package worker

import (
    "errors"
    "io"
    "time"

    "lms-dws/internal/util/timeutil"

    "github.com/jlaffaye/ftp"
)

// IFTPConnector ftp connector interface
type IFTPConnector interface {
    Quit() error
    Logout() error
    Login(username string, password string) error
    List(path string) ([]*ftp.Entry, error)
    Retr(filepath string) (io.Reader, error)
}

type ftpConnector struct {
    Conn *ftp.ServerConn
}

// DialTimeout return IFTPConnector
func DialTimeout(addr string, timeout time.Duration) (IFTPConnector, error) {
    var (
        err  error
        conn *ftp.ServerConn
    )

    // https://github.com/jlaffaye/ftp/issues/112
    // Tricky way force to exit incase connection hang
    // Consider switch to use https://github.com/goftp/server

    isTimeout := timeutil.TimeoutWithFunc(timeout, func() {
        conn, err = ftp.DialTimeout(addr, timeout)
    })

    if isTimeout {
        return nil, errors.New("Dial is timeout")
    }

    if err != nil {
        return nil, err
    }

    return &ftpConnector{
        Conn: conn,
    }, nil
}

func (f *ftpConnector) Quit() error {
    return f.Conn.Quit()
}

func (f *ftpConnector) Logout() error {
    return f.Conn.Logout()
}

func (f *ftpConnector) Login(username string, password string) error {
    return f.Conn.Login(username, password)
}

func (f *ftpConnector) List(path string) ([]*ftp.Entry, error) {
    return f.Conn.List(path)
}

func (f *ftpConnector) Retr(path string) (io.Reader, error) {
    return f.Conn.Retr(path)
}