from pyisda.curve import YieldCurve, BadDay, SpreadCurve
from pyisda.credit_index import CreditIndex
from pyisda.legs import FeeLeg, ContingentLeg
from pyisda.logging import enable_logging
import datetime
import math
import pandas as pd
from yieldcurve import YC, ql_to_jp
from quantlib.settings import Settings
from quantlib.time.api import Date
import numpy as np
from db import dbconn
from concurrent.futures import ProcessPoolExecutor, as_completed
from itertools import zip_longest, chain

def get_singlenames_quotes(indexname, date):
    conn = dbconn('serenitasdb')
    with conn.cursor() as c:
        c.execute("SELECT * FROM curve_quotes(%s, %s)", vars=(indexname, date))
        return [r for r in c]

def build_curve(r, today_date, yc, start_date, step_in_date, value_date, end_dates):
    spread_curve = 1e-4 * np.array(r['spread_curve'][1:])
    upfront_curve = 1e-2 * np.array(r['upfront_curve'][1:])
    recovery_curve = np.array(r['recovery_curve'][1:])
    sc = SpreadCurve(today_date, yc, start_date, step_in_date, value_date,
                     end_dates, spread_curve, upfront_curve, recovery_curve, True)
    return (r['cds_ticker'], sc)

def grouper(iterable, n, fillvalue=None):
    "Collect data into fixed-length chunks or blocks"
    # grouper('ABCDEFG', 3, 'x') --> ABC DEF Gxx
    args = [iter(iterable)] * n
    return zip_longest(fillvalue=fillvalue, *args)

def build_curves_dist(quotes, args, workers=4):
    ## about twice as fast as the non distributed version
    ## non thread safe for some reason so need ProcessPool
    with ProcessPoolExecutor(workers) as e:
        fs = [e.submit(build_curves, *(q, args)) for q in grouper(quotes, 30)]
    return list(chain.from_iterable([f.result() for f in as_completed(fs)]))

def build_curves(quotes, args):
    return [build_curve(q, *args) for q in quotes if q is not None]


def all_curves_pv(curves, today_date, jp_yc, start_date, step_in_date, value_date, maturities):
    r = {}
    for d in maturities:
        tenor = {}
        coupon_leg = FeeLeg(start_date, d, True, 1., 1.)
        default_leg = ContingentLeg(start_date, d, True)
        accrued = coupon_leg.accrued(step_in_date)
        tickers = []
        data = []
        for ticker, sc in curves:
            coupon_leg_pv = coupon_leg.pv(today_date, step_in_date, value_date, jp_yc, sc, False)
            default_leg_pv = default_leg.pv(today_date, step_in_date, value_date,
                                            jp_yc, sc, 0.4)
            tickers.append(ticker)
            data.append((coupon_leg_pv-accrued, default_leg_pv))
        r[pd.Timestamp(d)] = pd.DataFrame.from_records(data,
                                                       index=tickers,
                                                       columns=['duration', 'protection_pv'])
    return pd.concat(r, axis=1).swaplevel(axis=1).sort_index(axis=1,level=0)

def stack_curves(curves):
    dates = [d for d, _ in curves[0].inspect()['data']]
    hazard_rates = np.empty((len(curves), len(dates)))
    for i, sc in enumerate(curves):
        hazard_rates[i] = np.array([h for _, h in sc.inspect()['data']])
    return hazard_rates, dates

def forward_hazard_rates(sc):
    r = []
    t = []
    t1 = 0
    h1 = 0
    base_date = sc.base_date
    for d, h in sc.inspect()['data']:
        h2 = math.log1p(h)
        t2 = (d - base_date).days / 365
        r.append( (h2 * t2 - h1 * t1) / (t2 - t1) )
        t.append(t2)
        h1, t1 = h2, t2
    return t, r

Settings().evaluation_date = Date(6, 2, 2017)
yc = YC()
jp_yc = ql_to_jp(yc)
today_date = datetime.date(2017, 2, 6)
step_in_date = datetime.date(2017, 2, 7)
value_date = datetime.date(2017, 2, 9)
start_date = datetime.date(2016, 12, 20)
end_dates = [datetime.date(2017, 12, 20),
             datetime.date(2018, 12, 20),
             datetime.date(2019, 12, 20),
             datetime.date(2020, 12, 20),
             datetime.date(2021, 12, 20),
             datetime.date(2023, 12, 20),
             datetime.date(2026, 12, 20)]

quotes = get_singlenames_quotes("ig27", today_date)
maturities = [datetime.date(2019, 12, 20),
              datetime.date(2021, 12, 20),
              datetime.date(2023, 12, 20),
              datetime.date(2026, 12, 20)]
args = (today_date, jp_yc, start_date, step_in_date, value_date, maturities)
curves = build_curves_dist(quotes, args)
test = all_curves_pv(curves, *args)
ig27 = CreditIndex(start_date, maturities, curves)
test2 = ig27.pv_vec(step_in_date, value_date, jp_yc, 0.4)

from index_data import get_index_quotes
quotes = get_index_quotes("IG", 27, ['3yr', '5yr', '7yr', '10yr'])

def calibrate_portfolio(index, step_in_date, value_date, yc, recovery, quotes):
    for i, m in index.maturities:
        eps = brentq(lambda epsilon: index.pv(step_in_date, value_date, m, yc, recovery, epsilon)
                     - quote, -0.15, 0.3)