package templates import ( "bytes" "errors" "net/mail" "os" "path" "strings" "text/template" "time" "github.com/mitchellh/go-homedir" ) type TemplateData struct { To []*mail.Address Cc []*mail.Address Bcc []*mail.Address From []*mail.Address Date time.Time Subject string // Only available when replying with a quote OriginalText string OriginalFrom []*mail.Address OriginalDate time.Time } func TestTemplateData() TemplateData { defaults := map[string]string{ "To": "John Doe ", "Cc": "Josh Doe ", "From": "Jane Smith ", "Subject": "This is only a test", "OriginalText": "This is only a test text", "OriginalFrom": "John Doe ", "OriginalDate": time.Now().Format("Mon Jan 2, 2006 at 3:04 PM"), } return ParseTemplateData(defaults) } func ParseTemplateData(defaults map[string]string) TemplateData { originalDate, _ := time.Parse("Mon Jan 2, 2006 at 3:04 PM", defaults["OriginalDate"]) td := TemplateData{ To: parseAddressList(defaults["To"]), Cc: parseAddressList(defaults["Cc"]), Bcc: parseAddressList(defaults["Bcc"]), From: parseAddressList(defaults["From"]), Date: time.Now(), Subject: defaults["Subject"], OriginalText: defaults["Original"], OriginalFrom: parseAddressList(defaults["OriginalFrom"]), OriginalDate: originalDate, } return td } func parseAddressList(list string) []*mail.Address { addrs, err := mail.ParseAddressList(list) if err != nil { return nil } return addrs } func wrapLine(text string, lineWidth int) string { words := strings.Fields(text) if len(words) == 0 { return text } wrapped := words[0] spaceLeft := lineWidth - len(wrapped) for _, word := range words[1:] { if len(word)+1 > spaceLeft { wrapped += "\n" + word spaceLeft = lineWidth - len(word) } else { wrapped += " " + word spaceLeft -= 1 + len(word) } } return wrapped } func wrapText(text string, lineWidth int) string { text = strings.ReplaceAll(text, "\r\n", "\n") lines := strings.Split(text, "\n") var wrapped string for _, line := range lines { wrapped += wrapLine(line, lineWidth) + "\n" } return wrapped } // Wraping lines at 70 so that with the "> " of the quote it is under 72 func quote(text string) string { text = strings.ReplaceAll(text, "\r\n", "\n") quoted := "> " + wrapText(text, 70) quoted = strings.ReplaceAll(quoted, "\n", "\n> ") return quoted } var templateFuncs = template.FuncMap{ "quote": quote, "wrapText": wrapText, "dateFormat": time.Time.Format, } func findTemplate(templateName string, templateDirs []string) (string, error) { for _, dir := range templateDirs { templateFile, err := homedir.Expand(path.Join(dir, templateName)) if err != nil { return "", err } if _, err := os.Stat(templateFile); os.IsNotExist(err) { continue } return templateFile, nil } return "", errors.New("Can't find template - " + templateName) } func ParseTemplateFromFile(templateName string, templateDirs []string, data interface{}) ([]byte, error) { templateFile, err := findTemplate(templateName, templateDirs) if err != nil { return nil, err } emailTemplate, err := template.New(templateName).Funcs(templateFuncs).ParseFiles(templateFile) if err != nil { return nil, err } var outString bytes.Buffer if err := emailTemplate.Execute(&outString, data); err != nil { return nil, err } return outString.Bytes(), nil } func ParseTemplate(templateText string, data interface{}) ([]byte, error) { emailTemplate, err := template.New("email_template").Funcs(templateFuncs).Parse(templateText) if err != nil { return nil, err } var outString bytes.Buffer if err := emailTemplate.Execute(&outString, data); err != nil { return nil, err } return outString.Bytes(), nil }