import pprint
import copy


class JsonPayload:
    def __init__(self, request):
        """
        Object to wrap up simple functionality for parsing a JSON response.
        """
        # Try to load as json
        self.json = request.get_json()
        # Store raw response data
        self.data = request.get_data()

    def param(self, key, default=None, convert=None):
        """Check if a key exists in a JSON/dictionary payload, and returns it."""
        # If no JSON payload exists, return early
        if not self.json:
            return None

        if key in self.json:
            val = self.json[key]
        else:
            val = default

        if convert:
            val = convert(val)

        return val


def axes_to_array(coordinate_dictionary, axis_keys=['x', 'y', 'z'], base_array=None):
    """Takes key-value pairs of a JSON value, and maps onto an array"""
    # If no base array is given
    if not base_array:
        # Create an array of zeros
        base_array = [0]*len(axis_keys)
    else:
        # Create a copy of the passed base_array
        base_array = copy.copy(base_array)

    # Do the mapping
    for axis, key in enumerate(axis_keys):
        if key in coordinate_dictionary:
            base_array[axis] = coordinate_dictionary[key]

    return base_array


def parse_payload(request):
    """Convert request to JSON. Will eventually handle error-checking."""
    # TODO: Handle invalid JSON payloads
    state = request.get_json()
    return state


def get_from_payload(payload, key, default=None):
    """Check if a key exists in a JSON/dictionary payload, and returns it."""
    if key in payload:
        return payload[key]
    else:
        return default


def gen(camera):
    """Video streaming generator function."""
    while True:
        # the obtained frame is a jpeg
        frame = camera.get_frame()

        yield (b'--frame\r\n'
               b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n')


def get_bool(get_arg):
    """Convert GET request argument string to a Python bool"""
    if (
        get_arg == 'true' or
        get_arg == 'True' or
        get_arg == '1'):
        return True
    else:
        return False


def list_routes(app):
    """Print available functions."""
    pprint.pprint(list(map(lambda x: repr(x), app.url_map.iter_rules())))