"""Import configuration files and returns default values if undefined."""

# Standard Library
import os
import copy
import math
import asyncio
import getpass
from pathlib import Path

# Third Party
import yaml
import ujson as json
from aiofile import AIOFile
from pydantic import ValidationError

# Project
from hyperglass.util import log, check_path
from hyperglass.constants import (
    CREDIT,
    LOG_LEVELS,
    LOG_HANDLER,
    DEFAULT_HELP,
    DEFAULT_TERMS,
    DEFAULT_DETAILS,
    LOG_HANDLER_FILE,
    SUPPORTED_QUERY_TYPES,
)
from hyperglass.exceptions import ConfigError, ConfigInvalid, ConfigMissing
from hyperglass.configuration.models import params as _params
from hyperglass.configuration.models import routers as _routers
from hyperglass.configuration.models import commands as _commands
from hyperglass.configuration.markdown import get_markdown

# Project Directories
WORKING_DIR = Path(__file__).resolve().parent
CONFIG_PATHS = (
    Path("/etc/hyperglass/"),
    Path.home() / "hyperglass",
    WORKING_DIR.parent.parent,
    WORKING_DIR.parent,
    WORKING_DIR,
)
CONFIG_FILES = (
    ("hyperglass.yaml", False),
    ("devices.yaml", True),
    ("commands.yaml", False),
)


async def _check_config_paths():
    """Verify supported configuration directories exist and are readable."""
    config_path = None
    for path in CONFIG_PATHS:
        checked = await check_path(path)
        if checked is not None:
            config_path = checked
            break
    if config_path is None:
        raise ConfigError(
            """
No configuration directories were determined to both exist and be readable
by hyperglass. hyperglass is running as user '{un}' (UID '{uid}'), and tried to access
the following directories:
{dir}""".format(
                un=getpass.getuser(),
                uid=os.getuid(),
                dir="\n".join([" - " + str(p) for p in CONFIG_PATHS]),
            )
        )
    log.info("Configuration directory: {d}", d=str(config_path))
    return config_path


async def _check_config_files(directory):
    """Verify config files exist and are readable.

    Arguments:
        directory {Path} -- Config directory Path object

    Raises:
        ConfigMissing: Raised if a required config file does not pass checks.

    Returns:
        {tuple} -- main config, devices config, commands config
    """
    files = ()
    for file in CONFIG_FILES:
        file_name, required = file
        file_path = directory / file_name

        checked = await check_path(file_path)

        if checked is None and required:
            raise ConfigMissing(missing_item=str(file_path))

        if checked is None and not required:
            log.warning(
                "'{f}' was not found, but is not required to run hyperglass. "
                + "Defaults will be used.",
                f=str(file_path),
            )
        files += (file_path,)

    return files


CONFIG_PATH = asyncio.run(_check_config_paths())

CONFIG_MAIN, CONFIG_DEVICES, CONFIG_COMMANDS = asyncio.run(
    _check_config_files(CONFIG_PATH)
)


def _set_log_level(debug, log_file=None):
    """Set log level based on debug state.

    Arguments:
        debug {bool} -- Debug state from config file

    Returns:
        {bool} -- True
    """
    stdout_handler = LOG_HANDLER.copy()
    file_handler = LOG_HANDLER_FILE.copy()

    if debug:
        log_level = "DEBUG"
        stdout_handler["level"] = log_level
        file_handler["level"] = log_level

    if log_file is not None:
        file_handler.update({"sink": log_file})
        log_handlers = [stdout_handler, file_handler]
    else:
        log_handlers = [stdout_handler]

    log.remove()
    log.configure(handlers=log_handlers, levels=LOG_LEVELS)
    if debug:
        log.debug("Debugging enabled")
    return True


async def _config_main():
    """Open main config file and load YAML to dict.

    Returns:
        {dict} -- Main config file
    """
    config = {}
    try:
        async with AIOFile(CONFIG_MAIN, "r") as cf:
            raw = await cf.read()
            config = yaml.safe_load(raw)
    except (yaml.YAMLError, yaml.MarkedYAMLError) as yaml_error:
        raise ConfigError(error_msg=str(yaml_error)) from None
    return config


async def _config_commands():
    """Open commands config file and load YAML to dict.

