# -*- coding: utf-8 -*-
# Copyright (c) 2017 Tomek Wójcik <tomek@bthlabs.pl>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
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# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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# furnished to do so, subject to the following conditions:
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# The above copyright notice and this permission notice shall be included in
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# THE SOFTWARE.
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"""
q3stats.lib.queries
===================

This module contains functions for querying the database.
"""

import datetime

import sqlalchemy as sa

from q3stats.models import Game, Score

SQL_TOP_PLAYERS = """SELECT
    scores.player,
    sum(scores.%s) as sum_frags
FROM scores
LEFT JOIN games ON games.id = scores.game_id
WHERE
    games.date >= :date_start
    AND games.date < :date_end
GROUP BY scores.player
ORDER BY sum_frags DESC
LIMIT :limit"""


def get_game_dates(db_session):
    """Returns a list of unique game dates."""
    dates_query = sa.sql.expression.select([Game.__table__.c.date]).\
        distinct(Game.__table__.c.date).\
        order_by(Game.__table__.c.date.desc())

    dates = [x.date for x in db_session.execute(dates_query)]
    return dates


def get_player_sessions(db_session, player, limit=7):
    """Returns a list of unique sessions for the *player*."""
    player_sessions_query = sa.sql.expression.\
        select([Game.__table__.c.date]).\
        distinct(Game.__table__.c.date).\
        select_from(Game.__table__.join(
            Score.__table__, Score.__table__.c.game_id == Game.__table__.c.id
        )).\
        where(Score.__table__.c.player == player).\
        order_by(Game.__table__.c.date.desc()).\
        limit(limit)

    player_sessions = [
        x.date for x in db_session.execute(player_sessions_query)
    ]

    return player_sessions


def get_top_players(session, agg_by='kills', limit=3):
    """Returns a list of ``(player, score)`` tuples identifying top players
    in the current month.

    Use the *agg_by* kwargs to specify aggregation level. Valid values are
    ``kills`` and ``suicides``."""
    assert agg_by in ('kills', 'suicides')

    date_start = datetime.datetime.now().replace(day=1).date()
    date_end = None

    if date_start.month == 12:
        date_end = datetime.date(
            date_start.year + 1, 1, 1
        )
    else:
        date_end = datetime.date(
            date_start.year, date_start.month + 1, 1
        )

    query = SQL_TOP_PLAYERS % agg_by
    params = {
        'date_start': date_start, 'date_end': date_end, 'limit': limit
    }

    return [
        (x.player, x.sum_frags) for x in session.execute(query, params)
    ]