// Copyright (C) 2019-2025, Lux Industries Inc. All rights reserved.
// See the file LICENSE for licensing terms.

// Package runtime provides chain wiring and runtime dependencies for VMs.
// This package is part of the consensus module and provides the Runtime struct
// that VMs use for chain configuration, logging, validators, etc.
//
// Use stdlib context.Context for cancellation/deadlines.
// Use *Runtime for chain wiring (IDs, logging, validators, etc.)
package runtime

import (
	"context"
	"sync"
	"time"

	validators "github.com/luxfi/consensus/validator"
	"github.com/luxfi/database"
	"github.com/luxfi/ids"
	"github.com/luxfi/metric"
	"github.com/luxfi/warp"
)

// Element represents an atomic operation element.
// This mirrors vm/chains/atomic.Element to avoid import cycles.
type Element struct {
	Key    []byte   `serialize:"true"`
	Value  []byte   `serialize:"true"`
	Traits [][]byte `serialize:"true"`
}

// Requests represents atomic operation requests.
// This mirrors vm/chains/atomic.Requests to avoid import cycles.
type Requests struct {
	RemoveRequests [][]byte   `serialize:"true"`
	PutRequests    []*Element `serialize:"true"`
}

// ValidatorState is an alias to validators.State for convenience
type ValidatorState = validators.State

// Runtime provides chain wiring and runtime dependencies for VMs.
// This is separate from stdlib context.Context which handles cancellation/deadlines.
//
// Use context.Context for:
//   - Cancellation signals
//   - Request deadlines
//   - Request-scoped values (sparingly)
//
// Use *Runtime for:
//   - Chain IDs, network IDs
//   - Node identity (NodeID, PublicKey)
//   - Logging, metrics
//   - Database handles
//   - Validator state
//   - Upgrade configurations
type Runtime struct {
	// NetworkID is the numeric network identifier (1=mainnet, 2=testnet)
	NetworkID uint32 `json:"networkID"`

	// ChainID identifies the specific chain within the network
	ChainID ids.ID `json:"chainID"`

	// NodeID identifies this node
	NodeID ids.NodeID `json:"nodeID"`

	// PublicKey is the node's BLS public key bytes
	PublicKey []byte `json:"publicKey"`

	// XChainID is the X-Chain identifier
	XChainID ids.ID `json:"xChainID"`

	// CChainID is the C-Chain identifier
	CChainID ids.ID `json:"cChainID"`

	// UTXOAssetID is the primary asset ID (X-chain native, typically LUX)
	UTXOAssetID ids.ID `json:"utxoAssetID"`

	// ChainDataDir is the directory for chain-specific data
	ChainDataDir string `json:"chainDataDir"`

	// StartTime is when the node started
	StartTime time.Time `json:"startTime"`

	// ValidatorState provides validator information (uses consensus/validators.State)
	ValidatorState validators.State

	// Keystore provides key management
	Keystore Keystore

	// Metrics provides metrics tracking
	Metrics Metrics

	// Log provides logging
	Log Logger

	// SharedMemory provides cross-chain atomic operations
	SharedMemory SharedMemory

	// BCLookup provides blockchain alias lookup
	BCLookup BCLookup

	// WarpSigner provides BLS signing for Warp messages
	WarpSigner WarpSigner

	// Lock for thread-safe access to runtime fields
	Lock sync.RWMutex
}

// BCLookup provides blockchain alias lookup
type BCLookup interface {
	Lookup(alias string) (ids.ID, error)
	PrimaryAlias(id ids.ID) (string, error)
	Aliases(id ids.ID) ([]string, error)
}

// Keystore provides key management
type Keystore interface {
	GetDatabase(username, password string) (interface{}, error)
	NewAccount(username, password string) error
}

// Logger provides logging functionality
type Logger interface {
	Debug(msg string, fields ...interface{})
	Info(msg string, fields ...interface{})
	Warn(msg string, fields ...interface{})
	Error(msg string, fields ...interface{})
	Fatal(msg string, fields ...interface{})
}

// Metrics provides metrics tracking.
// Matches api/metrics.MultiGatherer interface.
type Metrics interface {
	metric.Gatherer
	Register(name string, gatherer metric.Gatherer) error
}

// SharedMemory is the canonical interface for cross-chain atomic operations.
// This interface mirrors vm/chains/atomic.SharedMemory to avoid import cycles.
type SharedMemory interface {
	// Get fetches values corresponding to keys that have been sent from peerChainID
	Get(peerChainID ids.ID, keys [][]byte) (values [][]byte, err error)

