viye: internal/plumbing/tldr/tldr.go (66ef839)

1

package tldr

2

3

import (

4

	"context"

5

	"errors"

6

	"fmt"

7

	"io"

8

	"net/http"

9

	"os"

10

	"path/filepath"

11

	"runtime"

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	"strings"

13

14

	"github.com/olexsmir/viye/internal/viye"

15

16

17

type Tool struct{}

18

19

func (Tool) Name() string               { return "tldr" }

20

func (Tool) Match(c *viye.Context) bool { return c.Cmd == "tldr" }

21

func (Tool) Execute(c *viye.Context) (string, error) {

22

	if len(c.Args) == 0 {

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		return "", fmt.Errorf("usage: tldr <command> [subcommand...]")

24

25

	content, err := page(c.Args)

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	if err != nil {

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		return "", err

28

29

	return viye.FormatOutput(render(content)), nil

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31

32

const baseURL = "https://raw.githubusercontent.com/tldr-pages/tldr/main"

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34

func page(args []string) ([]byte, error) {

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	cache := filepath.Join(mustUserCacheDir(), "tealdeer", "tldr-pages", "pages.en")

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	var remote []string

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	for _, dir := range []string{"common", platformDir()} {

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		for _, name := range names(args) {

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			if b, err := os.ReadFile(filepath.Join(cache, dir, name)); err == nil {

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				return b, nil

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			remote = append(remote, baseURL+"/pages.en/"+dir+"/"+name)

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44

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	for _, url := range remote {

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		if body, err := fetch(url); err == nil {

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			return body, nil

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		} else if !errors.Is(err, errNotFound) {

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			return nil, err

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51

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	return nil, fmt.Errorf("no tldr found for %q", strings.Join(args, " "))

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54

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var errNotFound = errors.New("page not found")

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func fetch(url string) ([]byte, error) {

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	ctx, cancel := context.WithTimeout(context.Background(), viye.Timeout)

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	defer cancel()

60

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	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)

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	if err != nil {

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		return nil, err

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	resp, err := http.DefaultClient.Do(req)

66

	if err != nil {

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		return nil, err

68

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	defer resp.Body.Close()

70

	if resp.StatusCode == http.StatusNotFound {

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		return nil, errNotFound

72

73

	if resp.StatusCode != http.StatusOK {

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		return nil, fmt.Errorf("failed to fetch tldr page: %s", resp.Status)

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	return io.ReadAll(resp.Body)

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78

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func names(args []string) []string {

80

	n := []string{strings.Join(args, "-") + ".md"}

81

	if len(args) > 1 {

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		n = append(n, args[0]+".md")

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	return n

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86

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// platformDir maps the running OS to its tealdeer page directory.

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func platformDir() string {

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	switch runtime.GOOS {

90

	case "darwin":

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		return "osx"

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	default:

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		return runtime.GOOS

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95

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func mustUserCacheDir() string {

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	dir, err := os.UserCacheDir()

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	if err != nil {

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		panic(fmt.Sprintf("failed to get user cache dir: %v", err))

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	return dir

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// render strips tldr markdown to plain text: "# name" -> "name", "> text" ->

106

// "text", "`code`" -> 2-space-indented code directly under its description.

107

func render(content []byte) string {

108

	var out []string

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	for line := range strings.SplitSeq(string(content), "\n") {

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		switch {

111

		case strings.HasPrefix(line, "# "):

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			out = append(out, strings.TrimPrefix(line, "# "))

113

		case strings.HasPrefix(line, "> "):

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			out = append(out, strings.TrimPrefix(line, "> "))

115

		case strings.HasPrefix(line, "`") && strings.HasSuffix(line, "`"):

116

			if out[len(out)-1] == "" { // close the gap between desc and code

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				out = out[:len(out)-1]

118

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			out = append(out, "  "+strings.Trim(line, "`"))

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		default:

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			out = append(out, line)

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123

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	for len(out) > 0 && out[len(out)-1] == "" { // drop trailing blank

125

		out = out[:len(out)-1]

126

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	return strings.Join(out, "\n")

