"""Blueprint for OpenAPI spec API."""

import os

from flask import Blueprint, request, send_from_directory
from owsrequest import flask_request
from owsresponse import response
from owsresponse.adaptors.flask import flaskify

from royalties.constants import error

spec_api = Blueprint('spec_api', __name__, url_prefix='/spec')

SPEC_DIR = os.path.join(
    os.path.dirname(os.path.dirname(os.path.dirname(__file__))), 'spec'
)
SPEC_FILENAME = 'ows_royalties-1.0.0.yaml'


@spec_api.route('')
def serve_openapi_spec():
    """Serve the OpenAPI specification."""
    access_rule_decision = flask_request.verify_rules_access_standalone(request)
    if not access_rule_decision:
        return flaskify(
            response.create_error_response(
                code=error.ERROR_CODE_AUTHORIZATION,
                message='Unauthorized',
                status=403,
            )
        )

    try:
        return send_from_directory(SPEC_DIR, SPEC_FILENAME)
    except FileNotFoundError:
        return flaskify(
            response.create_error_response(
                code=error.ERROR_CODE_GENERAL,
                message='Specification file not found',
                status=404,
            )
        )