"""Policy attributes and policy values
This Space is a child Space of :mod:`~simplelife.model.Projection`,
and it holds policy attributes and policy values used
by :mod:`~simplelife.model.Projection`
and by :mod:`~simplelife.model.Projection.Assumptions`, another child Space
of :mod:`~simplelife.model.Projection`.
Some Cells in this Space, such as :func:`Product` and :func:`IssueAge`,
are for retrieving attributes for the selected policy from :attr:`PolicyData`.
Some other Cells, such as :func:`GrossPremRate` are for
calculating policy values for the policy from the attributes and
product specs looked up through :attr:`SpecLookup`.
.. figure:: /images/projects/simplelife/model/Policy/diagram1.png
.. rubric:: Parameters
Since :mod:`~simplelife.model.Projection` is parameterized with
:attr:`PolicyID` and :attr:`ScenID`, this Space is also
parameterized as a child space of :mod:`~simplelife.model.Projection`.
For example, ``simplelife.Projection[1].Policy.GrossPremRate()``
represents the gross premium rate for Policy 1.
Attributes:
    PolicyID(:obj:`int`): Policy ID
    ScenID(:obj:`int`, optional): Scenario ID, defaults to 1.
.. rubric:: References
Attributes:
    LifeTable: :mod:`~simplelife.model.LifeTable` Space
    PolicyData: `ExcelRange`_ object holding data read from the
        Excel range *PolicyData* in *input.xlsx*.
    SpecLookup: :func:`~simplelife.model.Input.SpecLookup`
    PremTerm: Alias for :func:`PolicyTerm`
.. _ExcelRange:
   https://docs.modelx.io/en/latest/reference/dataclient.html#excelrange
"""
from modelx.serialize.jsonvalues import *
_formula = None
_bases = []
_allow_none = None
_spaces = []
# ---------------------------------------------------------------------------
# Cells
[docs]
def AnnPremRate():
    """Annualized Premium Rate per Sum Assured"""
    return GrossPremRate() * (1/10 if PremFreq() == 0 else PremFreq()) 
[docs]
def CashValueRate(t):
    """Cash Value Rate per Sum Assured"""
    return max(ReserveNLP_Rate('PREM', t) - SurrCharge(t), 0) 
[docs]
def GrossPremRate():
    """Gross Premium Rate per Sum Assured per payment"""
    alpha = LoadAcqSA()
    beta = LoadMaintPrem()
    gamma = LoadMaintSA()
    gamma2 = LoadMaintSA2()
    delta = LoadMaintPremWaiverPrem()
    x, n, m = IssueAge(), PolicyTerm(), PremTerm()
    comf = LifeTable[Sex(), IntRate('PREM'), TableID('PREM')]
    if Product() == 'TERM' or Product() == 'WL':
        return (comf.Axn(x, n) + alpha + gamma * comf.AnnDuenx(x, n, PremFreq())
                + gamma2 * comf.AnnDuenx(x, n-m, 1, m)) / (1-beta-delta) / PremFreq() / comf.AnnDuenx(x, m, PremFreq())
    elif Product() == 'ENDW':
        return (comf.Exn(x, n) + comf.Axn(x, n) + alpha + gamma * comf.AnnDuenx(x, n, PremFreq())
                + gamma2 * comf.AnnDuenx(x, n-m, 1, m)) / (1-beta-delta) / PremFreq() / comf.AnnDuenx(x, m, PremFreq())
    else:
        raise ValueError('invalid product') 
[docs]
def GrossPremTable():
    """Gross premium table"""
    return None 
[docs]
def InitSurrCharge():
    """Initial Surrender Charge Rate"""
    param1 = _space.SpecLookup.match("SurrChargeParam1", Product(), PolicyType(), Gen()).value
    param2 = _space.SpecLookup.match("SurrChargeParam2", Product(), PolicyType(), Gen()).value
    if param1 is None or param2 is None:
        raise ValueError('SurrChargeParam not found')
    return param1 + param2 * min(PolicyTerm() / 10, 1) 
[docs]
def IntRate(RateBasis):
    """Interest Rate"""
    if RateBasis == 'PREM':
        basis = 'IntRatePrem'
    elif RateBasis == 'VAL':
        basis = 'IntRateVal'
    else:
        raise ValueError('invalid RateBasis')
    result = _space.SpecLookup.match(basis, Product(), PolicyType(), Gen()).value
    if result is not None:
        return result
    else:
        raise ValueError('invalid RateBais') 
[docs]
def LoadAcqSA():
    """Acquisition Loading per Sum Assured"""
    param1 = SpecLookup("LoadAcqSAParam1", Product())
