1 package fs
2 
3 import (
4 	"errors"
5 	"fmt"
6 	"io"
7 	"io/fs"
8 	"path"
9 	"strconv"
10 	"strings"
11 	"time"
12 
13 	"olowe.co/apub/lemmy"
14 )
15 
16 type FS struct {
17 	Client  *lemmy.Client
18 	started bool
19 }
20 
21 func (fsys *FS) start() error {
22 	if fsys.Client == nil {
23 		fsys.Client = &lemmy.Client{}
24 	}
25 	fsys.started = true
26 	return nil
27 }
28 
29 func (fsys *FS) Open(name string) (fs.File, error) {
30 	if !fs.ValidPath(name) {
31 		return nil, &fs.PathError{"open", name, fs.ErrInvalid}
32 	} else if strings.Contains(name, `\`) {
33 		return nil, &fs.PathError{"open", name, fs.ErrInvalid}
34 	}
35 	name = path.Clean(name)
36 
37 	if !fsys.started {
38 		if err := fsys.start(); err != nil {
39 			return nil, fmt.Errorf("start fs: %w", err)
40 		}
41 	}
42 	if name == "." {
43 		return fsys.openRoot()
44 	}
45 
46 	elems := strings.Split(name, "/")
47 	// We've only got communities, then posts/comments.
48 	// Anything deeper cannot exist.
49 	if len(elems) > 3 {
50 		return nil, &fs.PathError{"open", name, fs.ErrNotExist}
51 	}
52 
53 	community, _, err := fsys.Client.LookupCommunity(elems[0])
54 	if errors.Is(err, lemmy.ErrNotFound) {
55 		return nil, &fs.PathError{"open", name, fs.ErrNotExist}
56 	} else if err != nil {
57 		return nil, &fs.PathError{"open", name, err}
58 	}
59 	if len(elems) == 1 {
60 		return &lFile{
61 			info:   &community,
62 			buf:    io.NopCloser(strings.NewReader(community.Name())),
63 			client: fsys.Client,
64 		}, nil
65 	}
66 
67 	id, err := strconv.Atoi(elems[1])
68 	if err != nil {
69 		return nil, &fs.PathError{"open", name, fmt.Errorf("bad post id")}
70 	}
71 	post, err := fsys.Client.LookupPost(id)
72 	if errors.Is(err, lemmy.ErrNotFound) {
73 		return nil, &fs.PathError{"open", name, fs.ErrNotExist}
74 	} else if err != nil {
75 		return nil, &fs.PathError{"open", name, err}
76 	}
77 	if len(elems) == 2 {
78 		return &lFile{
79 			info:   &post,
80 			buf:    io.NopCloser(strings.NewReader(post.Name())),
81 			client: fsys.Client,
82 		}, nil
83 	}
84 	if elems[2] == "post" {
85 		info, err := postFile(&post).Stat()
86 		if err != nil {
87 			return nil, &fs.PathError{"open", name, fmt.Errorf("prepare post file info: %w", err)}
88 		}
89 		return &lFile{
90 			info:   info,
91 			buf:    io.NopCloser(postText(&post)),
92 			client: fsys.Client,
93 		}, nil
94 	}
95 
96 	id, err = strconv.Atoi(elems[2])
97 	if err != nil {
98 		return nil, &fs.PathError{"open", name, fmt.Errorf("bad comment id")}
99 	}
100 	comment, err := fsys.Client.LookupComment(id)
101 	if errors.Is(err, lemmy.ErrNotFound) {
102 		return nil, &fs.PathError{"open", name, fs.ErrNotExist}
103 	} else if err != nil {
104 		return nil, &fs.PathError{"open", name, err}
105 	}
106 	return &lFile{
107 		info:   &comment,
108 		buf:    io.NopCloser(commentText(&comment)),
109 		client: fsys.Client,
110 	}, nil
111 }
112 
113 func (fsys *FS) openRoot() (fs.File, error) {
114 	dirinfo := new(dirInfo)
115 	communities, err := fsys.Client.Communities(lemmy.ListAll)
116 	if err != nil {
117 		return nil, err
118 	}
119 	for _, c := range communities {
120 		c := c
121 		dent := fs.FileInfoToDirEntry(&c)
122 		dirinfo.entries = append(dirinfo.entries, dent)
123 	}
124 	return &dummy{
125 		name:     ".",
126 		mode:     fs.ModeDir | 0444,
127 		contents: []byte("hello, world!"),
128 		dirinfo:  dirinfo,
129 		mtime:    time.Now(),
130 	}, nil
131 }