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# to you under the Apache License, Version 2.0 (the
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#
#   http://www.apache.org/licenses/LICENSE-2.0
#
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import json
from base64 import b64decode

from common.util import is_json
from command.psql import Psql
from common.authorize import Authorize
from common.command_data import CommandData


class ApiError(Exception):
    pass


def build_error(message: str):
    return {
        "statusCode": 400,
        "body": message
    }


def build_response(data: CommandData):
    meta_data = data.get_metadata()
    result = {
        "statusCode": meta_data['status'],
        "body": meta_data['result']
    }
    if is_json(meta_data['result']):
        result['headers'] = { 'Content-Type': 'application/json' }
    return result


def parse_body(args):
    try:
        return b64decode(args['__ow_body']).decode().strip()
    except Exception as e:
        print(e)
        raise ApiError("could not parse __ow_body as base64")


def main(args):
    """
    Action implementing a generic command wrapper for the nuv devel plugin. The action must be called with a POST request receiving a JSON
    payload similar to this one
    {
        "command":"select * from table"
    }

    the invoker must provide a x-impersonate-auth header containing the Openwhisk BASIC authentication of the wsku/user the action should impersonate
    when submitting the command. Every specific provider will support specific request type and command.
    WARNING: the body will be received as base64 encoded string as this action will be deployed with --web raw enabled flag
    """
    headers = args['__ow_headers']
    if 'x-impersonate-auth' not in headers:
        return build_error("invalid request, missing mandatory header: x-impersonate-auth")

    if len(args['__ow_body']) == 0:
        return build_error("invalid request, no command payload received")

    try:
        user_data = Authorize(args['couchdb_host'], args['couchdb_user'], args['couchdb_password']).login(
            headers['x-impersonate-auth'])
        cmd = CommandData(json.loads(parse_body(args)))
        return build_response(Psql(user_data).execute(cmd))
    except Exception as e:
        return build_error(f"failed to execute nuv devel psql. Reason: {str(e)}")