/
assets.go
432 lines (385 loc) · 11.5 KB
/
assets.go
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package stellarnet
import (
"bytes"
"errors"
"fmt"
"net/url"
"strings"
"github.com/stellar/go/xdr"
)
// AssetBase is an interface that any of the various data
// structures can implement.
type AssetBase interface {
TypeString() string
CodeString() string
IssuerString() string
}
// AssetMinimal is a bare-bones representation of an asset.
type AssetMinimal struct {
AssetType string
AssetCode string
AssetIssuer string
}
// NewAssetMinimal makes an AssetMinimal, inferring the asset
// type from the length of the asset code.
func NewAssetMinimal(code, issuer string) (AssetMinimal, error) {
a := AssetMinimal{
AssetCode: code,
AssetIssuer: issuer,
}
if len(code) == 0 && len(issuer) == 0 {
a.AssetType = "native"
return a, nil
}
var err error
a.AssetType, err = assetCodeToType(code)
if err != nil {
return AssetMinimal{}, err
}
return a, nil
}
// TypeString implements AssetBase.
func (a AssetMinimal) TypeString() string {
return a.AssetType
}
// CodeString implements AssetBase.
func (a AssetMinimal) CodeString() string {
return a.AssetCode
}
// IssuerString implements AssetBase.
func (a AssetMinimal) IssuerString() string {
return a.AssetIssuer
}
// AssetSummary summarizes the data returned by horizon for an asset.
// UnverifiedWellKnownLink is a link supplied by the asset issuer that
// needs verification.
type AssetSummary struct {
UnverifiedWellKnownLink string
AssetType string
AssetCode string
AssetIssuer string
Amount string
NumAccounts int
}
// TypeString implements AssetBase.
func (a *AssetSummary) TypeString() string {
return a.AssetType
}
// CodeString implements AssetBase.
func (a *AssetSummary) CodeString() string {
return a.AssetCode
}
// IssuerString implements AssetBase.
func (a *AssetSummary) IssuerString() string {
return a.AssetIssuer
}
// Asset returns details about an asset that matches assetCode
// from issuerID.
func Asset(assetCode string, issuerID AddressStr) (*AssetSummary, error) {
link, err := horizonLink(Client().HorizonURL, "/assets")
if err != nil {
return nil, errMap(err)
}
u, err := url.Parse(link)
if err != nil {
return nil, errMap(err)
}
q := u.Query()
q.Set("asset_code", assetCode)
q.Set("asset_issuer", issuerID.String())
u.RawQuery = q.Encode()
var page AssetsPage
err = getDecodeJSONStrict(u.String(), Client().HTTP.Get, &page)
if err != nil {
return nil, errMap(err)
}
if len(page.Embedded.Records) == 0 {
return nil, ErrAssetNotFound
}
if len(page.Embedded.Records) > 1 {
return nil, errors.New("invalid assets response: multiple matches")
}
r := page.Embedded.Records[0]
summary := AssetSummary{
UnverifiedWellKnownLink: r.Links.WellKnown.Href,
AssetType: r.AssetType,
AssetCode: r.AssetCode,
AssetIssuer: r.AssetIssuer,
Amount: r.Amount,
NumAccounts: r.NumAccounts,
}
return &summary, nil
}
// AssetsWithCode returns all assets that use assetCode (e.g. 'USD')
// and throws an error if there are none.
func AssetsWithCode(assetCode string) ([]AssetSummary, error) {
searchArg := AssetSearchArg{
AssetCode: assetCode,
IssuerID: "",
}
res, err := AssetSearch(searchArg)
if len(res) == 0 {
return nil, ErrAssetNotFound
}
return res, err
}
// AssetSearchArg is the argument for passing to AssetSearch
type AssetSearchArg struct {
AssetCode string // this is case sensitive
IssuerID string
}
// AssetSearch returns assets from horizon that match either an
// asset code or an issuerID or both. It will not throw an error
// if there are no valid matches.
func AssetSearch(arg AssetSearchArg) (res []AssetSummary, err error) {
if arg.AssetCode == "" && arg.IssuerID == "" {
// bail on an empty search
return res, nil
}
link, err := horizonLink(Client().HorizonURL, "/assets")
if err != nil {
return nil, errMap(err)
}
u, err := url.Parse(link)
if err != nil {
return nil, errMap(err)
}
q := u.Query()
if len(arg.AssetCode) > 0 {
q.Set("asset_code", arg.AssetCode)
}
if len(arg.IssuerID) > 0 {
q.Set("asset_issuer", arg.IssuerID)
}
u.RawQuery = q.Encode()
var page AssetsPage
err = getDecodeJSONStrict(u.String(), Client().HTTP.Get, &page)
if err != nil {
return nil, errMap(err)
}
summaries := make([]AssetSummary, len(page.Embedded.Records))
for i, r := range page.Embedded.Records {
summaries[i] = AssetSummary{
UnverifiedWellKnownLink: r.Links.WellKnown.Href,
AssetType: r.AssetType,
AssetCode: r.AssetCode,
AssetIssuer: r.AssetIssuer,
Amount: r.Amount,
NumAccounts: r.NumAccounts,
}
}
return summaries, nil
}
// AssetList returns a list of assets from horizon (max 200 at a time). Order should be asc or desc. Continue
// calling this with the same order and the previous cursor to fetch all of them.
