import csv
import datetime
import json
import logging
import os
import os.path
import psycopg2
import re
import sys
import yaml

sys.path.append('.')
from csv import reader
from common import root
from db import dbconn

logger = logging.getLogger(__name__)

pattern1 = re.compile("REINVEST\[\w+::REINV_TBA(\d)\]\[DEAL,(\d+)\]=.*$")
# reinv end date
pattern2 = re.compile("(STANDARD_VAR\[)\w+(::#REINV_END,\d+\]=)(\d.*$)")
# reinvprices 1
pattern3 = re.compile("STANDARD_VAR\[\w+::#PRICE100_TBA(\d),(\d+)\]=")
pattern5 = re.compile("STANDARD_VAR\[\w+::#REINVPCT_TBA(\d),(\d+)\]=")
pattern7 = re.compile("KINGS3")
pattern8 = re.compile("(#COLLATREINV_REINV_PCT_EXT\[)\w+(::\*\]\[DEAL,\d+\])=100")
pattern9 = re.compile("(?P<a>SEVERITY\[\w+,\d+\]=)mkt\(70\)")

# we use 84 so that it's both dividable by 2 and 3
global_reinvfloatpercentage = 84
global_reinvfixedpercentage = 16

def get_reinv_assets(conn, dealname, workdate):
    sqlstr = 'select * from et_historicaldealinfo(%s, %s) where ReinvFlag IS TRUE'
    d = {}
    with conn.cursor() as c:
        c.execute(sqlstr, (dealname, workdate))
        for line in c:
            d[line['issuername']] = line['fixedorfloat']
    conn.commit()
    return d

def get_recovery(conn, dealname, workdate, defaultrecovery = 50):
    """ compute average price of defaulted assets """
    sqlstr = "select sum(coalesce(price, %s) * currentbalance)/sum(currentbalance) " + \
             "from et_aggdealinfo_historical(%s, %s) where defaultedflag is True"
    with conn.cursor() as c:
        c.execute(sqlstr, (defaultrecovery, dealname, workdate))
        try:
            recovery, = c.fetchone()
        except TypeError:
            recovery = defaultrecovery
        finally:
            if not recovery:
                recovery = defaultrecovery
    conn.commit()
    return float(recovery)

def get_reinvenddate(conn, dealname):
    sqlstr = 'SELECT reinv_end_date from deal_indicative where dealname=%s'
    with conn.cursor() as c:
        c.execute(sqlstr, (dealname,))
        reinvenddate, = c.fetchone()
    conn.commit()
    if reinvenddate:
        return reinvenddate.strftime("%Y%m%d")
    else:
        raise Exception("missing reinvestment end date")

def generate_scenarios(workdate, dealname, conn):
    prometheus = os.path.join(root, "Scenarios", "prometheus.sss")
    n_scenarios = 100
    basedir = os.path.join(root, "Scenarios", "Intex curves_" + workdate)
    defaultedprice = get_recovery(conn, dealname, workdate)
    replace = "\g<a>{0:.3f}".format(defaultedprice)
    try:
        with open(os.path.join(basedir, "csv", dealname + ".config")) as fh:
            config = yaml.load(fh)
    except IOError:
        logger.error("{0}: config file doesn't exist".format(dealname))
        return
    reinvflag = config['reinvflag']
    if reinvflag:
        reinvenddate = get_reinvenddate(conn, dealname)
        reinv_assets = get_reinv_assets(conn, dealname, workdate)
        n_float_assets = len([v for v in reinv_assets.values() if v == 'FLOAT'])
        n_fixed_assets = len([v for v in reinv_assets.values() if v == 'FIXED'])
        rollingmat = config['rollingmat']
        if n_fixed_assets == 0:
            reinvfixedpercentage = 0
        else:
            reinvfixedpercentage = global_reinvfixedpercentage / n_fixed_assets
        if n_float_assets > 0:
            reinvfloatpercentage = (100 - n_fixed_assets * reinvfixedpercentage)/n_float_assets

    try:
        with open(os.path.join(basedir, "csv", dealname + "-reinvprices.csv"), "r") as fh:
            dr = csv.DictReader(fh)
            reinvprices = {f: [] for f in dr.fieldnames}
            for line in dr:
                for f in dr.fieldnames:
                    reinvprices[f].append("{0:.3f}".format(float(line[f])))
    except IOError:
        reinvflag = False

    sssfile = os.path.join(basedir, "sss", dealname + ".sss")
    if not os.path.exists(os.path.join(basedir, "sss")):
        os.makedirs(os.path.join(basedir, "sss"))
    cdrscenarios = os.path.join(basedir, "csv", dealname + "-cdr.csv")
    recoveryscenarios = os.path.join(basedir, "csv", dealname + "-recovery.csv")
    fhsss = open(sssfile, "w")
    fhcdr = open(cdrscenarios, "r")
    fhrecovery = open(recoveryscenarios, "r")
    csvcdr = reader(fhcdr)
    csvrecovery = reader(fhrecovery)
    cdrline = next(csvcdr)
    cdrline = "\t".join(["{0:.3f}".format(float(cdr)) for cdr in cdrline])
    recoveryline = next(csvrecovery)
    recoveryline = "\t".join(["{0:.3f}".format(float(recovery)) for recovery in recoveryline])

    i=1
    with open(prometheus) as fh:
        for line in fh:
            line = line.rstrip()

