# This file is part of Tryton.  The COPYRIGHT file at the top level of
# this repository contains the full copyright notices and license terms.
from decimal import Decimal
from collections import defaultdict

from sql.aggregate import Sum
from sql.operators import Concat

from trytond.model import fields
from trytond.pyson import Eval
from trytond.transaction import Transaction
from trytond.pool import Pool, PoolMeta
from trytond.tools import reduce_ids, grouped_slice

from trytond.modules.currency.fields import Monetary
from trytond.modules.product import price_digits, round_price


class Work(metaclass=PoolMeta):
    __name__ = 'project.work'
    product = fields.Many2One('product.product', 'Product',
        domain=[
            ('type', '=', 'service'),
            ],
        context={
            'company': Eval('company', -1),
            },
        depends=['company'])
    list_price = Monetary(
        "List Price", currency='currency', digits=price_digits)
    revenue = fields.Function(Monetary(
            "Revenue", currency='currency', digits='currency'),
        'get_total')
    cost = fields.Function(Monetary(
            "Cost", currency='currency', digits='currency'),
        'get_total')
    currency = fields.Function(fields.Many2One('currency.currency',
        'Currency'), 'on_change_with_currency')

    @classmethod
    def __setup__(cls):
        pool = Pool()

        super(Work, cls).__setup__()

        try:
            pool.get('purchase.line')
        except KeyError:
            pass
        else:
            # Add purchase lines if purchase is activated
            cls.purchase_lines = fields.One2Many('purchase.line', 'work',
                'Purchase Lines', domain=[
                    ('purchase.company', '=', Eval('company', -1)),
                    ('type', '=', 'line'),
                    ],
                depends=['company'])

    @classmethod
    def _get_cost(cls, works):
        pool = Pool()
        Line = pool.get('timesheet.line')
        Work = pool.get('timesheet.work')
        transaction = Transaction()
        cursor = transaction.connection.cursor()

        costs = dict.fromkeys([w.id for w in works], 0)

        table = cls.__table__()
        work = Work.__table__()
        line = Line.__table__()

        # Timesheet cost
        work_ids = [w.id for w in works]
        for sub_ids in grouped_slice(work_ids):
            red_sql = reduce_ids(table.id, sub_ids)
            cursor.execute(*table.join(work,
                    condition=(
                        Concat(cls.__name__ + ',', table.id) == work.origin)
                    ).join(line, condition=line.work == work.id
                    ).select(table.id, Sum(line.cost_price * line.duration),
                    where=red_sql,
                    group_by=[table.id]))
            for work_id, cost in cursor:
                # SQLite stores timedelta as float
                if not isinstance(cost, float):
                    cost = cost.total_seconds()
                # Convert from seconds
                cost /= 60 * 60
                costs[work_id] += Decimal(str(cost))

        # Purchase cost
        if hasattr(cls, 'purchase_lines'):
            for work_id, cost in cls._purchase_cost(works).items():
                costs[work_id] += cost

        for work in works:
            costs[work.id] = work.company.currency.round(costs[work.id])
        return costs

    @classmethod
    def _purchase_cost(cls, works):
        'Compute direct purchase cost'
        pool = Pool()
        Currency = pool.get('currency.currency')
        PurchaseLine = pool.get('purchase.line')
        InvoiceLine = pool.get('account.invoice.line')
        Invoice = pool.get('account.invoice')
        Company = pool.get('company.company')

        cursor = Transaction().connection.cursor()
        table = cls.__table__()
        purchase_line = PurchaseLine.__table__()
        invoice_line = InvoiceLine.__table__()
        invoice = Invoice.__table__()
        company = Company.__table__()

        amounts = defaultdict(Decimal)
        work_ids = [w.id for w in works]
        work2currency = {}
        iline2work = {}
        for sub_ids in grouped_slice(work_ids):
            where = reduce_ids(table.id, sub_ids)
            cursor.execute(*table.join(purchase_line,
                    condition=purchase_line.work == table.id
                    ).join(invoice_line,
                    condition=invoice_line.origin == Concat(
                        'purchase.line,', purchase_line.id)
                    ).join(invoice,
                    condition=invoice_line.invoice == invoice.id
                    ).select(invoice_line.id, table.id,
                    where=where & ~invoice.state.in_(['draft', 'cancelled'])))
            iline2work.update(cursor)

            cursor.execute(*table.join(company,
                    condition=table.company == company.id
                    ).select(table.id, company.currency,
                    where=where))
            work2currency.update(cursor)

        currencies = Currency.browse(set(work2currency.values()))
        id2currency = {c.id: c for c in currencies}

        invoice_lines = InvoiceLine.browse(list(iline2work.keys()))
        for invoice_line in invoice_lines:
            invoice = invoice_line.invoice
            work_id = iline2work[invoice_line.id]
            currency_id = work2currency[work_id]
            currency = id2currency[currency_id]
            if currency != invoice.currency:
                with Transaction().set_context(date=invoice.currency_date):
                    amount = Currency.compute(invoice.currency,
                        invoice_line.amount, currency)
            else:
                amount = invoice_line.amount
            amounts[work_id] += amount
        return amounts

    @classmethod
    def _get_revenue(cls, works):
        revenues = dict.fromkeys(map(int, works), Decimal(0))
        for work in works:
            if not work.list_price:
                continue
            if work.price_list_hour:
                revenue = work.company.currency.round(
                    work.list_price * Decimal(str(work.effort_hours)))
            else:
                revenue = work.list_price
            revenues[work.id] = work.company.currency.round(revenue)
        return revenues

    @fields.depends('company')
    def on_change_with_currency(self, name=None):
        if self.company:
            return self.company.currency.id

    @fields.depends('product', 'company')
    def on_change_product(self):
        pool = Pool()
        User = pool.get('res.user')
        ModelData = pool.get('ir.model.data')
        Uom = pool.get('product.uom')
        Currency = pool.get('currency.currency')

        if not self.product:
            return

        if self.price_list_hour:
            hour_uom = Uom(ModelData.get_id('product', 'uom_hour'))
            self.list_price = Uom.compute_price(
                self.product.default_uom, self.product.list_price, hour_uom)
        else:
            self.list_price = self.product.list_price

        if self.company:
            user = User(Transaction().user)
            if user.company != self.company:
                if user.company.currency != self.company.currency:
                    self.list_price = Currency.compute(user.company.currency,
                        self.list_price, self.company.currency, round=False)

        self.list_price = round_price(self.list_price)

    @property
    def price_list_hour(self):
        pool = Pool()
        ModelData = pool.get('ir.model.data')
        Category = pool.get('product.uom.category')
        if not self.product:
            return
        time = Category(ModelData.get_id('product', 'uom_cat_time'))
        return self.product.default_uom_category == time
