# -*- coding: utf-8 -*-
# Part of Odoo, Flectra. See LICENSE file for full copyright and licensing details.

from flectra import models, fields, api, _
from flectra.addons import decimal_precision as dp
from flectra.tools.safe_eval import safe_eval
from flectra.exceptions import UserError, ValidationError


class PriceRule(models.Model):
    _name = "delivery.price.rule"
    _description = "Delivery Price Rules"
    _order = 'sequence, list_price, id'

    @api.depends('variable', 'operator', 'max_value', 'list_base_price', 'list_price', 'variable_factor')
    def _compute_name(self):
        for rule in self:
            name = 'if %s %s %s then' % (rule.variable, rule.operator, rule.max_value)
            if rule.list_base_price and not rule.list_price:
                name = '%s fixed price %s' % (name, rule.list_base_price)
            elif rule.list_price and not rule.list_base_price:
                name = '%s %s times %s' % (name, rule.list_price, rule.variable_factor)
            else:
                name = '%s fixed price %s plus %s times %s' % (name, rule.list_base_price, rule.list_price, rule.variable_factor)
            rule.name = name

    name = fields.Char(compute='_compute_name')
    sequence = fields.Integer(required=True, default=10)
    carrier_id = fields.Many2one('delivery.carrier', 'Carrier', required=True, ondelete='cascade')

    variable = fields.Selection([('weight', 'Weight'), ('volume', 'Volume'), ('wv', 'Weight * Volume'), ('price', 'Price'), ('quantity', 'Quantity')], required=True, default='weight')
    operator = fields.Selection([('==', '='), ('<=', '<='), ('<', '<'), ('>=', '>='), ('>', '>')], required=True, default='<=')
    max_value = fields.Float('Maximum Value', required=True)
    list_base_price = fields.Float(string='Sale Base Price', digits=dp.get_precision('Product Price'), required=True, default=0.0)
    list_price = fields.Float('Sale Price', digits=dp.get_precision('Product Price'), required=True, default=0.0)
    variable_factor = fields.Selection([('weight', 'Weight'), ('volume', 'Volume'), ('wv', 'Weight * Volume'), ('price', 'Price'), ('quantity', 'Quantity')], 'Variable Factor', required=True, default='weight')


class ProviderGrid(models.Model):
    _inherit = 'delivery.carrier'

    delivery_type = fields.Selection(selection_add=[('base_on_rule', 'Based on Rules')])
    price_rule_ids = fields.One2many('delivery.price.rule', 'carrier_id', 'Pricing Rules', copy=True)

    def base_on_rule_rate_shipment(self, order):
        carrier = self._match_address(order.partner_shipping_id)
        if not carrier:
            return {'success': False,
                    'price': 0.0,
                    'error_message': _('Error: no matching grid.'),
                    'warning_message': False}

        try:
            price_unit = self._get_price_available(order)
        except UserError as e:
            return {'success': False,
                    'price': 0.0,
                    'error_message': e.name,
                    'warning_message': False}
        if order.company_id.currency_id.id != order.pricelist_id.currency_id.id:
            price_unit = order.company_id.currency_id.with_context(date=order.date_order).compute(price_unit, order.pricelist_id.currency_id)

        return {'success': True,
                'price': price_unit,
                'error_message': False,
                'warning_message': False}

    def _get_price_available(self, order):
        self.ensure_one()
        total = weight = volume = quantity = 0
        total_delivery = 0.0
        for line in order.order_line:
            if line.state == 'cancel':
                continue
            if line.is_delivery:
                total_delivery += line.price_total
            if not line.product_id or line.is_delivery:
                continue
            qty = line.product_uom._compute_quantity(line.product_uom_qty, line.product_id.uom_id)
            weight += (line.product_id.weight or 0.0) * qty
            volume += (line.product_id.volume or 0.0) * qty
            quantity += qty
        total = (order.amount_total or 0.0) - total_delivery

        total = order.currency_id.with_context(date=order.date_order).compute(total, order.company_id.currency_id)

        return self._get_price_from_picking(total, weight, volume, quantity)

    def _get_price_from_picking(self, total, weight, volume, quantity):
        price = 0.0
        criteria_found = False
        price_dict = {'price': total, 'volume': volume, 'weight': weight, 'wv': volume * weight, 'quantity': quantity}
        for line in self.price_rule_ids:
            test = safe_eval(line.variable + line.operator + str(line.max_value), price_dict)
            if test:
                price = line.list_base_price + line.list_price * price_dict[line.variable_factor]
                criteria_found = True
                break
        if not criteria_found:
            raise UserError(_("No price rule matching this order; delivery cost cannot be computed."))

        return price

    def base_on_rule_send_shipping(self, pickings):
        res = []
        for p in pickings:
            carrier = self._match_address(p.partner_id)
            if not carrier:
                raise ValidationError(_('Error: no matching grid.'))
            res = res + [{'exact_price': p.carrier_id._get_price_available(p.sale_id) if p.sale_id else 0.0,  # TODO cleanme
                          'tracking_number': False}]
        return res

    def base_on_rule_get_tracking_link(self, picking):
        return False

    def base_on_rule_cancel_shipment(self, pickings):
        raise NotImplementedError()