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

import copy
import logging
import uuid
from lxml import etree, html

from odoo import api, models, _
from odoo.osv import expression
from odoo.exceptions import ValidationError

_logger = logging.getLogger(__name__)

EDITING_ATTRIBUTES = ['data-oe-model', 'data-oe-id', 'data-oe-field', 'data-oe-xpath', 'data-note-id']


class IrUiView(models.Model):
    _inherit = 'ir.ui.view'

    #------------------------------------------------------
    # Save from html
    #------------------------------------------------------

    @api.model
    def extract_embedded_fields(self, arch):
        return arch.xpath('//*[@data-oe-model != "ir.ui.view"]')

    @api.model
    def extract_oe_structures(self, arch):
        return arch.xpath('//*[hasclass("oe_structure")][contains(@id, "oe_structure")]')

    @api.model
    def get_default_lang_code(self):
        return False

    @api.model
    def save_embedded_field(self, el):
        Model = self.env[el.get('data-oe-model')]
        field = el.get('data-oe-field')

        model = 'ir.qweb.field.' + el.get('data-oe-type')
        converter = self.env[model] if model in self.env else self.env['ir.qweb.field']

        try:
            value = converter.from_html(Model, Model._fields[field], el)
        except ValueError:
            raise ValidationError(_("Invalid field value for %s: %s", Model._fields[field].string, el.text_content().strip()))

        if value is not None:
            # TODO: batch writes?
            if not self.env.context.get('lang') and self.get_default_lang_code():
                Model.browse(int(el.get('data-oe-id'))).with_context(lang=self.get_default_lang_code()).write({field: value})
            else:
                Model.browse(int(el.get('data-oe-id'))).write({field: value})

    def save_oe_structure(self, el):
        self.ensure_one()

        if el.get('id') in self.key:
            # Do not inherit if the oe_structure already has its own inheriting view
            return False

        arch = etree.Element('data')
        xpath = etree.Element('xpath', expr="//*[hasclass('oe_structure')][@id='{}']".format(el.get('id')), position="replace")
        arch.append(xpath)
        attributes = {k: v for k, v in el.attrib.items() if k not in EDITING_ATTRIBUTES}
        structure = etree.Element(el.tag, attrib=attributes)
        structure.text = el.text
        xpath.append(structure)
        for child in el.iterchildren(tag=etree.Element):
            structure.append(copy.deepcopy(child))

        vals = {
            'inherit_id': self.id,
            'name': '%s (%s)' % (self.name, el.get('id')),
            'arch': self._pretty_arch(arch),
            'key': '%s_%s' % (self.key, el.get('id')),
            'type': 'qweb',
            'mode': 'extension',
        }
        vals.update(self._save_oe_structure_hook())
        self.env['ir.ui.view'].create(vals)

        return True

    @api.model
    def _save_oe_structure_hook(self):
        return {}

    @api.model
    def _pretty_arch(self, arch):
        # remove_blank_string does not seem to work on HTMLParser, and
        # pretty-printing with lxml more or less requires stripping
        # whitespace: http://lxml.de/FAQ.html#why-doesn-t-the-pretty-print-option-reformat-my-xml-output
        # so serialize to XML, parse as XML (remove whitespace) then serialize
        # as XML (pretty print)
        arch_no_whitespace = etree.fromstring(
            etree.tostring(arch, encoding='utf-8'),
            parser=etree.XMLParser(encoding='utf-8', remove_blank_text=True))
        return etree.tostring(
            arch_no_whitespace, encoding='unicode', pretty_print=True)

    @api.model
    def _are_archs_equal(self, arch1, arch2):
        # Note that comparing the strings would not be ok as attributes order
        # must not be relevant
        if arch1.tag != arch2.tag:
            return False
        if arch1.text != arch2.text:
            return False
        if arch1.tail != arch2.tail:
            return False
        if arch1.attrib != arch2.attrib:
            return False
        if len(arch1) != len(arch2):
            return False
        return all(self._are_archs_equal(arch1, arch2) for arch1, arch2 in zip(arch1, arch2))

    def replace_arch_section(self, section_xpath, replacement, replace_tail=False):
        # the root of the arch section shouldn't actually be replaced as it's
        # not really editable itself, only the content truly is editable.
        self.ensure_one()
        arch = etree.fromstring(self.arch.encode('utf-8'))
        # => get the replacement root
        if not section_xpath:
            root = arch
        else:
            # ensure there's only one match
            [root] = arch.xpath(section_xpath)

        root.text = replacement.text

        # We need to replace some attrib for styles changes on the root element
        for attribute in ('style', 'class'):
            if attribute in replacement.attrib:
                root.attrib[attribute] = replacement.attrib[attribute]