    Returns:
        {dict} -- Commands config file
    """
    if CONFIG_COMMANDS is None:
        config = {}
    else:
        try:
            async with AIOFile(CONFIG_COMMANDS, "r") as cf:
                raw = await cf.read()
                config = yaml.safe_load(raw) or {}
                log.debug(f"Unvalidated commands: {config}")
        except (yaml.YAMLError, yaml.MarkedYAMLError) as yaml_error:
            raise ConfigError(error_msg=str(yaml_error)) from None
    return config


async def _config_devices():
    """Open devices config file and load YAML to dict.

    Returns:
        {dict} -- Devices config file
    """
    try:
        async with AIOFile(CONFIG_DEVICES, "r") as cf:
            raw = await cf.read()
            config = yaml.safe_load(raw)
            log.debug(f"Unvalidated device config: {config}")
    except (yaml.YAMLError, yaml.MarkedYAMLError) as yaml_error:
        raise ConfigError(error_msg=str(yaml_error)) from None
    return config


user_config = asyncio.run(_config_main())

# Logging Config
try:
    _debug = user_config["general"]["debug"]
except KeyError:
    _debug = True

# Read raw debug value from config to enable debugging quickly.
_set_log_level(_debug)

_user_commands = asyncio.run(_config_commands())
_user_devices = asyncio.run(_config_devices())

# Map imported user config files to expected schema:
try:
    params = _params.Params(**user_config)
    commands = _commands.Commands.import_params(_user_commands)
    devices = _routers.Routers._import(_user_devices.get("routers", {}))
except ValidationError as validation_errors:
    errors = validation_errors.errors()
    log.error(errors)
    for error in errors:
        raise ConfigInvalid(
            field=": ".join([str(item) for item in error["loc"]]),
            error_msg=error["msg"],
        )

"""
Perform post-config initialization string formatting or other
functions that require access to other config levels. E.g.,
something in 'params.web.text' needs to be formatted with a value
from params.
"""
try:
    params.web.text.subtitle = params.web.text.subtitle.format(
        **params.dict(exclude={"web", "queries", "messages"})
    )
    if params.cache.timeout >= 60:
        _cache_timeout = math.ceil(params.cache.timeout / 60)
        _cache_period = "minutes"
    elif params.cache.timeout < 60:
        _cache_timeout = params.cache.timeout
        _cache_period = "seconds"
    params.web.text.cache = params.web.text.cache.format(
        timeout=_cache_timeout, period=_cache_period
    )
except KeyError:
    pass


# Re-evaluate debug state after config is validated
_set_log_level(params.debug, params.log_file)


def _build_frontend_networks():
    """Build filtered JSON structure of networks for frontend.

    Schema:
    {
        "device.network.display_name": {
            "device.name": {
                "display_name": "device.display_name",
                "vrfs": [
                    "Global",
                    "vrf.display_name"
                ]
            }
        }
    }

    Raises:
        ConfigError: Raised if parsing/building error occurs.

    Returns:
        {dict} -- Frontend networks
    """
    frontend_dict = {}
    for device in devices.routers:
        if device.network.display_name in frontend_dict:
            frontend_dict[device.network.display_name].update(
                {
                    device.name: {
                        "display_name": device.network.display_name,
                        "vrfs": [vrf.display_name for vrf in device.vrfs],
                    }
                }
            )
        elif device.network.display_name not in frontend_dict:
            frontend_dict[device.network.display_name] = {
                device.name: {
                    "display_name": device.network.display_name,
                    "vrfs": [vrf.display_name for vrf in device.vrfs],
                }
            }
    frontend_dict["default_vrf"] = devices.default_vrf
    if not frontend_dict:
        raise ConfigError(error_msg="Unable to build network to device mapping")
    return frontend_dict


def _build_frontend_devices():
    """Build filtered JSON structure of devices for frontend.

    Schema:
    {
        "device.name": {
            "display_name": "device.display_name",
            "vrfs": [
                "Global",
                "vrf.display_name"
            ]
        }
    }

    Raises:
        ConfigError: Raised if parsing/building error occurs.

