save state
  | EmergencyRollback        -- Revert to safe state
  | RebootToStandardKernel   -- Exit nano kernel
  
structure Vote where
  proposalId    : ProposalID
  voter         : TriumvirateRole
  decision      : VoteDecision
  timestamp     : Timestamp
  witness       : BindResult              -- Why we voted this way
  
inductive VoteDecision where
  | Yes         -- Approve
  | No          -- Reject
  | Abstain     -- Cannot decide
  | Veto        -- Warden emergency veto
  deriving Repr, BEq

structure Decision where
  proposal      : Proposal
  votes         : Array Vote
  outcome       : DecisionOutcome
  timestamp     : Timestamp
  
inductive DecisionOutcome where
  | Accepted    -- 2+ Yes, no Veto
  | Rejected    -- 2+ No or 1 Veto
  | Pending     -- Waiting for votes
  | Disputed    -- Split vote, needs Judge

-- ═══════════════════════════════════════════════════════════════════════════
-- §3  Consensus Algorithm
-- ═══════════════════════════════════════════════════════════════════════════

/-- Core consensus: collect votes, decide outcome.
    
    Rules:
    1. Builder proposes (always Yes to own proposal)
    2. Warden validates (Yes if evidence checks out, No if not)
    3. Judge adjudicates (Yes/No based on overall merit, or extends deliberation)
    
    4. Warden can Veto at any time (emergency stop)
    5. If split, Judge decides (breaks ties)
    
    6. Decision recorded with full witness chain
    -/]

def processProposal (proposal : Proposal) : IO Decision := do
  -- Broadcast proposal to all instances
  broadcastToChannel proposal
  
  -- Collect votes (with timeout)
  let votes ← collectVotes proposal.id (timeout := 5000)  -- 5 second timeout
  
  -- Count votes
  let yesCount := votes.count (\v => v.decision == .Yes)
  let noCount := votes.count (\v => v.decision == .No)
  let vetoCount := votes.count (\v => v.decision == .Veto)
  
  -- Determine outcome
  let outcome :=
    if vetoCount > 0 then
      -- Warden veto always wins
      .Rejected
    else if yesCount >= 2 then
      -- Majority approval
      .Accepted
    else if noCount >= 2 then
      -- Majority rejection
      .Rejected
    else
      -- Split or incomplete
      .Disputed
  
  -- If disputed, Judge decides
  let finalOutcome ←
    if outcome == .Disputed then
      let judgeVote ← findJudgeVote votes
      if judgeVote.decision == .Yes then
        pure .Accepted
      else if judgeVote.decision == .No then
        pure .Rejected
      else
        pure .Pending  -- Judge abstained, stay pending
    else
      pure outcome
  
  -- Record decision
  let decision := {
    proposal := proposal
    votes := votes
    outcome := finalOutcome
    timestamp := now ()
  }
  
  -- Log with BindResult witness
  let witness := {
    lawful := finalOutcome == .Accepted
    cost := computeConsensusCost votes
    witness := "CONSENSUS:" ++ proposal.id ++
               ";outcome:" ++ finalOutcome.toString ++
               ";yes:" ++ yesCount.toString ++
               ";no:" ++ noCount.toString ++
               ";veto:" ++ vetoCount.toString
    klass := .control
  }
  logWitness globalWitnessLog witness
  
  return decision

/-- Warden validation: check proposal evidence.
    This is the "proof validation" role. -/]

def wardenValidate (proposal : Proposal) : IO VoteDecision := do
  -- Check all evidence BindResults
  for evidence in proposal.evidence do
    if !evidence.lawful then
      -- Unlawful evidence
      return .No
    
    if evidence.cost > Q0_16.half then
      -- High cost, flag for scrutiny
      consoleLog "[WARDEN] High cost evidence: " ++ evidence.witness
  
  -- Check for known attack patterns
  if detectAttackPattern proposal then
    consoleLog "[WARDEN] Attack pattern detected in proposal " ++ proposal.id
    return .Veto  -- Emergency stop
  
  -- Check evidence chain integrity
  if !verifyEvidenceChain proposal.evidence then
    consoleLog "[WARDEN] Evidence chain failed verification"
    return .No
  
  -- All checks passed
  return .Yes

/-- Builder proposal generation. -/]

def builderPropose (action : ProposedAction) : IO Proposal := do
  let evidence ← gatherEvidenceForAction action
  
  return {
    id := generateProposalID
    proposer := .Builder
    action := action
    timestamp := now ()
    evidence := evidence
  }

/-- Judge adjudication: break ties, decide disputes. -/]

def judgeAdjudicate (votes : Array Vote) : IO VoteDecision := do
  -- Review all evidence
  let allEvidence := votes.flatMap (\v => v.witness)
  
  -- Consider system state
  let systemLoad ← getSystemLoad
  let recentFailures ← getRecentFailureCount
  
  -- Conservative if system stressed
  if systemLoad > 0.8 || recentFailures > 3 then
    -- Be cautious
    if votes.any (\v => v.decision == .No) then
      return .No  -- Reject if any No in stressed system
  
