1 package apub
2 
3 import (
4 	"bytes"
5 	"crypto/rsa"
6 	"encoding/json"
7 	"fmt"
8 	"io"
9 	"net/http"
10 	"os"
11 	"strings"
12 )
13 
14 var defaultClient Client = Client{Client: http.DefaultClient}
15 
16 func Lookup(id string) (*Activity, error) {
17 	return defaultClient.Lookup(id)
18 }
19 
20 func LookupActor(id string) (*Actor, error) {
21 	return defaultClient.LookupActor(id)
22 }
23 
24 type Client struct {
25 	*http.Client
26 	Key   *rsa.PrivateKey
27 	Actor *Actor
28 }
29 
30 func (c *Client) Lookup(id string) (*Activity, error) {
31 	if !strings.HasPrefix(id, "http") {
32 		return nil, fmt.Errorf("id is not a HTTP URL")
33 	}
34 	if c.Client == nil {
35 		c.Client = http.DefaultClient
36 	}
37 
38 	req, err := http.NewRequest(http.MethodGet, id, nil)
39 	if err != nil {
40 		return nil, err
41 	}
42 	req.Header.Set("Accept", ContentType)
43 	if c.Key != nil && c.Actor != nil {
44 		if err := Sign(req, c.Key, c.Actor.PublicKey.ID); err != nil {
45 			return nil, fmt.Errorf("sign http request: %w", err)
46 		}
47 	}
48 	resp, err := c.Do(req)
49 	if err != nil {
50 		return nil, err
51 	}
52 	defer resp.Body.Close()
53 	if resp.StatusCode == http.StatusNotFound {
54 		return nil, ErrNotExist
55 	} else if resp.StatusCode >= 400 {
56 		return nil, fmt.Errorf("non-ok response status %s", resp.Status)
57 	}
58 	return Decode(resp.Body)
59 }
60 
61 func (c *Client) LookupActor(id string) (*Actor, error) {
62 	activity, err := c.Lookup(id)
63 	if err != nil {
64 		return nil, err
65 	}
66 	return activityToActor(activity), nil
67 }
68 
69 func activityToActor(activity *Activity) *Actor {
70 	actor := &Actor{
71 		AtContext: activity.AtContext,
72 		ID:        activity.ID,
73 		Type:      activity.Type,
74 		Name:      activity.Name,
75 		Username:  activity.Username,
76 		Inbox:     activity.Inbox,
77 		Outbox:    activity.Outbox,
78 		Followers: activity.Followers,
79 		Published: activity.Published,
80 		Summary:   activity.Summary,
81 	}
82 	if activity.PublicKey != nil {
83 		actor.PublicKey = *activity.PublicKey
84 	}
85 	return actor
86 }
87 
88 func (c *Client) Send(inbox string, activity *Activity) (*Activity, error) {
89 	b, err := json.Marshal(activity)
90 	if err != nil {
91 		return nil, fmt.Errorf("encode outgoing activity: %w", err)
92 	}
93 	req, err := http.NewRequest(http.MethodPost, inbox, bytes.NewReader(b))
94 	if err != nil {
95 		return nil, err
96 	}
97 	req.Header.Set("Content-Type", ContentType)
98 	if err := Sign(req, c.Key, c.Actor.PublicKey.ID); err != nil {
99 		return nil, fmt.Errorf("sign outgoing request: %w", err)
100 	}
101 	resp, err := c.Do(req)
102 	if err != nil {
103 		return nil, err
104 	}
105 	switch resp.StatusCode {
106 	case http.StatusOK, http.StatusAccepted, http.StatusNoContent:
107 		return nil, nil
108 	case http.StatusNotFound:
109 		return nil, fmt.Errorf("no such inbox %s", inbox)
110 	default:
111 		io.Copy(os.Stderr, resp.Body)
112 		resp.Body.Close()
113 		return nil, fmt.Errorf("non-ok response status %s", resp.Status)
114 	}
115 }