gno.land/r/moul/x/daily/escrow/v0⧉

1package escrow23import (4	"chain"5	"chain/runtime/unsafe"6	"errors"7	"strconv"8	"strings"910	"gno.land/p/nt/avl/v0"11)1213// State constants for a deal's lifecycle.14const (15	StateOpen     = "Open"16	StateSettled  = "Settled"17	StateCanceled = "Canceled"18)1920// Deal is a 2-party escrow record. Accounting only: no funds move,21// this tracks agreement and mutual confirmation between two parties.22type Deal struct {23	ID           int24	Creator      address25	Counterparty address26	Terms        string27	State        string28	CreatorOK    bool29	CounterOK    bool30}3132var (33	deals  = avl.NewTree() // id (string) -> *Deal34	nextID int35)3637var (38	errNotFound   = errors.New("escrow: deal not found")39	errNotParty   = errors.New("escrow: caller is not a party to this deal")40	errNotOpen    = errors.New("escrow: deal is not open")41	errNotCreator = errors.New("escrow: only the creator can cancel")42	errBadAddr    = errors.New("escrow: invalid counterparty address")43	errSelfDeal   = errors.New("escrow: counterparty must differ from creator")44)4546// Create opens a new escrow deal between the caller (creator) and the47// given counterparty, governed by a free-form terms string. Returns the48// new deal id. Panics on invalid input (cross-realm abort).49func Create(cur realm, counterparty address, terms string) int {50	if !counterparty.IsValid() {51		panic(errBadAddr)52	}53	creator := unsafe.PreviousRealm().Address()54	if counterparty == creator {55		panic(errSelfDeal)56	}5758	id := nextID59	nextID++6061	d := &Deal{62		ID:           id,63		Creator:      creator,64		Counterparty: counterparty,65		Terms:        terms,66		State:        StateOpen,67	}68	deals.Set(strconv.Itoa(id), d)6970	chain.Emit("Created", "id", strconv.Itoa(id),71		"creator", creator.String(), "counterparty", counterparty.String())72	return id73}7475// Confirm records confirmation by whichever party is calling. Once both76// parties have confirmed, the deal transitions to Settled.77func Confirm(cur realm, id int) {78	d := mustGet(id)79	if d.State != StateOpen {80		panic(errNotOpen)81	}82	caller := unsafe.PreviousRealm().Address()8384	switch caller {85	case d.Creator:86		d.CreatorOK = true87	case d.Counterparty:88		d.CounterOK = true89	default:90		panic(errNotParty)91	}9293	chain.Emit("Confirmed", "id", strconv.Itoa(id), "party", caller.String())9495	if d.CreatorOK && d.CounterOK {96		d.State = StateSettled97		chain.Emit("Settled", "id", strconv.Itoa(id))98	}99}100101// Cancel voids an open deal. Only the creator may cancel, and only102// before the deal has settled.103func Cancel(cur realm, id int) {104	d := mustGet(id)105	if d.State != StateOpen {106		panic(errNotOpen)107	}108	caller := unsafe.PreviousRealm().Address()109	if caller != d.Creator {110		panic(errNotCreator)111	}112	d.State = StateCanceled113	chain.Emit("Canceled", "id", strconv.Itoa(id))114}115116func mustGet(id int) *Deal {117	v := deals.Get(strconv.Itoa(id))118	if v == nil {119		panic(errNotFound)120	}121	return v.(*Deal)122}123124// Render lists all escrow deals with their parties, terms, and state.125// When path is a numeric id, renders just that deal.126func Render(path string) string {127	path = strings.TrimSpace(strings.Trim(path, "/"))128	if path != "" {129		if id, err := strconv.Atoi(path); err == nil {130			v := deals.Get(strconv.Itoa(id))131			if v == nil {132				return "# Escrow\n\nDeal `" + path + "` not found.\n"133			}134			return renderOne(v.(*Deal))135		}136	}137138	var b strings.Builder139	b.WriteString("# Escrow\n\n")140	b.WriteString("2-party escrow deals (accounting only — no funds move).\n\n")141142	if deals.Size() == 0 {143		b.WriteString("_No deals yet._\n")144		return b.String()145	}146147	b.WriteString("| ID | Creator | Counterparty | State | Confirmations | Terms |\n")148	b.WriteString("|----|---------|--------------|-------|---------------|-------|\n")149	deals.Iterate("", "", func(_ string, v interface{}) bool {150		d := v.(*Deal)151		b.WriteString("| " + strconv.Itoa(d.ID) +152			" | " + short(d.Creator) +153			" | " + short(d.Counterparty) +154			" | " + d.State +155			" | " + confs(d) +156			" | " + escapePipe(d.Terms) + " |\n")157		return false158	})159	return b.String()160}161162func renderOne(d *Deal) string {163	var b strings.Builder164	b.WriteString("# Escrow Deal #" + strconv.Itoa(d.ID) + "\n\n")165	b.WriteString("- **State:** " + d.State + "\n")166	b.WriteString("- **Creator:** " + d.Creator.String() + " (" + yn(d.CreatorOK) + ")\n")167	b.WriteString("- **Counterparty:** " + d.Counterparty.String() + " (" + yn(d.CounterOK) + ")\n")168	b.WriteString("- **Terms:** " + d.Terms + "\n")169	return b.String()170}171172func confs(d *Deal) string {173	n := 0174	if d.CreatorOK {175		n++176	}177	if d.CounterOK {178		n++179	}180	return strconv.Itoa(n) + "/2"181}182183func yn(b bool) string {184	if b {185		return "confirmed"186	}187	return "pending"188}189190func short(a address) string {191	s := a.String()192	if len(s) <= 12 {193		return s194	}195	return s[:8] + "…" + s[len(s)-4:]196}197198func escapePipe(s string) string {199	return strings.ReplaceAll(s, "|", "\\|")200}201