# Copyright 2017 RedHat, inc
#
# This file is part of Ansible
#
# Ansible 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 3 of the License, or
# (at your option) any later version.
#
# Ansible 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 Ansible.  If not, see <http://www.gnu.org/licenses/>.
#############################################
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type

DOCUMENTATION = '''
    vars: host_group_vars
    version_added: "2.4"
    short_description: In charge of loading group_vars and host_vars
    description:
        - Loads YAML vars into corresponding groups/hosts in group_vars/ and host_vars/ directories.
        - Files are restricted by extension to one of .yaml, .json, .yml or no extension.
        - Hidden (starting with '.') and backup (ending with '~') files and directories are ignored.
        - Only applies to inventory sources that are existing paths.
    options:
      _valid_extensions:
        default: [".yml", ".yaml", ".json"]
        description:
          - "Check all of these extensions when looking for 'variable' files which should be YAML or JSON or vaulted versions of these."
          - 'This affects vars_files, include_vars, inventory and vars plugins among others.'
        env:
          - name: ANSIBLE_YAML_FILENAME_EXT
        ini:
          - section: yaml_valid_extensions
            key: defaults
        type: list
'''

import os
from ansible import constants as C
from ansible.errors import AnsibleParserError
from ansible.module_utils._text import to_bytes, to_native, to_text
from ansible.plugins.vars import BaseVarsPlugin
from ansible.inventory.host import Host
from ansible.inventory.group import Group
from ansible.utils.vars import combine_vars

FOUND = {}


class VarsModule(BaseVarsPlugin):

    def get_vars(self, loader, path, entities, cache=True):
        ''' parses the inventory file '''

        if not isinstance(entities, list):
            entities = [entities]

        super(VarsModule, self).get_vars(loader, path, entities)

        data = {}
        for entity in entities:
            if isinstance(entity, Host):
                subdir = 'host_vars'
            elif isinstance(entity, Group):
                subdir = 'group_vars'
            else:
                raise AnsibleParserError("Supplied entity must be Host or Group, got %s instead" % (type(entity)))

            # avoid 'chroot' type inventory hostnames /path/to/chroot
            if not entity.name.startswith(os.path.sep):
                try:
                    found_files = []
                    # load vars
                    b_opath = os.path.realpath(to_bytes(os.path.join(self._basedir, subdir)))
                    opath = to_text(b_opath)
                    key = '%s.%s' % (entity.name, opath)
                    if cache and key in FOUND:
                        found_files = FOUND[key]
                    else:
                        # no need to do much if path does not exist for basedir
                        if os.path.exists(b_opath):
                            if os.path.isdir(b_opath):
                                self._display.debug("\tprocessing dir %s" % opath)
                                found_files = loader.find_vars_files(opath, entity.name)
                                FOUND[key] = found_files
                            else:
                                self._display.warning("Found %s that is not a directory, skipping: %s" % (subdir, opath))

                    for found in found_files:
                        new_data = loader.load_from_file(found, cache=True, unsafe=True)
                        if new_data:  # ignore empty files
                            data = combine_vars(data, new_data)

                except Exception as e:
                    raise AnsibleParserError(to_native(e))
        return data
