[Client] Add vtxo expiration details to balance & Fix coin selection

* add expiry details in balance command

* coin selection: sort vtxos by olderFirst

* rename type

* balance: add next expiration

* add next expiration in offchain_balance json

* print duration in nextExpiration

* fix dust coin selection

* refactor sort

client/unilateral_redeem.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"time"
 
 	"github.com/ark-network/ark/common/tree"
 	"github.com/btcsuite/btcd/btcec/v2/schnorr"
@@ -12,12 +13,12 @@ import (
 )
 
 type RedeemBranch interface {
-	// UpdatePath checks for transactions of the branch onchain and updates the branch accordingly
-	UpdatePath() error
-	// Redeem will sign the branch of the tree and return the associated signed pset + the vtxo input
+	// RedeemPath returns the list of transactions to broadcast in order to access the vtxo output
 	RedeemPath() ([]string, error)
 	// AddInput adds the vtxo input created by the branch
 	AddVtxoInput(updater *psetv2.Updater) error
+	// ExpireAt returns the expiration time of the branch
+	ExpireAt() (*time.Time, error)
 }
 
 type redeemBranch struct {
@@ -25,10 +26,22 @@ type redeemBranch struct {
 	branch       []*psetv2.Pset
 	internalKey  *secp256k1.PublicKey
 	sweepClosure *taproot.TapElementsLeaf
+	lifetime     time.Duration
+	explorer     Explorer
 }
 
-func newRedeemBranch(ctx *cli.Context, congestionTree tree.CongestionTree, vtxo vtxo) (RedeemBranch, error) {
-	sweepClosure, _, err := findSweepClosure(congestionTree)
+func newRedeemBranch(
+	ctx *cli.Context,
+	explorer Explorer,
+	congestionTree tree.CongestionTree,
+	vtxo vtxo,
+) (RedeemBranch, error) {
+	sweepClosure, seconds, err := findSweepClosure(congestionTree)
+	if err != nil {
+		return nil, err
+	}
+
+	lifetime, err := time.ParseDuration(fmt.Sprintf("%ds", seconds))
 	if err != nil {
 		return nil, err
 	}
@@ -58,43 +71,21 @@ func newRedeemBranch(ctx *cli.Context, congestionTree tree.CongestionTree, vtxo
 		branch:       branch,
 		internalKey:  internalKey,
 		sweepClosure: sweepClosure,
+		lifetime:     lifetime,
+		explorer:     explorer,
 	}, nil
 }
 
-// UpdatePath checks for transactions of the branch onchain and updates the branch accordingly
-func (r *redeemBranch) UpdatePath() error {
-	for i := len(r.branch) - 1; i >= 0; i-- {
-		pset := r.branch[i]
-		unsignedTx, err := pset.UnsignedTx()
-		if err != nil {
-			return err
-		}
-
-		txHash := unsignedTx.TxHash().String()
-
-		_, err = getTxHex(txHash)
-		if err != nil {
-			continue
-		}
-
-		// if no error, the tx exists onchain, so we can remove it (+ the parents) from the branch
-		if i == len(r.branch)-1 {
-			r.branch = []*psetv2.Pset{}
-		} else {
-			r.branch = r.branch[i+1:]
-		}
-
-		break
-	}
-
-	return nil
-}
-
 // RedeemPath returns the list of transactions to broadcast in order to access the vtxo output
 func (r *redeemBranch) RedeemPath() ([]string, error) {
 	transactions := make([]string, 0, len(r.branch))
 
-	for _, pset := range r.branch {
+	offchainPath, err := r.offchainPath()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, pset := range offchainPath {
 		for i, input := range pset.Inputs {
 			if len(input.TapLeafScript) == 0 {
 				return nil, fmt.Errorf("tap leaf script not found on input #%d", i)
@@ -183,3 +174,68 @@ func (r *redeemBranch) AddVtxoInput(updater *psetv2.Updater) error {
 
 	return nil
 }
+
+func (r *redeemBranch) ExpireAt() (*time.Time, error) {
+	lastKnownBlocktime := int64(0)
+
+	confirmed, blocktime, _ := getTxBlocktime(r.vtxo.poolTxid)
+
+	if confirmed {
+		lastKnownBlocktime = blocktime
+	} else {
+		expirationFromNow := time.Now().Add(time.Minute).Add(r.lifetime)
+		return &expirationFromNow, nil
+	}
+
+	for _, pset := range r.branch {
+		utx, _ := pset.UnsignedTx()
+		txid := utx.TxHash().String()
+
+		confirmed, blocktime, err := getTxBlocktime(txid)
+		if err != nil {
+			break
+		}
+
+		if confirmed {
+			lastKnownBlocktime = blocktime
+			continue
+		}
+
+		break
+	}
+
+	t := time.Unix(lastKnownBlocktime, 0).Add(r.lifetime)
+	return &t, nil
+}
+
+// offchainPath checks for transactions of the branch onchain and returns only the offchain part
+func (r *redeemBranch) offchainPath() ([]*psetv2.Pset, error) {
+	offchainPath := append([]*psetv2.Pset{}, r.branch...)
+
+	for i := len(r.branch) - 1; i >= 0; i-- {
+		pset := r.branch[i]
+		unsignedTx, err := pset.UnsignedTx()
+		if err != nil {
+			fmt.Println("error", err)
+			return nil, err
+		}
+
+		txHash := unsignedTx.TxHash().String()
+
+		_, err = r.explorer.GetTxHex(txHash)
+		if err != nil {
+			continue
+		}
+
+		// if no error, the tx exists onchain, so we can remove it (+ the parents) from the branch
+		if i == len(r.branch)-1 {
+			offchainPath = []*psetv2.Pset{}
+		} else {
+			offchainPath = r.branch[i+1:]
+		}
+
+		break
+	}
+
+	return offchainPath, nil
+}