Rename folders (#97)

* Rename arkd folder & drop cli

* Rename ark cli folder & update docs

* Update readme

* Fix

* scripts: add build-all

* Add target to build cli for all platforms

* Update build scripts

---------

Co-authored-by: tiero <3596602+tiero@users.noreply.github.com>

server/internal/core/domain/payment.go

@@ -0,0 +1,129 @@
+package domain
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"hash"
+
+	"github.com/google/uuid"
+)
+
+const dustAmount = 450
+
+type Payment struct {
+	Id        string
+	Inputs    []Vtxo
+	Receivers []Receiver
+}
+
+func NewPayment(inputs []Vtxo) (*Payment, error) {
+	p := &Payment{
+		Id:     uuid.New().String(),
+		Inputs: inputs,
+	}
+	if err := p.validate(true); err != nil {
+		return nil, err
+	}
+	return p, nil
+}
+
+func (p *Payment) AddReceivers(receivers []Receiver) (err error) {
+	if p.Receivers == nil {
+		p.Receivers = make([]Receiver, 0)
+	}
+	p.Receivers = append(p.Receivers, receivers...)
+	defer func() {
+		if err != nil {
+			p.Receivers = p.Receivers[:len(p.Receivers)-len(receivers)]
+		}
+	}()
+	err = p.validate(false)
+	return
+}
+
+func (p Payment) TotalInputAmount() uint64 {
+	tot := uint64(0)
+	for _, in := range p.Inputs {
+		tot += in.Amount
+	}
+	return tot
+}
+
+func (p Payment) TotalOutputAmount() uint64 {
+	tot := uint64(0)
+	for _, r := range p.Receivers {
+		tot += r.Amount
+	}
+	return tot
+}
+
+func (p Payment) validate(ignoreOuts bool) error {
+	if len(p.Id) <= 0 {
+		return fmt.Errorf("missing id")
+	}
+	if len(p.Inputs) <= 0 {
+		return fmt.Errorf("missing inputs")
+	}
+	if ignoreOuts {
+		return nil
+	}
+	if len(p.Receivers) <= 0 {
+		return fmt.Errorf("missing outputs")
+	}
+	// Check that input and output and output amounts match.
+	inAmount := p.TotalInputAmount()
+	outAmount := uint64(0)
+	for _, r := range p.Receivers {
+		if len(r.OnchainAddress) <= 0 && len(r.Pubkey) <= 0 {
+			return fmt.Errorf("missing receiver destination")
+		}
+		if r.Amount < dustAmount {
+			return fmt.Errorf("receiver amount must be greater than dust")
+		}
+		outAmount += r.Amount
+	}
+	if inAmount != outAmount {
+		return fmt.Errorf("input and output amounts mismatch")
+	}
+	return nil
+}
+
+type VtxoKey struct {
+	Txid string
+	VOut uint32
+}
+
+func (k VtxoKey) Hash() string {
+	calcHash := func(buf []byte, hasher hash.Hash) []byte {
+		_, _ = hasher.Write(buf)
+		return hasher.Sum(nil)
+	}
+
+	hash160 := func(buf []byte) []byte {
+		return calcHash(calcHash(buf, sha256.New()), sha256.New())
+	}
+
+	buf, _ := hex.DecodeString(k.Txid)
+	buf = append(buf, byte(k.VOut))
+	return hex.EncodeToString(hash160(buf))
+}
+
+type Receiver struct {
+	Pubkey         string
+	Amount         uint64
+	OnchainAddress string
+}
+
+func (r Receiver) IsOnchain() bool {
+	return len(r.OnchainAddress) > 0
+}
+
+type Vtxo struct {
+	VtxoKey
+	Receiver
+	PoolTx   string
+	Spent    bool
+	Redeemed bool
+	Swept    bool
+}