path: root/python/analytics/index.py

import analytics
import array
import datetime
import pandas as pd

from .credit_default_swap import CreditDefaultSwap
from . import serenitas_engine, dawn_engine, DataError

try:
    from bbg_helpers import BBG_IP, retrieve_data, init_bbg_session
except ModuleNotFoundError:
    pass
from pandas.tseries.offsets import BDay
from pyisda.curve import SpreadCurve


def g(index, spread, exercise_date, pv=None):
    """computes the strike clean price using the expected forward yield curve. """
    step_in_date = exercise_date + datetime.timedelta(days=1)
    exercise_date_settle = pd.Timestamp(exercise_date) + 3 * BDay()
    if spread is None and index._sc is not None:
        sc = index._sc
        prot = index._default_leg.pv(
            exercise_date,
            step_in_date,
            exercise_date_settle,
            index._yc,
            index._sc,
            index.recovery,
        )
    else:
        rates = array.array("d", [spread * 1e-4])
        upfront = 0.0 if pv is None else pv
        sc = SpreadCurve(
            exercise_date,
            index._yc,
            index.start_date,
            step_in_date,
            exercise_date_settle,
            [index.end_date],
            rates,
            array.array("d", [upfront]),
            array.array("d", [index.recovery]),
        )
    a = index._fee_leg.pv(
        exercise_date, step_in_date, exercise_date_settle, index._yc, sc, True
    )

    if pv is not None:
        return 1e4 * pv / a + spread
    else:
        if spread is None:
            return prot - a * index.fixed_rate * 1e-4
        else:
            return (spread - index.fixed_rate) * a * 1e-4


class CreditIndex(CreditDefaultSwap):
    __slots__ = (
        "_indic",
        "_version",
        "_cumloss",
        "index_type",
        "series",
        "tenor",
        "_quote_is_price",
    )

    def __init__(
        self,
        index_type=None,
        series=None,
        tenor=None,
        value_date=datetime.date.today(),
        notional=10_000_000,
        redcode=None,
        maturity=None,
    ):
        if all([redcode, maturity]):
            r = serenitas_engine.execute(
                "SELECT index, series, tenor FROM index_desc "
                "WHERE redindexcode=%s AND maturity = %s",
                (redcode, maturity),
            )
            index_type, series, tenor = next(r)

        if all([index_type, series, tenor]):
            sql_str = (
                "SELECT indexfactor, lastdate, maturity, coupon, "
                "issue_date, version, cumulativeloss "
                "FROM index_desc WHERE index=%s AND series=%s AND tenor = %s "
                "ORDER BY lastdate ASC"
            )
            params = (index_type.upper(), series, tenor)
        else:
            raise ValueError("Not enough information to load the index.")
        try:
            df = pd.read_sql_query(
                sql_str,
                serenitas_engine,
                parse_dates=["lastdate", "issue_date"],
                params=params,
            )
            maturity = df.maturity[0]
            coupon = df.coupon[0]
            if tenor is None:
                tenor = df.tenor[0]
            index_type = index_type.upper() if index_type else df.loc[0, "index"]
            series = series if series else df.series.iat[0]
            df.loc[df.lastdate.isnull(), "lastdate"] = maturity
        except DataError as e:
            print(e)
            return None
        else:
            recovery = 0.3 if index_type == "HY" else 0.4
            super().__init__(
                value_date, maturity, recovery, coupon, notional, df.issue_date[0]
            )
            self._quote_is_price = index_type == "HY"
            self._indic = tuple(
                (ld.date(), factor / 100, cumloss, version)
                for ld, factor, cumloss, version in (
                    df[
                        ["lastdate", "indexfactor", "cumulativeloss", "version"]
                    ].itertuples(index=False)
                )
            )
            self.index_type = index_type
            self.series = series
            self.tenor = tenor

            tenor = tenor.upper()
            if tenor.endswith("R"):
                tenor = tenor[:-1]
            self.name = "CDX {} CDSI S{} {}".format(index_type, series, tenor)
            if index_type in ["IG", "HY"]:
                self.currency = "USD"
            else:
                self.currency = "EUR"
            self.value_date = value_date

    @classmethod
    def from_tradeid(cls, trade_id):
        r = dawn_engine.execute(
            """
        SELECT index, series, tenor, trade_date, notional, security_desc,
        protection, upfront
        FROM cds
        LEFT JOIN index_desc
        ON security_id = redindexcode AND cds.maturity = index_desc.maturity
        WHERE id=%s""",
            (trade_id,),
        )
        rec = r.fetchone()
        if rec is None:
            raise ValueError(f"No index trade for id: {trade_id}")
        instance = cls(rec.index, rec.series, rec.tenor, rec.trade_date, rec.notional)

        instance.name = rec.security_desc
        instance.direction = rec.protection
        instance.value_date = rec.trade_date
        instance.pv = rec.upfront
        instance.reset_pv()
        return instance

