apollo-backend/internal/reddit/client.go
Andre Medeiros 2b0078c8f2 I'm an idiot
2021-07-13 14:40:56 -04:00

189 lines
4 KiB
Go

package reddit
import (
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
"net/http/httptrace"
"regexp"
"strings"
"time"
"github.com/DataDog/datadog-go/statsd"
"github.com/valyala/fastjson"
)
const (
tokenURL = "https://www.reddit.com/api/v1/access_token"
)
type Client struct {
id string
secret string
client *http.Client
tracer *httptrace.ClientTrace
parser *fastjson.Parser
statsd *statsd.Client
}
func SplitID(id string) (string, string) {
if parts := strings.Split(id, "_"); len(parts) == 2 {
return parts[0], parts[1]
}
return "", ""
}
func PostIDFromContext(context string) string {
exps := []*regexp.Regexp{
regexp.MustCompile(`\/r\/[^\/]*\/comments\/([^\/]*)\/.*`),
}
for _, exp := range exps {
matches := exp.FindStringSubmatch(context)
if len(matches) != 2 {
continue
}
return matches[1]
}
return ""
}
func NewClient(id, secret string, statsd *statsd.Client) *Client {
tracer := &httptrace.ClientTrace{
GotConn: func(info httptrace.GotConnInfo) {
if info.Reused {
statsd.Incr("reddit.api.connections.reused", []string{}, 0.1)
if info.WasIdle {
idleTime := float64(int64(info.IdleTime) / int64(time.Millisecond))
statsd.Histogram("reddit.api.connections.idle_time", idleTime, []string{}, 0.1)
}
} else {
statsd.Incr("reddit.api.connections.created", []string{}, 0.1)
}
},
}
client := &http.Client{}
parser := &fastjson.Parser{}
return &Client{
id,
secret,
client,
tracer,
parser,
statsd,
}
}
type AuthenticatedClient struct {
*Client
refreshToken string
accessToken string
expiry *time.Time
}
func (rc *Client) NewAuthenticatedClient(refreshToken, accessToken string) *AuthenticatedClient {
return &AuthenticatedClient{rc, refreshToken, accessToken, nil}
}
func (rac *AuthenticatedClient) request(r *Request) ([]byte, error) {
req, err := r.HTTPRequest()
if err != nil {
return nil, err
}
req = req.WithContext(httptrace.WithClientTrace(req.Context(), rac.tracer))
start := time.Now()
resp, err := rac.client.Do(req)
rac.statsd.Incr("reddit.api.calls", r.tags, 0.1)
rac.statsd.Histogram("reddit.api.latency", float64(time.Now().Sub(start).Milliseconds()), r.tags, 0.1)
if err != nil {
rac.statsd.Incr("reddit.api.errors", r.tags, 0.1)
return nil, err
}
defer resp.Body.Close()
bb, err := ioutil.ReadAll(resp.Body)
if err != nil {
rac.statsd.Incr("reddit.api.errors", r.tags, 0.1)
return nil, err
}
if resp.StatusCode != 200 {
rac.statsd.Incr("reddit.api.errors", r.tags, 0.1)
// Try to parse a json error. Otherwise we generate a generic one
rerr := &Error{}
if jerr := json.Unmarshal(bb, rerr); jerr != nil {
return nil, fmt.Errorf("error from reddit: %d", resp.StatusCode)
}
return nil, rerr
}
return bb, nil
}
func (rac *AuthenticatedClient) RefreshTokens() (*RefreshTokenResponse, error) {
req := NewRequest(
WithTags([]string{"url:/api/v1/access_token"}),
WithMethod("POST"),
WithURL(tokenURL),
WithBody("grant_type", "refresh_token"),
WithBody("refresh_token", rac.refreshToken),
WithBasicAuth(rac.id, rac.secret),
)
body, err := rac.request(req)
if err != nil {
return nil, err
}
rtr := &RefreshTokenResponse{}
json.Unmarshal([]byte(body), rtr)
return rtr, nil
}
func (rac *AuthenticatedClient) MessageInbox(from string) (*MessageListingResponse, error) {
req := NewRequest(
WithTags([]string{"url:/api/v1/message/inbox"}),
WithMethod("GET"),
WithToken(rac.accessToken),
WithURL("https://oauth.reddit.com/message/inbox.json"),
WithQuery("before", from),
)
body, err := rac.request(req)
if err != nil {
return nil, err
}
mlr := &MessageListingResponse{}
json.Unmarshal([]byte(body), mlr)
return mlr, nil
}
func (rac *AuthenticatedClient) Me() (*MeResponse, error) {
req := NewRequest(
WithTags([]string{"url:/api/v1/me"}),
WithMethod("GET"),
WithToken(rac.accessToken),
WithURL("https://oauth.reddit.com/api/v1/me"),
)
body, err := rac.request(req)
if err != nil {
return nil, err
}
mr := &MeResponse{}
err = json.Unmarshal(body, mr)
return mr, err
}