initial commit

pop3proto.go

@@ -0,0 +1,144 @@
+package pop3
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	_ "log"
+	"net/textproto"
+	"strings"
+)
+
+type ResponseError string
+
+func (r ResponseError) Error() string {
+	return string(r)
+}
+
+type Conn struct {
+	Reader
+	Writer
+	conn io.ReadWriteCloser
+}
+
+func NewConn(conn io.ReadWriteCloser) *Conn {
+	return &Conn{
+		Reader: Reader{R: textproto.NewReader(bufio.NewReader(conn))},
+		Writer: Writer{W: bufio.NewWriter(conn)},
+		conn:   conn,
+	}
+}
+
+func (c *Conn) Close() error {
+	return c.conn.Close()
+}
+
+type Reader struct {
+	R *textproto.Reader
+}
+
+func (r *Reader) ReadLine() (string, error) {
+	return r.R.ReadLine()
+	// for debug
+	// l, err := r.R.ReadLine()
+	// log.Printf("> %s\n", l)
+	// return l, err
+}
+
+func (r *Reader) ReadLines() ([]string, error) {
+	var lines []string
+	var line string
+	var err error
+
+	for {
+		line, err = r.R.ReadLine()
+
+		if err != nil {
+			return nil, err
+		}
+
+		if line == "." {
+			return lines, nil
+		}
+
+		lines = append(lines, line)
+	}
+}
+
+func (r *Reader) ReadToPeriod() (string, error) {
+	lines, err := r.ReadLines()
+
+	if err != nil {
+		return "", nil
+	}
+
+	return strings.Join(lines, "\r\n"), nil
+}
+
+func (r *Reader) ReadResponse() (string, error) {
+	line, err := r.ReadLine()
+
+	if err != nil {
+		return "", err
+	}
+
+	return r.parseResponse(line)
+}
+
+func (r *Reader) parseResponse(line string) (string, error) {
+	var index int
+
+	if index = strings.Index(line, " "); index < 0 {
+		return "", ResponseError(fmt.Sprintf("レスポンスのフォーマットが不正です。: %s", line))
+	}
+
+	switch strings.ToUpper(line[:index]) {
+	case "+OK":
+		return line[index+1:], nil
+	case "-ERR":
+		return "", ResponseError(line[index+1:])
+	default:
+		return "", ResponseError(fmt.Sprintf("レスポンスの内容が不明です。: %s", line))
+	}
+}
+
+var crnl = []byte{'\r', '\n'}
+
+type Writer struct {
+	W *bufio.Writer
+}
+
+func (w *Writer) WriteLine(format string, args ...interface{}) error {
+	var err error
+
+	if _, err = fmt.Fprintf(w.W, format, args...); err != nil {
+		return err
+	}
+
+	if _, err = w.W.Write(crnl); err != nil {
+		return err
+	}
+
+	return w.W.Flush()
+
+	// for debug
+	// var err error
+
+	// l := fmt.Sprintf(format, args...)
+
+	// if _, err = fmt.Fprint(w.W, l); err != nil {
+	// 	return err
+	// }
+
+	// if _, err = w.W.Write(crnl); err != nil {
+	// 	return err
+	// }
+
+	// if err = w.W.Flush(); err != nil {
+	// 	return err
+	// }
+
+	// log.Printf("< %s\n", l)
+
+	// return nil
+}