import pandas as pd
import re
import psycopg2.sql as sql
import datetime
import pickle
from . import logger
from functools import partial, lru_cache
from quantlib.time.imm import next_date
from quantlib.time.api import Date, pydate_from_qldate
from unicodedata import normalize


def list_imm_dates(date):
    d = Date.from_datetime(date)
    r = []
    for i in range(10):
        d = next_date(d, False)
        r.append(pydate_from_qldate(d))
    return r


def makedf(r, indextype, quote_source):
    if indextype == "IG":
        cols = [
            "strike",
            "rec_bid",
            "rec_offer",
            "delta_rec",
            "pay_bid",
            "pay_offer",
            "delta_pay",
            "vol",
        ]
    else:
        cols = [
            "strike",
            "rec_bid",
            "rec_offer",
            "delta_rec",
            "pay_bid",
            "pay_offer",
            "delta_pay",
            "vol",
            "price_vol",
        ]
    if quote_source == "BAML":
        cols.append("gamma")
    if quote_source == "GS":
        cols.append("tail")
    df = pd.DataFrame.from_records(r, columns=cols)
    for col in ["delta_rec", "delta_pay", "vol", "price_vol", "gamma", "tail"]:
        if col in df:
            try:
                df[col] = df[col].str.rstrip("%").astype("float") / 100
            except ValueError:  # typo in one email
                df[col] = (
                    pd.to_numeric(df[col].str.rstrip("%").str.replace("n", "")) / 100
                )
    if quote_source == "GS":
        for col in ["pay_bid", "pay_offer", "rec_bid", "rec_offer"]:
            df[col] = df[col].str.strip("-")
        df["delta_pay"] *= -1
    for k in df:
        if df.dtypes[k] == "object":
            df[k] = df[k].str.replace(",", "")
            try:
                df[k] = pd.to_numeric(df[k])
            except ValueError as e:
                logger.info(e)
                logger.error("couldn't convert column")
                df[k] = pd.to_numeric(
                    df[k]
                    .str.replace("n", "")
                    .str.replace("\\", "")
                    .str.replace("M", "")
                )
    df.set_index("strike", inplace=True)
    return df


def parse_quotedate(fh, date_received):
    for line in fh:
        line = line.rstrip()
        if "At:" in line or "Sent:" in line:
            for p in [
                "%m/%d/%y %H:%M:%S",
                "%b  %d %Y %H:%M:%S",
                "%m/%d  %H:%M:%S",
                "%B %d, %Y %I:%M %p",
            ]:
                try:
                    quotedate = pd.to_datetime(line, format=p, exact=False)
                except ValueError:
                    continue
                else:
                    if quotedate.year == 1900:  # p='%m/%d  %H:%M:%S'
                        quotedate = quotedate.replace(year=date_received.year)
                    quotedate = quotedate.tz_localize("America/New_York")
                    break
            else:
                raise RuntimeError("can't parse date from {line}")
            return quotedate
    else:
        raise RuntimeError("no date received in the email")


def parse_refline(line):
    regex = (
        r"Ref:(?P<ref>\S+)\s+(?:Fwd Px:(?P<fwdprice>\S+)\s+)?"
        r"Fwd(?: Spd)?:(?P<fwdspread>\S+)\s+Fwd Bpv:(?P<fwdbpv>\S+)"
        r"\s+Expiry:(?P<expiry>\S+)"
    )
    m = re.match(regex, line)
    try:
        d = m.groupdict()
        d["expiry"] = pd.to_datetime(d["expiry"], format="%d-%b-%y")
    except AttributeError:
        raise RuntimeError(f"can't parse refline {line}")
    return d


def parse_baml(fh, index_desc, *args):
    option_stack = {}
    fwd_index = []
    line = ""
    while True:
        if line == "":
            try:
                line = next(fh)
            except StopIteration:
                break
        if line.startswith("Ref"):
            d = parse_refline(line)
            d.update(index_desc)
            df, line = parse_baml_block(fh, index_desc["index"])
            option_stack[d["expiry"]] = df
            fwd_index.append(d)
        else:
            line = ""
    return option_stack, fwd_index


