cmd/shrt/internal/help/help.go in go-shrt

at v0.4.1

1
// See LICENSE file for copyright and license details
2
3
// Package help implements the "shrt help" command
4
package help
5
6
import (
7
	"context"
8
	"fmt"
9
	"io"
10
	"log"
11
	"strings"
12
	"text/template"
13
14
	"djmo.ch/go-shrt/cmd/shrt/internal/base"
15
)
16
17
var usageTmpl = `{{ if .Usage }}usage: {{ .Usage }}
18
19
{{ end }}{{ .LongHelp | trim }}{{ if .Subcommands }}
20
21
The commands are:
22
{{ range .Subcommands -}}{{ if .Runnable }}
23
	{{ .Name | printf "%-8s"}}{{ .ShortHelp }}{{ end }}{{ end }}
24
25
Use "shrt help <command>" for more information about a command.
26
27
Additional topics are:
28
{{ range .Subcommands -}}{{ if (not .Runnable) }}
29
	{{ .Name | printf "%-12s"}}{{ .ShortHelp }}{{ end }}{{ end }}
30
31
Use "shrt help <topic>" for more information about that topic.{{ end }}
32
`
33
34
func Help(ctx context.Context) {
35
	var (
36
		args = ctx.Value("args").([]string)
37
		w    = ctx.Value("w").(io.Writer)
38
	)
39
	if args == nil {
40
		args = []string{}
41
	}
42
	switch len(args) {
43
	case 0:
44
		printUsage(w, base.Shrt)
45
	case 1:
46
		if args[0] == "documentation" {
47
			printDocumentation(w)
48
			return
49
		}
50
		cmd := base.FindCommand(args[0])
51
		if cmd == nil {
52
			log.Fatal("unknown subcommand ", args[0])
53
		}
54
		printUsage(w, cmd)
55
	default:
56
		log.Fatal("help expects at most one argument")
57
	}
58
}
59
60
func printDocumentation(w io.Writer) {
61
	fmt.Fprintln(w, "// See LICENSE file for copyright and license details")
62
	fmt.Fprintln(w, "// Code generated by 'go test ./cmd/shrt -v -run=TestDocsUpToDate -fixdocs'; DO NOT EDIT")
63
	fmt.Fprintln(w, "// Edit the code in other files and then execute 'go generate ./cmd/shrt' to generate this one.")
64
	fmt.Fprintln(w)
65
	fmt.Fprintln(w, "/*")
66
	printUsage(w, base.Shrt)
67
	for _, cmd := range base.Shrt.Subcommands {
68
		if cmd.LongHelp != "" {
69
			fmt.Fprintln(w)
70
			fmt.Fprintf(w, "# %s%s\n", strings.ToTitle(string(cmd.ShortHelp[0])),
71
				cmd.ShortHelp[1:])
72
			fmt.Fprintln(w)
73
			printUsage(w, cmd)
74
		}
75
	}
76
	fmt.Fprintln(w, "*/")
77
	fmt.Fprintln(w, "package main")
78
}
79
80
func printUsage(w io.Writer, cmd *base.Command) {
81
	tmpl := template.New(cmd.Name)
82
	tmpl.Funcs(template.FuncMap{"trim": strings.TrimSpace})
83
	template.Must(tmpl.Parse(usageTmpl))
84
	tmpl.Execute(w, cmd)
85
}