"""
schedule_v2.py: property to get venue linked to an event

# tag::SCHEDULE2_DEMO[]
    >>> event = Record.fetch('event.33950')  # <1>
    >>> event  # <2>
    <Event 'There *Will* Be Bugs'>
    >>> event.venue  # <3>
    <Record serial=1449>
    >>> event.venue.name  # <4>
    'Portland 251'
    >>> event.venue_serial  # <5>
    1449

# end::SCHEDULE2_DEMO[]
"""

# tag::SCHEDULE2_RECORD[]
import inspect  # <1>
import json

JSON_PATH = 'data/osconfeed.json'

class Record:

    __index = None  # <2>

    def __init__(self, **kwargs):
        self.__dict__.update(kwargs)

    def __repr__(self):
        return f'<{self.__class__.__name__} serial={self.serial!r}>'

    @staticmethod  # <3>
    def fetch(key):
        if Record.__index is None:  # <4>
            Record.__index = load()
        return Record.__index[key]  # <5>
# end::SCHEDULE2_RECORD[]


# tag::SCHEDULE2_EVENT[]
class Event(Record):  # <1>

    def __repr__(self):
        try:
            return f'<{self.__class__.__name__} {self.name!r}>'  # <2>
        except AttributeError:
            return super().__repr__()

    @property
    def venue(self):
        key = f'venue.{self.venue_serial}'
        return self.__class__.fetch(key)  # <3>
# end::SCHEDULE2_EVENT[]

# tag::SCHEDULE2_LOAD[]
def load(path=JSON_PATH):
    records = {}
    with open(path) as fp:
        raw_data = json.load(fp)
    for collection, raw_records in raw_data['Schedule'].items():
        record_type = collection[:-1]  # <1>
        cls_name = record_type.capitalize()  # <2>
        cls = globals().get(cls_name, Record)  # <3>
        if inspect.isclass(cls) and issubclass(cls, Record):  # <4>
            factory = cls  # <5>
        else:
            factory = Record  # <6>
        for raw_record in raw_records:  # <7>
            key = f'{record_type}.{raw_record["serial"]}'
            records[key] = factory(**raw_record)  # <8>
    return records
# end::SCHEDULE2_LOAD[]