    Returns:
        {dict} -- Frontend devices
    """
    frontend_dict = {}
    for device in devices.routers:
        if device.name in frontend_dict:
            frontend_dict[device.name].update(
                {
                    "network": device.network.display_name,
                    "display_name": device.display_name,
                    "vrfs": [
                        {"id": vrf.name, "display_name": vrf.display_name}
                        for vrf in device.vrfs
                    ],
                }
            )
        elif device.name not in frontend_dict:
            frontend_dict[device.name] = {
                "network": device.network.display_name,
                "display_name": device.display_name,
                "vrfs": [
                    {"id": vrf.name, "display_name": vrf.display_name}
                    for vrf in device.vrfs
                ],
            }
    if not frontend_dict:
        raise ConfigError(error_msg="Unable to build network to device mapping")
    return frontend_dict


def _build_networks():
    """Build filtered JSON Structure of networks & devices for Jinja templates.

    Raises:
        ConfigError: Raised if parsing/building error occurs.

    Returns:
        {dict} -- Networks & devices
    """
    networks = []
    _networks = list(set({device.network.display_name for device in devices.routers}))

    for _network in _networks:
        network_def = {"display_name": _network, "locations": []}
        for device in devices.routers:
            if device.network.display_name == _network:
                network_def["locations"].append(
                    {
                        "name": device.name,
                        "display_name": device.display_name,
                        "network": device.network.display_name,
                        "vrfs": [
                            {"id": vrf.name, "display_name": vrf.display_name}
                            for vrf in device.vrfs
                        ],
                    }
                )
        networks.append(network_def)

    if not networks:
        raise ConfigError(error_msg="Unable to build network to device mapping")
    return networks


def _build_vrfs():
    vrfs = []
    for device in devices.routers:
        for vrf in device.vrfs:
            vrf_dict = {"id": vrf.name, "display_name": vrf.display_name}
            if vrf_dict not in vrfs:
                vrfs.append(vrf_dict)
    return vrfs


content_params = json.loads(
    params.json(include={"primary_asn", "org_name", "site_title", "site_description"})
)


def _build_vrf_help():
    """Build a dict of vrfs as keys, help content as values.

    Returns:
        {dict} -- Formatted VRF help
    """
    all_help = {}
    for vrf in devices.vrf_objects:

        vrf_help = {}
        for command in SUPPORTED_QUERY_TYPES:
            cmd = getattr(vrf.info, command)
            help_params = {**content_params, **cmd.params.dict()}

            if help_params["title"] is None:
                command_params = getattr(params.queries, command)
                help_params[
                    "title"
                ] = f"{vrf.display_name}: {command_params.display_name}"

            md = asyncio.run(
                get_markdown(
                    config_path=cmd,
                    default=DEFAULT_DETAILS[command],
                    params=help_params,
                )
            )

            vrf_help.update(
                {command: {"content": md, "enable": cmd.enable, "params": help_params}}
            )

        all_help.update({vrf.name: vrf_help})

    return all_help


content_vrf = _build_vrf_help()

content_help_params = copy.copy(content_params)
content_help_params["title"] = params.web.help_menu.title
content_help = asyncio.run(
    get_markdown(
        config_path=params.web.help_menu,
        default=DEFAULT_HELP,
        params=content_help_params,
    )
)

content_terms_params = copy.copy(content_params)
content_terms_params["title"] = params.web.terms.title
content_terms = asyncio.run(
    get_markdown(
        config_path=params.web.terms, default=DEFAULT_TERMS, params=content_terms_params
    )
)
content_credit = CREDIT

vrfs = _build_vrfs()
networks = _build_networks()
frontend_networks = _build_frontend_networks()
frontend_devices = _build_frontend_devices()
_frontend_fields = {
    "debug": ...,
    "primary_asn": ...,
    "request_timeout": ...,
    "org_name": ...,
    "google_analytics": ...,
    "site_description": ...,
    "web": ...,
    "messages": ...,
}
_frontend_params = params.dict(include=_frontend_fields)
_frontend_params.update(
    {
        "queries": {**params.queries.map, "list": params.queries.list},
        "devices": frontend_devices,
        "networks": networks,
        "vrfs": vrfs,
        "content": {
            "help_menu": content_help,
            "terms": content_terms,
            "credit": content_credit,
            "vrf": content_vrf,
        },
    }
)
frontend_params = _frontend_params

URL_DEV = f"http://localhost:{str(params.listen_port)}/api/"
URL_PROD = "/api/"

REDIS_CONFIG = {
    "host": str(params.cache.host),
    "port": params.cache.port,
    "decode_responses": True,
}