func AssetList(cursor string, limit int, order string) (res []AssetSummary, nextCursor string, err error) {
if limit < 1 || limit > 200 {
limit = 200
}
link, err := horizonLink(Client().HorizonURL, "/assets")
if err != nil {
return nil, "", errMap(err)
}
u, err := url.Parse(link)
if err != nil {
return nil, "", errMap(err)
}
q := u.Query()
q.Set("limit", fmt.Sprintf("%d", limit))
q.Set("order", order)
q.Set("cursor", cursor)
u.RawQuery = q.Encode()
var page AssetsPage
err = getDecodeJSONStrict(u.String(), Client().HTTP.Get, &page)
if err != nil {
return nil, "", errMap(err)
}
parsedNextLink, err := url.Parse(page.Links.Next.Href)
if err != nil {
return nil, "", errMap(err)
}
queryParams, err := url.ParseQuery(parsedNextLink.RawQuery)
if err != nil {
return nil, "", errMap(err)
}
cursorParam, ok := queryParams["cursor"]
if !ok {
err = errors.New("no next cursor in asset list")
return nil, "", errMap(err)
}
nextCursor = cursorParam[0]
assets := make([]AssetSummary, len(page.Embedded.Records))
for i, r := range page.Embedded.Records {
assets[i] = AssetSummary{
UnverifiedWellKnownLink: r.Links.WellKnown.Href,
AssetType: r.AssetType,
AssetCode: r.AssetCode,
AssetIssuer: r.AssetIssuer,
Amount: r.Amount,
NumAccounts: r.NumAccounts,
}
}
return assets, nextCursor, nil
}
func makeXDRChangeTrustAsset(assetCode string, issuerID AddressStr) (xdr.ChangeTrustAsset, error) {
if len(assetCode) == 0 && len(issuerID) == 0 {
return xdr.NewChangeTrustAsset(xdr.AssetTypeAssetTypeNative, nil)
}
issuer, err := issuerID.AccountID()
if err != nil {
return xdr.ChangeTrustAsset{}, err
}
x := len(assetCode)
switch {
case x >= 1 && x <= 4:
asset := xdr.AlphaNum4{Issuer: issuer}
copy(asset.AssetCode[:], []byte(assetCode[0:x]))
return xdr.NewChangeTrustAsset(xdr.AssetTypeAssetTypeCreditAlphanum4, asset)
case x >= 5 && x <= 1:
asset := xdr.AlphaNum12{Issuer: issuer}
copy(asset.AssetCode[:], []byte(assetCode[0:x]))
return xdr.NewChangeTrustAsset(xdr.AssetTypeAssetTypeCreditAlphanum12, asset)
default:
return xdr.ChangeTrustAsset{}, errors.New("invalid assetCode length")
}
}
func makeXDRAsset(assetCode string, issuerID AddressStr) (xdr.Asset, error) {
if len(assetCode) == 0 && len(issuerID) == 0 {
return xdr.NewAsset(xdr.AssetTypeAssetTypeNative, nil)
}
issuer, err := issuerID.AccountID()
if err != nil {
return xdr.Asset{}, err
}
x := len(assetCode)
switch {
case x >= 1 && x <= 4:
asset := xdr.AlphaNum4{Issuer: issuer}
copy(asset.AssetCode[:], []byte(assetCode[0:x]))
return xdr.NewAsset(xdr.AssetTypeAssetTypeCreditAlphanum4, asset)
case x >= 5 && x <= 12:
asset := xdr.AlphaNum12{Issuer: issuer}
copy(asset.AssetCode[:], []byte(assetCode[0:x]))
return xdr.NewAsset(xdr.AssetTypeAssetTypeCreditAlphanum12, asset)
default:
return xdr.Asset{}, errors.New("invalid assetCode length")
}
}
func assetCodeToType(code string) (string, error) {
x := len(code)
switch {
case x == 0:
return "native", nil
case x >= 1 && x <= 4:
return "credit_alphanum4", nil
case x >= 5 && x <= 12:
return "credit_alphanum12", nil
default:
return "", errors.New("invalid assetCode length")
}
}
func assetBaseIssuer(a AssetBase) (AddressStr, error) {
return NewAddressStr(a.IssuerString())
}
func assetBaseToXDR(a AssetBase) (xdr.Asset, error) {
if len(a.CodeString()) == 0 && len(a.IssuerString()) == 0 {
return xdr.NewAsset(xdr.AssetTypeAssetTypeNative, nil)
}
issuerAddress, err := assetBaseIssuer(a)
if err != nil {
return xdr.Asset{}, err
}
issuerID, err := issuerAddress.AccountID()
if err != nil {
return xdr.Asset{}, err
}
x := len(a.CodeString())
switch {
case x >= 1 && x <= 4:
asset := xdr.AlphaNum4{Issuer: issuerID}
copy(asset.AssetCode[:], []byte(a.CodeString()[0:x]))
return xdr.NewAsset(xdr.AssetTypeAssetTypeCreditAlphanum4, asset)
case x >= 5 && x <= 12:
asset := xdr.AlphaNum12{Issuer: issuerID}
copy(asset.AssetCode[:], []byte(a.CodeString()[0:x]))
return xdr.NewAsset(xdr.AssetTypeAssetTypeCreditAlphanum12, asset)
default:
return xdr.Asset{}, errors.New("invalid asset code length")
}
}
// XDRToAssetMinimal transforms xdr.Asset to AssetMinimal.
