import Tkinter as tk
import paramiko
import time


class Application(tk.Tk):
    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)

        container = tk.Frame(self)
        container.grid(row=0, column=0, sticky="nsew")
        container.grid_rowconfigure(0, weight=1)
        container.grid_columnconfigure(0, weight=1)

        self.frames = {}
        for F in (Login, MainWindow):
            frame = F(container, self)
            self.frames[F] = frame
            frame.grid(row=0, column=0, sticky="nsew")

        self.show_frame(Login)

    def show_frame(self, cont):
        frame = self.frames[cont]
        frame.tkraise()


class Login(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.ssh_client = paramiko.SSHClient()
        self.ssh_client.set_missing_host_key_policy(paramiko.AutoAddPolicy())

        self.parent = parent
        self.controller = controller
        self.grid(row=0, column=0)

        self.user = tk.StringVar()
        self.user.set("my_username")  # Default user

        self.host_options = ["host1", "host2"]
        self.host = tk.StringVar()
        self.host.set(self.host_options[0])  # Default hostname

        l_user = tk.Label(self, text="Username: ")
        l_user.grid(row=0, column=0, sticky=tk.E)

        self.entry_user = tk.Entry(self)
        self.entry_user.grid(row=0, column=1, sticky=tk.W)
        self.entry_user.insert(0, self.user.get())

        l_pwd = tk.Label(self, text="Password: ")
        l_pwd.grid(row=1, column=0, sticky=tk.E)

        self.entry_pwd = tk.Entry(self, show="*")
        self.entry_pwd.grid(row=1, column=1, sticky=tk.W)

        l_host = tk.Label(self, text="Hostname: ")
        l_host.grid(row=2, column=0, sticky=tk.E)

        optionmenu_host = tk.OptionMenu(self, self.host, *self.host_options)
        optionmenu_host.grid(row=2, column=1, sticky=tk.W)

        b_login = tk.Button(self, text="Log in", command=self.authorize)
        b_login.grid(row=3, column=0, sticky=tk.W)

        b_quit = tk.Button(self, text="Quit", command=self.parent.destroy)
        b_quit.grid(row=4, column=0, sticky=tk.W)

    def authorize(self):
        try:
            self.ssh_client.connect(hostname=self.host.get(), username=self.entry_user.get(), password=self.entry_pwd.get())
            self.controller.show_frame(MainWindow)
        except paramiko.AuthenticationException:
            l_error = tk.Label(self, text="Login failed...", fg="red")
            l_error.grid(row=4, column=1, sticky=tk.W)
            l_error.after(2000, l_error.destroy)


class MainWindow(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.grid(row=0, column=0)

        l = tk.Label(self, text="Log in was successful!")
        l.grid(row=0, column=0, sticky=tk.W)


###################################
# run application
if __name__ == "__main__":
    app = Application()
    app.mainloop()
###################################