import json
import pathlib
from typing import Any, cast

import typer
import yaml
from click.exceptions import Exit
from fastapi import FastAPI

from url_shortener.api.app import get_app
from url_shortener.config import settings

cli = typer.Typer(short_help="Perform API commands.", no_args_is_help=True)


@cli.command("gen-spec")
def gen_spec() -> None:
    """
    Generate OpenAPI specification.
    """
    app = get_app()

    dump_schema(app, filepath=settings.openapi_filepath)

    typer.secho(
        (
            f"OpenAPI specification was successfully "
            f"generated to `{settings.openapi_filepath}`",
        ),
        fg="green",
    )


@cli.command("check-spec")
def check_spec() -> None:
    """
    Check that service has the latest OpenAPI specification.
    """

    app = get_app()

    if not check_schema(app, filepath=settings.openapi_filepath):
        typer.secho(
            "The OpenAPI specification for the service does not match the actual one. "
            "Please, generate new one with `python manage.py api gen-spec`.",
            fg="red",
        )
        raise Exit(1)

    typer.secho("You have the latest OpenAPI specification generated.", fg="green")


def dump_schema(api: FastAPI, *, filepath: pathlib.Path) -> None:
    with filepath.open("w+") as fp:
        yaml.dump(json.loads(json.dumps(api.openapi())), stream=fp, sort_keys=False)


def check_schema(api: FastAPI, *, filepath: pathlib.Path) -> bool:
    with filepath.open() as fp:
        return cast(dict[str, Any], yaml.safe_load(fp)) == api.openapi()