func XDRToAssetMinimal(x xdr.Asset) (AssetMinimal, error) {
switch x.Type {
case xdr.AssetTypeAssetTypeNative:
return AssetMinimal{}, nil
case xdr.AssetTypeAssetTypeCreditAlphanum4:
a := x.MustAlphaNum4()
n := bytes.IndexByte(a.AssetCode[:], 0)
if n == -1 {
n = 4
}
return AssetMinimal{AssetCode: string(a.AssetCode[:n]), AssetIssuer: a.Issuer.Address()}, nil
case xdr.AssetTypeAssetTypeCreditAlphanum12:
a := x.MustAlphaNum12()
n := bytes.IndexByte(a.AssetCode[:], 0)
if n == -1 {
n = 12
}
return AssetMinimal{AssetCode: string(a.AssetCode[:n]), AssetIssuer: a.Issuer.Address()}, nil
default:
return AssetMinimal{}, errors.New("invalid xdr asset type")
}
}
// ChangeTrustXDRToAssetMinimal transforms xdr.ChangeTrustAsset to AssetMinimal.
func ChangeTrustXDRToAssetMinimal(x xdr.ChangeTrustAsset) (AssetMinimal, error) {
switch x.Type {
case xdr.AssetTypeAssetTypeNative:
return AssetMinimal{}, nil
case xdr.AssetTypeAssetTypeCreditAlphanum4:
a := x.MustAlphaNum4()
n := bytes.IndexByte(a.AssetCode[:], 0)
if n == -1 {
n = 4
}
return AssetMinimal{AssetCode: string(a.AssetCode[:n]), AssetIssuer: a.Issuer.Address()}, nil
case xdr.AssetTypeAssetTypeCreditAlphanum12:
a := x.MustAlphaNum12()
n := bytes.IndexByte(a.AssetCode[:], 0)
if n == -1 {
n = 12
}
return AssetMinimal{AssetCode: string(a.AssetCode[:n]), AssetIssuer: a.Issuer.Address()}, nil
default:
return AssetMinimal{}, errors.New("invalid xdr asset type")
}
}
// AssetBaseSummary returns a string summary of an asset.
func AssetBaseSummary(a AssetBase) string {
if a.TypeString() == "native" {
return "XLM"
}
if a.CodeString() == "" && a.IssuerString() == "" {
return "XLM"
}
return strings.TrimSpace(a.CodeString()) + "/" + strings.TrimSpace(a.IssuerString())
}
// XDRAssetSummary returns a string summary of an xdr.Asset.
func XDRAssetSummary(x xdr.Asset) string {
a, err := XDRToAssetMinimal(x)
if err != nil {
return "invalid asset"
}
return AssetBaseSummary(a)
}
// XDRAssetAmountSummary returns a summary of an amount and an asset.
func XDRAssetAmountSummary(amt xdr.Int64, asset xdr.Asset) string {
return StringFromStellarXdrAmount(amt) + " " + XDRAssetSummary(asset)
}
// XDRChangeTrustAssetSummary returns a string summary of an xdr.ChangeTrustAsset.
func XDRChangeTrustAssetSummary(x xdr.ChangeTrustAsset) string {
a, err := ChangeTrustXDRToAssetMinimal(x)
if err != nil {
return "invalid asset"
}
return AssetBaseSummary(a)
}