from __future__ import absolute_import, division, print_function
__metaclass__ = type

from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.basic import env_fallback
from ansible.module_utils.urls import Request, SSLValidationError, ConnectionError
from ansible.module_utils.six.moves.urllib.parse import urlparse, urlencode
from ansible.module_utils.six.moves.urllib.error import HTTPError
from ansible.module_utils.six.moves.http_cookiejar import CookieJar
from ansible.module_utils.six.moves.configparser import ConfigParser, NoOptionError
from socket import gethostbyname
import re
from json import loads, dumps
from os.path import isfile, expanduser, split, join
from os import access, R_OK, getcwd


class ConfigFileException(Exception):
    pass


class ItemNotDefined(Exception):
    pass


class TowerModule(AnsibleModule):
    url = None
    honorred_settings = ['host', 'username', 'password', 'verify_ssl', 'oauth_token']
    host = '127.0.0.1'
    username = None
    password = None
    verify_ssl = True
    oauth_token = None
    oauth_token_id = None
    session = None
    cookie_jar = CookieJar()
    authenticated = False
    json_output = {'changed': False}
    config_name = 'tower_cli.cfg'

    def __init__(self, argument_spec, **kwargs):
        args = dict(
            tower_host=dict(required=False, fallback=(env_fallback, ['TOWER_HOST'])),
            tower_username=dict(required=False, fallback=(env_fallback, ['TOWER_USERNAME'])),
            tower_password=dict(no_log=True, required=False, fallback=(env_fallback, ['TOWER_PASSWORD'])),
            validate_certs=dict(type='bool', aliases=['tower_verify_ssl'], required=False, fallback=(env_fallback, ['TOWER_VERIFY_SSL'])),
            tower_oauthtoken=dict(type='str', no_log=True, required=False, fallback=(env_fallback, ['TOWER_OAUTH_TOKEN'])),
            tower_config_file=dict(type='path', required=False, default=None),
        )
        args.update(argument_spec)
        kwargs['supports_check_mode'] = True

        super(TowerModule, self).__init__(argument_spec=args, **kwargs)

        self.load_config_files()

        # Parameters specified on command line will override settings in any config
        if self.params.get('tower_host'):
            self.host = self.params.get('tower_host')
        if self.params.get('tower_username'):
            self.username = self.params.get('tower_username')
        if self.params.get('tower_password'):
            self.password = self.params.get('tower_password')
        if self.params.get('validate_certs') is not None:
            self.verify_ssl = self.params.get('validate_certs')
        if self.params.get('tower_oauthtoken'):
            self.oauth_token = self.params.get('tower_oauthtoken')

        # Perform some basic validation
        if not re.match('^https{0,1}://', self.host):
            self.host = "https://{0}".format(self.host)

        # Try to parse the hostname as a url
        try:
            self.url = urlparse(self.host)
        except Exception as e:
            self.fail_json(msg="Unable to parse tower_host as a URL ({1}): {0}".format(self.host, e))

        # Try to resolve the hostname
        hostname = self.url.netloc.split(':')[0]
        try:
            gethostbyname(hostname)
        except Exception as e:
            self.fail_json(msg="Unable to resolve tower_host ({1}): {0}".format(hostname, e))

        self.session = Request(cookies=self.cookie_jar)

    def load_config_files(self):
        # Load configs like TowerCLI would have from least import to most
        config_files = [join('/etc/tower/', self.config_name), join(expanduser("~"), ".{0}".format(self.config_name))]
        local_dir = getcwd()
        config_files.append(join(local_dir, self.config_name))
        while split(local_dir)[1]:
            local_dir = split(local_dir)[0]
            config_files.insert(2, join(local_dir, self.config_name))

        for config_file in config_files:
            try:
                self.load_config(config_file)
            except ConfigFileException:
                # Since some of these may not exist or can't be read, we really don't care
                pass

