# -*- coding: utf-8 -*-

import psycopg2


class StubPsycopg2(list):
    """A stubbed version of the psycopg2 module, used to implement PostgreSQL
       server interaction tests, without having to talk to a running
       PostgreSQL server instance."""
    def __init__(self, *connections):
        self.conn_params = None
        super().__init__(connections)

    def add(self, connection):
        self.append(connection)
        return self

    def add_auth_failure(self):
        return self.add(psycopg2.OperationalError(
            'FATAL: password authentication failed for user "test"'))

    def add_conn_timeout(self):
        return self.add(psycopg2.OperationalError('timeout expired'))

    def add_conn_failure(self):
        return self.add(psycopg2.OperationalError(
            'could not connect to server: No route to host / Is the ' +
            'server running on host "..." and accepting / TCP/IP ' +
            'connections on port ...?'))
        return self

    def add_admin_startup(self):
        return self.add(psycopg2.errors.OperationalError(
            'FATAL: the database system is starting up'))

    def add_admin_shutdown(self):
        return self.add(psycopg2.errors.AdminShutdown(
            'terminating connection due to administrator command'))

    def add_connection(self, connection):
        return self.add(connection)

    def connect(self, **conn_params):
        self.conn_params = conn_params
        response = self.pop(0)
        if isinstance(response, Exception):
            raise response
        return response


class StubConnection(list):
    """A stubbed version of a psycopg2 connection, used to implement
       PostgreSQL server interaction tests, without having to talk to a
       running PostgreSQL server instance."""
    def __init__(self, *cursors):
        super().__init__(cursors)
        self.connected = True
        self.autocommit = False
    
    def close(self):
        self.connected = False

    def cursor(self):
        if not self.connected:
            raise psycopg2.InterfaceError("connection already closed")
        response = self.pop(0)
        if isinstance(response, Exception):
            raise response
        return response


class StubCursor(list):
    """A stubbed version of a psycopg2 cursor, used to implement PostgreSQL
       server interaction tests, without having to talk to a running
       PostgreSQL server instance."""
    def __init__(self, *results):
        super().__init__(results)
        self.statusmessage = None
        self.rows = None
        self.query = None
        self.params = None

    def __enter__(self):
        return self

    def __exit__(self, a, b, c):
        pass

    def execute(self, query, params=()):
        self.query = query
        self.params = params
        response = self.pop(0)
        if isinstance(response, Exception):
            raise response
        if callable(response):
            return response(query)
        status, rows = response
        self.statusmessage = status
        self.rows = rows if rows is not None else []

    def fetchone(self):
        if self.rows is None:
            raise psycopg2.ProgrammingError("no results to fetch")
        try:
            return self.rows.pop(0) 
        except IndexError:
            return None