def parse_baml_block(fh, indextype):
    next(fh)  # skip header
    r = []
    line = ""
    for line in fh:
        line = line.strip()
        if line.startswith("Ref") or line == "":
            break
        line = re.sub("[/|]", " ", line)
        vals = re.sub(" +", " ", line).rstrip().split(" ")
        if len(vals) < 3:  # something went wrong
            line = ""
            break
        r.append(vals)
    return makedf(r, indextype, "BAML"), line


def parse_bnp_block(fh, indextype, skip_header=True):
    if skip_header:
        next(fh)  # skip header
    r = []
    for line in fh:
        line = line.strip()
        if "\xa0" in line:
            line = normalize("NFKD", line)
        if line.startswith("Ref") or line == "":
            break
        line = re.sub("[/|]", " ", line)
        vals = re.sub(" +", " ", line).rstrip().split(" ")
        if indextype == "HY":
            vals += [""]
        if len(vals) < 3:  # something went wrong
            line = ""
            break
        r.append(vals)
    return makedf(r, indextype, "BNP")


def parse_cs_block(fh, indextype):
    next(fh)  # skip header
    r = []
    for line in fh:
        line = line.strip()
        if line.startswith("Ref") or line == "":
            break
        line = re.sub("[/|]", " ", line)
        vals = re.sub(" +", " ", line).rstrip().split(" ")
        if len(vals) == 1:
            logger.info("spurious line", line)
            continue
        strike, *rest = vals
        # CS quotes payer first, so we need to move things around a bit
        if indextype == "IG":
            vals = (strike, *rest[3:6], *rest[:3], rest[6])
        elif indextype == "HY":
            vals = (strike, *rest[3:6], *rest[:3], *rest[6:8])
        r.append(vals)
    return makedf(r, indextype, "CS")


def parse_ms_block(fh, indextype):
    line = next(fh)  # skip header
    if line.strip() == "":  # empty block
        return None
    r = []
    for line in fh:
        line = line.rstrip()
        if line == "":
            break
        strike, payer, receiver, vol = line.split("|")
        strike = strike.strip()
        if indextype == "HY":
            strike = strike.split()[0]
        try:
            pay_bid, pay_offer, pay_delta = payer.strip().split()
            rec_bid, rec_offer, rec_delta = receiver.strip().split()
        except ValueError:
            try:
                pay_mid, pay_delta = payer.strip().split()
                rec_mid, rec_delta = receiver.strip().split()
                pay_bid, pay_offer = pay_mid, pay_mid
                rec_bid, rec_offer = rec_mid, rec_mid
            except ValueError:
                raise RuntimeError("Couldn't parse line: {line}")

        vals = [strike, rec_bid, rec_offer, rec_delta, pay_bid, pay_offer, pay_delta]
        vol = vol.strip()
        if indextype == "HY":
            try:
                price_vol, vol = vol.replace("[", "").replace("]", "").split()
            except ValueError:
                price_vol, vol, vol_change, be = (
                    vol.replace("[", "").replace("]", "").split()
                )
            vals += [vol, price_vol]
        else:
            if " " in vol:
                vol, vol_change, be = vol.split()
            vals += [vol]
        r.append(vals)
    return makedf(r, indextype, "MS")


def parse_nomura_block(fh, indextype):
    next(fh)  # skip header
    r = []
    for line in fh:
        line = line.rstrip()
        if "EXPIRY" in line or line == "":
            break
        strike, receiver, payer, vol, _ = line.split("|", 4)
        strike = strike.strip()
        pay, pay_delta = payer.strip().split()
        rec, rec_delta = receiver.strip().split()
        pay_bid, pay_offer = pay.split("/")
        rec_bid, rec_offer = rec.split("/")
        vol = vol.strip()
        vals = [
            strike,
            rec_bid,
            rec_offer,
            rec_delta,
            pay_bid,
            pay_offer,
            pay_delta,
            vol,
        ]
        if indextype == "HY":  # we don't have price vol
            vals.append(None)
        r.append(vals)
    else:
        return None, makedf(r, indextype, "NOM")
    return line, makedf(r, indextype, "NOM")


