# Copyright (C) 2004-2010 Tiny SPRL (<http://tiny.be>).
# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).

import difflib

from odoo import _, api, fields, models


class DocumentPageHistory(models.Model):
    """This model is necessary to manage a document history."""

    _name = "document.page.history"
    _description = "Document Page History"
    _order = "id DESC"

    page_id = fields.Many2one("document.page", "Page", ondelete="cascade")
    name = fields.Char(index=True)
    summary = fields.Char(index=True)
    content = fields.Html(sanitize=False)
    diff = fields.Html(compute="_compute_diff")

    company_id = fields.Many2one(
        "res.company",
        "Company",
        help="If set, page is accessible only from this company",
        related="page_id.company_id",
        store=True,
        index=True,
        readonly=True,
    )

    def _compute_diff(self):
        """Shows a diff between this version and the previous version"""
        history = self.env["document.page.history"]
        for rec in self:
            prev = history.search(
                [
                    ("page_id", "=", rec.page_id.id),
                    ("create_date", "<", rec.create_date),
                ],
                limit=1,
                order="create_date DESC",
            )
            rec.diff = self._get_diff(prev.id, rec.id)

    @api.model
    def _get_diff(self, v1, v2):
        """Return the difference between two version of document version."""
        text1 = v1 and self.browse(v1).content or ""
        text2 = v2 and self.browse(v2).content or ""
        # Include line breaks to make it more readable
        # TODO: consider using a beautify library directly on the content
        text1 = text1.replace("</p><p>", "</p>\r\n<p>")
        text2 = text2.replace("</p><p>", "</p>\r\n<p>")
        line1 = text1.splitlines(True)
        line2 = text2.splitlines(True)
        if line1 == line2:
            return _("There are no changes in revisions.")
        else:
            diff = difflib.HtmlDiff()
            return diff.make_table(
                line1,
                line2,
                "Revision-{}".format(v1),
                "Revision-{}".format(v2),
                context=True,
            )

    def name_get(self):
        return [(rec.id, "%s #%i" % (rec.page_id.name, rec.id)) for rec in self]
