from __future__ import division
from db import dbconn
import datetime
from sys import argv

def affected_indices(company_id, conn):
    """returns the list of indices containing company_id"""

    with conn.cursor() as c:
        sqlstr = """SELECT * FROM
        (SELECT unnest(index_list) AS basketid FROM bbg_issuers WHERE company_id=%s) a
        JOIN index_version USING (basketid)
        WHERE lastdate='infinity'"""
        c.execute(sqlstr, (company_id,))
        recordslist = c.fetchall()
    return recordslist

def create_newindices(recordslist, lastdate, nissuers, conn):
    """create the new indices versions and update the old"""
    insertstr = """INSERT INTO index_version(Index, Series, Version, IndexFactor,
    CumulativeLoss, lastdate) Values(%(index)s, %(series)s, %(version)s, %(indexfactor)s,
    %(cumulativeloss)s, %(lastdate)s) RETURNING basketid"""

    updatestr = "UPDATE index_version SET lastdate=%s WHERE basketid=%s"

    with conn.cursor() as c:
        newids = {}
        for r in recordslist:
            r['indexfactor'] -= 100/nissuers
            r['version'] += 1
            r['cumulativeloss'] += (100-recovery)/nissuers
            r['lastdate'] = 'infinity'
            c.execute(insertstr, r)
            newids[r['basketid']] = c.fetchone()[0]
        for oldid in newids.keys():
            c.execute(updatestr, (lastdate, oldid))
    conn.commit()
    return newids

def update_indexmembers(newids, company_id, conn):
    with conn.cursor() as c:
        for oldid, newid in newids.items():
            c.execute("""update bbg_issuers set index_list=index_list||%s where company_id in
            (select company_id from bbg_issuers where %s=Any(index_list)
            and company_id != %s)""", (newid, oldid, company_id))
    conn.commit()

if __name__=="__main__":
    if len(argv) == 1:
        print("""Usage:
    python handle_default.py <company_id> <date> <recovery> <n_issuers>
For instance:
    python handle_default.py 210065 2015-02-19 15.875 100""")
    else:
        with dbconn('serenitasdb') as serenitasdb:
            company_id = int(argv[1])
            lastdate = datetime.datetime.strptime(argv[2], "%Y-%m-%d")
            recovery = float(argv[3])
            n_issuers = float(argv[4])
            recordslist = affected_indices(company_id, serenitasdb)
            print(recordslist)
            newids = create_newindices(recordslist, lastdate, n_issuers, serenitasdb)
            update_indexmembers(newids, company_id, serenitasdb)