go-mastodon/mastodon.go

385 lines
8.6 KiB
Go

// Package mastodon provides functions and structs for accessing the mastodon API.
package mastodon
import (
"bytes"
"context"
"encoding/json"
"errors"
"fmt"
"io"
"mime/multipart"
"net/http"
"net/url"
"os"
"path"
"path/filepath"
"strings"
"time"
"github.com/tomnomnom/linkheader"
)
// Config is a setting for access mastodon APIs.
type Config struct {
Server string
ClientID string
ClientSecret string
AccessToken string
}
// Client is a API client for mastodon.
type Client struct {
http.Client
Config *Config
UserAgent string
}
func (c *Client) doAPI(ctx context.Context, method string, uri string, params interface{}, res interface{}, pg *Pagination) error {
u, err := url.Parse(c.Config.Server)
if err != nil {
return err
}
u.Path = path.Join(u.Path, uri)
var req *http.Request
ct := "application/x-www-form-urlencoded"
if values, ok := params.(url.Values); ok {
var body io.Reader
if method == http.MethodGet {
if pg != nil {
values = pg.setValues(values)
}
u.RawQuery = values.Encode()
} else {
body = strings.NewReader(values.Encode())
}
req, err = http.NewRequest(method, u.String(), body)
if err != nil {
return err
}
} else if file, ok := params.(string); ok {
f, err := os.Open(file)
if err != nil {
return err
}
defer f.Close()
var buf bytes.Buffer
mw := multipart.NewWriter(&buf)
part, err := mw.CreateFormFile("file", filepath.Base(file))
if err != nil {
return err
}
_, err = io.Copy(part, f)
if err != nil {
return err
}
err = mw.Close()
if err != nil {
return err
}
req, err = http.NewRequest(method, u.String(), &buf)
if err != nil {
return err
}
ct = mw.FormDataContentType()
} else if reader, ok := params.(io.Reader); ok {
var buf bytes.Buffer
mw := multipart.NewWriter(&buf)
part, err := mw.CreateFormFile("file", "upload")
if err != nil {
return err
}
_, err = io.Copy(part, reader)
if err != nil {
return err
}
err = mw.Close()
if err != nil {
return err
}
req, err = http.NewRequest(method, u.String(), &buf)
if err != nil {
return err
}
ct = mw.FormDataContentType()
} else {
if method == http.MethodGet && pg != nil {
u.RawQuery = pg.toValues().Encode()
}
req, err = http.NewRequest(method, u.String(), nil)
if err != nil {
return err
}
}
req = req.WithContext(ctx)
req.Header.Set("Authorization", "Bearer "+c.Config.AccessToken)
if params != nil {
req.Header.Set("Content-Type", ct)
}
if c.UserAgent != "" {
req.Header.Set("User-Agent", c.UserAgent)
}
var resp *http.Response
backoff := time.Second
for {
resp, err = c.Do(req)
if err != nil {
return err
}
defer resp.Body.Close()
// handle status code 429, which indicates the server is throttling
// our requests. Do an exponential backoff and retry the request.
if resp.StatusCode == 429 {
if backoff > time.Hour {
break
}
select {
case <-time.After(backoff):
case <-ctx.Done():
return ctx.Err()
}
backoff = time.Duration(1.5 * float64(backoff))
continue
}
break
}
if resp.StatusCode != http.StatusOK {
return parseAPIError("bad request", resp)
} else if res == nil {
return nil
} else if pg != nil {
if lh := resp.Header.Get("Link"); lh != "" {
pg2, err := newPagination(lh)
if err != nil {
return err
}
*pg = *pg2
}
}
return json.NewDecoder(resp.Body).Decode(&res)
}
// NewClient return new mastodon API client.
func NewClient(config *Config) *Client {
return &Client{
Client: *http.DefaultClient,
Config: config,
}
}
// Authenticate get access-token to the API.
func (c *Client) Authenticate(ctx context.Context, username, password string) error {
params := url.Values{
"client_id": {c.Config.ClientID},
"client_secret": {c.Config.ClientSecret},
"grant_type": {"password"},
"username": {username},
"password": {password},
"scope": {"read write follow"},
}
return c.authenticate(ctx, params)
}
// AuthenticateToken logs in using a grant token returned by Application.AuthURI.