def parse_sg_block(fh, indextype, expiration_dates):
    r = []
    for line in fh:
        line = line.rstrip()
        if line == "":
            break
        if indextype == "IG":
            option_type, strike, price, delta, vol, expiry = line.split()
        else:
            option_type, strike, strike_spread, price, delta, vol, expiry = line.split()

        expiry_month = datetime.datetime.strptime(expiry, "%b-%y").month
        expiry = next(
            pd.Timestamp(d) for d in expiration_dates if d.month == expiry_month
        )
        if option_type == "Rec":
            rec_bid, rec_offer = price.split("/")
            pay_bid, pay_offer = None, None
            rec_delta, pay_delta = delta, None
        else:
            pay_bid, pay_offer = price.split("/")
            rec_bid, rec_offer = None, None
            rec_delta, pay_delta = None, delta
        vals = [
            strike,
            rec_bid,
            rec_offer,
            rec_delta,
            pay_bid,
            pay_offer,
            pay_delta,
            vol,
        ]
        if indextype == "HY":
            vals.append(None)
        r.append(vals)
    return expiry, makedf(r, indextype, "SG")


def parse_gs_block(fh, indextype):
    # skip header
    while True:
        line = next(fh)
        if line.strip().startswith("Stk"):
            break

    r = []
    for line in fh:
        line = line.rstrip()
        if line == "":
            continue
        if line.startswith("Expiry") or line.startswith("Assumes"):
            break
        vals = line.split()
        if indextype == "HY":
            vals.pop(2)
            vals.pop(9)
        else:
            vals.pop(1)
            vals.pop(8)
        strike = vals.pop(0)
        if indextype == "HY":
            vals.pop(0)  # pop the spread
        pay, pay_delta = vals[:2]
        pay_bid, pay_offer = pay.split("/")
        rec_bid, rec_offer = vals[2].split("/")
        vol = vals[3]
        tail = vals[6]
        vals = [strike, rec_bid, rec_offer, None, pay_bid, pay_offer, pay_delta, vol]
        if indextype == "HY":
            vals.append(None)
        vals.append(tail)
        r.append(vals)
    return makedf(r, indextype, "GS"), line


def parse_citi_block(fh, indextype):
    next(fh)  # skip header
    r = []
    for line in fh:
        line = line.rstrip()
        if line == "":
            break
        if indextype == "HY":
            strike, payers, receivers, vol, price_vol = line.split("|")
        else:
            strike, payers, receivers, vol = line.split("|")
        strike = strike.strip()
        pay_bid, pay_offer = payers.split("/")
        pay_bid = pay_bid.strip()
        pay_offer = pay_offer.strip()
        pay_offer, pay_delta = pay_offer.split()
        rec_bid, rec_offer = receivers.split("/")
        rec_bid = rec_bid.strip()
        rec_offer = rec_offer.strip()
        rec_offer, rec_delta = rec_offer.split()
        vol = vol.strip()
        vol = vol.split()[0]
        if indextype == "HY":
            price_vol = price_vol.strip()
            r.append(
                [
                    strike,
                    rec_bid,
                    rec_offer,
                    rec_delta,
                    pay_bid,
                    pay_offer,
                    pay_delta,
                    vol,
                    price_vol,
                ]
            )
        else:
            r.append(
                [
                    strike,
                    rec_bid,
                    rec_offer,
                    rec_delta,
                    pay_bid,
                    pay_offer,
                    pay_delta,
                    vol,
                ]
            )
    return makedf(r, indextype, "CITI")


