"""Helper to check the configuration file."""
from collections import OrderedDict
import os
from typing import List, NamedTuple, Optional

import attr
import voluptuous as vol

from homeassistant import loader
from homeassistant.config import (
    CONF_CORE,
    CONF_PACKAGES,
    CORE_CONFIG_SCHEMA,
    YAML_CONFIG_FILE,
    _format_config_error,
    config_per_platform,
    extract_domain_configs,
    load_yaml_config_file,
    merge_packages_config,
)
from homeassistant.core import HomeAssistant
from homeassistant.exceptions import HomeAssistantError
from homeassistant.helpers.typing import ConfigType
from homeassistant.requirements import (
    RequirementsNotFound,
    async_get_integration_with_requirements,
)
import homeassistant.util.yaml.loader as yaml_loader


class CheckConfigError(NamedTuple):
    """Configuration check error."""

    message: str
    domain: Optional[str]
    config: Optional[ConfigType]


@attr.s
class HomeAssistantConfig(OrderedDict):
    """Configuration result with errors attribute."""

    errors: List[CheckConfigError] = attr.ib(factory=list)

    def add_error(
        self,
        message: str,
        domain: Optional[str] = None,
        config: Optional[ConfigType] = None,
    ) -> "HomeAssistantConfig":
        """Add a single error."""
        self.errors.append(CheckConfigError(str(message), domain, config))
        return self

    @property
    def error_str(self) -> str:
        """Return errors as a string."""
        return "\n".join([err.message for err in self.errors])


async def async_check_ha_config_file(hass: HomeAssistant) -> HomeAssistantConfig:
    """Load and check if Home Assistant configuration file is valid.

    This method is a coroutine.
    """
    result = HomeAssistantConfig()

    def _pack_error(
        package: str, component: str, config: ConfigType, message: str
    ) -> None:
        """Handle errors from packages: _log_pkg_error."""
        message = f"Package {package} setup failed. Component {component} {message}"
        domain = f"homeassistant.packages.{package}.{component}"
        pack_config = core_config[CONF_PACKAGES].get(package, config)
        result.add_error(message, domain, pack_config)

    def _comp_error(ex: Exception, domain: str, config: ConfigType) -> None:
        """Handle errors from components: async_log_exception."""
        result.add_error(_format_config_error(ex, domain, config), domain, config)

    # Load configuration.yaml
    config_path = hass.config.path(YAML_CONFIG_FILE)
    try:
        if not await hass.async_add_executor_job(os.path.isfile, config_path):
            return result.add_error("File configuration.yaml not found.")
        config = await hass.async_add_executor_job(load_yaml_config_file, config_path)
    except FileNotFoundError:
        return result.add_error(f"File not found: {config_path}")
    except HomeAssistantError as err:
        return result.add_error(f"Error loading {config_path}: {err}")
    finally:
        yaml_loader.clear_secret_cache()

    # Extract and validate core [homeassistant] config
    try:
        core_config = config.pop(CONF_CORE, {})
        core_config = CORE_CONFIG_SCHEMA(core_config)
        result[CONF_CORE] = core_config
    except vol.Invalid as err:
        result.add_error(err, CONF_CORE, core_config)
        core_config = {}

    # Merge packages
    await merge_packages_config(
        hass, config, core_config.get(CONF_PACKAGES, {}), _pack_error
    )
    core_config.pop(CONF_PACKAGES, None)

    # Filter out repeating config sections
    components = {key.split(" ")[0] for key in config.keys()}

    # Process and validate config
    for domain in components:
        try:
            integration = await async_get_integration_with_requirements(hass, domain)
        except (RequirementsNotFound, loader.IntegrationNotFound) as ex:
            result.add_error(f"Component error: {domain} - {ex}")
            continue

        try:
            component = integration.get_component()
        except ImportError as ex:
            result.add_error(f"Component error: {domain} - {ex}")
            continue

        config_schema = getattr(component, "CONFIG_SCHEMA", None)
        if config_schema is not None:
            try:
                config = config_schema(config)
                result[domain] = config[domain]
            except vol.Invalid as ex:
                _comp_error(ex, domain, config)
                continue

        component_platform_schema = getattr(
            component,
            "PLATFORM_SCHEMA_BASE",
            getattr(component, "PLATFORM_SCHEMA", None),
        )

        if component_platform_schema is None:
            continue

        platforms = []
        for p_name, p_config in config_per_platform(config, domain):
            # Validate component specific platform schema
            try:
                p_validated = component_platform_schema(p_config)
            except vol.Invalid as ex:
                _comp_error(ex, domain, config)
                continue

            # Not all platform components follow same pattern for platforms
            # So if p_name is None we are not going to validate platform
            # (the automation component is one of them)
            if p_name is None:
                platforms.append(p_validated)
                continue

            try:
                p_integration = await async_get_integration_with_requirements(
                    hass, p_name
                )
                platform = p_integration.get_platform(domain)
            except (
                loader.IntegrationNotFound,
                RequirementsNotFound,
                ImportError,
            ) as ex:
                result.add_error(f"Platform error {domain}.{p_name} - {ex}")
                continue

            # Validate platform specific schema
            platform_schema = getattr(platform, "PLATFORM_SCHEMA", None)
            if platform_schema is not None:
                try:
                    p_validated = platform_schema(p_validated)
                except vol.Invalid as ex:
                    _comp_error(ex, f"{domain}.{p_name}", p_validated)
                    continue

            platforms.append(p_validated)

        # Remove config for current component and add validated config back in.
        for filter_comp in extract_domain_configs(config, domain):
            del config[filter_comp]
        result[domain] = platforms

    return result
