from datetime import datetime, timedelta
from urllib.parse import urljoin

import requests


class PromAPI:
    def __init__(self, endpoint='http://127.0.0.1:9090/'):
        """
        :param endpoint: address of
        """
        self.endpoint = endpoint

    @staticmethod
    def _to_timestamp(input_):
        """
        Convert string input to UNIX timestamp for Prometheus
        :param input_:
        :return:
        """
        if type(input_) == datetime:
            return input_.timestamp()
        if input_ == 'now':
            return datetime.utcnow().isoformat('T')
        if type(input_) is str:
            input_ = float(input_)
        if type(input_) in [int, float]:
            if input_ > 0:
                return input_
            if input_ == 0:  # return now
                return datetime.utcnow().isoformat('T')
            if input_ < 0:
                return (datetime.utcnow() + timedelta(seconds=input_)).isoformat('T')
        #assert type(input_) == float

    def query(self, query='prometheus_build_info'):
        return self._get(
            uri='/api/v1/query',
            params=dict(
                query=query
            )
        )

    def query_range(self, query='prometheus_build_info', start=-60, end='now', duration=60):
        """Get ser"""
        params = {
            'query': query
        }
        if end is not None:
            params['end'] = self._to_timestamp(end) + 'Z'
        if start:
            params['start'] = self._to_timestamp(start) + 'Z'
        if duration:
            params['step'] = duration
        print(params)
        return self._get(
            uri='/api/v1/query_range',
            params=params
        )

    def series(self, match='prometheus_build_info', start=-86400, end='now'):
        """Get ser"""
        params = {
            'match[]': match
        }
        if end is not None:
            params['end'] = self._to_timestamp(end) + 'Z'
        if start:
            params['start'] = self._to_timestamp(start) + 'Z'
        print(params)
        return self._get(
            uri='/api/v1/series',
            params=params
        )

    def _get(self, uri, params, method='GET'):
        url = urljoin(self.endpoint, uri)
        assert method == 'GET'
        result = requests.get(
            url=url,
            params=params
        )
        return result.json()