def parse_ms(fh, index_desc, *args):
    option_stack = {}
    fwd_index = []
    for line in fh:
        line = line.rstrip()
        if "EXPIRY" in line:
            expiry = line.split(" ")[1]
            expiry = pd.to_datetime(expiry, format="%d-%b-%Y")
            block = parse_ms_block(fh, index_desc["index"])
            fwd_index.append({"expiry": expiry, **index_desc})
            if block is None or block.empty:
                logger.warning("MS: block is empty for {expiry} expiry")
            else:
                option_stack[expiry] = block
    return option_stack, fwd_index


def parse_nom(fh, index_desc, *args):
    option_stack = {}
    fwd_index = []

    def aux(line, fh, index_desc, option_stack, fwd_index):
        expiry = line.split(" ")[0]
        expiry = pd.to_datetime(expiry, format="%d-%b-%y")
        next_line, df = parse_nomura_block(fh, index_desc["index"])
        option_stack[expiry] = df
        fwd_index.append({"expiry": expiry, **index_desc})
        if next_line:
            if "EXPIRY" in next_line:
                aux(next_line, fh, index_desc, option_stack, fwd_index)
            else:
                raise RuntimeError(f"Don't know what to do with {line}.")

    for line in fh:
        line = line.rstrip()
        if "EXPIRY" in line:
            aux(line, fh, index_desc, option_stack, fwd_index)
    return option_stack, fwd_index


def parse_sg(fh, index_desc):
    option_stack = {}
    fwd_index = []

    expiration_dates = index_desc.pop("expiration_dates")
    for line in fh:
        line = line.rstrip()
        if line.startswith("Type"):
            expiry, df = parse_sg_block(fh, index_desc["index"], expiration_dates)
            option_stack[expiry] = df
            fwd_index.append({"expiry": expiry, **index_desc})
    return option_stack, fwd_index


def parse_gs(fh, index_desc):
    option_stack = {}
    fwd_index = []
    pat = re.compile(r"Expiry (\d{2}\w{3}\d{2}) \((?:([\S]+) )?([\S]+)\)")

    line = next(fh).strip()
    while True:
        if line.startswith("Expiry"):
            m = pat.match(line)
            if m:
                expiry, fwdprice, fwdspread = m.groups()
                expiry = pd.to_datetime(expiry, format="%d%b%y")
                fwd_index.append(
                    {
                        **index_desc,
                        **{
                            "fwdspread": fwdspread,
                            "fwdprice": fwdprice,
                            "expiry": expiry,
                        },
                    }
                )
                option_stack[expiry], line = parse_gs_block(fh, index_desc["index"])
            else:
                logger.error("Can't parse expiry line:", line)
        elif line.startswith("Assumes"):
            break
        else:
            try:
                line = next(fh).strip()
            except StopIteration:
                break

    return option_stack, fwd_index


def parse_citi(fh, index_desc):
    option_stack = {}
    fwd_index = []
    pat = re.compile(r"Exp: (\d{2}-\w{3}-\d{2})[^R]*Ref:[^\d]*([\d.]+)")
    for line in fh:
        line = line.strip()
        if line.startswith("Exp"):
            m = pat.match(line)
            if m:
                expiry, ref = m.groups()
                expiry = pd.to_datetime(expiry, format="%d-%b-%y")
                fwd_index.append({"ref": ref, "expiry": expiry, **index_desc})
                option_stack[expiry] = parse_citi_block(fh, index_desc["index"])
            else:
                logger.error("Can't parse expiry line:", line)
    return option_stack, fwd_index


def parse_cs(fh, index_desc):
    option_stack = {}
    fwd_index = []
    regex = {
        "HY": r"Ref:\s*(?P<ref>[\d.]+)\s*Fwd: (?P<fwdprice>[\d.]+)\s*Expiry: (?P<expiry>\d{2}-\w{3}-\d{2})",
        "IG": r"Ref:\s*(?P<ref>[\d.]+)\s*Fwd: (?P<fwdspread>[\d.]+)\s*Expiry: (?P<expiry>\d{2}-\w{3}-\d{2})\s*Fwd dv01:\s*(?P<fwdbpv>[\d.]*).*",
    }
    pat = re.compile(regex[index_desc["index"]])

