sdk/vm_extensions.go

// Package sdk provides extensions to the Lux SDK for building various VMs
// This extends the existing Lux SDK at ~/work/lux/sdk
package sdk

import (
	"context"
	"crypto/ecdsa"
	"fmt"
	"math/big"
	"sync"
	"time"

	"github.com/luxfi/database"
	"github.com/luxfi/ids"
	log "github.com/luxfi/log"
)

// Context represents VM context
type Context struct {
	NetworkID uint32
	ChainID   ids.ID
	NodeID    ids.NodeID
}

// VMBuilder provides a unified interface for building VMs on Lux
// This extends the existing SDK with additional capabilities needed for:
// DEXVM, AIVM, FHEVM, MPCVM, QuantumVM, and more
type VMBuilder struct {
	// Core SDK components (existing)
	Context   *Context
	DB        database.Database
	State     StateDB
	Consensus ConsensusEngine
	Network   NetworkManager

	// Extended components for various VMs
	Extensions map[string]VMExtension
	Features   *FeatureSet

	mu sync.RWMutex
}

// VMExtension represents VM-specific functionality
type VMExtension interface {
	Name() string
	Initialize(builder *VMBuilder) error
	Start(ctx context.Context) error
	Stop() error
}

// FeatureSet defines features a VM can enable
type FeatureSet struct {
	// Consensus features
	QuantumResistant bool // Corona lattice-based
	BLSAggregation   bool // BLS signature aggregation
	VerkleWitnesses  bool // Verkle tree witnesses
	FPC              bool // Fast Probabilistic Consensus

	// Cryptographic features
	FHE         bool // Fully Homomorphic Encryption
	MPC         bool // Multi-Party Computation
	ZKProofs    bool // Zero-Knowledge Proofs
	PostQuantum bool // Post-quantum cryptography

	// Execution features
	GPU  bool // GPU acceleration
	FPGA bool // FPGA acceleration
	DPDK bool // Kernel bypass networking
	RDMA bool // Remote Direct Memory Access

	// Application features
	DEX     bool // Decentralized exchange
	AI      bool // AI/ML capabilities
	Oracle  bool // Oracle functionality
	Privacy bool // Privacy features
	Storage bool // Decentralized storage
}

// =============================================================================
// DEX Extension - For DEXVM
// =============================================================================

type DEXExtension struct {
	OrderBooks    map[string]*OrderBook
	Clearinghouse *Clearinghouse
	FundingEngine *FundingEngine
	Bridge        *CrossChainBridge
	Vaults        *VaultManager
	StakingPools  *StakingManager
	Multisig      *MultisigManager
}

func (e *DEXExtension) Name() string { return "dex" }

func (e *DEXExtension) Initialize(builder *VMBuilder) error {
	// Initialize DEX components
	e.OrderBooks = make(map[string]*OrderBook)
	e.Clearinghouse = NewClearinghouse()
	e.FundingEngine = NewFundingEngine()
	e.Bridge = NewCrossChainBridge()
	e.Vaults = NewVaultManager()
	e.StakingPools = NewStakingManager()
	e.Multisig = NewMultisigManager()

	// Register DEX-specific state handlers
	_ = builder.State.RegisterHandler("orderbook", e.handleOrderBookState) //nolint:errcheck
	_ = builder.State.RegisterHandler("positions", e.handlePositionState)  //nolint:errcheck

	return nil
}

func (e *DEXExtension) Start(ctx context.Context) error {
	// Start DEX services
	go e.runMatchingEngine(ctx)
	go e.runSettlement(ctx)
	go e.runFunding(ctx)
	return nil
}

func (e *DEXExtension) Stop() error {
	// Stop DEX services
	return nil
}

func (e *DEXExtension) handleOrderBookState(key, value []byte) error {
	// Handle order book state updates
	return nil
}

func (e *DEXExtension) handlePositionState(key, value []byte) error {
	// Handle position state updates
	return nil
}

func (e *DEXExtension) runMatchingEngine(ctx context.Context) {
	// Run order matching engine
}

func (e *DEXExtension) runSettlement(ctx context.Context) {
	// Run settlement processor
}

func (e *DEXExtension) runFunding(ctx context.Context) {
	// Run funding calculator
}

