import os

import re

import django_extensions

from django.core.management.base import CommandError, LabelCommand, _make_writeable

from optparse import make_option

class Command(LabelCommand):

    option_list = LabelCommand.option_list + (

        make_option('--template', '-t', action='store', dest='app_template', 

            help='The path to the app template'),

        make_option('--parent_path', '-p', action='store', dest='parent_path', 

            help='The parent path of the app to be created'),

    )

    help = ("Creates a Django application directory structure based on the specified template directory.")

    args = "[appname]"

    label = 'application name'

    requires_model_validation = False

    can_import_settings = True

    def handle_label(self, label, **options):

        project_dir = os.getcwd()

        project_name = os.path.split(project_dir)[-1]

        app_name =label

        app_template = options.get('app_template') or os.path.join(django_extensions.__path__[0], 'conf', 'app_template')

        app_dir = os.path.join(options.get('parent_path') or project_dir, app_name)

        if not os.path.exists(app_template):

            raise CommandError("The template path, %r, does not exist." % app_template)

        if not re.search(r'^\w+$', label):

            raise CommandError("%r is not a valid application name. Please use only numbers, letters and underscores." % label)

        try:

            os.makedirs(app_dir)

        except OSError, e:

            raise CommandError(e)

        copy_template(app_template, app_dir, project_name, app_name)

def copy_template(app_template, copy_to, project_name, app_name):

    """copies the specified template directory to the copy_to location"""

    import shutil

    # walks the template structure and copies it

    for d, subdirs, files in os.walk(app_template):

        relative_dir = d[len(app_template)+1:]

        if relative_dir and not os.path.exists(os.path.join(copy_to, relative_dir)):

            os.mkdir(os.path.join(copy_to, relative_dir))

        for i, subdir in enumerate(subdirs):

            if subdir.startswith('.'):

                del subdirs[i]

        for f in files:

            if f.endswith('.pyc') or f.startswith('.DS_Store'):

                continue

            path_old = os.path.join(d, f)

            path_new = os.path.join(copy_to, relative_dir, f.replace('app_name', app_name))

            if os.path.exists(path_new):

                path_new = os.path.join(copy_to, relative_dir, f)

                if os.path.exists(path_new):

                    continue

            path_new = path_new.rstrip(".tmpl")

            fp_old = open(path_old, 'r')

            fp_new = open(path_new, 'w')

            fp_new.write(fp_old.read().replace('{{ app_name }}', app_name).replace('{{ project_name }}', project_name))

            fp_old.close()

            fp_new.close()

            try:

                shutil.copymode(path_old, path_new)

                _make_writeable(path_new)

            except OSError:

                sys.stderr.write(style.NOTICE("Notice: Couldn't set permission bits on %s. You're probably using an uncommon filesystem setup. No problem.\n" % path_new))