from sql import Literal, Null
from sql.aggregate import Max, Min, Sum
from sql.functions import CurrentTimestamp

from trytond.model import ModelSQL, ModelView, fields
from trytond.pool import Pool
from trytond.transaction import Transaction


class CTRMPhysicalPositionContext(ModelView):
    "CTRM Physical Position Context"
    __name__ = 'ctrm.reporting.position.physical.context'

    as_of = fields.Date("As of")
    product = fields.Many2One('product.product', "Product")
    supplier = fields.Many2One('party.party', "Supplier")
    client = fields.Many2One('party.party', "Client")
    currency = fields.Many2One('currency.currency', "Currency")
    position_type = fields.Selection([
            (None, ""),
            ('open', 'Open'),
            ('physic', 'Physic'),
            ('shipped', 'Shipped'),
            ('hedge', 'Hedge'),
            ('priced', 'Priced'),
            ], "Position Type")

    @classmethod
    def default_as_of(cls):
        Date = Pool().get('ir.date')
        return Date.today()


class CTRMPhysicalPosition(ModelSQL, ModelView):
    "CTRM Physical Position"
    __name__ = 'ctrm.reporting.position.physical'

    product = fields.Many2One('product.product', "Product")
    supplier = fields.Many2One('party.party', "Supplier")
    client = fields.Many2One('party.party', "Client")
    currency = fields.Many2One('currency.currency', "Currency")
    uom = fields.Many2One('product.uom', "Unit")
    position_type = fields.Selection([
            ('open', 'Open'),
            ('physic', 'Physic'),
            ('shipped', 'Shipped'),
            ('hedge', 'Hedge'),
            ('priced', 'Priced'),
            ], "Position Type")
    physical_qty = fields.Numeric("Physical Quantity", digits=(16, 5))
    hedged_qty = fields.Numeric("Hedged Quantity", digits=(16, 5))
    net_exposure = fields.Numeric("Net Exposure", digits=(16, 5))
    amount = fields.Numeric("Amount", digits=(16, 2))
    mtm = fields.Numeric("MTM", digits=(16, 2))
    pnl = fields.Numeric("P&L", digits=(16, 2))
    period_start = fields.Date("Period Start")
    period_end = fields.Date("Period End")

    @classmethod
    def table_query(cls):
        OpenPosition = Pool().get('open.position')
        op = OpenPosition.__table__()

        context = Transaction().context
        as_of = context.get('as_of')
        product = context.get('product')
        supplier = context.get('supplier')
        client = context.get('client')
        currency = context.get('currency')
        position_type = context.get('position_type')

        where = Literal(True)
        if as_of:
            where &= ((op.period_start == Null) | (op.period_start <= as_of))
            where &= ((op.period_end == Null) | (op.period_end >= as_of))
        if product:
            where &= op.product == product
        if supplier:
            where &= op.supplier == supplier
        if client:
            where &= op.client == client
        if currency:
            where &= op.currency == currency
        if position_type:
            where &= op.type == position_type

        group_by = [
            op.product,
            op.supplier,
            op.client,
            op.currency,
            op.uom,
            op.type,
            op.period_start,
            op.period_end,
            ]

        return op.select(
            Literal(0).as_('create_uid'),
            CurrentTimestamp().as_('create_date'),
            Literal(None).as_('write_uid'),
            Literal(None).as_('write_date'),
            Min(op.id).as_('id'),
            op.product.as_('product'),
            op.supplier.as_('supplier'),
            op.client.as_('client'),
            op.currency.as_('currency'),
            op.uom.as_('uom'),
            op.type.as_('position_type'),
            Sum(op.physical_qty).as_('physical_qty'),
            Sum(op.hedged_qty).as_('hedged_qty'),
            Sum(op.net_exposure).as_('net_exposure'),
            Sum(op.amount).as_('amount'),
            Sum(op.mtm).as_('mtm'),
            Sum(op.amount - op.mtm).as_('pnl'),
            Max(op.period_start).as_('period_start'),
            Max(op.period_end).as_('period_end'),
            where=where,
            group_by=group_by)