#!/usr/bin/env python

"""
Implementation of Linux 'cp' command
with r and f modes.
"""

__author__ = 'Irshad Ahmad Bhat'
__email__  = 'bhatirshad127@gmail.com'


import os
import sys
import stat

def copyfile(file_path, targer_dir):
    os.chdir(file_path[:file_path.rindex('/')])
    file_name = file_path[file_path.rindex('/')+1:]
    if not os.access(file_name, os.R_OK):
        if sys.argv[1] !='-f':
            print "permission denied"
            sys.exit()
        else:
            acc_mode = os.stat(file_name)
            os.chmod(file_name, acc_mode.st_mode | stat.S_IREAD)
    file_pointer = open(file_name, 'rb')
    temp_file = file_pointer.read()
    file_pointer.close()
    os.chdir(target_dir)
    file_pointer =open(file_name, 'wb')
    file_pointer.write(temp_file)
    file_pointer.close()
    print "Done..."

def recursive_copy(source_dir, target_dir):
    if not (os.access(source_dir, os.X_OK) and os.access(source_dir, os.R_OK)):
        if 'f' not in sys.argv[1]:
            print "permission denied"
            sys.exit()
        else:
            acc_mode = os.stat(source_dir)
            os.chmod(source_dir, acc_mode.st_mode | stat.S_IXUSR)
            os.chmod(source_dir, acc_mode.st_mode | stat.S_IREAD)
    os.chdir(target_dir)
    os.makedirs(source_dir[source_dir.rindex('/')+1:])
    target_dir2 = target_dir +'/'+ source_dir[source_dir.rindex('/')+1:]
    wlk = os.walk(source_dir)
    root, dirnames, filenames = next(wlk)
    for new_file in filenames:
        os.chdir(source_dir)
        if not os.access(new_file, os.R_OK):
            if 'f' not in sys.argv[1]:
                print "permission denied"
                sys.exit()
            else:
                acc_mode = os.stat(new_file)
                os.chmod(new_file, acc_mode.st_mode | stat.S_IREAD)
        file_pointer = open(root+'/'+new_file, 'rb')
        temp_file = file_pointer.read()
        file_pointer.close()
        os.chdir(target_dir2)
        file_pointer =open(new_file, 'wb')
        file_pointer.write(temp_file)
        file_pointer.close()
    for new_dir in dirnames:
        recursive_copy(root+'/'+new_dir,target_dir2)

if __name__ == "__main__":

    if len(sys.argv)==4 and os.path.isdir(sys.argv[2]):
        if not (sys.argv[1] == '-r' or sys.argv[1] == '-rf' or sys.argv[1] == '-fr'):
            inv = list(set(sys.argv[1]) - set('-rf'))
            if inv: print "invalid option -- '{}'".format(inv[0])
            else: print "omitting directory '{}'".format(sys.argv[2])
            sys.exit()
        else:
            if not (os.path.isdir(sys.argv[3])):
                print "'{}': No such file or directory".format(sys.argv[3])
                sys.exit()
            source_dir = os.path.abspath(sys.argv[2])
            target_dir = os.path.abspath(sys.argv[3])
            top = target_dir +'/'+ source_dir[source_dir.rindex('/')+1:]
            if source_dir == top:
                print "'{}' and '{}' are the same file".format(sys.argv[2],top)
                sys.exit()
            if os.path.exists(top):
                for root, dirs, files in os.walk(top, topdown=False):
                    for name in files:
                        os.remove(os.path.join(root, name))
                    for name in dirs:
                        os.rmdir(os.path.join(root, name))
                os.rmdir(top)
            recursive_copy(source_dir,target_dir)
            print "Done..."
    elif len(sys.argv) == 3 or (len(sys.argv) == 4 and os.path.isfile(sys.argv[2])):
        if len(sys.argv) == 4:
            file_path = sys.argv[2]
            target_dir = sys.argv[3]
        else:
            file_path = sys.argv[1]
            target_dir = sys.argv[2]
            if not (os.path.exists(file_path) and os.path.exists(target_dir)):
                print "'{}': No such file or directory".format(file_path)
            if os.path.isdir(file_path):
                print "omitting directory '{}'".format(file_path)
                sys.exit()
        copyfile(os.path.abspath(file_path),os.path.abspath(target_dir))
    else:
        if len(sys.argv) != 4:
            print "Enter valid arguments"
            sys.exit()
        print "'{}': No such file or directory".format(sys.argv[2]