#!/usr/bin/env python

'''automated testing library for testing Samba against windows'''

import pexpect, subprocess
import sys, os, time, re

class wintest():
    '''testing of Samba against windows VMs'''

    def __init__(self):
        self.vars = {}
        self.list_mode = False
        os.putenv('PYTHONUNBUFFERED', '1')

    def setvar(self, varname, value):
        '''set a substitution variable'''
        self.vars[varname] = value

    def setwinvars(self, vm, prefix='WIN'):
        '''setup WIN_XX vars based on a vm name'''
        for v in ['VM', 'HOSTNAME', 'USER', 'PASS', 'SNAPSHOT', 'BASEDN', 'REALM', 'DOMAIN']:
            vname = '%s_%s' % (vm, v)
            if vname in self.vars:
                self.setvar("%s_%s" % (prefix,v), self.substitute("${%s}" % vname))
            else:
                self.vars.pop("%s_%s" % (prefix,v), None)

    def info(self, msg):
        '''print some information'''
        if not self.list_mode:
            print(self.substitute(msg))

    def load_config(self, fname):
        '''load the config file'''
        f = open(fname)
        for line in f:
            line = line.strip()
            if len(line) == 0 or line[0] == '#':
                continue
            colon = line.find(':')
            if colon == -1:
                raise RuntimeError("Invalid config line '%s'" % line)
            varname = line[0:colon].strip()
            value   = line[colon+1:].strip()
            self.setvar(varname, value)

    def list_steps_mode(self):
        '''put wintest in step listing mode'''
        self.list_mode = True

    def set_skip(self, skiplist):
        '''set a list of tests to skip'''
        self.skiplist = skiplist.split(',')

    def skip(self, step):
        '''return True if we should skip a step'''
        if self.list_mode:
            print("\t%s" % step)
            return True
        return step in self.skiplist

    def substitute(self, text):
        """Substitute strings of the form ${NAME} in text, replacing
        with substitutions from vars.
        """
        if isinstance(text, list):
            ret = text[:]
            for i in range(len(ret)):
                ret[i] = self.substitute(ret[i])
            return ret

        while True:
            var_start = text.find("${")
            if var_start == -1:
                return text
            var_end = text.find("}", var_start)
            if var_end == -1:
                return text
            var_name = text[var_start+2:var_end]
            if not var_name in self.vars:
                raise RuntimeError("Unknown substitution variable ${%s}" % var_name)
            text = text.replace("${%s}" % var_name, self.vars[var_name])
        return text

    def have_var(self, varname):
        '''see if a variable has been set'''
        return varname in self.vars


    def putenv(self, key, value):
        '''putenv with substitution'''
        os.putenv(key, self.substitute(value))

    def chdir(self, dir):
        '''chdir with substitution'''
        os.chdir(self.substitute(dir))


    def run_cmd(self, cmd, dir=".", show=None, output=False, checkfail=True):
        cmd = self.substitute(cmd)
        if isinstance(cmd, list):
            self.info('$ ' + " ".join(cmd))
        else:
            self.info('$ ' + cmd)
        if output:
            return subprocess.Popen([cmd], shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, cwd=dir).communicate()[0]
        if isinstance(cmd, list):
            shell=False
        else:
            shell=True
        if checkfail:
            return subprocess.check_call(cmd, shell=shell, cwd=dir)
        else:
            return subprocess.call(cmd, shell=shell, cwd=dir)


    def cmd_output(self, cmd):
        '''return output from and command'''
        cmd = self.substitute(cmd)
        return self.run_cmd(cmd, output=True)

    def cmd_contains(self, cmd, contains, nomatch=False, ordered=False, regex=False):
        '''check that command output contains the listed strings'''
        out = self.cmd_output(cmd)
        self.info(out)
        for c in self.substitute(contains):
            if regex:
                m = re.search(c, out)
                if m is None:
                    start = -1
                    end = -1
                else:
                    start = m.start()
                    end = m.end()
            else:
                start = out.find(c)
                end = start + len(c)
            if nomatch:
                if start != -1:
                    raise RuntimeError("Expected to not see %s in %s" % (c, cmd))
            else:
                if start == -1:
                    raise RuntimeError("Expected to see %s in %s" % (c, cmd))
            if ordered and start != -1:
                out = out[end:]

