from odoo import api, fields, models, _
from odoo.exceptions import UserError

class CommercialInvoice(models.Model):
    _name = 'commercial.invoice'
    _description = 'Commercial Invoice for Export'
    _inherit = ['mail.thread', 'mail.activity.mixin']
    _order = 'date desc, id desc'

    name = fields.Char(string='Reference', required=True, copy=False, readonly=True, default='New')
    date = fields.Date(string='Export Date', required=True, default=fields.Date.context_today)
    state = fields.Selection([
        ('draft', 'Draft'),
        ('done', 'Done'),
        ('cancelled', 'Cancelled')
    ], string='Status', default='draft', tracking=True)

    # Related parties
    partner_id = fields.Many2one('res.partner', string='Consignee', required=True)
    importer_id = fields.Many2one('res.partner', string='Importer of Record')
    customs_broker_id = fields.Many2one('res.partner', string='Customs Broker')
    company_id = fields.Many2one('res.company', string='Company', required=True, default=lambda self: self.env.company)
    currency_id = fields.Many2one('res.currency', string='Currency', required=True,
                                 default=lambda self: self.env.company.currency_id)
    related_parties = fields.Boolean(string='Related Parties', default=False)


    # Invoice lines and related fields
    invoice_ids = fields.Many2many('account.move', string='Invoices', domain=[('move_type', '=', 'out_invoice')])
    payment_term_id = fields.Many2one('account.payment.term', string='Payment Terms')
    incoterm_id = fields.Many2one('account.incoterms', string='Incoterms')

    # Shipping details
    number_of_packages = fields.Integer(string='Number of Packages')
    total_weight = fields.Float(string='Total Weight (kg)')
    packaging_cost = fields.Monetary(string='Packaging Cost', currency_field='currency_id')
    freight_cost = fields.Monetary(string='Freight Cost', currency_field='currency_id')
    insurance_cost = fields.Monetary(string='Insurance Cost', currency_field='currency_id')
    other_cost = fields.Monetary(string='Other Costs', currency_field='currency_id')

    # Computed fields
    invoice_amount = fields.Monetary(string='Invoice Amount', currency_field='currency_id',
                                   compute='_compute_amounts', store=True)
    total_amount = fields.Monetary(string='Total Amount', currency_field='currency_id',
                                 compute='_compute_amounts', store=True)

    @api.model_create_multi
    def create(self, vals_list):
        for vals in vals_list:
            if vals.get('name', 'New') == 'New':
                vals['name'] = self.env['ir.sequence'].next_by_code('commercial.invoice') or 'New'
        return super().create(vals_list)

    @api.depends('invoice_ids', 'packaging_cost', 'freight_cost', 'insurance_cost', 'other_cost')
    def _compute_amounts(self):
        for record in self:
            record.invoice_amount = sum(record.invoice_ids.mapped('amount_total'))
            record.total_amount = (record.invoice_amount + record.packaging_cost + 
                                 record.freight_cost + record.insurance_cost + record.other_cost)

    def action_confirm(self):
        self.write({'state': 'done'})

    def action_draft(self):
        self.write({'state': 'draft'})

    def action_cancel(self):
        self.write({'state': 'cancelled'})

    @api.onchange('partner_id')
    def _onchange_partner_id(self):
        if self.partner_id:
            self.payment_term_id = self.partner_id.property_payment_term_id

    @api.model
    def _prepare_commercial_invoice_from_invoices(self, invoices):
        """Prepare commercial invoice values from a set of invoices."""
        if not invoices:
            raise UserError(_("No invoices selected."))

        # Get unique values for key fields
        currencies = invoices.mapped('currency_id')
        payment_terms = invoices.mapped('invoice_payment_term_id')
        incoterms = invoices.mapped('invoice_incoterm_id')
        companies = invoices.mapped('company_id')

        # Validate consistency
        if len(currencies) > 1:
            raise UserError(_("Selected invoices have different currencies."))
        if len(companies) > 1:
            raise UserError(_("Selected invoices are from different companies."))

        # Get shipping and billing partners
        shipping_partners = invoices.mapped('partner_shipping_id.commercial_partner_id')
        billing_partners = invoices.mapped('partner_id.commercial_partner_id')

        # Prepare values
        vals = {
            'invoice_ids': [(6, 0, invoices.ids)],
            'company_id': companies[0].id,
            'currency_id': currencies[0].id,
            'partner_id': shipping_partners[0].id if len(shipping_partners) == 1 else False,
            'importer_id': billing_partners[0].id if len(billing_partners) == 1 else False,
            'payment_term_id': payment_terms[0].id if len(payment_terms) == 1 else False,
            'incoterm_id': incoterms[0].id if len(incoterms) == 1 else False,
        }

        return vals

    @api.model
    def create_from_invoices(self, invoices):
        """Create a commercial invoice from a set of invoices."""
        vals = self._prepare_commercial_invoice_from_invoices(invoices)
        return self.create(vals)