"""This is a utility class to make shell scripting easier in Python.
It combines Pexpect and wraps many Standard Python Library functions
to make them look more shell-like.

PEXPECT LICENSE

    This license is approved by the OSI and FSF as GPL-compatible.
        http://opensource.org/licenses/isc-license.txt

    Copyright (c) 2012, Noah Spurrier <noah@noah.org>
    PERMISSION TO USE, COPY, MODIFY, AND/OR DISTRIBUTE THIS SOFTWARE FOR ANY
    PURPOSE WITH OR WITHOUT FEE IS HEREBY GRANTED, PROVIDED THAT THE ABOVE
    COPYRIGHT NOTICE AND THIS PERMISSION NOTICE APPEAR IN ALL COPIES.
    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
    MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

"""

import pexpect, os, sys, re
from types import *

class ExceptionPsh(pexpect.ExceptionPexpect):

    """Raised for Psh exceptions.
    """

class ExceptionErrorCode(ExceptionPsh):

    """Raised when an program returns an error code.
    """

    def __init__(self, string, err_code, cmd_output):

        ExceptionPsh.__init__(self,string)
        self.error  = err_code
        self.output = cmd_output 

class psh (object):

    def __init__ (self,exp):

        self.exp = exp
        self.default_timeout = 30 # Seconds
    
    def ls (self, path=''):

        fileStr = self.run("ls %s" % path)
        return fileStr.split()
      
    def cd (self, path='-'):

        return self.run("cd %s" % path)
      
    def rm (self, path=''):

        return self.run("/bin/rm -f %s" % path)
      
    def cp (self, path_from='', path_to=''):

        return self.run("/bin/cp %s %s" % (path_from, path_to))

    def mv (self, path_from='', path_to=''):

        return self.run("/bin/mv %s %s" % (path_from, path_to))
      
    def pwd (self):

        return self.run("/bin/pwd")
      
    def which (self, exe_name):

        return self.run("/usr/bin/which %s" % exe_name)
                            
    def chown (self, path, user='', group=None, recurse=False):

        xtra_flags = ""
        if recurse: xtra_flags = "-R"
        if group: group = ':' + group
        else: group = ""
        
        return self.run("/bin/chmod %s %s%s %s" % (recurse,user,group,path))

    def chmod (self, path, perms='', recurse=False):

        xtra_flags = ""
        if recurse: xtra_flags = "-R"        
        return self.run("/usr/bin/chmod %s %s %s" % (xtra_flags, perms, path))
      
    def chattr (self, path, attrs='', recurse=False):

        xtra_flags = ""
        if recurse: xtra_flags = "-R"        
        return self.run("/usr/bin/chattr %s %s %s" % (xtra_flags, attrs, path))

    def cat (self, path):

        return self.run("/bin/cat %s" % path)
      
    def run (self, cmd, stim_resp_dict = {}, timeout=None):

       (ret, output) = self.run_raw(cmd, stim_resp_dict, timeout)
       if ret == 0: return output
       raise ExceptionErrorCode("Running command [%s] returned error [%d]" % (cmd,ret), ret, output)

    def run_raw(self, cmd, stim_resp_dict=None, timeout=None):

        """Someone contributed this, but now I've lost touch and I forget the motive of this.
        It was sort of a sketch at the time which doesn't make this any easier to prioritize, but
        it seemed important at the time.
        """

        if not timeout: timeout = self.default_timeout

        def cmd_exp_loop(param):
            if type(param) is DictType:
                param = (param,)
            for item in param:
                if type(item) is type(()) or type(item) is type([]):
                    cmd_exp_loop(item)
                elif type(item) is type(""):
                    self.exp.send(item)
                elif type(item) is type({}):
                    dict = item
                    while(1):
                        stimulus = dict.keys()
                        idx = self.exp.expect_exact(stimulus, timeout)
                        keys = dict.keys()
                        respond = dict[keys[idx]]
                        if type(respond) is type({}) or type(respond) is type(()) or type(item) is type([]):
                            cmd_exp_loop(respond)
                        if type(respond) is type(""):
                            self.exp.send(respond)
                        elif type(respond) is InstanceType and Exception in inspect.getmro(respond.__class__):
                            raise respond
                        elif type(respond) is type(0):
                            return (respond, self.exp.before)
                        elif respond is None:
                            break
                        else:
                            self.exp.send(str(respond))

        if stim_resp_dict == None:
            stim_resp_dict = {}

        self.exp.sendline("")
        if not self.exp.prompt(): raise SessionException("No prompt")
        self.exp.sendline(cmd)
        self.exp.expect_exact([cmd])
        stim_resp_dict[re.compile(self.exp.PROMPT)] = None
        cmd_exp_loop(stim_resp_dict)

        output = self.exp.before
        # Get the return code
        self.exp.sendline("echo $?")
        self.exp.expect_exact(["echo $?"])
        if not self.exp.prompt(): raise SessionException("No prompt", 0, self.exp.before)
        try:
            reg = re.compile("^(\d+)")
            s = self.exp.before.strip()
            #print s
            #pdb.set_trace()
            s = reg.search(s).groups()[0]
            error_code = int(s)
        except ValueError:
            log.error("Cannot parse %s into an int!" % self.exp.before)
            raise

        if not output[0:2] == '\r\n':
            log.warning("Returned output lacks leading \\r\\n which may indicate a tae error")
            log.debug2("Offending output string: [%s]" % output)
            return (error_code, output)
        else:
            return(error_code, output[2:])
  
#    def pipe (self, cmd, string_to_send):