# TODO to extract the discovery stuff into a util at the top level and then use it both here and old discovery.py
import logging
import sys
from collections import OrderedDict

from config_app.c_app import app
from config_app.config_endpoints.api import method_metadata
from config_app.config_endpoints.common import fully_qualified_name, PARAM_REGEX, TYPE_CONVERTER

logger = logging.getLogger(__name__)


def generate_route_data():
  include_internal = True
  compact = True

  def swagger_parameter(name, description, kind='path', param_type='string', required=True,
                        enum=None, schema=None):
    # https://github.com/swagger-api/swagger-spec/blob/master/versions/2.0.md#parameterObject
    parameter_info = {
      'name': name,
      'in': kind,
      'required': required
    }

    if schema:
      parameter_info['schema'] = {
        '$ref': '#/definitions/%s' % schema
      }
    else:
      parameter_info['type'] = param_type

    if enum is not None and len(list(enum)) > 0:
      parameter_info['enum'] = list(enum)

    return parameter_info

  paths = {}
  models = {}
  tags = []
  tags_added = set()
  operation_ids = set()

  for rule in app.url_map.iter_rules():
    endpoint_method = app.view_functions[rule.endpoint]

    # Verify that we have a view class for this API method.
    if not 'view_class' in dir(endpoint_method):
      continue

    view_class = endpoint_method.view_class

    # Hide the class if it is internal.
    internal = method_metadata(view_class, 'internal')
    if not include_internal and internal:
      continue

    # Build the tag.
    parts = fully_qualified_name(view_class).split('.')
    tag_name = parts[-2]
    if not tag_name in tags_added:
      tags_added.add(tag_name)
      tags.append({
        'name': tag_name,
        'description': (sys.modules[view_class.__module__].__doc__ or '').strip()
      })

    # Build the Swagger data for the path.
    swagger_path = PARAM_REGEX.sub(r'{\2}', rule.rule)
    full_name = fully_qualified_name(view_class)
    path_swagger = {
      'x-name': full_name,
      'x-path': swagger_path,
      'x-tag': tag_name
    }

    related_user_res = method_metadata(view_class, 'related_user_resource')
    if related_user_res is not None:
      path_swagger['x-user-related'] = fully_qualified_name(related_user_res)

    paths[swagger_path] = path_swagger

    # Add any global path parameters.
    param_data_map = view_class.__api_path_params if '__api_path_params' in dir(
      view_class) else {}
    if param_data_map:
      path_parameters_swagger = []
      for path_parameter in param_data_map:
        description = param_data_map[path_parameter].get('description')
        path_parameters_swagger.append(swagger_parameter(path_parameter, description))

      path_swagger['parameters'] = path_parameters_swagger

    # Add the individual HTTP operations.
    method_names = list(rule.methods.difference(['HEAD', 'OPTIONS']))
    for method_name in method_names:
      # https://github.com/swagger-api/swagger-spec/blob/master/versions/2.0.md#operation-object
      method = getattr(view_class, method_name.lower(), None)
      if method is None:
        logger.debug('Unable to find method for %s in class %s', method_name, view_class)
        continue

      operationId = method_metadata(method, 'nickname')
      operation_swagger = {
        'operationId': operationId,
        'parameters': [],
      }

      if operationId is None:
        continue

      if operationId in operation_ids:
        raise Exception('Duplicate operation Id: %s' % operationId)

      operation_ids.add(operationId)

      # Mark the method as internal.
      internal = method_metadata(method, 'internal')
      if internal is not None:
        operation_swagger['x-internal'] = True

      if include_internal:
        requires_fresh_login = method_metadata(method, 'requires_fresh_login')
        if requires_fresh_login is not None:
          operation_swagger['x-requires-fresh-login'] = True

      # Add the path parameters.
      if rule.arguments:
        for path_parameter in rule.arguments:
          description = param_data_map.get(path_parameter, {}).get('description')
          operation_swagger['parameters'].append(
            swagger_parameter(path_parameter, description))

      # Add the query parameters.
      if '__api_query_params' in dir(method):
        for query_parameter_info in method.__api_query_params:
          name = query_parameter_info['name']
          description = query_parameter_info['help']
          param_type = TYPE_CONVERTER[query_parameter_info['type']]
          required = query_parameter_info['required']

          operation_swagger['parameters'].append(
            swagger_parameter(name, description, kind='query',
                              param_type=param_type,
                              required=required,
                              enum=query_parameter_info['choices']))

      # Add the OAuth security block.
      # https://github.com/swagger-api/swagger-spec/blob/master/versions/2.0.md#securityRequirementObject
      scope = method_metadata(method, 'oauth2_scope')
      if scope and not compact:
        operation_swagger['security'] = [{'oauth2_implicit': [scope.scope]}]

      # Add the responses block.
      # https://github.com/swagger-api/swagger-spec/blob/master/versions/2.0.md#responsesObject
      response_schema_name = method_metadata(method, 'response_schema')
      if not compact:
        if response_schema_name:
          models[response_schema_name] = view_class.schemas[response_schema_name]

        models['ApiError'] = {
          'type': 'object',
          'properties': {
            'status': {
              'type': 'integer',
              'description': 'Status code of the response.'
            },
            'type': {
              'type': 'string',
              'description': 'Reference to the type of the error.'
            },
            'detail': {
              'type': 'string',
              'description': 'Details about the specific instance of the error.'
            },
            'title': {
              'type': 'string',
              'description': 'Unique error code to identify the type of error.'
            },
            'error_message': {
              'type': 'string',
              'description': 'Deprecated; alias for detail'
            },
            'error_type': {
              'type': 'string',
              'description': 'Deprecated; alias for detail'
            }
          },
          'required': [
            'status',
            'type',
            'title',
          ]
        }

        responses = {
          '400': {
            'description': 'Bad Request',
          },

          '401': {
            'description': 'Session required',
          },

          '403': {
            'description': 'Unauthorized access',
          },

          '404': {
            'description': 'Not found',
          },
        }

        for _, body in responses.items():
          body['schema'] = {'$ref': '#/definitions/ApiError'}

        if method_name == 'DELETE':
          responses['204'] = {
            'description': 'Deleted'
          }
        elif method_name == 'POST':
          responses['201'] = {
            'description': 'Successful creation'
          }
        else:
          responses['200'] = {
            'description': 'Successful invocation'
          }

          if response_schema_name:
            responses['200']['schema'] = {
              '$ref': '#/definitions/%s' % response_schema_name
            }

        operation_swagger['responses'] = responses

      # Add the request block.
      request_schema_name = method_metadata(method, 'request_schema')
      if request_schema_name and not compact:
        models[request_schema_name] = view_class.schemas[request_schema_name]

        operation_swagger['parameters'].append(
          swagger_parameter('body', 'Request body contents.', kind='body',
                            schema=request_schema_name))

      # Add the operation to the parent path.
      if not internal or (internal and include_internal):
        path_swagger[method_name.lower()] = operation_swagger

  tags.sort(key=lambda t: t['name'])
  paths = OrderedDict(sorted(paths.items(), key=lambda p: p[1]['x-tag']))

  if compact:
    return {'paths': paths}