# -*- coding: utf-8 -*-

import base64
import io
import logging
from collections import defaultdict

from odoo import models, api, fields
from odoo.tools.pdf import OdooPdfFileReader, OdooPdfFileWriter

_logger = logging.getLogger(__name__)

class IrAttachment(models.Model):
    _inherit = 'ir.attachment'

    document_ids = fields.One2many('documents.document', 'attachment_id', export_string_translation=False)

    def get_documents_operation_add_destination(self):
        self.ensure_one()
        return {'destination': 'MY', 'display_name': self.env._('My Drive')}

    @api.model
    def _pdf_split(self, new_files=None, open_files=None):
        """Creates and returns new pdf attachments based on existing data.

        :param new_files: the array that represents the new pdf
            structure::

                [{
                    'name': 'New File Name',
                    'new_pages': [{
                        'old_file_index': 7,
                        'old_page_number': 5,
                    }],
                }]
        :param open_files: array of open file objects.
        :returns: the new PDF attachments
        """
        vals_list = []
        pdf_from_files = [OdooPdfFileReader(open_file, strict=False) for open_file in open_files]
        
        for new_file in new_files:
            output = OdooPdfFileWriter()
            used_pages_by_pdf = defaultdict(set)
            for page in new_file['new_pages']:
                file_index = int(page['old_file_index'])
                page_index = page['old_page_number'] - 1
                input_pdf = pdf_from_files[file_index]
                output.addPage(input_pdf.getPage(page_index))
                used_pages_by_pdf[file_index].add(page_index)
                if len(used_pages_by_pdf[file_index]) != input_pdf.getNumPages():
                    continue
                try:
                    for fname, fcontent in input_pdf.getAttachments():
                        output.addAttachment(name=fname, data=fcontent)
                except Exception:  # noqa: BLE001
                    _logger.warning(
                        'Impossible to add (all) attachments from pdf at index %i',
                        file_index, exc_info=True,
                    )
            with io.BytesIO() as stream:
                output.write(stream)
                vals_list.append({
                    'name': new_file['name'] + ".pdf",
                    'datas': base64.b64encode(stream.getvalue()),
                })
        return self.create(vals_list)

    def _create_document(self, vals):
        """
        Implemented by bridge modules that create new documents if attachments are linked to
        their business models.

        :param vals: the create/write dictionary of ir attachment
        :return: True if new documents are created
        """
        # Special case for documents
        if vals.get('res_model') == 'documents.document' and vals.get('res_id'):
            document = self.env['documents.document'].search_fetch(
                [('id', '=', vals['res_id'])], [])
            if document and not document.attachment_id and document.type == 'binary':
                document.attachment_id = self[0].id
            return False

        # Generic case for all other models
        res_model = vals.get('res_model')
        res_id = vals.get('res_id')
        model = self.env.get(res_model)
        if model is not None and res_id and issubclass(self.pool[res_model], self.pool['documents.mixin']):
            vals_list = [
                model.browse(res_id)._get_document_vals(attachment)
                for attachment in self
                if not attachment.res_field and model.browse(res_id)._check_create_documents()
            ]
            vals_list = [vals for vals in vals_list if vals]  # Remove empty values
            self.env['documents.document'].create(vals_list)
            return True
        return False

    @api.model_create_multi
    def create(self, vals_list):
        attachments = super().create(vals_list)
        for attachment, vals in zip(attachments, vals_list):
            # the context can indicate that this new attachment is created from documents, and therefore
            # doesn't need a new document to contain it.
            if not self.env.context.get('no_document') and not attachment.res_field:
                attachment.sudo()._create_document(dict(vals, res_model=attachment.res_model, res_id=attachment.res_id))
        return attachments

    def write(self, vals):
        old_values = {
            att.id: (att.res_model, att.res_id)
            for att in self
        } if 'res_model' in vals or 'res_id' in vals else {}
        res = super().write(vals)
        for attachment in self:
            if (
                old_values and old_values.get(attachment.id) != (attachment.res_model, attachment.res_id)
                and not self.env.context.get('no_document') and not attachment.res_field
            ):
                attachment.sudo()._create_document(dict(res_model=attachment.res_model, res_id=attachment.res_id))
        return res