	// Indexed returns a paginated result of values with given traits from peerChainID
	Indexed(
		peerChainID ids.ID,
		traits [][]byte,
		startTrait,
		startKey []byte,
		limit int,
	) (values [][]byte, lastTrait, lastKey []byte, err error)

	// Apply atomically applies requests to chainID keys in the map with batches
	Apply(requests map[ids.ID]*Requests, batches ...database.Batch) error
}

// WarpSigner provides BLS signing for Warp messages.
// Matches warp.Signer interface exactly.
type WarpSigner = warp.Signer

// VMContext is an interface that VM contexts must implement
// This allows different context types (node, plugin, etc.) to be used interchangeably
type VMContext interface {
	GetNetworkID() uint32
	GetChainID() ids.ID
	GetNodeID() ids.NodeID
	GetPublicKey() []byte
	GetXChainID() ids.ID
	GetCChainID() ids.ID
	GetAssetID() ids.ID
	GetChainDataDir() string
	GetLog() interface{}
	GetSharedMemory() interface{}
	GetMetrics() interface{}
	GetValidatorState() interface{}
	GetBCLookup() interface{}
	GetWarpSigner() interface{}
}

// runtimeKeyType is the context key type for storing Runtime
type runtimeKeyType struct{}

var runtimeKey = runtimeKeyType{}

// WithRuntime adds Runtime to a context.Context
func WithRuntime(ctx context.Context, rt *Runtime) context.Context {
	return context.WithValue(ctx, runtimeKey, rt)
}

// FromContext extracts Runtime from a context.Context
func FromContext(ctx context.Context) *Runtime {
	if rt, ok := ctx.Value(runtimeKey).(*Runtime); ok {
		return rt
	}
	return nil
}

// GetChainID gets the chain ID from context
func GetChainID(ctx context.Context) ids.ID {
	if rt := FromContext(ctx); rt != nil {
		return rt.ChainID
	}
	return ids.Empty
}

// GetNetworkID gets the numeric network ID from context
func GetNetworkID(ctx context.Context) uint32 {
	if rt := FromContext(ctx); rt != nil {
		return rt.NetworkID
	}
	return 0
}

// GetNodeID gets the node ID from context
func GetNodeID(ctx context.Context) ids.NodeID {
	if rt := FromContext(ctx); rt != nil {
		return rt.NodeID
	}
	return ids.EmptyNodeID
}

// IsPrimaryNetwork checks if the network is the primary network
func IsPrimaryNetwork(ctx context.Context) bool {
	if rt := FromContext(ctx); rt != nil {
		return rt.NetworkID == 1
	}
	return false
}

// GetValidatorState gets the validator state from context
func GetValidatorState(ctx context.Context) validators.State {
	if rt := FromContext(ctx); rt != nil {
		return rt.ValidatorState
	}
	return nil
}

// GetWarpSigner gets the warp signer from context
func GetWarpSigner(ctx context.Context) WarpSigner {
	if rt := FromContext(ctx); rt != nil {
		return rt.WarpSigner
	}
	return nil
}

// IDs holds the IDs for runtime context
type IDs struct {
	NetworkID    uint32
	ChainID      ids.ID
	NodeID       ids.NodeID
	PublicKey    []byte
	UTXOAssetID  ids.ID
	ChainDataDir string `json:"chainDataDir"`
}

// WithIDs adds IDs to the context via Runtime
func WithIDs(ctx context.Context, id IDs) context.Context {
	rt := FromContext(ctx)
	if rt == nil {
		rt = &Runtime{}
	}
	rt.NetworkID = id.NetworkID
	rt.ChainID = id.ChainID
	rt.NodeID = id.NodeID
	rt.PublicKey = id.PublicKey
	rt.UTXOAssetID = id.UTXOAssetID
	rt.ChainDataDir = id.ChainDataDir
	return WithRuntime(ctx, rt)
}

// WithValidatorState adds validator state to the context
func WithValidatorState(ctx context.Context, vs validators.State) context.Context {
	rt := FromContext(ctx)
	if rt == nil {
		rt = &Runtime{}
	}
	rt.ValidatorState = vs
	return WithRuntime(ctx, rt)
}

// GetTimestamp returns the current timestamp
func GetTimestamp() int64 {
	return time.Now().Unix()
}

// AsBCLookup returns the BCLookup interface for blockchain alias lookup.
// This method is used by VMs (particularly coreth) to resolve chain aliases.
func (r *Runtime) AsBCLookup() BCLookup {
	if r == nil {
		return nil
	}
	return r.BCLookup
}

// GetValidatorOutput is re-exported from validator package for convenience
type GetValidatorOutput = validators.GetValidatorOutput