128

1	package tldr
2
3	import (
4	"context"
5	"errors"
6	"fmt"
7	"io"
8	"net/http"
9	"os"
10	"path/filepath"
11	"runtime"
12	"strings"
13
14	"github.com/olexsmir/viye/internal/viye"
15	)
16
17	type Tool struct{}
18
19	func (Tool) Name() string { return "tldr" }
20	func (Tool) Match(c *viye.Context) bool { return c.Cmd == "tldr" }
21	func (Tool) Execute(c *viye.Context) (string, error) {
22	if len(c.Args) == 0 {
23	return "", fmt.Errorf("usage: tldr <command> [subcommand...]")
24	}
25	content, err := page(c.Args)
26	if err != nil {
27	return "", err
28	}
29	return viye.FormatOutput(render(content)), nil
30	}
31
32	const baseURL = "https://raw.githubusercontent.com/tldr-pages/tldr/main"
33
34	func page(args []string) ([]byte, error) {
35	cache := filepath.Join(mustUserCacheDir(), "tealdeer", "tldr-pages", "pages.en")
36	var remote []string
37	for _, dir := range []string{"common", platformDir()} {
38	for _, name := range names(args) {
39	if b, err := os.ReadFile(filepath.Join(cache, dir, name)); err == nil {
40	return b, nil
41	}
42	remote = append(remote, baseURL+"/pages.en/"+dir+"/"+name)
43	}
44	}
45	for _, url := range remote {
46	if body, err := fetch(url); err == nil {
47	return body, nil
48	} else if !errors.Is(err, errNotFound) {
49	return nil, err
50	}
51	}
52	return nil, fmt.Errorf("no tldr found for %q", strings.Join(args, " "))
53	}
54
55	var errNotFound = errors.New("page not found")
56
57	func fetch(url string) ([]byte, error) {
58	ctx, cancel := context.WithTimeout(context.Background(), viye.Timeout)
59	defer cancel()
60
61	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
62	if err != nil {
63	return nil, err
64	}
65	resp, err := http.DefaultClient.Do(req)
66	if err != nil {
67	return nil, err
68	}
69	defer resp.Body.Close()
70	if resp.StatusCode == http.StatusNotFound {
71	return nil, errNotFound
72	}
73	if resp.StatusCode != http.StatusOK {
74	return nil, fmt.Errorf("failed to fetch tldr page: %s", resp.Status)
75	}
76	return io.ReadAll(resp.Body)
77	}
78
79	func names(args []string) []string {
80	n := []string{strings.Join(args, "-") + ".md"}
81	if len(args) > 1 {
82	n = append(n, args[0]+".md")
83	}
84	return n
85	}
86
87	// platformDir maps the running OS to its tealdeer page directory.
88	func platformDir() string {
89	switch runtime.GOOS {
90	case "darwin":
91	return "osx"
92	default:
93	return runtime.GOOS
94	}
95	}
96
97	func mustUserCacheDir() string {
98	dir, err := os.UserCacheDir()
99	if err != nil {
100	panic(fmt.Sprintf("failed to get user cache dir: %v", err))
101	}
102	return dir
103	}
104
105	// render strips tldr markdown to plain text: "# name" -> "name", "> text" ->
106	// "text", "`code`" -> 2-space-indented code directly under its description.
107	func render(content []byte) string {
108	var out []string
109	for line := range strings.SplitSeq(string(content), "\n") {
110	switch {
111	case strings.HasPrefix(line, "# "):
112	out = append(out, strings.TrimPrefix(line, "# "))
113	case strings.HasPrefix(line, "> "):
114	out = append(out, strings.TrimPrefix(line, "> "))
115	case strings.HasPrefix(line, "`") && strings.HasSuffix(line, "`"):
116	if out[len(out)-1] == "" { // close the gap between desc and code
117	out = out[:len(out)-1]
118	}
119	out = append(out, " "+strings.Trim(line, "`"))
120	default:
121	out = append(out, line)
122	}
123	}
124	for len(out) > 0 && out[len(out)-1] == "" { // drop trailing blank
125	out = out[:len(out)-1]
126	}
127	return strings.Join(out, "\n")
128	}