import json
import requests
import urllib


class OpenAPIMethod:
    def __init__(self, url, name, descriptor, catalog):
        self.url = url
        self.__name__ = name

        assert 'post' in descriptor, 'Only POST methods are supported'
        post_descriptor = descriptor['post']

        self.__doc__ = post_descriptor['description']
        parameters = post_descriptor.get('parameters', [])
        request_body = post_descriptor.get('requestBody')

        self.parameters = {p['name']: p for p in parameters}
        assert all(param['in'] == 'query' for param in self.parameters.values()), f'Only query path parameters are supported (path: {url}, descriptor: {json.dumps(descriptor)})'

        self.body = None
        if request_body:
            assert 'application/json' in request_body['content'], f'Only application/json is supported for request body (path: {url}, descriptor: {json.dumps(descriptor)})'

            body_name = 'body'
            i = 2
            while body_name in self.parameters:
                body_name = f'body{i}'
                i += 1

            self.body = dict(
                name=body_name,
                required=request_body['required'],
                schema=request_body['content']['application/json']['schema'],
            )

        self.parameters_schema = dict(
            type='object',
            properties={
                **({
                    self.body['name']: self.body['schema']
                } if self.body else {}),
                **{
                    name: param['schema']
                    for name, param in self.parameters.items()
                }
            },
            components=catalog.get('components'),
            required=[name for name, param in self.parameters.items() if param['required']] + ([self.body['name']] if self.body and self.body['required'] else [])
        )

    def __call__(self, **kwargs):
        if self.body:
            body = kwargs.pop(self.body['name'], None)
            if self.body['required']:
                assert body is not None, f'Missing required body parameter: {self.body["name"]}'
        else:
            body = None

        query_params = {}
        for name, param in self.parameters.items():
            value = kwargs.pop(name, None)
            if param['required']:
                assert value is not None, f'Missing required parameter: {name}'

            assert param['in'] == 'query', 'Only query parameters are supported'
            query_params[name] = value

        params = "&".join(f"{name}={urllib.parse.quote(value)}" for name, value in query_params.items())
        url = f'{self.url}?{params}'
        response = requests.post(url, json=body)
        response.raise_for_status()
        response_json = response.json()

        return response_json


def openapi_methods_from_endpoint(url):
    catalog_url = f'{url}/openapi.json'
    catalog_response = requests.get(catalog_url)
    catalog_response.raise_for_status()
    catalog = catalog_response.json()

    methods = [
        OpenAPIMethod(url=f'{url}{path}', name=path.replace('/', ' ').strip().replace(' ', '_'), descriptor=descriptor, catalog=catalog)
        for path, descriptor in catalog['paths'].items()
    ]
    return methods