    for line in fh:
        line = line.strip()
        if line.startswith("Ref"):
            m = pat.match(line)
            if m:
                d = m.groupdict()
                d["expiry"] = pd.to_datetime(d["expiry"], format="%d-%b-%y")
                fwd_index.append({**index_desc, **d})
                option_stack[d["expiry"]] = parse_cs_block(fh, index_desc["index"])
            else:
                logger.error("Can't parse expiry line:", line, "filename:", fh.name)
    return option_stack, fwd_index


def parse_bnp(fh, index_desc):
    option_stack = {}
    fwd_index = []
    regex = r"Ref\s+(?P<ref>[\d.]+)\s+-\s+(?P<expiry>\w{3}\d{2})\s+-\s+Fwd\s+(?P<fwdspread>[\d.]+)"
    expiration_dates = index_desc.pop("expiration_dates")
    pat = re.compile(regex)
    for line in fh:
        line = line.strip()
        if line.startswith("Ref"):
            c = line.find("Strike")
            if c != -1:
                line = line[:c].rstrip()
            m = pat.match(line)
            if m:
                d = m.groupdict()
                if index_desc["index"] == "HY":
                    d["fwdprice"] = d.pop("fwdspread")
                expiry_month = datetime.datetime.strptime(d["expiry"], "%b%y").month
                d["expiry"] = next(
                    d for d in expiration_dates if d.month == expiry_month
                )
                fwd_index.append({**index_desc, **d})
                option_stack[d["expiry"]] = parse_bnp_block(
                    fh, index_desc["index"], c == -1
                )
            else:
                logger.error(f"Can't parse expiry line: {line} for filename: {fh.name}")
    return option_stack, fwd_index


subject_baml = re.compile(r"(?:Fwd:){0,2}(?:BAML )?(\D{2})(\d{1,2})\s")
subject_ms = re.compile(
    r"[^$]*\$\$ MS CDX OPTIONS: (IG|HY)(\d{2})[^-]*- REF[^\d]*([\d.]+)"
)
subject_nom = re.compile(r"(?:Fwd:)?CDX (IG|HY)(\d{2}).*- REF:[^\d]*([\d.]+)")
subject_gs = re.compile(r"(?:FW: |Fwd: )?GS (IG|HY)(\d{2}) 5y.*- Ref [^\d]*([\d.]+)")
subject_sg = re.compile(r"SG OPTIONS - CDX (IG|HY) S(\d{2}).* REF[^\d]*([\d.]+)")
subject_citi = re.compile(r"(?:Fwd:)?Citi Options: (IG|HY)(\d{2}) 5Y")
subject_cs = re.compile(
    r"CS CDX (?P<index>IG|HY)(?P<series>\d{2})_?v?(?P<version>\d)? Options -\s+(?:\d{2}/\d{2}/\d{2}\s+)?Ref = (?P<ref>[\d.]+)[^\d]*"
)
subject_bnp = re.compile(r"CDX OPTIONS RUN: (IG|HY)(\d{2}).*")


def get_current_version(index, series, d, conn):
    with conn.cursor() as c:
        c.execute(
            "select max(version) FROM index_version "
            "WHERE index=%s and series=%s and %s <= lastdate",
            (index.upper(), series, d),
        )
        version, = c.fetchone()
    return version


def parse_email(email, date_received, conn):
    get_version = lru_cache()(partial(get_current_version, conn=conn))
    with email.open("rt") as fh:
        subject = fh.readline().lstrip()

