"""Util functions for Projections ETL."""

from datetime import datetime
from datetime import timedelta

from flows import datastore
from flows import s3
from flows.theatrical_cuts import queries


def get_upc_theatrical_cuts_anchor_date(upc):
    """Get the anchor date of a UPC from the datastore records.

    Args:
        upc (str): UPC to lookup.

    Returns:
        date: UPC's anchor date.
    """
    results = datastore.query(
        queries.THEATRICAL_CUTS_ANCHOR_DATE, {'upc': upc})
    row = results.fetchone()
    return row[0]


def get_cuts_upc(drop_url):
    """Get UPC value from cuts file.

    Args:
        drop_url (str): S3 cuts file url.

    Returns:
        str: UPC value.
    """
    data = s3.download_csv(drop_url)
    return data[0][0]


def transpose_weekly_percentage(row, anchor_date, upc):
    """Transform theatrical cuts csv data to db table format.

    Args:
        row (list): row with percentage from csv.
        anchor_date (str): anchor date in ISO format: YYYY-MM-DD.
        upc (str): release UPC.

    Yields:
        dict: {percentage, upc, start_date, end_date}.
    """
    start_date = datetime.strptime(anchor_date, '%Y-%m-%d').date()
    dates = [{
        'start_date': (start_date + timedelta(days=i * 7)).isoformat(),
        'end_date': (start_date + timedelta(days=(i + 1) * 7 - 1)).isoformat()}
        for i in range(len(row)-1)]
    for cell, date in zip(row[1:], dates):
        yield dict(percentage=100 - float(cell), upc=upc, **date)


def transpose_percentage_data(row, anchor_date, upc):
    """Transform theatrical cuts csv data to db table format.

    Args:
        row (list): row with percentage from csv.
        anchor_date (str): anchor date in ISO format: YYYY-MM-DD.
        upc (str): release UPC.

    Yields:
        dict: {upc, date, percent}.
    """
    start_date = datetime.strptime(anchor_date, '%Y-%m-%d').date()
    dates = [
        (start_date + timedelta(days=i * 7)).isoformat()
        for i in range(len(row)-1)]
    for percentage, date in zip(row[1:], dates):
        yield dict(percentage=float(percentage), upc=upc, date=date)