import json
from json import JSONDecodeError
from typing import Sequence

import click


class JSONList(click.ParamType):

    def convert(self, value: str, _, __) -> Sequence:
        try:
            with open(value) as f:
                json_list = json.load(f)
                if not isinstance(json_list, list):
                    self.fail("{value} is not a list of objects.")
                return json_list
        except OSError:
            self.fail("Cannot open {value}.")
        except JSONDecodeError as e:
            self.fail("Invalid JSON {e}")


@click.command()
@click.argument("json_list", type=JSONList())
def json_to_jsonl(json_list):
    """
    Take JSON file that is a list and print it out as a JSONL file.
    """
    for obj in json_list:
        print(json.dumps(obj))


if __name__ == "__main__":
    json_to_jsonl()