  -- Otherwise, check overall merit
  let meritScore := computeMeritScore votes
  
  if meritScore > 0.7 then
    return .Yes
  else if meritScore < 0.3 then
    return .No
  else
    return .Abstain  -- Can't decide, let it stay pending

-- ═══════════════════════════════════════════════════════════════════════════
-- §4  Fault Tolerance — Handling Instance Failure
-- ═══════════════════════════════════════════════════════════════════════════

/-- Detect if an instance has failed ("pulled into dimension 822yTe~").
    If one fails, the other two continue with reduced quorum. -/]

def checkInstanceHealth : IO Unit := do
  for i in [0, 1, 2] do
    let lastBeat := commChannel.healthBeats[i]
    let timeSince := now () - lastBeat
    
    if timeSince > HEARTBEAT_TIMEOUT then
      -- Instance i has failed
      consoleLog "[TRIUMVIRATE] Instance " ++ i.toString ++ " has failed (no heartbeat)"
      
      -- Mark as unhealthy
      markInstanceUnhealthy i
      
      -- If we still have 2 healthy instances, continue in degraded mode
      let healthyCount := countHealthyInstances
      
      if healthyCount >= 2 then
        consoleLog "[TRIUMVIRATE] Continuing in degraded mode with " ++ healthyCount.toString ++ " instances"
        enterDegradedMode
      else
        -- Only 1 or 0 instances left
        consoleLog "[TRIUMVIRATE] CRITICAL: Insufficient quorum, entering safe mode"
        enterSafeMode

/-- Degraded mode: 2-instance operation.
    Both must agree (unanimous consent since only 2). -/]

def enterDegradedMode : IO Unit := do
  -- Change consensus rule: require unanimous (2/2 instead of 2/3)
  setConsensusRule .Unanimous
  
  -- Increase health check frequency
  setHealthCheckInterval 500  -- Check every 500ms
  
  -- Log degraded entry
  let witness := {
    lawful := true
    cost := Q0_16.half
    witness := "DEGRADED_MODE:2_instances_active"
    klass := .control
  }
  logWitness globalWitnessLog witness

/-- Safe mode: emergency halt of all modifications.
    System is read-only until quorum restored. -/]

def enterSafeMode : IO Unit := do
  -- Reject all new proposals
  setProposalPolicy .RejectAll
  
  -- Checkpoint current state
  emergencyCheckpoint
  
  -- Attempt to restart failed instance
  spawn $ attemptInstanceRecovery
  
  -- Log safe mode entry
  let witness := {
    lawful := false  -- This is a failure mode
    cost := Q0_16.one
    witness := "SAFE_MODE:quorum_lost"
    klass := .control
  }
  logWitness globalWitnessLog witness

-- ═══════════════════════════════════════════════════════════════════════════
-- §5  Integration with GCL Self-Host
-- ═══════════════════════════════════════════════════════════════════════════

/-- Child kernel proposals go through triumvirate consensus. -/]

def proposeChildKernel (candidate : ChildKernel) : IO Decision := do
  let proposal ← builderPropose (.AcceptChildKernel candidate)
  
  -- Warden validates
  let wardenVote ← wardenValidate proposal
  
  -- If Warden vetos, immediate rejection
  if wardenVote == .Veto then
    return {
      proposal := proposal
      votes := #[{voter := .Warden, decision := .Veto, witness := mkUnlawful "Validation failed" .control}]
      outcome := .Rejected
      timestamp := now ()
    }
  
  -- Otherwise full consensus
  processProposal proposal

-- ═══════════════════════════════════════════════════════════════════════════
-- §6  Main Loop
-- ═══════════════════════════════════════════════════════════════════════════

def triumvirateMainLoop : IO Unit := do
  forever $ do
    -- Check health of all instances
    checkInstanceHealth
    
    -- Process any pending proposals
    while (hasPendingProposals) $ do
      let proposal ← dequeueProposal
      let decision ← processProposal proposal
      executeDecision decision
    
    -- Send heartbeat
    sendHeartbeat myInstanceId
    
    -- Small delay to prevent busy-waiting
    sleep 10  -- 10ms

/-- Execute an accepted decision. -/]

def executeDecision (decision : Decision) : IO Unit :=
  if decision.outcome != .Accepted then
    return ()  -- Nothing to do
  
  match decision.proposal.action with
  | .AcceptChildKernel child =>
      -- Boot the child
      bootChildWithTriumvirate child
      
  | .MigrateProcess pid dst =>
      -- Execute migration
      executeProcessMigration pid dst
      
  | .UpdateTopology change =>
      -- Apply topology change
      applyTopologyUpdate change
      
  | .CheckpointSystem =>
      -- Save full system state
      performSystemCheckpoint
      
  | .EmergencyRollback =>
      -- Revert to last checkpoint
      performEmergencyRollback
      
  | .RebootToStandardKernel =>
      -- Exit nano kernel, return to Linux
      kexecToStandardKernel

end TriumvirateKernel