import warnings
warnings.filterwarnings("ignore", r".*Decimal objects natively")  # noqa

# speed up cdecimal if available
try:
    import cdecimal
    import sys
    sys.modules['decimal'] = cdecimal
except ImportError:
    pass

from sqlalchemy import __version__
from sqlalchemy import Column, Integer, create_engine, ForeignKey, \
    String, Numeric

from sqlalchemy.orm import Session, relationship

from sqlalchemy.ext.declarative import declarative_base
import random
import os
from decimal import Decimal

Base = declarative_base()


class Employee(Base):
    __tablename__ = 'employee'

    id = Column(Integer, primary_key=True)
    name = Column(String(100), nullable=False)
    type = Column(String(50), nullable=False)

    __mapper_args__ = {'polymorphic_on': type}


class Boss(Employee):
    __tablename__ = 'boss'

    id = Column(Integer, ForeignKey('employee.id'), primary_key=True)
    golf_average = Column(Numeric)

    __mapper_args__ = {'polymorphic_identity': 'boss'}


class Grunt(Employee):
    __tablename__ = 'grunt'

    id = Column(Integer, ForeignKey('employee.id'), primary_key=True)
    savings = Column(Numeric)

    employer_id = Column(Integer, ForeignKey('boss.id'))

    employer = relationship("Boss", backref="employees",
                            primaryjoin=Boss.id == employer_id)

    __mapper_args__ = {'polymorphic_identity': 'grunt'}


if os.path.exists('orm2010.db'):
    os.remove('orm2010.db')
# use a file based database so that cursor.execute() has some
# palpable overhead.
engine = create_engine('sqlite:///orm2010.db')

Base.metadata.create_all(engine)

sess = Session(engine)


def runit(status, factor=1, query_runs=5):
    num_bosses = 100 * factor
    num_grunts = num_bosses * 100

    bosses = [
        Boss(
            name="Boss %d" % i,
            golf_average=Decimal(random.randint(40, 150))
        )
        for i in range(num_bosses)
    ]

    sess.add_all(bosses)
    status("Added %d boss objects" % num_bosses)

    grunts = [
        Grunt(
            name="Grunt %d" % i,
            savings=Decimal(random.randint(5000000, 15000000) / 100)
        )
        for i in range(num_grunts)
    ]
    status("Added %d grunt objects" % num_grunts)

    while grunts:
        # this doesn't associate grunts with bosses evenly,
        # just associates lots of them with a relatively small
        # handful of bosses
        batch_size = 100
        batch_num = (num_grunts - len(grunts)) / batch_size
        boss = sess.query(Boss).filter_by(name="Boss %d" % batch_num).first()
        for grunt in grunts[0:batch_size]:
            grunt.employer = boss

        grunts = grunts[batch_size:]

    sess.commit()
    status("Associated grunts w/ bosses and committed")

    # do some heavier reading
    for i in range(query_runs):
        status("Heavy query run #%d" % (i + 1))

        report = []

        # load all the Grunts, print a report with their name, stats,
        # and their bosses' stats.
        for grunt in sess.query(Grunt):
            report.append((
                            grunt.name,
                            grunt.savings,
                            grunt.employer.name,
                            grunt.employer.golf_average
                        ))

        sess.close()  # close out the session


def run_with_profile(runsnake=False, dump=False):
    import cProfile
    import pstats
    filename = "orm2010.profile"

    if os.path.exists("orm2010.profile"):
        os.remove("orm2010.profile")

    def status(msg):
        print(msg)

    cProfile.runctx('runit(status)', globals(), locals(), filename)
    stats = pstats.Stats(filename)

    counts_by_methname = dict((key[2],
                               stats.stats[key][0]) for key in stats.stats)

    print("SQLA Version: %s" % __version__)
    print("Total calls %d" % stats.total_calls)
    print("Total cpu seconds: %.2f" % stats.total_tt)
    print('Total execute calls: %d'
          % counts_by_methname["<method 'execute' of 'sqlite3.Cursor' "
                               "objects>"])
    print('Total executemany calls: %d'
          % counts_by_methname.get("<method 'executemany' of 'sqlite3.Cursor' "
                                   "objects>", 0))

    if dump:
        stats.sort_stats('time', 'calls')
        stats.print_stats()

    if runsnake:
        os.system("runsnake %s" % filename)


def run_with_time():
    import time
    now = time.time()

    def status(msg):
        print("%d - %s" % (time.time() - now, msg))

    runit(status, 10)
    print("Total time: %d" % (time.time() - now))


if __name__ == '__main__':
    import argparse

    parser = argparse.ArgumentParser()
    parser.add_argument('--profile', action='store_true',
                        help='run shorter test suite w/ cprofilng')
    parser.add_argument('--dump', action='store_true',
                        help='dump full call profile (implies --profile)')
    parser.add_argument('--runsnake', action='store_true',
                        help='invoke runsnakerun (implies --profile)')

    args = parser.parse_args()

    args.profile = args.profile or args.dump or args.runsnake

    if args.profile:
        run_with_profile(runsnake=args.runsnake, dump=args.dump)
    else:
        run_with_time()