// =============================================================================
// AI Extension - For AIVM (Attestation/AI VM)
// =============================================================================

type AIExtension struct {
	ModelRegistry   *ModelRegistry
	InferenceEngine *InferenceEngine
	AttestationGen  *AttestationGenerator
	ProofVerifier   *ProofVerifier
	TrainingManager *TrainingManager
}

type ModelRegistry struct {
	Models map[string]*AIModel
	// TODO: mu will be used for concurrent access
	_ sync.RWMutex
}

type AIModel struct {
	ID           string
	Hash         []byte
	Provider     string
	Architecture string // transformer, cnn, rnn, etc
	Parameters   int64  // Number of parameters
	Attestation  []byte // Cryptographic attestation
	Performance  *ModelPerformance
}

type ModelPerformance struct {
	Accuracy   float64
	Latency    time.Duration
	Throughput float64
}

func (e *AIExtension) Name() string { return "ai" }

func (e *AIExtension) Initialize(builder *VMBuilder) error {
	e.ModelRegistry = &ModelRegistry{
		Models: make(map[string]*AIModel),
	}
	e.InferenceEngine = NewInferenceEngine()
	e.AttestationGen = NewAttestationGenerator()
	e.ProofVerifier = NewProofVerifier()
	e.TrainingManager = NewTrainingManager()

	// Enable GPU if available
	if builder.Features.GPU {
		e.InferenceEngine.EnableGPU()
	}

	return nil
}

func (e *AIExtension) Start(ctx context.Context) error {
	// Start AI services
	go e.runInferenceService(ctx)
	go e.runAttestationService(ctx)
	return nil
}

func (e *AIExtension) Stop() error { return nil }

func (e *AIExtension) runInferenceService(ctx context.Context) {
	// Run inference service
}

func (e *AIExtension) runAttestationService(ctx context.Context) {
	// Generate attestations for AI models
}

// =============================================================================
// FHE Extension - For FHEVM (Fully Homomorphic Encryption VM)
// =============================================================================

type FHEExtension struct {
	Scheme         FHEScheme
	KeyManager     *FHEKeyManager
	EncryptedState map[string]*EncryptedValue
	Computer       *HomomorphicComputer
}

type FHEScheme string

const (
	SchemeCKKS FHEScheme = "ckks" // For approximate arithmetic
	SchemeBFV  FHEScheme = "bfv"  // For exact arithmetic
	SchemeTFHE FHEScheme = "tfhe" // For boolean circuits
)

type EncryptedValue struct {
	Ciphertext []byte
	Level      int // Noise level
	Metadata   map[string]interface{}
}

type FHEKeyManager struct {
	PublicKey     []byte
	EvaluationKey []byte
	RelinKey      []byte
	GaloisKeys    map[int][]byte
}

type HomomorphicComputer struct {
	scheme FHEScheme
}

func (c *HomomorphicComputer) Add(a, b *EncryptedValue) *EncryptedValue {
	// Homomorphic addition
	return nil
}

func (c *HomomorphicComputer) Multiply(a, b *EncryptedValue) *EncryptedValue {
	// Homomorphic multiplication
	return nil
}

func (e *FHEExtension) Name() string { return "fhe" }

func (e *FHEExtension) Initialize(builder *VMBuilder) error {
	e.Scheme = SchemeCKKS // Default to CKKS
	e.KeyManager = NewFHEKeyManager()
	e.EncryptedState = make(map[string]*EncryptedValue)
	e.Computer = &HomomorphicComputer{scheme: e.Scheme}

	return nil
}

func (e *FHEExtension) Start(ctx context.Context) error { return nil }
func (e *FHEExtension) Stop() error                     { return nil }