        for source in ["BAML", "GS", "MS", "NOM", "SG", "CITI", "CS", "BNP"]:
            m = globals()[f"subject_{source.lower()}"].match(subject)
            if m:
                version = None
                if source in ["BAML", "CITI", "BNP"]:
                    indextype, series = m.groups()
                elif source == "CS":
                    d = m.groupdict()
                    version = d.get("version")
                    indextype = d["index"]
                    series = d["series"]
                    ref = float(d["ref"])
                else:
                    indextype, series, ref = m.groups()
                    ref = float(ref)
                series = int(series)
                cur_pos = fh.tell()
                try:
                    quotedate = parse_quotedate(fh, date_received)
                except RuntimeError:
                    logger.warning(
                        "couldn't find received date in message: "
                        f"{email.name}, using {date_received}"
                    )
                    quotedate = pd.Timestamp(date_received).tz_localize(
                        "America/New_York"
                    )
                    fh.seek(cur_pos)
                if version is None:
                    version = get_version(indextype, series, quotedate)
                parse_fun = globals()[f"parse_{source.lower()}"]
                key = (quotedate, indextype, series, source)
                index_desc = {
                    "quotedate": quotedate,
                    "index": indextype,
                    "series": series,
                    "version": version,
                }
                if source in ["GS", "MS", "NOM", "SG"]:
                    index_desc["ref"] = ref
                if source in ["BNP", "SG"]:
                    index_desc["expiration_dates"] = list_imm_dates(quotedate)
                option_stack, fwd_index = parse_fun(fh, index_desc)
                if fwd_index:
                    fwd_index = pd.DataFrame.from_records(fwd_index, index="quotedate")
                    fwd_index["quote_source"] = source
                else:
                    raise RuntimeError("empty email " + fh.name)
                return (key, (option_stack, fwd_index))
        else:
            raise RuntimeError(
                f"can't parse subject line: {subject} for email {email.name}"
            )


def write_todb(swaption_stack, index_data, conn):
    def gen_sql_str(query, table_name, columns):
        return query.format(
            sql.Identifier(table_name),
            sql.SQL(", ").join(sql.Identifier(c) for c in columns),
            sql.SQL(", ").join(sql.Placeholder() * len(columns)),
        )

    query = sql.SQL(
        "INSERT INTO {}({}) VALUES({}) " "ON CONFLICT DO NOTHING RETURNING ref_id"
    )
    sql_str = gen_sql_str(query, "swaption_ref_quotes", index_data.columns)
    query = sql.SQL("INSERT INTO {}({}) VALUES({}) " "ON CONFLICT DO NOTHING")
    with conn.cursor() as c:
        for t in index_data.itertuples(index=False):
            c.execute(sql_str, t)
            try:
                ref_id, = next(c)
            except StopIteration:
                continue
            else:
                try:
                    df = swaption_stack.loc[
                        (t.quotedate, t.index, t.series, t.expiry, t.quote_source),
                    ]
                except KeyError as e:
                    logger.warning(
                        "missing key in swaption_stack: "
                        f"{t.quotedate}, {t.index}, {t.series}, {t.expiry}, {t.quote_source}"
                    )
                    continue
                except IndexError:
                    breakpoint()
                df["ref_id"] = ref_id
                c.executemany(
                    gen_sql_str(query, "swaption_quotes", df.columns),
                    df.itertuples(index=False),
                )
            conn.commit()


def get_email_list(date):
    """returns a list of email file names for a given date

    Parameters
    ----------
    date : string
    """
    with open(".pickle", "rb") as fh:
        already_uploaded = pickle.load(fh)
    df = pd.DataFrame.from_dict(already_uploaded, orient="index")
    df.columns = ["quotedate"]
    df = df.reset_index().set_index("quotedate")
    return df.loc[date, "index"].tolist()


def pickle_drop_date(date):
    with open(".pickle", "rb") as fh:
        already_uploaded = pickle.load(fh)
    newdict = {k: v for k, v in already_uploaded.items() if v.date() != date}
    with open(".pickle", "wb") as fh:
        pickle.dump(newdict, fh)