#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import os, os.path
import shutil

# FUNCTIONS
########################################
def yes_no_question(question="Yes or no?", default=False):
    prompt=""
    if(default is True):
        prompt = " [Y/n]"
    else:
        prompt = " [y/N]"

    answer = input(question + prompt).lower()

    if(len(answer) == 0):
        return default
    else:
        answer = answer[0]

    if(default is True):
        if answer in ['n','0']:
            return False
    else:
        if answer in ['y','o','1']:
            return True

    return default

def contractuser(path):
    home = os.path.expanduser("~")

    if path.startswith(home):
        return path.replace(home, "~", 1) # Replace only one instance:
                                          # the first one
    else:
        return path

def copy_file_or_directory(logger, path_dst, path_src, overwrite=True):

    # Expand '~' as user's home dir
    dst = os.path.expanduser(path_dst)
    src = os.path.expanduser(path_src)

    if overwrite:

        # --------------------------------------
        def replace_backup():
            try:
                logger.info("Putting backup back in place")
                shutil.move(dst + ".bak", dst)

            except FileNotFoundError:
                logger.error("No backup of %s found. Oops" % dst)
                return False

            except PermissionError:
                logger.error("Cannot replace backup %s because of permissions"
                             % (dst + ".bak"))
                return False

            except FileExistsError:
                logger.error("%s has been created, you need to chose "        \
                             "manually to keep it or to use the backup %s"
                             % (dst, dst + ".bak"))
                return False

            return True
        # --------------------------------------


        try:
            logger.info("Moving old directory %s" % dst)
            shutil.move(dst, dst + ".bak")

        except FileNotFoundError:
            logger.info("No file %s exists yet" % dst)

        except PermissionError:
            logger.error("Unable to write %s, please check permissions"
                         % (dst + ".bak"))
            return False

        except FileExistsError:
            logger.error("%s already exists" % (dst + ".bak"))
            return False
    

    # No overwrite ? No problem.
    else:

         def replace_backup():
             return True


    # Copy the conf dir
    # --------------------------------------
    try:
        logger.info("Copying directory %s" % src)
        shutil.copytree(src, dst)

    except FileNotFoundError:
        logger.error("%s does not seem to exist" % src)
        replace_backup()
        return False

    except PermissionError:
        logger.error("Unable to write %s, please check permissions" % dst)
        replace_backup()
        return False

    except FileExistsError:
        logger.error("The directory '%s' already exists" % dst)
        replace_backup()
        return False

    # It's not a dir, it's a file !
    # --------------------------------------
    except NotADirectoryError:

        # Try not to overwrite an existing file.
        # Note that if 'overwrite' was set to True, any existing file would
        # have been moved at this point.
        if os.path.exists(dst):
            logger.error("The file %s already exists" % dst)
            replace_backup()
            return False

        try:
            logger.info("Copying file %s" % src)
            shutil.copyfile(src, dst)

        except PermissionError:
            logger.error("Unable to write %s, please check permissions" % dst)
            replace_backup()
            return False

    # Everything went well, time to remove the backup
    # --------------------------------------
    if overwrite:
        delete_file_or_dir((dst + ".bak"), logger)

    # The End.
    return True


# ======================================
def delete_file_or_dir(path, logger=None):

    # Set logger to '/dev/null' if it's not set
    if logger is None:
        logger = logging.getLogger("/dev/null")
        logger.addHandler(logging.NullHandler())

    # Try it as a dir first
    try:
        logger.info("Removing directory %s" % path)
        shutil.rmtree(path)

    except FileNotFoundError:
        logger.warning("File %s seems to be already deleted" % path)
        return False
    except PermissionError:
        logger.warning("Cannot remove dir %s, you will have to do it manually"
                       % path)
        return False

    # If not, try it as a file
    except NotADirectoryError:
        try:
            logger.info("Removing file %s" % path)
            os.remove(path)

        except PermissionError:
            logger.warning( "Cannot remove file %s, you'll have to do it "    \
                            "manually"
                            % path )
            return False

    return True