"""Supply Chain TSV parser and methods."""
import csv
import os

from oto import response

from product_configuration.constants import supply_chain as supply_chain_ids
from product_configuration.supply_chain import supply_chain_configuration_schemas # noqa


APP_BASE_PATH = os.getcwd()
SUPPLY_CHAIN_BASE_PATH = 'product_configuration/supply_chain'

SUPPLY_CHAIN_MAPPING = {
    supply_chain_ids.GRAS_SUPPLY_CHAIN_ID: os.path.join(
        APP_BASE_PATH, SUPPLY_CHAIN_BASE_PATH, 'gras.tsv'),
    supply_chain_ids.PROPER_SUPPLY_CHAIN_ID: os.path.join(
        APP_BASE_PATH, SUPPLY_CHAIN_BASE_PATH, 'proper.tsv'),
    supply_chain_ids.AMAZON_SUPPLY_CHAIN_ID: os.path.join(
        APP_BASE_PATH, SUPPLY_CHAIN_BASE_PATH, 'amazon.tsv'),
    supply_chain_ids.FORTY_FIVE_PRESS_SUPPLY_CHAIN_ID: os.path.join(
        APP_BASE_PATH, SUPPLY_CHAIN_BASE_PATH, '45press.tsv')
}


def parse(path):
    """Parse a `.tsv` file.

    Args:
        path (str): absolute path to the file to parse

    Returns:
        parsed_tsv (list): containing rows of the tsv.
    """
    with open(path) as tsv:
        dict_reader = csv.DictReader(tsv, delimiter='\t')
        return [{key: tsv_row[key] or None
                for key in tsv_row.keys()}
                for tsv_row in dict_reader]


def get_supply_chain_path(supply_chain_id):
    """Return path to appropriate supply chain data.

    Args:
        supply_chain_id (int): id of the supply chain.

    Returns:
        path (str): absolute path to the appropriate supply chain data.
    """
    return SUPPLY_CHAIN_MAPPING[supply_chain_id]


def get_configurations(supply_chain_id):
    """Get list of configurations for a supply chain.

    Args:
        supply_chain_id (int): id of the supply chain

    Returns:
        Response - list of supply chains
    """
    supply_chain_path = get_supply_chain_path(supply_chain_id)
    parsed_tsv = parse(supply_chain_path)

    return response.Response(status=200, message=parsed_tsv)


def get_configuration_by_distribution_format(
        supply_chain_id, distribution_format_id):
    """Get a single configuration by distribution format id.

    Args:
        supply_chain_id (int): id of the supply chain.
        distribution_format_id (int): id of the distribution format
            configuration to retrieve.
    Returns:
        response.Response: a single configuration object.
    """
    configurations = get_configurations(supply_chain_id)
    configuration = list(filter(
        lambda c: c['distribution_format_id'] == str(distribution_format_id),
        configurations.message))

    if not len(configuration):
        return response.create_not_found_response()

    return response.Response(status=200, message=configuration[0])


def get_configuration_schemas():
    """Get list of supply chain configuration schemas.

    Returns:
        Response - list of supply chain configuration schemas.
    """
    return response.Response(
        status=200,
        message=supply_chain_configuration_schemas.SUPPLY_CHAIN_CONFIGURATION_SCHEMAS) # noqa


def is_supply_chain_id_valid(supply_chain_id):
    """Check validity of supplied supply chain id.

    Args:
        supply_chain_id (int): supply chain id to verify.

    Returns:
        boolean: supply chain validity.
    """
    return supply_chain_id in SUPPLY_CHAIN_MAPPING.keys()