# (c) 2015, Alejandro Guirao <lekumberri@gmail.com>
# (c) 2012-17 Ansible Project
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type

DOCUMENTATION = """
    lookup: shelvefile
    author: Alejandro Guirao <lekumberri@gmail.com>
    version_added: "2.0"
    short_description: read keys from Python shelve file
    description:
    optoins:
      _terms:
        description: sets of key value pairs of parameters
        options:
          key:
            description: key to query
            required: True
          file:
            description: path to shelve file
            required: True
"""

EXAMPLES = """
- name: retrieve a string value corresponding to a key inside a Python shelve file
  debug: msg="{{ lookup('shelvefile', 'file=path_to_some_shelve_file.db key=key_to_retrieve') }}
"""

RETURN = """
_list:
  description: value(s) of key(s) in shelve file(s)
"""
import shelve

from ansible.errors import AnsibleError, AnsibleAssertionError
from ansible.plugins.lookup import LookupBase
from ansible.module_utils._text import to_bytes, to_text


class LookupModule(LookupBase):

    def read_shelve(self, shelve_filename, key):
        """
        Read the value of "key" from a shelve file
        """
        d = shelve.open(to_bytes(shelve_filename))
        res = d.get(key, None)
        d.close()
        return res

    def run(self, terms, variables=None, **kwargs):

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

        ret = []

        for term in terms:
            paramvals = {"file": None, "key": None}
            params = term.split()

            try:
                for param in params:
                    name, value = param.split('=')
                    if name not in paramvals:
                        raise AnsibleAssertionError('%s not in paramvals' % name)
                    paramvals[name] = value

            except (ValueError, AssertionError) as e:
                # In case "file" or "key" are not present
                raise AnsibleError(e)

            key = paramvals['key']

            # Search also in the role/files directory and in the playbook directory
            shelvefile = self.find_file_in_search_path(variables, 'files', paramvals['file'])

            if shelvefile:
                res = self.read_shelve(shelvefile, key)
                if res is None:
                    raise AnsibleError("Key %s not found in shelve file %s" % (key, shelvefile))
                # Convert the value read to string
                ret.append(to_text(res))
                break
            else:
                raise AnsibleError("Could not locate shelve file in lookup: %s" % paramvals['file'])

        return ret
