from pathlib import Path
from typing import Dict, List

from pydantic import BaseModel
from strictyaml import YAML, load

import regression_model

# Project Directories
PACKAGE_ROOT = Path(regression_model.__file__).resolve().parent
ROOT = PACKAGE_ROOT.parent
CONFIG_FILE_PATH = PACKAGE_ROOT / "config.yml"
DATASET_DIR = PACKAGE_ROOT / "datasets"
TRAINED_MODEL_DIR = PACKAGE_ROOT / "trained_model"


class AppConfig(BaseModel):
    """
    Application-level config
    """

    package_name: str
    training_data_file: str
    test_data_file: str
    pipeline_save_file: str


class ModelConfig(BaseModel):
    """
    All configuration relevant to model
    training and feature engineering
    """

    target: str
    features: List[str]
    dropped_feature: str
    test_size: float
    random_state: int
    town: str
    remaining_lease: str
    with_outliers: List[str]
    with_rarelabels: List[str]
    skewed_features: List[str]
    by_onehot: List[str]
    by_ordinal: List[str]
    town_mappings: Dict[str, str]


class Config(BaseModel):
    """
    Master config object
    """

    app_config: AppConfig
    model_config: ModelConfig


def find_config_file() -> Path:
    """
    Locate the configuration file
    """
    if CONFIG_FILE_PATH.is_file():
        return CONFIG_FILE_PATH
    raise Exception(f"Config not found at {CONFIG_FILE_PATH}")


def fetch_config_from_yaml(cfg_path: Path = None) -> YAML:
    """
    Parse YAML containing the package configuration
    """
    if not cfg_path:
        cfg_path = find_config_file()

    if cfg_path:
        with open(cfg_path, "r") as conf_file:
            parsed_config = load(conf_file.read())
            return parsed_config
    raise OSError(f"Did not find config file at path: {cfg_path}")


def create_and_validate_config(parsed_config: YAML = None) -> Config:
    """
    Run validation on config values
    """
    if parsed_config is None:
        parsed_config = fetch_config_from_yaml()

    _config = Config(
        app_config=AppConfig(**parsed_config.data),
        model_config=ModelConfig(**parsed_config.data),
    )

    return _config


config = create_and_validate_config()