        # If we have a specified  tower config, load it
        if self.params.get('tower_config_file'):
            try:
                self.load_config(self.params.get('tower_config_file'))
            except ConfigFileException as cfe:
                # Since we were told specifically to load this we want to fail if we have an error
                self.fail_json(msg=cfe)

    def load_config(self, config_path):
        config = ConfigParser()
        # Validate the config file is an actual file
        if not isfile(config_path):
            raise ConfigFileException('The specified config file does not exist')

        if not access(config_path, R_OK):
            raise ConfigFileException("The specified config file can not be read")

        config.read(config_path)
        if not config.has_section('general'):
            self.warn("No general section in file, auto-appending")
            with open(config_path, 'r') as f:
                config.read_string('[general]\n%s' % f.read())

        for honorred_setting in self.honorred_settings:
            try:
                setattr(self, honorred_setting, config.get('general', honorred_setting))
            except (NoOptionError):
                pass

    def head_endpoint(self, endpoint, *args, **kwargs):
        return self.make_request('HEAD', endpoint, **kwargs)

    def get_endpoint(self, endpoint, *args, **kwargs):
        return self.make_request('GET', endpoint, **kwargs)

    def patch_endpoint(self, endpoint, *args, **kwargs):
        # Handle check mode
        if self.check_mode:
            self.json_output['changed'] = True
            self.exit_json(**self.json_output)

        return self.make_request('PATCH', endpoint, **kwargs)

    def post_endpoint(self, endpoint, *args, **kwargs):
        # Handle check mode
        if self.check_mode:
            self.json_output['changed'] = True
            self.exit_json(**self.json_output)

        return self.make_request('POST', endpoint, **kwargs)

    def delete_endpoint(self, endpoint, *args, **kwargs):
        # Handle check mode
        if self.check_mode:
            self.json_output['changed'] = True
            self.exit_json(**self.json_output)

        return self.make_request('DELETE', endpoint, **kwargs)

    def get_all_endpoint(self, endpoint, *args, **kwargs):
        response = self.get_endpoint(endpoint, *args, **kwargs)
        next_page = response['json']['next']

        if response['json']['count'] > 10000:
            self.fail_json(msg='The number of items being queried for is higher than 10,000.')

        while next_page is not None:
            next_response = self.get_endpoint(next_page)
            response['json']['results'] = response['json']['results'] + next_response['json']['results']
            next_page = next_response['json']['next']
        return response

    def get_one(self, endpoint, *args, **kwargs):
        response = self.get_endpoint(endpoint, *args, **kwargs)
        if response['status_code'] != 200:
            self.fail_json(msg="Got a {0} response when trying to get one from {1}".format(response['status_code'], endpoint))

        if 'count' not in response['json'] or 'results' not in response['json']:
            self.fail_json(msg="The endpoint did not provide count and results")

        if response['json']['count'] == 0:
            return None
        elif response['json']['count'] > 1:
            self.fail_json(msg="An unexpected number of items was returned from the API ({0})".format(response['json']['count']))

        return response['json']['results'][0]

    def resolve_name_to_id(self, endpoint, name_or_id):
        # Try to resolve the object by name
        response = self.get_endpoint(endpoint, **{'data': {'name': name_or_id}})
        if response['json']['count'] == 1:
            return response['json']['results'][0]['id']
        elif response['json']['count'] == 0:
            # If we got 0 items by name, maybe they gave us an ID, lets try looking it by by ID
            response = self.head_endpoint("{0}/{1}".format(endpoint, name_or_id), **{'return_none_on_404': True})
            if response is not None:
                return name_or_id
            self.fail_json(msg="The {0} {1} was not found on the Tower server".format(endpoint, name_or_id))
        else:
            self.fail_json(msg="Found too many names {0} at endpoint {1} try using an ID instead of a name".format(name_or_id, endpoint))

    def make_request(self, method, endpoint, *args, **kwargs):
        # Incase someone is calling us directly; make sure we were given a method, lets not just assume a GET
        if not method:
            raise Exception("The HTTP method must be defined")

        # Make sure we start with /api/vX
        if not endpoint.startswith("/"):
            endpoint = "/{0}".format(endpoint)
        if not endpoint.startswith("/api/"):
            endpoint = "/api/v2{0}".format(endpoint)
        if not endpoint.endswith('/') and '?' not in endpoint:
            endpoint = "{0}/".format(endpoint)

        # Extract the headers, this will be used in a couple of places
        headers = kwargs.get('headers', {})

        # Authenticate to Tower (if we've not already done so)
        if not self.authenticated:
            # This method will set a cookie in the cookie jar for us
            self.authenticate(**kwargs)
        if self.oauth_token:
            # If we have a oauth toekn we just use a bearer header
            headers['Authorization'] = 'Bearer {0}'.format(self.oauth_token)

