"""Base API handlers"""
# Copyright (c) Jupyter Development Team.
# Distributed under the terms of the Modified BSD License.

import json

try:
    # py3
    from http.client import responses
except ImportError:
    from httplib import responses

from tornado import web

from ..handlers import BaseHandler

class APIHandler(BaseHandler):
    def get_json_body(self):
        """Return the body of the request as JSON data."""
        if not self.request.body:
            return None
        body = self.request.body.strip().decode(u'utf-8')
        try:
            model = json.loads(body)
        except Exception:
            self.log.debug("Bad JSON: %r", body)
            self.log.error("Couldn't parse JSON", exc_info=True)
            raise web.HTTPError(400, 'Invalid JSON in body of request')
        return model
        
    
    def write_error(self, status_code, **kwargs):
        """Write JSON errors instead of HTML"""
        exc_info = kwargs.get('exc_info')
        message = ''
        status_message = responses.get(status_code, 'Unknown Error')
        if exc_info:
            exception = exc_info[1]
            # get the custom message, if defined
            try:
                message = exception.log_message % exception.args
            except Exception:
                pass

            # construct the custom reason, if defined
            reason = getattr(exception, 'reason', '')
            if reason:
                status_message = reason
        
        self.write(json.dumps({
            'status': status_code,
            'message': message or status_message,
        }))