# -*- coding: utf-8 -*-
# Part of Odoo. See LICENSE file for full copyright and licensing details.
import io
import base64

from odoo import api, models, fields, _
from odoo.exceptions import UserError, ValidationError
from odoo.tools.pdf import PdfFileReader, PdfReadError

class SignDuplicateTemplatePDF(models.TransientModel):
    _name = 'sign.duplicate.template.pdf'
    _description = 'Sign Duplicate Template with new PDF'

    new_pdf = fields.Binary(string="File name", required=True)
    original_template_id = fields.Many2one(
        'sign.template', string="Original File", required=True, ondelete='cascade',
        default=lambda self: self.env.context.get('active_id', None),
    )
    new_template = fields.Char('New Template Name')

    def duplicate_template_with_pdf(self):
        if not self._compare_page_templates(self.original_template_id.datas, self.new_pdf):
            raise UserError(_("The template has more pages than the current file, it can't be applied."))

        self.original_template_id.check_access_rights('write')
        self.original_template_id.check_access_rule('write')
        pdf = self.env['ir.attachment'].create({
            'name': self.new_template or self.original_template_id.name,
            'datas': self.new_pdf,
            'type': 'binary'
        })

        new_template = self.original_template_id.sudo().copy({
            'name': pdf.name,
            'attachment_id': pdf.id,
            'active': True,
            'favorited_ids': [(4, self.env.user.id)],
        })

        return new_template.go_to_custom_template()

    @api.model
    def _compare_page_templates(self, original_file, new_file):
        pages_original_file = PdfFileReader(io.BytesIO(base64.b64decode(original_file)), strict=False, overwriteWarnings=False).getNumPages()
        try:
            pages_new_file = PdfFileReader(io.BytesIO(base64.b64decode(new_file)), strict=False, overwriteWarnings=False).getNumPages()
        except PdfReadError:
            raise ValidationError(_("The uploaded file is not a valid PDF. Please upload a valid PDF file."))
        return pages_new_file >= pages_original_file