import datetime
import json
import os
import sys
import time

import boto3

from neo4j import GraphDatabase

LOG_FILE = os.path.join(os.path.dirname(__file__), 'fingerprint-logs.txt')
LOG_INFO = 'INFO'
LOG_ERROR = 'ERROR'

ENVIRONMENT = os.environ.get('ENVIRONMENT', 'qa')
NEO4J_URL = os.environ.get('NEO4J_URL', '***')
NEO4J_USERNAME = os.environ.get('NEO4J_USERNAME', '***')
NEO4J_PASSWORD = os.environ.get('NEO4J_PASSWORD', '***')
NEO4J_MAX_RETRY_TIME = 30

ORCHARD_ASSET_LIMIT = int(os.environ.get('ORCHARD_ASSET_LIMIT', 100))
ORCHARD_ASSET_OFFSET = str(os.environ.get('ORCHARD_ASSET_OFFSET', '0'))
ORCHARD_ASSET_EXT = str(os.environ.get('ORCHARD_ASSET_EXT', 'flac'))

GET_ORCHARD_ASSET_WITHOUT_ACR = '''
    MATCH (oa:OrchardAsset)
    WHERE NOT (oa)-[:FINGERPRINTED_AS]->()
    AND oa.id > $provided_offset
    AND oa.extension = $provided_ext
    RETURN oa
    ORDER BY oa.id
    LIMIT $provided_limit
'''

CHECK_ORCHARD_ASSET_WITH_ACR = '''
    MATCH (oa:OrchardAsset)-[:FINGERPRINTED_AS]->(:ACRID)
    WHERE oa.id = $provided_id
    RETURN oa
'''

def log(log_type, log_msg, final_log=False):
    with open(LOG_FILE, 'a') as log_file:
        ts = datetime.datetime.now().isoformat()
        msg = '[{}] [{}] {}\n'.format(ts, log_type, log_msg)
        log_file.write(msg)

        if final_log:
            log_file.write('----------\n')


def _get_driver():
    """Connect to Neo4J and return Neo4J driver."""
    try:
        driver = GraphDatabase.driver(
            NEO4J_URL,
            auth=(NEO4J_USERNAME, NEO4J_PASSWORD),
            encrypted=True,
            max_transaction_retry_time=NEO4J_MAX_RETRY_TIME)
        return driver
    except Exception as e:
        raise e


def _check_orchard_asset_processed(neo4j_driver, asset_id):
    with neo4j_driver.session() as session:
        nodes = session.run(
            CHECK_ORCHARD_ASSET_WITH_ACR,
            provided_id=asset_id
        )
        result = bool(nodes.data())
        session.close()
        return result


def _get_orchard_asset_to_process(neo4j_driver, asset_id):
    """Retrieve OrchardAsset to process."""
    with neo4j_driver.session() as session:
        assets = []
        nodes = session.run(
            GET_ORCHARD_ASSET_WITHOUT_ACR,
            provided_limit=ORCHARD_ASSET_LIMIT,
            provided_offset=asset_id,
            provided_ext=ORCHARD_ASSET_EXT
        )
        results = [record for record in nodes.data()]
        for result in results:
            asset = {
                'id': result['oa'].get('id'),
                'filename': result['oa'].get('filename'),
                'extension': result['oa'].get('extension')
            }
            assets.append(asset)

        session.close()

        return assets


try:
    log(LOG_INFO, 'Starting fingerprint script for {}'.format(ENVIRONMENT))
    neo4j_driver = _get_driver()

    gt_asset_id = ORCHARD_ASSET_OFFSET
    lambda_client = boto3.client('lambda', region_name='us-east-1')

    orchard_assets = []
    asset_id_to_check = None
    while True:

        # get last asset from previous batch
        if orchard_assets:
            asset_id_to_check = orchard_assets[-1].get('id')
            gt_asset_id = asset_id_to_check

        # retrieve new batch of assets
        log(LOG_INFO, 'Fetching new batch of assets > {}'.format(gt_asset_id))
        orchard_assets = _get_orchard_asset_to_process(neo4j_driver, gt_asset_id)  # noqa:E501
        if not orchard_assets:
            log(LOG_INFO, 'No assets to fingerprint')
            break

        # verify previous batch is done
        if asset_id_to_check:
            while True:
                if _check_orchard_asset_processed(neo4j_driver, asset_id_to_check):  # noqa:E501
                    break
                log(LOG_INFO, 'OrchardAsset with id: {} not fingerprinted yet, waiting....'.format(asset_id_to_check))  # noqa:E501
                time.sleep(15)

        # process batch of assets
        for asset in orchard_assets:
            payload = json.dumps({'asset': asset}).encode('utf-8')

            lambda_client.invoke(
                FunctionName='{}-lambda-acr-asset-fingerprinter'.format(ENVIRONMENT),  # noqa:E501
                InvocationType='Event',
                Payload=payload
            )
            log(LOG_INFO, 'OrchardAsset with id: {} sent for fingerprint'.format(asset.get('id')))  # noqa:E501

    neo4j_driver.close()
    log(LOG_INFO, 'Fingerprint script done', True)
    sys.exit()
except Exception as e:
    log(LOG_ERROR, 'Unexpected error: {}'.format(e), True)
    sys.exit(e)