#!/usr/bin/env python

# Copyright 2016 Google, Inc
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Analyzes text using the Google Cloud Natural Language API."""

import argparse
import json
import sys

from googleapiclient import discovery
import httplib2
from oauth2client.client import GoogleCredentials


def get_service():
    credentials = GoogleCredentials.get_application_default()
    scoped_credentials = credentials.create_scoped(
        ['https://www.googleapis.com/auth/cloud-platform'])
    http = httplib2.Http()
    scoped_credentials.authorize(http)
    return discovery.build('language', 'v1beta1', http=http)


def get_native_encoding_type():
    """Returns the encoding type that matches Python's native strings."""
    if sys.maxunicode == 65535:
        return 'UTF16'
    else:
        return 'UTF32'


def analyze_entities(text, encoding='UTF32'):
    body = {
        'document': {
            'type': 'PLAIN_TEXT',
            'content': text,
        },
        'encodingType': encoding,
    }

    service = get_service()

    request = service.documents().analyzeEntities(body=body)
    response = request.execute()

    return response


def analyze_sentiment(text):
    body = {
        'document': {
            'type': 'PLAIN_TEXT',
            'content': text,
        }
    }

    service = get_service()

    request = service.documents().analyzeSentiment(body=body)
    response = request.execute()

    return response


def analyze_syntax(text, encoding='UTF32'):
    body = {
        'document': {
            'type': 'PLAIN_TEXT',
            'content': text,
        },
        'features': {
            'extract_syntax': True,
        },
        'encodingType': encoding,
    }

    service = get_service()

    request = service.documents().annotateText(body=body)
    response = request.execute()

    return response


if __name__ == '__main__':
    parser = argparse.ArgumentParser(
        description=__doc__,
        formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument('command', choices=[
        'entities', 'sentiment', 'syntax'])
    parser.add_argument('text')

    args = parser.parse_args()

    if args.command == 'entities':
        result = analyze_entities(args.text, get_native_encoding_type())
    elif args.command == 'sentiment':
        result = analyze_sentiment(args.text)
    elif args.command == 'syntax':
        result = analyze_syntax(args.text, get_native_encoding_type())

    print(json.dumps(result, indent=2))