from odoo import api, fields, models


class ProductTemplate(models.Model):
    _inherit = 'product.template'

    lot_sequence_id = fields.Many2one(
        'ir.sequence',
        string='Serial/Lot Numbers Sequence',
        domain=[('code', '=', 'stock.lot.serial')],
        help='Technical Field: The Ir.Sequence record that is used to generate serial/lot numbers for this product'
    )
    serial_prefix_format = fields.Char(
        'Custom Lot/Serial',
        compute='_compute_serial_prefix_format',
        inverse='_inverse_serial_prefix_format',
        help='Set a prefix to generate serial/lot numbers automatically when receiving or producing this product. '
             'Use % codes like %(y)s for year, %(month)s for month, etc.'
    )
    next_serial = fields.Char(
        'Next Number',
        compute='_compute_next_serial',
        help='The next serial/lot number to be generated for this product'
    )

    @api.depends('lot_sequence_id', 'lot_sequence_id.prefix')
    def _compute_serial_prefix_format(self):
        for template in self:
            template.serial_prefix_format = template.lot_sequence_id.prefix or ""

    def _inverse_serial_prefix_format(self):
        valid_sequences = self.env['ir.sequence'].search([('prefix', 'in', self.mapped('serial_prefix_format'))])
        sequences_by_prefix = {seq.prefix: seq for seq in valid_sequences}
        for template in self:
            if template.serial_prefix_format:
                if template.serial_prefix_format in sequences_by_prefix:
                    template.lot_sequence_id = sequences_by_prefix[template.serial_prefix_format]
                else:
                    # Create a new sequence with the given prefix
                    new_sequence = self.env['ir.sequence'].create({
                        'name': f'{template.name} Serial Sequence',
                        'code': 'stock.lot.serial',
                        'prefix': template.serial_prefix_format,
                        'padding': 7,
                        'company_id': False,  # Global sequence to avoid cross-company conflicts
                    })
                    template.lot_sequence_id = new_sequence
                    sequences_by_prefix[template.serial_prefix_format] = new_sequence
            else:
                # Reset to default if no prefix
                template.lot_sequence_id = self.env.ref('stock.sequence_production_lots', raise_if_not_found=False)

    @api.depends('serial_prefix_format', 'lot_sequence_id')
    def _compute_next_serial(self):
        from datetime import datetime
        
        for template in self:
            if template.lot_sequence_id:
                seq = template.lot_sequence_id
                
                # Build the interpolation dictionary for date formatting
                now = datetime.now()
                interpolation_dict = {
                    'year': now.strftime('%Y'),
                    'y': now.strftime('%y'),
                    'month': now.strftime('%m'),
                    'day': now.strftime('%d'),
                    'doy': now.strftime('%j'),
                    'woy': now.strftime('%W'),
                    'weekday': now.strftime('%w'),
                    'h24': now.strftime('%H'),
                    'h12': now.strftime('%I'),
                    'min': now.strftime('%M'),
                    'sec': now.strftime('%S'),
                }
                
                # Format prefix and suffix with date codes
                try:
                    prefix = (seq.prefix or '') % interpolation_dict if seq.prefix else ''
                except (KeyError, ValueError):
                    prefix = seq.prefix or ''
                
                try:
                    suffix = (seq.suffix or '') % interpolation_dict if seq.suffix else ''
                except (KeyError, ValueError):
                    suffix = seq.suffix or ''
                
                template.next_serial = '{}{:0{}d}{}'.format(
                    prefix,
                    seq.number_next_actual,
                    seq.padding,
                    suffix
                )
            else:
                template.next_serial = '00001'