package tradeoffer
import (
"encoding/json"
"fmt"
"github.com/Philipp15b/go-steam/community"
"github.com/Philipp15b/go-steam/economy/inventory"
"github.com/Philipp15b/go-steam/netutil"
"github.com/Philipp15b/go-steam/steamid"
"io/ioutil"
"net/http"
"strconv"
"time"
)
type APIKey string
const apiUrl = "https://api.steampowered.com/IEconService/%s/v%d"
type Client struct {
client *http.Client
key APIKey
sessionId string
}
func NewClient(key APIKey, sessionId, steamLogin, steamLoginSecure string) *Client {
c := &Client{
new(http.Client),
key,
sessionId,
}
community.SetCookies(c.client, sessionId, steamLogin, steamLoginSecure)
return c
}
func (c *Client) GetOffer(offerId uint64) (*TradeOfferResult, error) {
resp, err := c.client.Get(fmt.Sprintf(apiUrl, "GetTradeOffer", 1) + "?" + netutil.ToUrlValues(map[string]string{
"key": string(c.key),
"tradeofferid": strconv.FormatUint(offerId, 10),
"language": "en_us",
}).Encode())
if err != nil {
return nil, err
}
defer resp.Body.Close()
t := new(struct {
Response *TradeOfferResult
})
if err = json.NewDecoder(resp.Body).Decode(t); err != nil {
return nil, err
}
if t.Response == nil || t.Response.Offer == nil {
return nil, newSteamErrorf("steam returned empty offer result\n")
}
return t.Response, nil
}
func (c *Client) GetOffers(getSent bool, getReceived bool, getDescriptions bool, activeOnly bool, historicalOnly bool, timeHistoricalCutoff *uint32) (*TradeOffersResult, error) {
if !getSent && !getReceived {
return nil, fmt.Errorf("getSent and getReceived can't be both false\n")
}
params := map[string]string{
"key": string(c.key),
}
if getSent {
params["get_sent_offers"] = "1"
}
if getReceived {
params["get_received_offers"] = "1"
}
if getDescriptions {
params["get_descriptions"] = "1"
params["language"] = "en_us"
}
if activeOnly {
params["active_only"] = "1"
}
if historicalOnly {
params["historical_only"] = "1"
}
if timeHistoricalCutoff != nil {
params["time_historical_cutoff"] = strconv.FormatUint(uint64(*timeHistoricalCutoff), 10)
}
resp, err := c.client.Get(fmt.Sprintf(apiUrl, "GetTradeOffers", 1) + "?" + netutil.ToUrlValues(params).Encode())
if err != nil {
return nil, err
}
defer resp.Body.Close()
t := new(struct {
Response *TradeOffersResult
})
if err = json.NewDecoder(resp.Body).Decode(t); err != nil {
return nil, err
}
if t.Response == nil {
return nil, newSteamErrorf("steam returned empty offers result\n")
}
return t.Response, nil
}
// action() is used by Decline() and Cancel()
// Steam only return success and error fields for malformed requests,
// hence client shall use GetOffer() to check action result
// It is also possible to implement Decline/Cancel using steamcommunity,
// which have more predictable responses
func (c *Client) action(method string, version uint, offerId uint64) error {
resp, err := c.client.Do(netutil.NewPostForm(fmt.Sprintf(apiUrl, method, version), netutil.ToUrlValues(map[string]string{
"key": string(c.key),
"tradeofferid": strconv.FormatUint(offerId, 10),
})))
if err != nil {
return err
}
defer resp.Body.Close()
if resp.StatusCode != 200 {
return fmt.Errorf(method+" error: status code %d", resp.StatusCode)
}
return nil
}
func (c *Client) Decline(offerId uint64) error {
return c.action("DeclineTradeOffer", 1, offerId)
}
func (c *Client) Cancel(offerId uint64) error {
return c.action("CancelTradeOffer", 1, offerId)
}
// Accept received trade offer
// It is best to confirm that offer was actually accepted
// by calling GetOffer after Accept and checking offer state
func (c *Client) Accept(offerId uint64) error {
baseurl := fmt.Sprintf("https://steamcommunity.com/tradeoffer/%d/", offerId)
req := netutil.NewPostForm(baseurl+"accept", netutil.ToUrlValues(map[string]string{
"sessionid": c.sessionId,
"serverid": "1",
"tradeofferid": strconv.FormatUint(offerId, 10),
}))
req.Header.Add("Referer", baseurl)
resp, err := c.client.Do(req)
if err != nil {
return err
}
defer resp.Body.Close()
t := new(struct {
StrError string `json:"strError"`
})
if err = json.NewDecoder(resp.Body).Decode(t); err != nil {
return err
}
if t.StrError != "" {
return newSteamErrorf("accept error: %v\n", t.StrError)
}
if resp.StatusCode != 200 {
return fmt.Errorf("accept error: status code %d", resp.StatusCode)
}
return nil
}
type TradeItem struct {
AppId uint32 `json:"appid"`
ContextId uint64 `json:"contextid,string"`
Amount uint64 `json:"amount"`
AssetId uint64 `json:"assetid,string,omitempty"`
CurrencyId uint64 `json:"currencyid,string,omitempty"`
}
// Sends a new trade offer to the given Steam user. You can optionally specify an access token if you've got one.
