# Copyright 2023 Akretion (https://www.akretion.com).
# @author Sébastien BEAU <sebastien.beau@akretion.com>
# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).


from collections import defaultdict

from odoo import api, models, tools

from ..tools import format_m2m

# To avoid conflict with other module and avoid too long function name
# specific tracking_manager method are prefixed with _tm


class Base(models.AbstractModel):
    _inherit = "base"

    @tools.ormcache()
    def is_tracked_by_o2m(self):
        return self._name in self.env["ir.model"]._get_model_tracked_by_o2m()

    def _tm_get_fields_to_notify(self):
        return (
            self.env["ir.model"]
            ._get_model_tracked_by_o2m()
            .get(self._name, {})
            .get("notify", [])
        )

    def _tm_get_fields_to_track(self):
        # We track manually
        # all fields that belong to a model tracked via a one2many
        # all the many2many fields
        return (
            self.env["ir.model"]
            ._get_model_tracked_by_o2m()
            .get(self._name, {})
            .get("fields", [])
        )

    def _tm_notify_owner(self, mode, changes=None):
        """Notify all model that have a one2many linked to the record changed"""
        self.ensure_one()
        data = self.env.cr.precommit.data.setdefault(
            "tracking.manager.data",
            defaultdict(lambda: defaultdict(lambda: defaultdict(list))),
        )
        for field_name, owner_field_name in self._tm_get_fields_to_notify():
            owner = self[field_name]
            data[owner._name][owner.id][owner_field_name].append(
                {
                    "mode": mode,
                    "record": self.display_name,
                    "changes": changes,
                }
            )

    def _tm_get_field_description(self, field_name):
        return self._fields[field_name].get_description(self.env)["string"]

    def _tm_get_changes(self, values):
        self.ensure_one()
        changes = []
        for field_name, before in values.items():
            field = self._fields[field_name]
            if before != self[field_name]:
                if field.type == "many2many":
                    old = format_m2m(before)
                    new = format_m2m(self[field_name])
                elif field.type == "many2one":
                    old = before.display_name
                    new = self[field_name]["display_name"]
                else:
                    old = before
                    new = self[field_name]
                changes.append(
                    {
                        "name": self._tm_get_field_description(field_name),
                        "old": old,
                        "new": new,
                    }
                )
        return changes

    def _tm_post_message(self, data):
        for model_name, model_data in data.items():
            for record_id, messages_by_field in model_data.items():
                record = self.env[model_name].browse(record_id)
                messages = [
                    {
                        "name": record._tm_get_field_description(field_name),
                        "messages": messages,
                    }
                    for field_name, messages in messages_by_field.items()
                ]
                # use sudo as user may not have access to mail.message
                record.sudo().message_post_with_view(
                    "tracking_manager.track_o2m_m2m_template",
                    values={"lines": messages},
                    subtype_id=self.env.ref("mail.mt_note").id,
                )

    def _tm_prepare_o2m_tracking(self):
        fnames = self._tm_get_fields_to_track()
        if not fnames:
            return
        self.env.cr.precommit.add(self._tm_finalize_o2m_tracking)
        initial_values = self.env.cr.precommit.data.setdefault(
            f"tracking.manager.before.{self._name}", {}
        )
        for record in self:
            values = initial_values.setdefault(record.id, {})
            if values is not None:
                for fname in fnames:
                    values.setdefault(fname, record[fname])

    def _tm_finalize_o2m_tracking(self):
        initial_values = self.env.cr.precommit.data.pop(
            f"tracking.manager.before.{self._name}", {}
        )
        for _id, values in initial_values.items():
            # Always use sudo in case that the record have been modified using sudo
            record = self.sudo().browse(_id)
            if not record.exists():
                # if a record have been modify and then deleted
                # it's not need to track the change so skip it
                continue
            changes = record._tm_get_changes(values)
            if changes:
                record._tm_notify_owner("update", changes)
        data = self.env.cr.precommit.data.pop("tracking.manager.data", {})
        self._tm_post_message(data)
        self.flush_model()

    def _tm_track_create_unlink(self, mode):
        self.env.cr.precommit.add(self._tm_finalize_o2m_tracking)
        for record in self:
            record._tm_notify_owner(mode)

    def write(self, vals):
        if self.is_tracked_by_o2m():
            self._tm_prepare_o2m_tracking()
        return super().write(vals)

    @api.model_create_multi
    def create(self, list_vals):
        records = super().create(list_vals)
        if self.is_tracked_by_o2m():
            records._tm_track_create_unlink("create")
        return records

    def unlink(self):
        if self.is_tracked_by_o2m():
            self._tm_track_create_unlink("unlink")
        return super().unlink()