        # Update the URL path with the endpoint
        self.url = self.url._replace(path=endpoint)

        if method in ['POST', 'PUT', 'PATCH']:
            headers.setdefault('Content-Type', 'application/json')
            kwargs['headers'] = headers
        elif kwargs.get('data'):
            self.url = self.url._replace(query=urlencode(kwargs.get('data')))

        data = {}
        if headers.get('Content-Type', '') == 'application/json':
            data = dumps(kwargs.get('data', {}))

        try:
            response = self.session.open(method, self.url.geturl(), headers=headers, validate_certs=self.verify_ssl, follow_redirects=True, data=data)
            self.url = self.url._replace(query=None)
        except(SSLValidationError) as ssl_err:
            self.fail_json(msg="Could not establish a secure connection to your host ({1}): {0}.".format(self.url.netloc, ssl_err))
        except(ConnectionError) as con_err:
            self.fail_json(msg="There was a network error of some kind trying to connect to your host ({1}): {0}.".format(self.url.netloc, con_err))
        except(HTTPError) as he:
            # Sanity check: Did the server send back some kind of internal error?
            if he.code >= 500:
                self.fail_json(msg='The host sent back a server error ({1}): {0}. Please check the logs and try again later'.format(self.url.path, he))
            # Sanity check: Did we fail to authenticate properly?  If so, fail out now; this is always a failure.
            elif he.code == 401:
                self.fail_json(msg='Invalid Tower authentication credentials for {0} (HTTP 401).'.format(self.url.path))
            # Sanity check: Did we get a forbidden response, which means that the user isn't allowed to do this? Report that.
            elif he.code == 403:
                self.fail_json(msg="You don't have permission to {1} to {0} (HTTP 403).".format(self.url.path, method))
            # Sanity check: Did we get a 404 response?
            # Requests with primary keys will return a 404 if there is no response, and we want to consistently trap these.
            elif he.code == 404:
                if kwargs.get('return_none_on_404', False):
                    return None
                self.fail_json(msg='The requested object could not be found at {0}.'.format(self.url.path))
            # Sanity check: Did we get a 405 response?
            # A 405 means we used a method that isn't allowed. Usually this is a bad request, but it requires special treatment because the
            # API sends it as a logic error in a few situations (e.g. trying to cancel a job that isn't running).
            elif he.code == 405:
                self.fail_json(msg="The Tower server says you can't make a request with the {0} method to this endpoing {1}".format(method, self.url.path))
            # Sanity check: Did we get some other kind of error?  If so, write an appropriate error message.
            elif he.code >= 400:
                # We are going to return a 400 so the module can decide what to do with it
                page_data = he.read()
                try:
                    return {'status_code': he.code, 'json': loads(page_data)}
                # JSONDecodeError only available on Python 3.5+
                except ValueError:
                    return {'status_code': he.code, 'text': page_data}
                # self.fail_json(msg='The Tower server claims it was sent a bad request.\n{0} {1}\nstatus code: {2}\n\nResponse: {3}'.format(
                #     method, self.url.path, he.code, he.read()))
            elif he.code == 204 and method == 'DELETE':
                # a 204 is a normal response for a delete function
                pass
            else:
                self.fail_json(msg="Unexpected return code when calling {0}: {1}".format(self.url.geturl(), he))
        except(Exception) as e:
            self.fail_json(msg="There was an unknown error when trying to connect to {2}: {0} {1}".format(type(e).__name__, e, self.url.geturl()))

        response_body = ''
        try:
            response_body = response.read()
        except(Exception) as e:
            self.fail_json(msg="Failed to read response body: {0}".format(e))

        response_json = {}
        if response_body and response_body != '':
            try:
                response_json = loads(response_body)
            except(Exception) as e:
                self.fail_json(msg="Failed to parse the response json: {0}".format(e))

        return {'status_code': response.status, 'json': response_json}

    def authenticate(self, **kwargs):
        if self.username and self.password:
            # Attempt to get a token from /api/v2/tokens/ by giving it our username/password combo
            # If we have a username and password we need to get a session cookie
            login_data = {
                "description": "Ansible Tower Module Token",
                "application": None,
                "scope": "write",
            }
            # Post to the tokens endpoint with baisc auth to try and get a token
            api_token_url = (self.url._replace(path='/api/v2/tokens/')).geturl()

            try:
                response = self.session.open(
                    'POST', api_token_url,
                    validate_certs=self.verify_ssl, follow_redirects=True,
                    force_basic_auth=True, url_username=self.username, url_password=self.password,
                    data=dumps(login_data), headers={'Content-Type': 'application/json'}
                )
            except(Exception) as e:
                # Sanity check: Did the server send back some kind of internal error?
                self.fail_json(msg='Failed to get token: {0}'.format(e))

            token_response = None
            try:
                token_response = response.read()
                response_json = loads(token_response)
                self.oauth_token_id = response_json['id']
                self.oauth_token = response_json['token']
            except(Exception) as e:
                self.fail_json(msg="Failed to extract token information from login response: {0}".format(e), **{'response': token_response})

