"""Generate zeroconf file."""
from collections import OrderedDict, defaultdict
import json
from typing import Dict

from .model import Integration, Config

BASE = """
\"\"\"Automatically generated by hassfest.

To update, run python3 -m script.hassfest
\"\"\"


ZEROCONF = {}

HOMEKIT = {}
""".strip()


def generate_and_validate(integrations: Dict[str, Integration]):
    """Validate and generate zeroconf data."""
    service_type_dict = defaultdict(list)
    homekit_dict = {}

    for domain in sorted(integrations):
        integration = integrations[domain]

        if not integration.manifest:
            continue

        service_types = integration.manifest.get('zeroconf', [])
        homekit = integration.manifest.get('homekit', {})
        homekit_models = homekit.get('models', [])

        if not service_types and not homekit_models:
            continue

        try:
            with open(str(integration.path / "config_flow.py")) as fp:
                content = fp.read()
                uses_discovery_flow = 'register_discovery_flow' in content

                if (service_types and not uses_discovery_flow and
                        ' async_step_zeroconf' not in content):
                    integration.add_error(
                        'zeroconf', 'Config flow has no async_step_zeroconf')
                    continue

                if (homekit_models and not uses_discovery_flow and
                        ' async_step_homekit' not in content):
                    integration.add_error(
                        'zeroconf', 'Config flow has no async_step_homekit')
                    continue

        except FileNotFoundError:
            integration.add_error(
                'zeroconf',
                'Zeroconf info in a manifest requires a config flow to exist'
            )
            continue

        for service_type in service_types:
            service_type_dict[service_type].append(domain)

        for model in homekit_models:
            if model in homekit_dict:
                integration.add_error(
                    'zeroconf',
                    'Integrations {} and {} have overlapping HomeKit '
                    'models'.format(domain, homekit_dict[model]))
                break

            homekit_dict[model] = domain

    # HomeKit models are matched on starting string, make sure none overlap.
    warned = set()
    for key in homekit_dict:
        if key in warned:
            continue

        # n^2 yoooo
        for key_2 in homekit_dict:
            if key == key_2 or key_2 in warned:
                continue

            if key.startswith(key_2) or key_2.startswith(key):
                integration.add_error(
                    'zeroconf',
                    'Integrations {} and {} have overlapping HomeKit '
                    'models'.format(homekit_dict[key], homekit_dict[key_2]))
                warned.add(key)
                warned.add(key_2)
                break

    zeroconf = OrderedDict((key, service_type_dict[key])
                           for key in sorted(service_type_dict))
    homekit = OrderedDict((key, homekit_dict[key])
                          for key in sorted(homekit_dict))

    return BASE.format(
        json.dumps(zeroconf, indent=4),
        json.dumps(homekit, indent=4),
    )


def validate(integrations: Dict[str, Integration], config: Config):
    """Validate zeroconf file."""
    zeroconf_path = config.root / 'homeassistant/generated/zeroconf.py'
    config.cache['zeroconf'] = content = generate_and_validate(integrations)

    with open(str(zeroconf_path), 'r') as fp:
        current = fp.read().strip()
        if current != content:
            config.add_error(
                "zeroconf",
                "File zeroconf.py is not up to date. "
                "Run python3 -m script.hassfest",
                fixable=True
            )
        return


def generate(integrations: Dict[str, Integration], config: Config):
    """Generate zeroconf file."""
    zeroconf_path = config.root / 'homeassistant/generated/zeroconf.py'
    with open(str(zeroconf_path), 'w') as fp:
        fp.write(config.cache['zeroconf'] + '\n')