// =============================================================================
// MPC Extension - For MPCVM (Multi-Party Computation VM)
// =============================================================================

type MPCExtension struct {
	Protocol     MPCProtocol
	Parties      map[string]*Party
	SecretShares map[string][]*SecretShare
	Computer     *MPCComputer
}

type MPCProtocol string

const (
	ProtocolGMW  MPCProtocol = "gmw"  // Goldreich-Micali-Wigderson
	ProtocolBGW  MPCProtocol = "bgw"  // Ben-Or-Goldwasser-Wigderson
	ProtocolSPDZ MPCProtocol = "spdz" // Fast MPC with preprocessing
	ProtocolABY  MPCProtocol = "aby"  // Mixed protocol
)

type Party struct {
	ID        string
	PublicKey *ecdsa.PublicKey
	Shares    map[string]*SecretShare
}

type SecretShare struct {
	ShareID   string
	PartyID   string
	Value     []byte
	Threshold int
}

type MPCComputer struct {
	protocol MPCProtocol
}

func (e *MPCExtension) Name() string { return "mpc" }

func (e *MPCExtension) Initialize(builder *VMBuilder) error {
	e.Protocol = ProtocolSPDZ // Default to SPDZ for efficiency
	e.Parties = make(map[string]*Party)
	e.SecretShares = make(map[string][]*SecretShare)
	e.Computer = &MPCComputer{protocol: e.Protocol}

	return nil
}

func (e *MPCExtension) Start(ctx context.Context) error { return nil }
func (e *MPCExtension) Stop() error                     { return nil }

// =============================================================================
// Quantum Extension - For QuantumVM (Post-Quantum Security)
// =============================================================================

type QuantumExtension struct {
	Lattice       *LatticeCrypto
	Corona      *CoronaConsensus
	QuantumProofs *QuantumProofSystem
}

type LatticeCrypto struct {
	Dimension         int
	Modulus           *big.Int
	StandardDeviation float64
	SecurityLevel     int // 128, 192, or 256 bits
}

type CoronaConsensus struct {
	Rounds       int // 2-round consensus
	Threshold    float64
	Certificates map[ids.ID]*QuantumCertificate
}

type QuantumCertificate struct {
	BlockID       ids.ID
	Round         int
	LatticeProof  []byte
	BLSSignature  []byte
	VerkleWitness []byte
}

type QuantumProofSystem struct {
	ProofType string // lattice, code-based, hash-based, multivariate
}

func (e *QuantumExtension) Name() string { return "quantum" }

func (e *QuantumExtension) Initialize(builder *VMBuilder) error {
	// Initialize with 256-bit post-quantum security
	e.Lattice = &LatticeCrypto{
		Dimension:         512,
		Modulus:           new(big.Int).Exp(big.NewInt(2), big.NewInt(256), nil),
		StandardDeviation: 3.2,
		SecurityLevel:     256,
	}

	e.Corona = &CoronaConsensus{
		Rounds:       2,
		Threshold:    0.67,
		Certificates: make(map[ids.ID]*QuantumCertificate),
	}

	e.QuantumProofs = &QuantumProofSystem{
		ProofType: "lattice",
	}

	// Enable quantum features
	builder.Features.QuantumResistant = true
	builder.Features.PostQuantum = true

	return nil
}

func (e *QuantumExtension) Start(ctx context.Context) error { return nil }
func (e *QuantumExtension) Stop() error                     { return nil }

// =============================================================================
// Helper Functions for SDK Extensions
// =============================================================================

// StateDB interface for state management (extends existing)
type StateDB interface {
	Get(key []byte) ([]byte, error)
	Put(key []byte, value []byte) error
	Delete(key []byte) error
	RegisterHandler(prefix string, handler StateHandler) error
}

type StateHandler func(key, value []byte) error

// Engine interface for consensus
type Engine interface {
	GetID() ids.ID
}

// ConsensusEngine interface (extends existing)
type ConsensusEngine interface {
	Engine
	SetQuantumMode(enabled bool)
	SetBLSAggregation(enabled bool)
	SetVerkleWitnesses(enabled bool)
}

// NetworkManager interface (extends existing)
type NetworkManager interface {
	Send(msg []byte, nodeID ids.NodeID) error
	Broadcast(msg []byte) error
	EnableDPDK() error
	EnableRDMA() error
}

// NewClearinghouse creates a new Clearinghouse instance.
func NewClearinghouse() *Clearinghouse { return &Clearinghouse{} }