        # If we have neiter of these then we can try un-authenticated access
        self.authenticated = True

    def default_check_mode(self):
        '''Execute check mode logic for Ansible Tower modules'''
        if self.check_mode:
            try:
                result = self.get_endpoint('ping')
                self.exit_json(**{'changed': True, 'tower_version': '{0}'.format(result['json']['version'])})
            except(Exception) as excinfo:
                self.fail_json(changed=False, msg='Failed check mode: {0}'.format(excinfo))

    def delete_if_needed(self, existing_item, handle_response=True, on_delete=None):
        # This will exit from the module on its own unless handle_response is False.
        #   if handle response is True and the method successfully deletes an item and on_delete param is defined
        #   the on_delete parameter will be called as a method pasing in this object and the json from the response
        # If you pass handle_response=False it will return one of two things:
        #   None if the existing_item is not defined (so no delete needs to happen)
        #   The response from Tower from calling the delete on the endpont. Its up to you to process the response and exit from the module
        # Note: common error codes from the Tower API can cause the module to fail even if handle_response is set to False
        if existing_item:
            # If we have an item, we can try to delete it
            try:
                item_url = existing_item['url']
                item_name = existing_item['name']
                item_type = existing_item['url']
                item_id = existing_item['id']
            except KeyError as ke:
                self.fail_json(msg="Unable to process delete of item due to missing data {0}".format(ke))

            response = self.delete_endpoint(item_url)

            if not handle_response:
                return response
            elif response['status_code'] in [202, 204]:
                if on_delete:
                    on_delete(self, response['json'])
                self.json_output['changed'] = True
                self.json_output['id'] = item_id
                self.exit_json(**self.json_output)
            else:
                if 'json' in response and '__all__' in response['json']:
                    self.fail_json(msg="Unable to delete {0} {1}: {2}".format(item_type, item_name, response['json']['__all__'][0]))
                elif 'json' in response:
                    # This is from a project delete if there is an active job against it
                    if 'error' in response['json']:
                        self.fail_json(msg="Unable to delete {0} {1}: {2}".format(item_type, item_name, response['json']['error']))
                    else:
                        self.fail_json(msg="Unable to delete {0} {1}: {2}".format(item_type, item_name, response['json']))
                else:
                    self.fail_json(msg="Unable to delete {0} {1}: {2}".format(item_type, item_name, response['status_code']))
        else:
            if not handle_response:
                return None
            else:
                self.exit_json(**self.json_output)

    def create_if_needed(self, existing_item, new_item, endpoint, handle_response=True, on_create=None, item_type='unknown'):
        #
        # This will exit from the module on its own unless handle_response is False.
        #   if handle response is True and the method successfully creates an item and on_create param is defined
        #    the on_create parameter will be called as a method pasing in this object and the json from the response
        # If you pass handle_response=False it will return one of two things:
        #    None if the existing_item is already defined (so no create needs to happen)
        #    The response from Tower from calling the patch on the endpont. Its up to you to process the response and exit from the module
        # Note: common error codes from the Tower API can cause the module to fail even if handle_response is set to False
        #
        if not endpoint:
            self.fail_json(msg="Unable to create new {} due to missing endpoint".format(item_type))

        if existing_item:
            try:
                item_url = existing_item['url']
            except KeyError as ke:
                self.fail_json(msg="Unable to process delete of item due to missing data {0}".format(ke))
            if not handle_response:
                return None
            else:
                self.exit_json(**self.json_output)
        else:
            # If we dont have an exisitng_item, we can try to create it

