import re

from odoo import models, fields, api
from odoo.exceptions import ValidationError


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

    item_code = fields.Char(
        string='Item Code',
        store=True,
        readonly=False,  # biar view bisa pakai; kita atur readonly di XML
        help='Kombinasi: parent_kode + kategori_kode + id(+4 digit) + nama_tanpa_spasi(lower). '
             'Read-only, dipakai sbg stock keeping unit code.',
    )

    @api.onchange('categ_id')
    def _onchange_categ_preview(self):
        """Saat create belum simpan id -> tampilkan pratinjau gabungan kode kategori."""
        if self.categ_id and not self.env.context.get('default_product_tmpl_id') \
                and not self.id and not self.item_code:
            cat = self.categ_id
            if cat and not cat.code:
                cat.code = f'{cat.id:02d}'
            parent = cat.parent_id.code if cat.parent_id else ''
            own = cat.code or ''
            self.item_code = f'{parent}{own}'

    @api.constrains('item_code')
    def _check_item_code_unique(self):
        for rec in self:
            if not rec.item_code:
                continue
            dup = self.search([('item_code', '=', rec.item_code), ('id', '!=', rec.id)], limit=1)
            if dup:
                raise ValidationError(
                    f'Item Code "{rec.item_code}" sudah dipakai oleh produk lain '
                    f'({dup.name}). Item Code harus unik.'
                )

    def _category_prefix(self, cat):
        """Return gabungan kode kategori (parent+own), 4 digit atau 00."""
        if not cat:
            return '00'
        if not cat.code:
            cat.code = f'{cat.id:02d}'
        parent_code = cat.parent_id.code if cat.parent_id else ''
        own_code = cat.code or ''
        return f'{parent_code}{own_code}'

    def _name_slug(self, name):
        slug = (name or '').lower().replace(',', '.')
        return re.sub(r'\s+', '', slug)

    def _full_item_code(self, obj):
        """Compute full item_code: prefix kategori + id:04d + name_slug."""
        prefix = self._category_prefix(obj.categ_id)
        oid = obj.id or 0
        return f'{prefix}{oid:04d}{self._name_slug(obj.name)}'

    @api.model_create_multi
    def create(self, vals_list):
        records = super().create(vals_list)
        for r in records:
            r.item_code = r._full_item_code(r)
        return records

    def write(self, vals):
        res = super().write(vals)
        if 'name' in vals or 'categ_id' in vals:
            for r in self:
                r.item_code = r._full_item_code(r)
        return res