// In addition, `counteredOfferId` can be non-nil, indicating the trade offer this is a counter for.
// On success returns trade offer id
func (c *Client) Create(other steamid.SteamId, accessToken *string, myItems, theirItems []TradeItem, counteredOfferId *uint64, message string) (uint64, error) {
// Create new trade offer status
to := map[string]interface{}{
"newversion": true,
"version": 3,
"me": map[string]interface{}{
"assets": myItems,
"currency": make([]struct{}, 0),
"ready": false,
},
"them": map[string]interface{}{
"assets": theirItems,
"currency": make([]struct{}, 0),
"ready": false,
},
}
jto, err := json.Marshal(to)
if err != nil {
panic(err)
}
// Create url parameters for request
data := map[string]string{
"sessionid": c.sessionId,
"serverid": "1",
"partner": other.ToString(),
"tradeoffermessage": message,
"json_tradeoffer": string(jto),
}
var referer string
if counteredOfferId != nil {
referer = fmt.Sprintf("https://steamcommunity.com/tradeoffer/%d/", *counteredOfferId)
data["tradeofferid_countered"] = strconv.FormatUint(*counteredOfferId, 10)
} else {
// Add token for non-friend offers
if accessToken != nil {
params := map[string]string{
"trade_offer_access_token": *accessToken,
}
paramsJson, err := json.Marshal(params)
if err != nil {
panic(err)
}
data["trade_offer_create_params"] = string(paramsJson)
referer = "https://steamcommunity.com/tradeoffer/new/?partner=" + strconv.FormatUint(uint64(other.GetAccountId()), 10) + "&token=" + *accessToken
} else {
referer = "https://steamcommunity.com/tradeoffer/new/?partner=" + strconv.FormatUint(uint64(other.GetAccountId()), 10)
}
}
// Create request
req := netutil.NewPostForm("https://steamcommunity.com/tradeoffer/new/send", netutil.ToUrlValues(data))
req.Header.Add("Referer", referer)
// Send request
resp, err := c.client.Do(req)
if err != nil {
return 0, err
}
defer resp.Body.Close()
t := new(struct {
StrError string `json:"strError"`
TradeOfferId uint64 `json:"tradeofferid,string"`
})
if err = json.NewDecoder(resp.Body).Decode(t); err != nil {
return 0, err
}
// strError code descriptions:
// 15 invalide trade access token
// 16 timeout
// 20 wrong contextid
// 25 can't send more offers until some is accepted/cancelled...
// 26 object is not in our inventory
// error code names are in internal/steamlang/enums.go EResult_name
if t.StrError != "" {
return 0, newSteamErrorf("create error: %v\n", t.StrError)
}
if resp.StatusCode != 200 {
return 0, fmt.Errorf("create error: status code %d", resp.StatusCode)
}
if t.TradeOfferId == 0 {
return 0, newSteamErrorf("create error: steam returned 0 for trade offer id")
}
return t.TradeOfferId, nil
}
func (c *Client) GetOwnInventory(contextId uint64, appId uint32) (*inventory.Inventory, error) {
return inventory.GetOwnInventory(c.client, contextId, appId)
}
func (c *Client) GetPartnerInventory(other steamid.SteamId, contextId uint64, appId uint32, offerId *uint64) (*inventory.Inventory, error) {
return inventory.GetFullInventory(func() (*inventory.PartialInventory, error) {
return c.getPartialPartnerInventory(other, contextId, appId, offerId, nil)
}, func(start uint) (*inventory.PartialInventory, error) {
return c.getPartialPartnerInventory(other, contextId, appId, offerId, &start)
})
}
func (c *Client) getPartialPartnerInventory(other steamid.SteamId, contextId uint64, appId uint32, offerId *uint64, start *uint) (*inventory.PartialInventory, error) {
data := map[string]string{
"sessionid": c.sessionId,
"partner": other.ToString(),
"contextid": strconv.FormatUint(contextId, 10),
"appid": strconv.FormatUint(uint64(appId), 10),
}
if start != nil {
data["start"] = strconv.FormatUint(uint64(*start), 10)
}
baseUrl := "https://steamcommunity.com/tradeoffer/%v/"
if offerId != nil {
baseUrl = fmt.Sprintf(baseUrl, *offerId)
} else {
baseUrl = fmt.Sprintf(baseUrl, "new")
}
req, err := http.NewRequest("GET", baseUrl+"partnerinventory/?"+netutil.ToUrlValues(data).Encode(), nil)
if err != nil {
panic(err)
}
req.Header.Add("Referer", baseUrl+"?partner="+strconv.FormatUint(uint64(other.GetAccountId()), 10))
return inventory.DoInventoryRequest(c.client, req)
}
// Can be used to verify accepted tradeoffer and find out received asset ids
func (c *Client) GetTradeReceipt(tradeId uint64) ([]*TradeReceiptItem, error) {
url := fmt.Sprintf("https://steamcommunity.com/trade/%d/receipt", tradeId)
resp, err := c.client.Get(url)
if err != nil {
return nil, err
}