//
// redirectURI should be the same as Application.RedirectURI.
func (c *Client) AuthenticateToken(ctx context.Context, authCode, redirectURI string) error {
params := url.Values{
"client_id": {c.Config.ClientID},
"client_secret": {c.Config.ClientSecret},
"grant_type": {"authorization_code"},
"code": {authCode},
"redirect_uri": {redirectURI},
}
return c.authenticate(ctx, params)
}
func (c *Client) authenticate(ctx context.Context, params url.Values) error {
u, err := url.Parse(c.Config.Server)
if err != nil {
return err
}
u.Path = path.Join(u.Path, "/oauth/token")
req, err := http.NewRequest(http.MethodPost, u.String(), strings.NewReader(params.Encode()))
if err != nil {
return err
}
req = req.WithContext(ctx)
req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
if c.UserAgent != "" {
req.Header.Set("User-Agent", c.UserAgent)
}
resp, err := c.Do(req)
if err != nil {
return err
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return parseAPIError("bad authorization", resp)
}
var res struct {
AccessToken string `json:"access_token"`
}
err = json.NewDecoder(resp.Body).Decode(&res)
if err != nil {
return err
}
c.Config.AccessToken = res.AccessToken
return nil
}
// Toot is struct to post status.
type Toot struct {
Status string `json:"status"`
InReplyToID ID `json:"in_reply_to_id"`
MediaIDs []ID `json:"media_ids"`
Sensitive bool `json:"sensitive"`
SpoilerText string `json:"spoiler_text"`
Visibility string `json:"visibility"`
}
// Mention hold information for mention.
type Mention struct {
URL string `json:"url"`
Username string `json:"username"`
Acct string `json:"acct"`
ID ID `json:"id"`
}
// Tag hold information for tag.
type Tag struct {
Name string `json:"name"`
URL string `json:"url"`
History []History `json:"history"`
}
// History hold information for history.
type History struct {
Day string `json:"day"`
Uses int64 `json:"uses"`
Accounts int64 `json:"accounts"`
}
// Attachment hold information for attachment.
type Attachment struct {
ID ID `json:"id"`
Type string `json:"type"`
URL string `json:"url"`
RemoteURL string `json:"remote_url"`
PreviewURL string `json:"preview_url"`
TextURL string `json:"text_url"`
Description string `json:"description"`
Meta AttachmentMeta `json:"meta"`
}
// AttachmentMeta holds information for attachment metadata.
type AttachmentMeta struct {
Original AttachmentSize `json:"original"`
Small AttachmentSize `json:"small"`
}
// AttachmentSize holds information for attatchment size.
type AttachmentSize struct {
Width int64 `json:"width"`
Height int64 `json:"height"`
Size string `json:"size"`
Aspect float64 `json:"aspect"`
}
// Emoji hold information for CustomEmoji.
type Emoji struct {
ShortCode string `json:"shortcode"`
StaticURL string `json:"static_url"`
URL string `json:"url"`
VisibleInPicker bool `json:"visible_in_picker"`
}
// Results hold information for search result.
type Results struct {
Accounts []*Account `json:"accounts"`
Statuses []*Status `json:"statuses"`
Hashtags []string `json:"hashtags"`
}
// Pagination is a struct for specifying the get range.
type Pagination struct {
MaxID ID
SinceID ID
MinID ID
Limit int64
}
func newPagination(rawlink string) (*Pagination, error) {
if rawlink == "" {
return nil, errors.New("empty link header")
}
p := &Pagination{}
for _, link := range linkheader.Parse(rawlink) {
switch link.Rel {
case "next":
maxID, err := getPaginationID(link.URL, "max_id")
if err != nil {
return nil, err
}
p.MaxID = maxID
case "prev":
sinceID, err := getPaginationID(link.URL, "since_id")
if err != nil {
return nil, err
}
p.SinceID = sinceID
minID, err := getPaginationID(link.URL, "min_id")
if err != nil {
return nil, err
}
p.MinID = minID
}
}
return p, nil
}
func getPaginationID(rawurl, key string) (ID, error) {
u, err := url.Parse(rawurl)
if err != nil {
return "", err
}
return ID(u.Query().Get(key)), nil
}
func (p *Pagination) toValues() url.Values {
return p.setValues(url.Values{})
}
func (p *Pagination) setValues(params url.Values) url.Values {
if p.MaxID != "" {
params.Set("max_id", string(p.MaxID))
}
if p.SinceID != "" {
params.Set("since_id", string(p.SinceID))
}
if p.MinID != "" {
params.Set("min_id", string(p.MinID))
}
if p.Limit > 0 {
params.Set("limit", fmt.Sprint(p.Limit))
}
return params
}