        # Note: after a standard edition, the tail *must not* be replaced
        if replace_tail:
            root.tail = replacement.tail
        # replace all children
        del root[:]
        for child in replacement:
            root.append(copy.deepcopy(child))

        return arch

    @api.model
    def to_field_ref(self, el):
        # filter out meta-information inserted in the document
        attributes = {k: v for k, v in el.attrib.items()
                           if not k.startswith('data-oe-')}
        attributes['t-field'] = el.get('data-oe-expression')

        out = html.html_parser.makeelement(el.tag, attrib=attributes)
        out.tail = el.tail
        return out

    @api.model
    def to_empty_oe_structure(self, el):
        out = html.html_parser.makeelement(el.tag, attrib=el.attrib)
        out.tail = el.tail
        return out

    @api.model
    def _set_noupdate(self):
        self.sudo().mapped('model_data_id').write({'noupdate': True})

    def save(self, value, xpath=None):
        """ Update a view section. The view section may embed fields to write

        Note that `self` record might not exist when saving an embed field

        :param str xpath: valid xpath to the tag to replace
        """
        self.ensure_one()

        arch_section = html.fromstring(
            value, parser=html.HTMLParser(encoding='utf-8'))

        if xpath is None:
            # value is an embedded field on its own, not a view section
            self.save_embedded_field(arch_section)
            return

        for el in self.extract_embedded_fields(arch_section):
            self.save_embedded_field(el)

            # transform embedded field back to t-field
            el.getparent().replace(el, self.to_field_ref(el))

        for el in self.extract_oe_structures(arch_section):
            if self.save_oe_structure(el):
                # empty oe_structure in parent view
                empty = self.to_empty_oe_structure(el)
                if el == arch_section:
                    arch_section = empty
                else:
                    el.getparent().replace(el, empty)

        new_arch = self.replace_arch_section(xpath, arch_section)
        old_arch = etree.fromstring(self.arch.encode('utf-8'))
        if not self._are_archs_equal(old_arch, new_arch):
            self._set_noupdate()
            self.write({'arch': self._pretty_arch(new_arch)})

    @api.model
    def _view_get_inherited_children(self, view):
        return view.inherit_children_ids

    @api.model
    def _view_obj(self, view_id):
        if isinstance(view_id, str):
            return self.search([('key', '=', view_id)], limit=1) or self.env.ref(view_id)
        elif isinstance(view_id, int):
            return self.browse(view_id)
        # It can already be a view object when called by '_views_get()' that is calling '_view_obj'
        # for it's inherit_children_ids, passing them directly as object record.
        return view_id

    # Returns all views (called and inherited) related to a view
    # Used by translation mechanism, SEO and optional templates

    @api.model
    def _views_get(self, view_id, get_children=True, bundles=False, root=True, visited=None):
        """ For a given view ``view_id``, should return:
                * the view itself
                * all views inheriting from it, enabled or not
                  - but not the optional children of a non-enabled child
                * all views called from it (via t-call)
            :returns recordset of ir.ui.view
        """
        try:
            view = self._view_obj(view_id)
        except ValueError:
            _logger.warning("Could not find view object with view_id '%s'", view_id)
            return self.env['ir.ui.view']

        if visited is None:
            visited = []
        while root and view.inherit_id:
            view = view.inherit_id

        views_to_return = view

        node = etree.fromstring(view.arch)
        xpath = "//t[@t-call]"
        if bundles:
            xpath += "| //t[@t-call-assets]"
        for child in node.xpath(xpath):
            try:
                called_view = self._view_obj(child.get('t-call', child.get('t-call-assets')))
            except ValueError:
                continue
            if called_view and called_view not in views_to_return and called_view.id not in visited:
                views_to_return += self._views_get(called_view, get_children=get_children, bundles=bundles, visited=visited + views_to_return.ids)

        if not get_children:
            return views_to_return

        extensions = self._view_get_inherited_children(view)