defer resp.Body.Close()
respBody, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, err
}
items, err := parseTradeReceipt(respBody)
if err != nil {
return nil, newSteamErrorf("failed to parse trade receipt: %v", err)
}
return items, nil
}
// Get duration of escrow in days. Call this before sending a trade offer
func (c *Client) GetPartnerEscrowDuration(other steamid.SteamId, accessToken *string) (*EscrowDuration, error) {
data := map[string]string{
"partner": strconv.FormatUint(uint64(other.GetAccountId()), 10),
}
if accessToken != nil {
data["token"] = *accessToken
}
return c.getEscrowDuration("https://steamcommunity.com/tradeoffer/new/?" + netutil.ToUrlValues(data).Encode())
}
// Get duration of escrow in days. Call this after receiving a trade offer
func (c *Client) GetOfferEscrowDuration(offerId uint64) (*EscrowDuration, error) {
return c.getEscrowDuration("http://steamcommunity.com/tradeoffer/" + strconv.FormatUint(offerId, 10))
}
func (c *Client) getEscrowDuration(queryUrl string) (*EscrowDuration, error) {
resp, err := c.client.Get(queryUrl)
if err != nil {
return nil, fmt.Errorf("failed to retrieve escrow duration: %v", err)
}
defer resp.Body.Close()
respBody, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, err
}
escrowDuration, err := parseEscrowDuration(respBody)
if err != nil {
return nil, newSteamErrorf("failed to parse escrow duration: %v", err)
}
return escrowDuration, nil
}
func (c *Client) GetOfferWithRetry(offerId uint64, retryCount int, retryDelay time.Duration) (*TradeOfferResult, error) {
var res *TradeOfferResult
return res, withRetry(
func() (err error) {
res, err = c.GetOffer(offerId)
return err
}, retryCount, retryDelay)
}
func (c *Client) GetOffersWithRetry(getSent bool, getReceived bool, getDescriptions bool, activeOnly bool, historicalOnly bool, timeHistoricalCutoff *uint32, retryCount int, retryDelay time.Duration) (*TradeOffersResult, error) {
var res *TradeOffersResult
return res, withRetry(
func() (err error) {
res, err = c.GetOffers(getSent, getReceived, getDescriptions, activeOnly, historicalOnly, timeHistoricalCutoff)
return err
}, retryCount, retryDelay)
}
func (c *Client) DeclineWithRetry(offerId uint64, retryCount int, retryDelay time.Duration) error {
return withRetry(
func() error {
return c.Decline(offerId)
}, retryCount, retryDelay)
}
func (c *Client) CancelWithRetry(offerId uint64, retryCount int, retryDelay time.Duration) error {
return withRetry(
func() error {
return c.Cancel(offerId)
}, retryCount, retryDelay)
}
func (c *Client) AcceptWithRetry(offerId uint64, retryCount int, retryDelay time.Duration) error {
return withRetry(
func() error {
return c.Accept(offerId)
}, retryCount, retryDelay)
}
func (c *Client) CreateWithRetry(other steamid.SteamId, accessToken *string, myItems, theirItems []TradeItem, counteredOfferId *uint64, message string, retryCount int, retryDelay time.Duration) (uint64, error) {
var res uint64
return res, withRetry(
func() (err error) {
res, err = c.Create(other, accessToken, myItems, theirItems, counteredOfferId, message)
return err
}, retryCount, retryDelay)
}
func (c *Client) GetOwnInventoryWithRetry(contextId uint64, appId uint32, retryCount int, retryDelay time.Duration) (*inventory.Inventory, error) {
var res *inventory.Inventory
return res, withRetry(
func() (err error) {
res, err = c.GetOwnInventory(contextId, appId)
return err
}, retryCount, retryDelay)
}
func (c *Client) GetPartnerInventoryWithRetry(other steamid.SteamId, contextId uint64, appId uint32, offerId *uint64, retryCount int, retryDelay time.Duration) (*inventory.Inventory, error) {
var res *inventory.Inventory
return res, withRetry(
func() (err error) {
res, err = c.GetPartnerInventory(other, contextId, appId, offerId)
return err
}, retryCount, retryDelay)
}
func (c *Client) GetTradeReceiptWithRetry(tradeId uint64, retryCount int, retryDelay time.Duration) ([]*TradeReceiptItem, error) {
var res []*TradeReceiptItem
return res, withRetry(
func() (err error) {
res, err = c.GetTradeReceipt(tradeId)
return err
}, retryCount, retryDelay)
}
func withRetry(f func() error, retryCount int, retryDelay time.Duration) error {
if retryCount <= 0 {
panic("retry count must be more than 0")
}
i := 0
for {
i++
if err := f(); err != nil {
// If we got steam error do not retry
if _, ok := err.(*SteamError); ok {
return err
}
if i == retryCount {
return err
}
time.Sleep(retryDelay)
continue
}
break
}
return nil
}