    @property
    def hy_equiv(self):
        try:
            ontr = analytics._ontr
        except AttributeError:
            return float("nan")
        risk = self.notional * self.risky_annuity / ontr.risky_annuity
        if self.index_type != "HY":
            risk *= analytics._beta[self.index_type]
        return risk

    @property
    def ref(self):
        if self._quote_is_price:
            return self.price
        else:
            return self.spread

    @ref.setter
    def ref(self, val):
        if self._quote_is_price:
            self.price = val
        else:
            self.spread = val

    def mark(self, **args):
        if self.value_date == datetime.date.today():
            with init_bbg_session(BBG_IP) as session:
                security = self.name + " Corp"
                field = "PX_LAST"
                ref_data = retrieve_data(session, [security], field)
            self.ref = ref_data[security][field]
        else:
            run = serenitas_engine.execute(
                """SELECT * FROM index_quotes
            WHERE index=%s AND series=%s AND tenor=%s AND date=%s""",
                (self.index_type, self.series, self.tenor, self.value_date),
            )
            rec = run.fetchone()
            self.spread = rec.closespread

    value_date = property(CreditDefaultSwap.value_date.__get__)

    @value_date.setter
    def value_date(self, d):
        CreditDefaultSwap.value_date.__set__(self, d)
        for lastdate, factor, cumloss, version in self._indic:
            if lastdate >= self.value_date:
                self._factor = factor
                self._version = version
                self._cumloss = cumloss
                break
        else:
            self._factor = 1.0
            self._version = 1

    @property
    def factor(self):
        return self._factor

    @property
    def version(self):
        return self._version

    @property
    def cumloss(self):
        return self._cumloss


class ForwardIndex:
    __slots__ = (
        "index",
        "forward_date",
        "exercise_date_settle",
        "df",
        "_forward_annuity",
        "_forward_pv",
        "_forward_spread",
        "__weakref__",
    )

    def __init__(self, index, forward_date, observer=True):
        self.index = index
        if isinstance(forward_date, pd.Timestamp):
            self.forward_date = forward_date.date()
        else:
            self.forward_date = forward_date
        self.exercise_date_settle = pd.Timestamp(forward_date) + 3 * BDay()
        self.df = index._yc.discount_factor(self.exercise_date_settle)
        self._update()
        if observer:
            self.index.observe(self)

    @classmethod
    def from_name(
        cls,
        index_type,
        series,
        tenor,
        forward_date,
        value_date=datetime.date.today(),
        notional=10e6,
    ):
        index = CreditIndex(index_type, series, tenor, value_date, notional)
        return cls(index, forward_date)

    @property
    def forward_annuity(self):
        return self._forward_annuity

    @property
    def forward_pv(self):
        return self._forward_pv

    @property
    def forward_spread(self):
        return self._forward_spread * 1e4

    @property
    def ref(self):
        return self.index.ref

    @ref.setter
    def ref(self, val):
        self.index.ref = val

    def __hash__(self):
        return hash(tuple(getattr(self, k) for k in ForwardIndex.__slots__[:-1]))

    def _update(self, *args):
        if self.index.value_date > self.forward_date:
            raise ValueError(
                f"Option expired: value_date {self.index.value_date}"
                f" is greater than forward_date: {self.forward_date}"
            )
        if self.index._sc is not None:
            step_in_date = self.forward_date + datetime.timedelta(days=1)
            a = self.index._fee_leg.pv(
                self.index.value_date,
                step_in_date,
                self.index.value_date,
                self.index._yc,
                self.index._sc,
                False,
            )
            Delta = self.index._fee_leg.accrued(step_in_date)
            q = self.index._sc.survival_probability(self.forward_date)
            self._forward_annuity = a - Delta * self.df * q
            self._forward_pv = (
                self._forward_annuity
                * (self.index.spread - self.index.fixed_rate)
                * 1e-4
            )
            fep = (1 - self.index.recovery) * (1 - q)
            self._forward_pv = self._forward_pv / self.df + fep
            self._forward_spread = (
                self.index._spread + fep * self.df / self._forward_annuity
            )
        else:
            self._forward_annuity, self._forward_pv, self._forward_spread = (
                None,
                None,
                None,
            )