gno.land/r/moul/x/daily/escrow/v1⧉

1package escrow23import (4	"chain"5	"chain/runtime/unsafe"6	"errors"7	"strconv"8	"strings"910	"gno.land/p/moul/kit/ui/v0"11	"gno.land/p/nt/avl/v0"12)1314// State constants for a deal's lifecycle.15const (16	StateOpen     = "Open"17	StateSettled  = "Settled"18	StateCanceled = "Canceled"19)2021// Deal is a 2-party escrow record. Accounting only: no funds move,22// this tracks agreement and mutual confirmation between two parties.23type Deal struct {24	ID           int25	Creator      address26	Counterparty address27	Terms        string28	State        string29	CreatorOK    bool30	CounterOK    bool31}3233var (34	deals  = avl.NewTree() // id (string) -> *Deal35	nextID int36)3738var (39	errNotFound   = errors.New("escrow: deal not found")40	errNotParty   = errors.New("escrow: caller is not a party to this deal")41	errNotOpen    = errors.New("escrow: deal is not open")42	errNotCreator = errors.New("escrow: only the creator can cancel")43	errBadAddr    = errors.New("escrow: invalid counterparty address")44	errSelfDeal   = errors.New("escrow: counterparty must differ from creator")45)4647// Create opens a new escrow deal between the caller (creator) and the48// given counterparty, governed by a free-form terms string. Returns the49// new deal id. Panics on invalid input (cross-realm abort).50func Create(cur realm, counterparty address, terms string) int {51	if !counterparty.IsValid() {52		panic(errBadAddr)53	}54	creator := unsafe.PreviousRealm().Address()55	if counterparty == creator {56		panic(errSelfDeal)57	}5859	id := nextID60	nextID++6162	d := &Deal{63		ID:           id,64		Creator:      creator,65		Counterparty: counterparty,66		Terms:        terms,67		State:        StateOpen,68	}69	deals.Set(strconv.Itoa(id), d)7071	chain.Emit("Created", "id", strconv.Itoa(id),72		"creator", creator.String(), "counterparty", counterparty.String())73	return id74}7576// Confirm records confirmation by whichever party is calling. Once both77// parties have confirmed, the deal transitions to Settled.78func Confirm(cur realm, id int) {79	d := mustGet(id)80	if d.State != StateOpen {81		panic(errNotOpen)82	}83	caller := unsafe.PreviousRealm().Address()8485	switch caller {86	case d.Creator:87		d.CreatorOK = true88	case d.Counterparty:89		d.CounterOK = true90	default:91		panic(errNotParty)92	}9394	chain.Emit("Confirmed", "id", strconv.Itoa(id), "party", caller.String())9596	if d.CreatorOK && d.CounterOK {97		d.State = StateSettled98		chain.Emit("Settled", "id", strconv.Itoa(id))99	}100}101102// Cancel voids an open deal. Only the creator may cancel, and only103// before the deal has settled.104func Cancel(cur realm, id int) {105	d := mustGet(id)106	if d.State != StateOpen {107		panic(errNotOpen)108	}109	caller := unsafe.PreviousRealm().Address()110	if caller != d.Creator {111		panic(errNotCreator)112	}113	d.State = StateCanceled114	chain.Emit("Canceled", "id", strconv.Itoa(id))115}116117func mustGet(id int) *Deal {118	v := deals.Get(strconv.Itoa(id))119	if v == nil {120		panic(errNotFound)121	}122	return v.(*Deal)123}124125// Render lists all escrow deals with their parties, terms, and state.126// When path is a numeric id, renders just that deal.127func Render(path string) string {128	path = strings.TrimSpace(strings.Trim(path, "/"))129	if path != "" {130		if id, err := strconv.Atoi(path); err == nil {131			v := deals.Get(strconv.Itoa(id))132			if v == nil {133				return "# Escrow\n\nDeal `" + path + "` not found.\n"134			}135			return renderOne(v.(*Deal))136		}137	}138139	var b strings.Builder140	b.WriteString("# Escrow\n\n")141	b.WriteString("2-party escrow deals (accounting only — no funds move).\n\n")142143	if deals.Size() == 0 {144		b.WriteString("_No deals yet._\n")145		return b.String()146	}147148	b.WriteString("| ID | Creator | Counterparty | State | Confirmations | Terms |\n")149	b.WriteString("|----|---------|--------------|-------|---------------|-------|\n")150	deals.Iterate("", "", func(_ string, v interface{}) bool {151		d := v.(*Deal)152		b.WriteString("| " + strconv.Itoa(d.ID) +153			" | " + ui.Addr(d.Creator) +154			" | " + ui.Addr(d.Counterparty) +155			" | " + d.State +156			" | " + confs(d) +157			" | " + ui.Cell(d.Terms) + " |\n")158		return false159	})160	return b.String()161}162163func renderOne(d *Deal) string {164	var b strings.Builder165	b.WriteString("# Escrow Deal #" + strconv.Itoa(d.ID) + "\n\n")166	b.WriteString("- **State:** " + d.State + "\n")167	b.WriteString("- **Creator:** " + d.Creator.String() + " (" + yn(d.CreatorOK) + ")\n")168	b.WriteString("- **Counterparty:** " + d.Counterparty.String() + " (" + yn(d.CounterOK) + ")\n")169	b.WriteString("- **Terms:** " + d.Terms + "\n")170	return b.String()171}172173func confs(d *Deal) string {174	n := 0175	if d.CreatorOK {176		n++177	}178	if d.CounterOK {179		n++180	}181	return strconv.Itoa(n) + "/2"182}183184func yn(b bool) string {185	if b {186		return "confirmed"187	}188	return "pending"189}190