# Copyright (c) Microsoft Corporation.
# Licensed under the MIT license.

import json
from io import BytesIO
from unittest import TestCase, main

import nni.protocol
from nni.msg_dispatcher import MsgDispatcher
from nni.protocol import CommandType, send, receive
from nni.tuner import Tuner
from nni.utils import extract_scalar_reward


class NaiveTuner(Tuner):
    def __init__(self):
        self.param = 0
        self.trial_results = []
        self.search_space = None
        self._accept_customized_trials()

    def generate_parameters(self, parameter_id, **kwargs):
        # report Tuner's internal states to generated parameters,
        # so we don't need to pause the main loop
        self.param += 2
        return {
            'param': self.param,
            'trial_results': self.trial_results,
            'search_space': self.search_space
        }

    def receive_trial_result(self, parameter_id, parameters, value, **kwargs):
        reward = extract_scalar_reward(value)
        self.trial_results.append((parameter_id, parameters['param'], reward, kwargs.get("customized")))

    def update_search_space(self, search_space):
        self.search_space = search_space


_in_buf = BytesIO()
_out_buf = BytesIO()


def _reverse_io():
    _in_buf.seek(0)
    _out_buf.seek(0)
    nni.protocol._out_file = _in_buf
    nni.protocol._in_file = _out_buf


def _restore_io():
    _in_buf.seek(0)
    _out_buf.seek(0)
    nni.protocol._in_file = _in_buf
    nni.protocol._out_file = _out_buf


class MsgDispatcherTestCase(TestCase):
    def test_msg_dispatcher(self):
        _reverse_io()  # now we are sending to Tuner's incoming stream
        send(CommandType.RequestTrialJobs, '2')
        send(CommandType.ReportMetricData, '{"parameter_id":0,"type":"PERIODICAL","value":"10"}')
        send(CommandType.ReportMetricData, '{"parameter_id":1,"type":"FINAL","value":"11"}')
        send(CommandType.UpdateSearchSpace, '{"name":"SS0"}')
        send(CommandType.RequestTrialJobs, '1')
        send(CommandType.KillTrialJob, 'null')
        _restore_io()

        tuner = NaiveTuner()
        dispatcher = MsgDispatcher(tuner)
        nni.msg_dispatcher_base._worker_fast_exit_on_terminate = False

        dispatcher.run()
        e = dispatcher.worker_exceptions[0]
        self.assertIs(type(e), AssertionError)
        self.assertEqual(e.args[0], 'Unsupported command: CommandType.KillTrialJob')

        _reverse_io()  # now we are receiving from Tuner's outgoing stream
        self._assert_params(0, 2, [], None)
        self._assert_params(1, 4, [], None)

        self._assert_params(2, 6, [[1, 4, 11, False]], {'name': 'SS0'})

        self.assertEqual(len(_out_buf.read()), 0)  # no more commands

    def _assert_params(self, parameter_id, param, trial_results, search_space):
        command, data = receive()
        self.assertIs(command, CommandType.NewTrialJob)
        data = json.loads(data)
        self.assertEqual(data['parameter_id'], parameter_id)
        self.assertEqual(data['parameter_source'], 'algorithm')
        self.assertEqual(data['parameters']['param'], param)
        self.assertEqual(data['parameters']['trial_results'], trial_results)
        self.assertEqual(data['parameters']['search_space'], search_space)


if __name__ == '__main__':
    main()
