"""Extract data on near-Earth objects and close approaches from CSV and JSON files.

The `load_neos` function extracts NEO data from a CSV file, formatted as
described in the project instructions, into a collection of `NearEarthObject`s.

The `load_approaches` function extracts close approach data from a JSON file,
formatted as described in the project instructions, into a collection of
`CloseApproach` objects.

The main module calls these functions with the arguments provided at the command
line, and uses the resulting collections to build an `NEODatabase`.

You'll edit this file in Task 2.
"""

import csv
import json
from models import NearEarthObject, CloseApproach


def load_neos(neo_csv_path):
    """Read near-Earth object information from a CSV file.

    :param neo_csv_path: A path to a CSV file containing data about near-Earth objects.
    :return: A collection of `NearEarthObject`s.
    """
    neos = []
    with open(neo_csv_path, "r") as csv_file:
        reader = csv.reader(csv_file)
        next(reader)
        for row in reader:
            neo = NearEarthObject(
                designation=row[3], name=row[4], diameter=row[15], hazardous=row[7]
            )
            neos.append(neo)
    return neos


def load_approaches(cad_json_path):
    """Read close approach data from a JSON file.

    :param cad_json_path: A path to a JSON file containing data about close approaches.
    :return: A collection of `CloseApproach`es.
    """
    approaches = []
    with open(cad_json_path, "r") as json_file:
        cad = json.load(json_file)
    for item in cad["data"]:
        # 0: pdes, 3: cd, 4: dist, 7: v_rel
        approach = CloseApproach(
            designation=item[0],
            time=item[3],
            distance=float(item[4]),
            velocity=float(item[7]),
        )

        approaches.append(approach)
    return approaches