input.go

  1// Originally taken from the git-appraise project
  2
  3package input
  4
  5import (
  6	"bufio"
  7	"bytes"
  8	"fmt"
  9	"github.com/MichaelMure/git-bug/repository"
 10	"github.com/pkg/errors"
 11	"io/ioutil"
 12	"os"
 13	"os/exec"
 14	"strings"
 15)
 16
 17var ErrEmptyMessage = errors.New("empty message")
 18var ErrEmptyTitle = errors.New("empty title")
 19
 20const bugTitleCommentTemplate = `%s%s
 21
 22# Please enter the title and comment message. The first non-empty line will be
 23# used as the title. Lines starting with '#' will be ignored.
 24# An empty title aborts the operation.
 25`
 26
 27func BugCreateEditorInput(repo repository.Repo, fileName string, preTitle string, preMessage string) (string, string, error) {
 28	if preMessage != "" {
 29		preMessage = "\n\n" + preMessage
 30	}
 31
 32	template := fmt.Sprintf(bugTitleCommentTemplate, preTitle, preMessage)
 33
 34	raw, err := LaunchEditorWithTemplate(repo, fileName, template)
 35
 36	if err != nil {
 37		return "", "", err
 38	}
 39
 40	lines := strings.Split(raw, "\n")
 41
 42	var title string
 43	var b strings.Builder
 44	for _, line := range lines {
 45		if strings.HasPrefix(line, "#") {
 46			continue
 47		}
 48
 49		if title == "" {
 50			trimmed := strings.TrimSpace(line)
 51			if trimmed != "" {
 52				title = trimmed
 53			}
 54			continue
 55		}
 56
 57		b.WriteString(line)
 58		b.WriteString("\n")
 59	}
 60
 61	if title == "" {
 62		return "", "", ErrEmptyTitle
 63	}
 64
 65	message := strings.TrimSpace(b.String())
 66
 67	return title, message, nil
 68}
 69
 70const bugCommentTemplate = `
 71
 72# Please enter the comment message. Lines starting with '#' will be ignored,
 73# and an empty message aborts the operation.
 74`
 75
 76func BugCommentEditorInput(repo repository.Repo, fileName string) (string, error) {
 77	raw, err := LaunchEditorWithTemplate(repo, fileName, bugCommentTemplate)
 78
 79	if err != nil {
 80		return "", err
 81	}
 82
 83	lines := strings.Split(raw, "\n")
 84
 85	var b strings.Builder
 86	for _, line := range lines {
 87		if strings.HasPrefix(line, "#") {
 88			continue
 89		}
 90		b.WriteString(line)
 91		b.WriteString("\n")
 92	}
 93
 94	message := strings.TrimSpace(b.String())
 95
 96	if message == "" {
 97		return "", ErrEmptyMessage
 98	}
 99
100	return message, nil
101}
102
103func LaunchEditorWithTemplate(repo repository.Repo, fileName string, template string) (string, error) {
104	path := fmt.Sprintf("%s/.git/%s", repo.GetPath(), fileName)
105
106	err := ioutil.WriteFile(path, []byte(template), 0644)
107
108	if err != nil {
109		return "", err
110	}
111
112	return LaunchEditor(repo, fileName)
113}
114
115// LaunchEditor launches the default editor configured for the given repo. This
116// method blocks until the editor command has returned.
117//
118// The specified filename should be a temporary file and provided as a relative path
119// from the repo (e.g. "FILENAME" will be converted to ".git/FILENAME"). This file
120// will be deleted after the editor is closed and its contents have been read.
121//
122// This method returns the text that was read from the temporary file, or
123// an error if any step in the process failed.
124func LaunchEditor(repo repository.Repo, fileName string) (string, error) {
125	path := fmt.Sprintf("%s/.git/%s", repo.GetPath(), fileName)
126	defer os.Remove(path)
127
128	editor, err := repo.GetCoreEditor()
129	if err != nil {
130		return "", fmt.Errorf("Unable to detect default git editor: %v\n", err)
131	}
132
133	cmd, err := startInlineCommand(editor, path)
134	if err != nil {
135		// Running the editor directly did not work. This might mean that
136		// the editor string is not a path to an executable, but rather
137		// a shell command (e.g. "emacsclient --tty"). As such, we'll try
138		// to run the command through bash, and if that fails, try with sh
139		args := []string{"-c", fmt.Sprintf("%s %q", editor, path)}
140		cmd, err = startInlineCommand("bash", args...)
141		if err != nil {
142			cmd, err = startInlineCommand("sh", args...)
143		}
144	}
145	if err != nil {
146		return "", fmt.Errorf("Unable to start editor: %v\n", err)
147	}
148
149	if err := cmd.Wait(); err != nil {
150		return "", fmt.Errorf("Editing finished with error: %v\n", err)
151	}
152
153	output, err := ioutil.ReadFile(path)
154
155	if err != nil {
156		return "", fmt.Errorf("Error reading edited file: %v\n", err)
157	}
158
159	return string(output), err
160}
161
162// FromFile loads and returns the contents of a given file. If - is passed
163// through, much like git, it will read from stdin. This can be piped data,
164// unless there is a tty in which case the user will be prompted to enter a
165// message.
166func FromFile(fileName string) (string, error) {
167	if fileName == "-" {
168		stat, err := os.Stdin.Stat()
169		if err != nil {
170			return "", fmt.Errorf("Error reading from stdin: %v\n", err)
171		}
172		if (stat.Mode() & os.ModeCharDevice) == 0 {
173			// There is no tty. This will allow us to read piped data instead.
174			output, err := ioutil.ReadAll(os.Stdin)
175			if err != nil {
176				return "", fmt.Errorf("Error reading from stdin: %v\n", err)
177			}
178			return string(output), err
179		}
180
181		fmt.Printf("(reading comment from standard input)\n")
182		var output bytes.Buffer
183		s := bufio.NewScanner(os.Stdin)
184		for s.Scan() {
185			output.Write(s.Bytes())
186			output.WriteRune('\n')
187		}
188		return output.String(), nil
189	}
190
191	output, err := ioutil.ReadFile(fileName)
192	if err != nil {
193		return "", fmt.Errorf("Error reading file: %v\n", err)
194	}
195	return string(output), err
196}
197
198func startInlineCommand(command string, args ...string) (*exec.Cmd, error) {
199	cmd := exec.Command(command, args...)
200	cmd.Stdin = os.Stdin
201	cmd.Stdout = os.Stdout
202	cmd.Stderr = os.Stderr
203	err := cmd.Start()
204	return cmd, err
205}