            # We have to rely on item_type being passed in since we don't have an existing item that declares its type
            # The item_name we will pull out from the new_item (if it exists)
            item_name = new_item.get('name', 'unknown')

            response = self.post_endpoint(endpoint, **{'data': new_item})
            if not handle_response:
                return response
            elif response['status_code'] == 201:
                self.json_output['name'] = response['json']['name']
                self.json_output['id'] = response['json']['id']
                self.json_output['changed'] = True
                if on_create is None:
                    self.exit_json(**self.json_output)
                else:
                    on_create(self, response['json'])
            else:
                if 'json' in response and '__all__' in response['json']:
                    self.fail_json(msg="Unable to create {0} {1}: {2}".format(item_type, item_name, response['json']['__all__'][0]))
                elif 'json' in response:
                    self.fail_json(msg="Unable to create {0} {1}: {2}".format(item_type, item_name, response['json']))
                else:
                    self.fail_json(msg="Unable to create {0} {1}: {2}".format(item_type, item_name, response['status_code']), **{'payload': kwargs['data']})

    def update_if_needed(self, existing_item, new_item, handle_response=True, on_update=None):
        # This will exit from the module on its own unless handle_response is False.
        #   if handle response is True and the method successfully updates an item and on_update param is defined
        #   the on_update parameter will be called as a method pasing in this object and the json from the response
        # If you pass handle_response=False it will return one of three things:
        #    None if the existing_item does not need to be updated
        #    The response from Tower from patching to the endpoint. Its up to you to process the response and exit from the module.
        #    an ItemNotDefined exception if the existing_item does not exist
        # Note: common error codes from the Tower API can cause the module to fail even if handle_response is set to False
        if existing_item:
            # If we have an item, we can see if needs an update
            try:
                item_url = existing_item['url']
                item_name = existing_item['name']
                item_type = existing_item['url']
                item_id = existing_item['id']
            except KeyError as ke:
                self.fail_json(msg="Unable to process update of item due to missing data {0}".format(ke))

            needs_update = False
            for field in new_item:
                existing_field = existing_item.get(field, None)
                new_field = new_item.get(field, None)
                # If the two items don't match and we are not comparing '' to None
                if existing_field != new_field and not (existing_field in (None, '') and new_field == ''):
                    # something dosent match so lets do it
                    neds_update = True
                    break

            if needs_update:
                response = self.patch_endpoint(item_url, **{'data': new_item})
                if not handle_response:
                    return response
                elif response['status_code'] == 200:
                    self.json_output['changed'] = True
                    self.json_output['id'] = item_id
                    if on_update is None:
                        self.exit_json(**self.json_output)
                    else:
                        on_update(self, response['json'])
                elif 'json' in response and '__all__' in response['json']:
                    self.fail_json(msg=response['json']['__all__'])
                else:
                    self.fail_json(**{'msg': "Unable to update {0} {1}, see response".format(item_type, item_name), 'response': response})
            else:
                if not handle_response:
                    return None

                # Since we made it here, we don't need to update, status ok
                self.json_output['changed'] = False
                self.json_output['id'] = item_id
                self.exit_json(**self.json_output)
        else:
            if handle_response:
                self.fail_json(msg="The exstiing item is not defined and thus cannot be updated")
            else:
                raise ItemNotDefined("Not given an existing item to update")

    def create_or_update_if_needed(self, existing_item, new_item, endpoint=None, handle_response=True, item_type='unknown', on_create=None, on_update=None):
        if existing_item:
            return self.update_if_needed(existing_item, new_item, handle_response=handle_response, on_update=on_update)
        else:
            return self.create_if_needed(existing_item, new_item, endpoint, handle_response=handle_response, on_create=on_create, item_type=item_type)

    def logout(self):
        if self.oauth_token_id is not None and self.username and self.password:
            # Attempt to delete our current token from /api/v2/tokens/
            # Post to the tokens endpoint with baisc auth to try and get a token
            api_token_url = (self.url._replace(path='/api/v2/tokens/{0}/'.format(self.oauth_token_id))).geturl()

            try:
                self.session.open(
                    'DELETE',
                    api_token_url,
                    validate_certs=self.verify_ssl,
                    follow_redirects=True,
                    force_basic_auth=True,
                    url_username=self.username,
                    url_password=self.password
                )
                self.oauth_token_id = None
                self.authenticated = False
            except(Exception) as e:
                # Sanity check: Did the server send back some kind of internal error?
                self.warn('Failed to release tower token {0}: {1}'.format(self.oauth_token_id, e))

    def fail_json(self, **kwargs):
        # Try to logout if we are authenticated
        self.logout()
        super(TowerModule, self).fail_json(**kwargs)

    def exit_json(self, **kwargs):
        # Try to logout if we are authenticated
        self.logout()
        super(TowerModule, self).exit_json(**kwargs)

    def is_job_done(self, job_status):
        if job_status in ['new', 'pending', 'waiting', 'running']:
            return False
        return True