"""Main application logic."""

import os
import sys

from ioda import config
from ioda.connectors import youtube
from ioda import const
from ioda import csv_dump
from ioda import db
from ioda import queries
from ioda.connectors.youtube import ServiceMapping

OUTPUT_DIR = 'output'


def generate_ioda_csv_files():
    """Load the data from RedShift and generate CSV files."""
    try:
        con = db.get_connection()
        if not con:
            sys.exit(1)

        print('Getting total number of assets...')
        count = db.get_total_records_count(con)
        print('Number of assets: {}'.format(count))
        if count % config.QUERY_LIMIT == 0:
            amount_of_csvs = count // config.QUERY_LIMIT
        else:
            amount_of_csvs = count // config.QUERY_LIMIT + 1

        if config.BATCH_NUMBER > amount_of_csvs:
            print('An error happend. BATCH_NUMBER out of range')
            return
        if not os.path.isdir(OUTPUT_DIR):
            os.mkdir(OUTPUT_DIR)

        generated_files = 0
        start_batch = config.BATCH_NUMBER - 1
        for i in range(start_batch, amount_of_csvs):
            csv_number = i + 1
            print('Get batch {}'.format(csv_number))
            data = db.get_batch(con, i*config.QUERY_LIMIT, config.QUERY_LIMIT)
            file_name = generate_file_name(csv_number, amount_of_csvs)
            print('Generating csv {}'.format(file_name))
            csv_dump.save_csv(data=data, file_name=file_name)
            print('{} generated'.format(file_name))
            generated_files += 1
        return generated_files
    except Exception as ex:
        print('An error happened. {}'.format(ex))
    finally:
        if con:
            con.close()


def generate_file_name(number, total_amount):
    """Generate file_name by template.

    Template is XXXX_of_YYYY.csv


    Args:
        number: number of current batch
        total_amount: total number of batches

    Returns:
        str: file name
    """
    return '{dir}/{number}_of_{total}.csv'.format(
        dir=OUTPUT_DIR,
        number=str(number).zfill(4),
        total=total_amount)


def save_youtube_metadata():
    """Load the data from RedShift, query YouTube and generate CSV files."""
    try:
        con = db.get_connection()
        if not con:
            sys.exit(1)

        print('Getting total number of assets...')
        count = db.get_total_records_count(con)
        print('Number of assets: {}'.format(count))

        # YouTube allows us to query up to 50 assets at once
        query_limit = 50
        if count % query_limit == 0:
            amount_of_csvs = count // query_limit
        else:
            amount_of_csvs = count // query_limit + 1

        if config.BATCH_NUMBER > amount_of_csvs:
            print('An error happend. BATCH_NUMBER out of range')
            return
        if not os.path.isdir(OUTPUT_DIR):
            os.mkdir(OUTPUT_DIR)

        google_client = ServiceMapping(config.GOOGLE_API_KEY_FILE).youtube_partner

        generated_files = 0
        start_batch = config.BATCH_NUMBER - 1
        for i in range(start_batch, amount_of_csvs):
            csv_number = i + 1
            print('Get batch {}'.format(csv_number))
            data = db.get_batch(
                con, i*query_limit, query_limit,
                queries.ASSET_ID_FIELD)
            asset_ids = ','.join([r[const.ASSET_ID].strip() for r in data])
            print(asset_ids)
            data = youtube.get_assets(google_client, asset_ids)
            file_name = generate_file_name(csv_number, amount_of_csvs)
            print('Generating csv {}'.format(file_name))
            csv_dump.save_csv(
                data=data,
                file_name=file_name,
                fields=csv_dump.YOUTUBE_CSV_FIELDS,
                row_mapper=csv_dump.create_csv_row_from_asset,
                write_header=False)
            print('{} generated'.format(file_name))
            generated_files += 1

        return generated_files
    except Exception as ex:
        print('An error happened. {}'.format(ex))
    finally:
        if con:
            con.close()