# jnet - library for requesting json
# Version: 0.0.4

import json
import socket
import urllib.error
import urllib.parse
import urllib.request

JSONType = "application/json"

# Request JSON from a web resource.
# Only returning an object if there is application/json data.
def requestJson(uri, params=None, extras={}):
    res = None
    
    reqUri = uri
    if params:
        reqUri += "?" + urllib.parse.urlencode(params)

    method = "GET"
    if "method" in extras:
        method = extras['method']

    headers = {"user-agent": "alpha/jnet"}
    if "headers" in extras:
        headers.update(extras['headers'])
    
    try:
        if "payload" in extras:
            req = urllib.request.Request(reqUri, method=method, data=extras['payload'], headers=headers)
            res = urllib.request.urlopen(req, None, 60)
        else:
            req = urllib.request.Request(reqUri, method=method, headers=headers)
            res = urllib.request.urlopen(req, None, 60)
    except socket.timeout:
        print("JNet: Timeout.")
        return None
    except urllib.error.HTTPError as exception:
        res = exception
        
    content = res.read()
    contentType = res.getheader("content-type", "")
    res = None
    
    if contentType.startswith(JSONType):
        res = json.loads(content)

    return res