#
# Gramps - a GTK+/GNOME based genealogy program
#
# Copyright (C) 2000-2007  Donald N. Allingham
# Copyright (C) 2009       Gary Burton
# Copyright (C) 2011       Tim G L Lyons
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

"""
File and folder related utility functions
"""

#-------------------------------------------------------------------------
#
# Python modules
#
#-------------------------------------------------------------------------
import os
import sys
import shutil
import hashlib
import logging
LOG = logging.getLogger(".gen.utils.file")

#-------------------------------------------------------------------------
#
# Gramps modules
#
#-------------------------------------------------------------------------
from ..constfunc import win, mac, get_env_var
from ..const import TEMP_DIR, USER_HOME, ENV, GRAMPS_LOCALE as glocale

#-------------------------------------------------------------------------
#
#  Constants
#
#-------------------------------------------------------------------------
_NEW_NAME_PATTERN = '%s%sUntitled_%d.%s'

#-------------------------------------------------------------------------
#
#  Functions
#
#-------------------------------------------------------------------------
def find_file( filename):
    # try the filename we got
    try:
        if os.path.isfile(filename):
            return(filename)
    except UnicodeError:
        LOG.error("Filename %s raised a Unicode Error %s.", repr(filename), err)

    LOG.debug("Filename %s not found.", repr(filename))
    return ''

def find_folder( filename):
    # try the filename we got
    try:
        if os.path.isdir(filename):
            return(filename)
    except UnicodeError as err:
        LOG.error("Filename %s raised a Unicode Error %s", repr(filename), err)

    LOG.debug("Filename %s either not found or not a directory.",
              repr(filename))
    return ''

def get_new_filename(ext, folder='~/'):
    ix = 1
    while os.path.isfile(os.path.expanduser(_NEW_NAME_PATTERN %
                                            (folder, os.path.sep, ix, ext))):
        ix = ix + 1
    return os.path.expanduser(_NEW_NAME_PATTERN % (folder, os.path.sep, ix, ext))

def get_empty_tempdir(dirname):
    """ Return path to TEMP_DIR/dirname, a guaranteed empty directory

    makes intervening directories if required
    fails if _file_ by that name already exists,
    or for inadequate permissions to delete dir/files or create dir(s)

    """
    dirpath = os.path.join(TEMP_DIR, str(dirname))
    if os.path.isdir(dirpath):
        shutil.rmtree(dirpath)
    os.makedirs(dirpath)
    return dirpath

def rm_tempdir(path):
    """Remove a tempdir created with get_empty_tempdir"""
    if path.startswith(TEMP_DIR) and os.path.isdir(path):
        shutil.rmtree(path)

def relative_path(original, base):
    """
    Calculate the relative path from base to original, with base a directory,
    and original an absolute path
    On problems, original is returned unchanged
    """
    if not os.path.isdir(base):
        return original
    #original and base must be absolute paths
    if not os.path.isabs(base):
        return original
    if not os.path.isabs(original):
        return original
    original = os.path.normpath(original)
    base = os.path.normpath(base)

    # If the db_dir and obj_dir are on different drives (win only)
    # then there cannot be a relative path. Return original obj_path
    (base_drive, base) = os.path.splitdrive(base)
    (orig_drive, orig_name) = os.path.splitdrive(original)
    if base_drive.upper() != orig_drive.upper():
        return original

    # Starting from the filepath root, work out how much of the filepath is
    # shared by base and target.
    base_list = (base).split(os.sep)
    target_list = (orig_name).split(os.sep)
    # make sure '/home/person' and 'c:/home/person' both give
    #   list ['home', 'person']
    base_list = [_f for _f in base_list if _f]
    target_list = [_f for _f in target_list if _f]
    i = -1
    # base path is normcase (lower case on Windows) so compare target in lower
    # on Windows as well
    for i in range(min(len(base_list), len(target_list))):
        if win():
            if base_list[i].lower() != target_list[i].lower():
                break
        else:
            if base_list[i] != target_list[i]:
                break
    else:
        #if break did not happen we are here at end, and add 1.
        i += 1
    rel_list = [os.pardir] * (len(base_list) - i) + target_list[i:]
    return os.path.join(*rel_list)

def expand_path(path, normalize = True):
    """
    Expand environment variables in a path
    Uses both the environment variables and the Gramps environment
    The expansion uses the str.format, e.g. "~/{GRAMPSHOME}/{VERSION}/filename.txt"
    We make the assumption that the user will not use a path that contain variable names
    (it is technically possible to use characters "{", "}" in  paths)
    """
    environment = dict(os.environ)
    environment.update(ENV)
    if not 'GRAMPSHOME' in environment:
        environment['GRAMPSHOME'] = USER_HOME
    path = path.format(**environment)
    if normalize:
        path = os.path.normcase(os.path.normpath(os.path.abspath(path)))
    return path

def media_path(db):
    """
    Given a database, return the mediapath to use as basedir for media
    """
    mpath = db.get_mediapath()
    return expand_media_path(mpath, db)

def expand_media_path(mpath, db):
    """
    Normalize a mediapath:
     - Relative mediapath are considered as relative to the database
     - Expand variables, see expand_path
     - Convert to absolute path
     - Convert slashes and case (on Windows)
    """
    # Use home dir if no media_path specified
    if mpath is None:
        mpath = os.path.abspath(USER_HOME)
    # Expand environment variables
    mpath = expand_path(mpath, False)
    # Relative mediapath are considered as relative to the database
    if not os.path.isabs(mpath):
        basepath = db.get_save_path()
        if not basepath:
            basepath = USER_HOME
        mpath = os.path.join(os.path.abspath(basepath), mpath)
    # Normalize path
    mpath = os.path.normcase(os.path.normpath(os.path.abspath(mpath)))
    return mpath

def media_path_full(db, filename):
    """
    Given a database and a filename of a media, return the media filename
    is full form, eg 'graves/tomb.png' becomes '/home/me/genea/graves/tomb.png
    """
    if os.path.isabs(filename):
        return filename
    mpath = media_path(db)
    return os.path.join(mpath, filename)

def search_for(name):
    if name.startswith( '"' ):
        name = name.split('"')[1]
    else:
        name = name.split()[0]
    if win():
        for i in get_env_var('PATH').split(';'):
            fname = os.path.join(i, name)
            if os.access(fname, os.X_OK) and not os.path.isdir(fname):
                return 1
        if os.access(name, os.X_OK) and not os.path.isdir(name):
            return 1
    else:
        for i in os.environ['PATH'].split(':'): #not win()
            fname = os.path.join(i, name)
            if os.access(fname, os.X_OK) and not os.path.isdir(fname):
                return 1
    return 0

def create_checksum(full_path):
    """
    Create a md5 hash for the given file.
    """
    full_path = os.path.normpath(full_path)
    try:
        with open(full_path, 'rb') as media_file:
            md5sum = hashlib.md5(media_file.read()).hexdigest()
    except IOError:
            md5sum = ''
    except UnicodeEncodeError:
            md5sum = ''
    return md5sum
