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

""" A python wrapper for nni rest api

Example:

import nnicli as nc

nc.start_nni('../../../../examples/trials/mnist/config.yml')

nc.set_endpoint('http://localhost:8080')

print(nc.version())
print(nc.get_experiment_status())

print(nc.get_job_statistics())
print(nc.list_trial_jobs())

nc.stop_nni()

"""

import sys
import os
import subprocess
import requests

__all__ = [
    'start_nni',
    'stop_nni',
    'set_endpoint',
    'version',
    'get_experiment_status',
    'get_experiment_profile',
    'get_trial_job',
    'list_trial_jobs',
    'get_job_statistics',
    'get_job_metrics',
    'export_data'
]

EXPERIMENT_PATH = 'experiment'
VERSION_PATH = 'version'
STATUS_PATH = 'check-status'
JOB_STATISTICS_PATH = 'job-statistics'
TRIAL_JOBS_PATH = 'trial-jobs'
METRICS_PATH = 'metric-data'
EXPORT_DATA_PATH = 'export-data'

API_ROOT_PATH = 'api/v1/nni'

_api_endpoint = None

def set_endpoint(endpoint):
    """set endpoint of nni rest server for nnicli, for example:
    http://localhost:8080
    """
    global _api_endpoint
    _api_endpoint = endpoint

def _check_endpoint():
    if _api_endpoint is None:
        raise AssertionError("Please call set_endpoint to specify nni endpoint")

def _nni_rest_get(api_path, response_type='json'):
    _check_endpoint()
    uri = '{}/{}/{}'.format(_api_endpoint, API_ROOT_PATH, api_path)
    res = requests.get(uri)
    if _http_succeed(res.status_code):
        if response_type == 'json':
            return res.json()
        elif response_type == 'text':
            return res.text
        else:
            raise AssertionError('Incorrect response_type')
    else:
        return None

def _http_succeed(status_code):
    return status_code // 100 == 2

def _create_process(cmd):
    if sys.platform == 'win32':
        process = subprocess.Popen(cmd, stdout=subprocess.PIPE, creationflags=subprocess.CREATE_NEW_PROCESS_GROUP)
    else:
        process = subprocess.Popen(cmd, stdout=subprocess.PIPE)

    while process.poll() is None:
        output = process.stdout.readline()
        if output:
            print(output.decode('utf-8').strip())
    return process.returncode

def start_nni(config_file):
    """start nni experiment with specified configuration file"""
    cmd = 'nnictl create --config {}'.format(config_file).split(' ')
    if _create_process(cmd) != 0:
        raise RuntimeError('Failed to start nni.')

def stop_nni():
    """stop nni experiment"""
    cmd = 'nnictl stop'.split(' ')
    if _create_process(cmd) != 0:
        raise RuntimeError('Failed to stop nni.')

def version():
    """return version of nni"""
    return _nni_rest_get(VERSION_PATH, 'text')

def get_experiment_status():
    """return experiment status as a dict"""
    return _nni_rest_get(STATUS_PATH)

def get_experiment_profile():
    """return experiment profile as a dict"""
    return _nni_rest_get(EXPERIMENT_PATH)

def get_trial_job(trial_job_id):
    """return trial job information as a dict"""
    assert trial_job_id is not None
    return _nni_rest_get(os.path.join(TRIAL_JOBS_PATH, trial_job_id))

def list_trial_jobs():
    """return information for all trial jobs as a list"""
    return _nni_rest_get(TRIAL_JOBS_PATH)

def get_job_statistics():
    """return trial job statistics information as a dict"""
    return _nni_rest_get(JOB_STATISTICS_PATH)

def get_job_metrics(trial_job_id=None):
    """return trial job metrics"""
    api_path = METRICS_PATH if trial_job_id is None else os.path.join(METRICS_PATH, trial_job_id)
    return _nni_rest_get(api_path)

def export_data():
    """return exported information for all trial jobs"""
    return _nni_rest_get(EXPORT_DATA_PATH)