            if "DEAL_NAME" in line:
                newline = "DEAL_NAME=" +  dealname.upper() + "\r\n"
                fhsss.write(newline)
                continue
            if not reinvflag and pattern8.match(line):
                line = re.sub(pattern8, r"\1{0}\2=0".format(dealname.upper()), line)
                fhsss.write(line + "\r\n")
                continue
            if not reinvflag and "DO_REINV" in line:
                fhsss.write("DO_REINV=0" + "\r\n")
                continue
            m = pattern1.match(line)
            if reinvflag and m:
                reinv_number, scen_number = m.groups()
                key = "REINV_TBA" + reinv_number
                if key in reinv_assets:
                    if reinv_assets[key] == "FLOAT":
                        coupon = 4
                    elif reinv_assets[key] == "FIXED":
                        coupon = 7
                    line = "REINVEST[{0}::REINV_TBA{1}][DEAL,{2}]=".format(dealname.upper(),
                                                                           reinv_number,
                                                                           scen_number)
                    line += "COUP_SPR={0}|AMORT=Bullet|USE_REINVEST_PIP=1|MAT_DATE={1}|".format(coupon,
                                                                                                rollingmat)
                    fhsss.write(line + "\r\n")
                continue
            if reinvflag and pattern2.match(line):
                line = re.sub(pattern2, r"\1{0}\2{1}", line).format(dealname.upper(), reinvenddate)
                fhsss.write(line + "\r\n")
                continue
            m = pattern3.match(line)
            if reinvflag and m:
                reinv_number, scen_number = m.groups()
                if dealname=="litpt3" and reinv_number=="1":
                    line = "STANDARD_VAR[LITPT3::#REINVLOANP100,{0}]".format(scen_number) + \
                           "={0}".format(" ".join(reinvprices["REINV_TBA1"]))
                    fhsss.write(line + "\r\n")
                    continue
                reinv_name = "REINV_TBA" + reinv_number
                if reinv_name in reinvprices:
                    line = \
                    "STANDARD_VAR[{0}::#PRICE100_TBA{1},{2}]={3}".format(dealname.upper(),
                                                                         reinv_number,
                                                                         scen_number,
                                                                         " ".join(reinvprices[reinv_name]))
                    fhsss.write(line + "\r\n")
                continue
            m = pattern5.match(line)
            if reinvflag and m:
                reinv_number, scen_number = m.groups()
                reinv_name = "REINV_TBA" + reinv_number
                if reinv_number=="1":
                    if dealname=="litpt3":
                        line = "STANDARD_VAR[LITPT3::#LOANREINVPCT,{0}]=100".format(scen_number)
                        fhsss.write(line + "\r\n")
                        continue
                    if dealname=="flags4":
                        line = "STANDARD_VAR[FLAGS4::#PCT100_TBA1,{0}]=100".format(scen_number)
                        fhsss.write(line + "\r\n")
                        continue
                if reinv_name in reinv_assets:
                    if reinv_assets[reinv_name] == 'FIXED':
                        line = "STANDARD_VAR[{0}::#REINVPCT_TBA{1},{2}]={3}".format(dealname.upper(),
                                                                                    reinv_number,
                                                                                    scen_number,
                                                                                    reinvfixedpercentage)
                    elif reinv_assets[reinv_name] == 'FLOAT':
                        line =  "STANDARD_VAR[{0}::#REINVPCT_TBA{1},{2}]={3}".format(dealname.upper(),
                                                                                     reinv_number,
                                                                                     scen_number,
                                                                                     reinvfloatpercentage)

                    fhsss.write(line + "\r\n")
                continue
            if pattern7.search(line):
                line = re.sub(pattern7, dealname.upper(), line)
                fhsss.write(line + "\r\n")
                continue
            if "LOSS_RATE[DEAL,{0}]".format(i) in line:
                newcdrline = "LOSS_RATE[DEAL,{0}]=".format(i) + cdrline
                fhsss.write(newcdrline + "\r\n")
                continue
            if "LOSS_SEVERITY[DEAL,{0}]".format(i) in line:
                newrecoveryline = "LOSS_SEVERITY[DEAL,{0}]=".format(i) + recoveryline
                fhsss.write(newrecoveryline + "\r\n")
                i = i + 1
                if i <= n_scenarios:
                    cdrline = next(csvcdr)
                    cdrline = "\t".join(["{0:.3f}".format(float(cdr)) for cdr in cdrline]) + "\r\n"
                    recoveryline = next(csvrecovery)
                    recoveryline = "\t".join(["{0:.3f}".format(float(recovery)) \
                                                  for recovery in recoveryline]) + "\r\n"
                continue
            if "LOSS_NONPERF_SEVERITY" in line:
                line = re.sub(pattern9, replace, line)
            fhsss.write(line + "\r\n")
    fhsss.close()
    fhrecovery.close()
    fhcdr.close()
    logger.info("generated scenarios for: {0}".format(dealname))

if __name__ == "__main__":
    if len(sys.argv) > 1:
        workdate = sys.argv[1]
    else:
        workdate = str(datetime.date.today())
    if len(sys.argv) > 2:
        dealnames = sys.argv[2:]
    else:
        dealnames = [d.split(".")[0] for d in
                    os.listdir(os.path.join(root,  "Scenarios",
                                            "Intex curves_" + workdate, "csv"))
                    if "RData" in d]
    ET = dbconn('etdb')
    for dealname in dealnames:
        generate_scenarios(workdate, dealname, ET)
    ET.close()