// NewFundingEngine creates a new FundingEngine instance.
func NewFundingEngine() *FundingEngine { return &FundingEngine{} }

// NewCrossChainBridge creates a new CrossChainBridge instance.
func NewCrossChainBridge() *CrossChainBridge { return &CrossChainBridge{} }

// NewVaultManager creates a new VaultManager instance.
func NewVaultManager() *VaultManager { return &VaultManager{} }

// NewStakingManager creates a new StakingManager instance.
func NewStakingManager() *StakingManager { return &StakingManager{} }

// NewMultisigManager creates a new MultisigManager instance.
func NewMultisigManager() *MultisigManager { return &MultisigManager{} }

// NewInferenceEngine creates a new InferenceEngine instance.
func NewInferenceEngine() *InferenceEngine { return &InferenceEngine{} }

// NewAttestationGenerator creates a new AttestationGenerator instance.
func NewAttestationGenerator() *AttestationGenerator { return &AttestationGenerator{} }

// NewProofVerifier creates a new ProofVerifier instance.
func NewProofVerifier() *ProofVerifier { return &ProofVerifier{} }

// NewTrainingManager creates a new TrainingManager instance.
func NewTrainingManager() *TrainingManager { return &TrainingManager{} }

// NewFHEKeyManager creates a new FHEKeyManager instance.
func NewFHEKeyManager() *FHEKeyManager { return &FHEKeyManager{} }

// Stub types for extensions
type OrderBook struct{}
type Clearinghouse struct{}
type FundingEngine struct{}
type CrossChainBridge struct{}
type VaultManager struct{}
type StakingManager struct{}
type MultisigManager struct{}
type InferenceEngine struct{ gpuEnabled bool }

func (e *InferenceEngine) EnableGPU() { e.gpuEnabled = true }

type AttestationGenerator struct{}
type ProofVerifier struct{}
type TrainingManager struct{}

// =============================================================================
// Builder Pattern for Creating VMs
// =============================================================================

// NewVMBuilder creates a new VM builder
func NewVMBuilder(ctx *Context, db database.Database) *VMBuilder {
	return &VMBuilder{
		Context:    ctx,
		DB:         db,
		Extensions: make(map[string]VMExtension),
		Features:   &FeatureSet{},
	}
}

// WithExtension adds an extension to the VM
func (b *VMBuilder) WithExtension(ext VMExtension) *VMBuilder {
	b.mu.Lock()
	defer b.mu.Unlock()

	b.Extensions[ext.Name()] = ext
	return b
}

// WithFeatures enables features
func (b *VMBuilder) WithFeatures(features *FeatureSet) *VMBuilder {
	b.Features = features
	return b
}

// Build builds the VM with all extensions
func (b *VMBuilder) Build() error {
	// Initialize all extensions
	for _, ext := range b.Extensions {
		if err := ext.Initialize(b); err != nil {
			return fmt.Errorf("failed to initialize %s: %w", ext.Name(), err)
		}
	}

	// Configure consensus based on features
	if b.Features.QuantumResistant {
		b.Consensus.SetQuantumMode(true)
	}
	if b.Features.BLSAggregation {
		b.Consensus.SetBLSAggregation(true)
	}
	if b.Features.VerkleWitnesses {
		b.Consensus.SetVerkleWitnesses(true)
	}

	// Configure network based on features
	if b.Features.DPDK {
		_ = b.Network.EnableDPDK() //nolint:errcheck
	}
	if b.Features.RDMA {
		_ = b.Network.EnableRDMA() //nolint:errcheck
	}

	return nil
}

// Start starts the VM
func (b *VMBuilder) Start() error {
	ctx := context.Background()

	// Start all extensions
	for _, ext := range b.Extensions {
		if err := ext.Start(ctx); err != nil {
			return fmt.Errorf("failed to start %s: %w", ext.Name(), err)
		}
	}

	return nil
}

// Stop stops the VM
func (b *VMBuilder) Stop() error {
	// Stop all extensions
	for _, ext := range b.Extensions {
		if err := ext.Stop(); err != nil {
			log.Warn("failed to stop extension", "name", ext.Name(), "error", err)
		}
	}

	return nil
}