    def retry_cmd(self, cmd, contains, retries=30, delay=2, wait_for_fail=False,
                  ordered=False, regex=False):
        '''retry a command a number of times'''
        while retries > 0:
            try:
                self.cmd_contains(cmd, contains, nomatch=wait_for_fail,
                                  ordered=ordered, regex=regex)
                return
            except:
                time.sleep(delay)
                retries = retries - 1
        raise RuntimeError("Failed to find %s" % contains)

    def pexpect_spawn(self, cmd, timeout=60):
        '''wrapper around pexpect spawn'''
        cmd = self.substitute(cmd)
        self.info("$ " + cmd)
        ret = pexpect.spawn(cmd, logfile=sys.stdout, timeout=timeout)

        def sendline_sub(line):
            line = self.substitute(line).replace('\n', '\r\n')
            return ret.old_sendline(line + '\r')

        def expect_sub(line, timeout=ret.timeout):
            line = self.substitute(line)
            return ret.old_expect(line, timeout=timeout)

        ret.old_sendline = ret.sendline
        ret.sendline = sendline_sub
        ret.old_expect = ret.expect
        ret.expect = expect_sub

        return ret

    def vm_poweroff(self, vmname, checkfail=True):
        '''power off a VM'''
        self.setvar('VMNAME', vmname)
        self.run_cmd("${VM_POWEROFF}", checkfail=checkfail)

    def vm_restore(self, vmname, snapshot):
        '''restore a VM'''
        self.setvar('VMNAME', vmname)
        self.setvar('SNAPSHOT', snapshot)
        self.run_cmd("${VM_RESTORE}")

    def ping_wait(self, hostname):
        '''wait for a hostname to come up on the network'''
        hostname = self.substitute(hostname)
        loops=10
        while loops > 0:
            try:
                self.run_cmd("ping -c 1 -w 10 %s" % hostname)
                break
            except:
                loops = loops - 1
        if loops == 0:
            raise RuntimeError("Failed to ping %s" % hostname)
        self.info("Host %s is up" % hostname)

    def port_wait(self, hostname, port, retries=200, delay=3, wait_for_fail=False):
        '''wait for a host to come up on the network'''
        self.retry_cmd("nc -v -z -w 1 %s %u" % (hostname, port), ['succeeded'],
                       retries=retries, delay=delay, wait_for_fail=wait_for_fail)

    def run_net_time(self, child):
        '''run net time on windows'''
        child.sendline("net time \\\\${HOSTNAME} /set")
        child.expect("Do you want to set the local computer")
        child.sendline("Y")
        child.expect("The command completed successfully")

    def run_date_time(self, child, time_tuple=None):
        '''run date and time on windows'''
        if time_tuple is None:
            time_tuple = time.localtime()
        child.sendline("date")
        child.expect("Enter the new date:")
        child.sendline(time.strftime("%m-%d-%y", time_tuple))
        child.expect("C:")
        child.sendline("time")
        child.expect("Enter the new time:")
        child.sendline(time.strftime("%H:%M:%S", time_tuple))
        child.expect("C:")


    def open_telnet(self, hostname, username, password, retries=60, delay=5, set_time=False):
        '''open a telnet connection to a windows server, return the pexpect child'''
        while retries > 0:
            child = self.pexpect_spawn("telnet " + hostname + " -l '" + username + "'")
            i = child.expect(["Welcome to Microsoft Telnet Service",
                              "No more connections are allowed to telnet server",
                              "Unable to connect to remote host",
                              "No route to host"])
            if i != 0:
                child.close()
                time.sleep(delay)
                retries -= 1
                continue
            child.expect("password:")
            child.sendline(password)
            child.expect("C:")
            if set_time:
                self.run_date_time(child, None)
            return child
        raise RuntimeError("Failed to connect with telnet")

    def kinit(self, username, password):
        '''use kinit to setup a credentials cache'''
        self.run_cmd("kdestroy")
        self.putenv('KRB5CCNAME', "${PREFIX}/ccache.test")
        username = self.substitute(username)
        s = username.split('@')
        if len(s) > 0:
            s[1] = s[1].upper()
        username = '@'.join(s)
        child = self.pexpect_spawn('kinit -V ' + username)
        child.expect("Password for")
        child.sendline(password)
        child.expect("Authenticated to Kerberos")