    param2 = SpecLookup("LoadAcqSAParam2", Product())
    return param1 + param2 * min(PolicyTerm() / 10, 1) 
[docs]
def LoadMaintPrem():
    """Maintenance Loading per Gross Premium"""
    if SpecLookup("LoadMaintPremParam1", Product()) is not None:
        return SpecLookup("LoadMaintPremParam1", Product())
    elif SpecLookup("LoadMaintPremParam2", Product()) is not None:
        param = SpecLookup("LoadMaintPremParam2", Product())
        return (param + min(10, PolicyTerm())) / 100
    else:
        raise ValueError('LoadMaintPrem parameters not found') 
[docs]
def LoadMaintPremWaiverPrem():
    """Maintenance Loading per Gross Premium for Premium Waiver"""
    if PremTerm() < 5:
        return 0.0005
    elif PremTerm() < 10:
        return 0.001
    else:
        return 0.002 
[docs]
def LoadMaintSA():
    """Maintenance Loading per Sum Assured during Premium Payment"""
    result = _space.SpecLookup.match("LoadMaintSA", Product(), PolicyType(), Gen()).value
    if result is not None:
        return result
    else:
        raise ValueError('lookup failed') 
[docs]
def LoadMaintSA2():
    """Maintenance Loading per Sum Assured after Premium Payment"""
    result = _space.SpecLookup.match("LoadMaintSA2", Product(), PolicyType(), Gen()).value
    if result is not None:
        return result
    else:
        raise ValueError('lookup failed') 
[docs]
def NetPremRate(basis):
    """Net Premium Rate"""
    gamma2 = LoadMaintSA2()
    comf = LifeTable[Sex(), IntRate(basis), TableID(basis)]
    x, n, m = IssueAge(), PolicyTerm(), PremTerm()
    if Product() == 'TERM' or Product() == 'WL':
        return (comf.Axn(x, n) + gamma2 * comf.AnnDuenx(x, n-m, 1, m)) / comf.AnnDuenx(x, n)
    elif Product() == 'ENDW':
        return (comf.Axn(x, n) + gamma2 * comf.AnnDuenx(x, n-m, 1, m)) / comf.AnnDuenx(x, n)
    else:
        raise ValueError('invalid product') 
[docs]
def ReserveNLP_Rate(basis, t):
    """Net level premium reserve rate"""
    gamma2 = LoadMaintSA2()
    lt = LifeTable[Sex(), IntRate(basis), TableID(basis)]
    x, n, m = IssueAge(), PolicyTerm(), PremTerm()
    if t <= m:
        return lt.Axn(x+t, n-t) + gamma2 * lt.AnnDuenx(x+t, n-m, 1, m-t) \
                
- NetPremRate(basis) * lt.AnnDuenx(x+t, m-t)
    else:
        return lt.Axn(x+t, n-t) + gamma2 * lt.AnnDuenx(x+t, n-m, 1, m-t) 
[docs]
def ReserveRate():
    """Valuation Reserve Rate per Sum Assured"""
    return None 
[docs]
def SurrCharge(t):
    """Surrender Charge Rate per Sum Assured"""
    m = PremTerm()
    return InitSurrCharge() * max((min(m, 10) - t) / min(m, 10), 0) 
[docs]
def TableID(RateBasis):
    """Mortality Table ID"""
    if RateBasis == 'PREM':
        basis = "MortTablePrem"
    elif RateBasis == 'VAL':
        basis = "MortTableVal"
    else:
        raise ValueError('invalid RateBasis')
    result = _space.SpecLookup.match(basis, Product(), PolicyType(), Gen()).value
    if result is not None:
        return result
    else:
        raise ValueError('invalid RateBais') 
[docs]
def UernPremRate():
    """Unearned Premium Rate"""
    return None 
Product = lambda: PolicyData[PolicyID, 'Product']
PolicyType = lambda: PolicyData[PolicyID, 'PolicyType']
Gen = lambda: PolicyData[PolicyID, 'Gen']
Channel = lambda: PolicyData[PolicyID, 'Channel']
Sex = lambda: PolicyData[PolicyID, 'Sex']
Duration = lambda: PolicyData[PolicyID, 'Duration']
IssueAge = lambda: PolicyData[PolicyID, 'IssueAge']
PremFreq = lambda: PolicyData[PolicyID, 'PremFreq']
PolicyTerm = lambda: PolicyData[PolicyID, 'PolicyTerm']
PolicyCount = lambda: PolicyData[PolicyID, 'PolicyCount']
SumAssured = lambda: PolicyData[PolicyID, 'SumAssured']
# ---------------------------------------------------------------------------
# References
LifeTable = ("Interface", ("...", "LifeTable"), "auto")
PolicyData = ("Pickle", 2325069946056)
SpecLookup = ("Interface", ("...", "Input", "SpecLookup"), "auto")
PremTerm = ("Interface", (".", "PolicyTerm"), "auto")