        # Keep children in a deterministic order regardless of their applicability
        for extension in extensions.sorted(key=lambda v: v.id):
            # only return optional grandchildren if this child is enabled
            if extension.id not in visited:
                for ext_view in self._views_get(extension, get_children=extension.active, root=False, visited=visited + views_to_return.ids):
                    if ext_view not in views_to_return:
                        views_to_return += ext_view
        return views_to_return

    @api.model
    def get_related_views(self, key, bundles=False):
        """ Get inherit view's informations of the template ``key``.
            returns templates info (which can be active or not)
            ``bundles=True`` returns also the asset bundles
        """
        user_groups = set(self.env.user.groups_id)
        View = self.with_context(active_test=False, lang=None)
        views = View._views_get(key, bundles=bundles)
        return views.filtered(lambda v: not v.groups_id or len(user_groups.intersection(v.groups_id)))

    # --------------------------------------------------------------------------
    # Snippet saving
    # --------------------------------------------------------------------------

    @api.model
    def _get_snippet_addition_view_key(self, template_key, key):
        return '%s.%s' % (template_key, key)

    @api.model
    def _snippet_save_view_values_hook(self):
        return {}

    def _find_available_name(self, name, used_names):
        attempt = 1
        candidate_name = name
        while candidate_name in used_names:
            attempt += 1
            candidate_name = f"{name} ({attempt})"
        return candidate_name

    @api.model
    def save_snippet(self, name, arch, template_key, snippet_key, thumbnail_url):
        """
        Saves a new snippet arch so that it appears with the given name when
        using the given snippets template.

        :param name: the name of the snippet to save
        :param arch: the html structure of the snippet to save
        :param template_key: the key of the view regrouping all snippets in
            which the snippet to save is meant to appear
        :param snippet_key: the key (without module part) to identify
            the snippet from which the snippet to save originates
        :param thumbnail_url: the url of the thumbnail to use when displaying
            the snippet to save
        """
        app_name = template_key.split('.')[0]
        snippet_key = '%s_%s' % (snippet_key, uuid.uuid4().hex)
        full_snippet_key = '%s.%s' % (app_name, snippet_key)

        # find available name
        current_website = self.env['website'].browse(self._context.get('website_id'))
        website_domain = current_website.website_domain()
        used_names = self.search(expression.AND([
            [('name', '=like', '%s%%' % name)], website_domain
        ])).mapped('name')
        name = self._find_available_name(name, used_names)

        # html to xml to add '/' at the end of self closing tags like br, ...
        xml_arch = etree.tostring(html.fromstring(arch), encoding='utf-8')
        new_snippet_view_values = {
            'name': name,
            'key': full_snippet_key,
            'type': 'qweb',
            'arch': xml_arch,
        }
        new_snippet_view_values.update(self._snippet_save_view_values_hook())
        self.create(new_snippet_view_values)

        custom_section = self.search([('key', '=', template_key)])
        snippet_addition_view_values = {
            'name': name + ' Block',
            'key': self._get_snippet_addition_view_key(template_key, snippet_key),
            'inherit_id': custom_section.id,
            'type': 'qweb',
            'arch': """
                <data inherit_id="%s">
                    <xpath expr="//div[@id='snippet_custom']" position="attributes">
                        <attribute name="class" remove="d-none" separator=" "/>
                    </xpath>
                    <xpath expr="//div[@id='snippet_custom_body']" position="inside">
                        <t t-snippet="%s" t-thumbnail="%s"/>
                    </xpath>
                </data>
            """ % (template_key, full_snippet_key, thumbnail_url),
        }
        snippet_addition_view_values.update(self._snippet_save_view_values_hook())
        self.create(snippet_addition_view_values)

    @api.model
    def rename_snippet(self, name, view_id, template_key):
        snippet_view = self.browse(view_id)
        key = snippet_view.key.split('.')[1]
        custom_key = self._get_snippet_addition_view_key(template_key, key)
        snippet_addition_view = self.search([('key', '=', custom_key)])
        if snippet_addition_view:
            snippet_addition_view.name = name + ' Block'
        snippet_view.name = name

    @api.model
    def delete_snippet(self, view_id, template_key):
        snippet_view = self.browse(view_id)
        key = snippet_view.key.split('.')[1]
        custom_key = self._get_snippet_addition_view_key(template_key, key)
        snippet_addition_view = self.search([('key', '=', custom_key)])
        (snippet_addition_view | snippet_view).unlink()