[REF] website_slides: introduce slide / user relationship and use it for vote

Purpose of this commit is to store a relationship between slides and users.
Indeed starting from now we will track more user interaction with the slides
module.

In this commit we introduce a model that is used to populate and decorate
the relationship between slides and users, slide.users. From slides or users
point of view it behaves like a many2many. It can also be used to store
more information about the user interaction with the slide.

We use it here to store the user vote. Like and dislike are not static
counters anymore but computed fields based on user votes. It is implemented
as a tristate field.

As it is a technical model no access on slide.users is granted. Controllers
and methods grant access to the relationship in order to avoid information
lead and keep technical details private.

Future commits improving the eLearning use of slides will notably store
information about user having read the slide, taken a quizz or gaining
karma depending on some actions performed on the slide.

This commit is linked to task ID 1934488 and PR #30620 .

3 files changed, 85 insertions, 37 deletions

diff --git a/addons/website_slides/controllers/main.py b/addons/website_slides/controllers/main.py
index 11b5fb0edeb..d85a9a15296 100644
--- a/addons/website_slides/controllers/main.py
+++ b/addons/website_slides/controllers/main.py
@@ -35,28 +35,6 @@ class WebsiteSlides(http.Controller):
             request.session[slide_key] = viewed_slides
         return True
 
-    def _check_session_slide_vote(self, slide, upvote=True):
-        if not request.session.get('__wslides_upvote'):
-            request.session['__wslides_upvote'] = []
-        if not request.session.get('__wslides_downvote'):
-            request.session['__wslides_downvote'] = []
-        if upvote and slide.id in request.session['__wslides_upvote']:
-            return False
-        if not upvote and slide.id in request.session['__wslides_downvote']:
-            return False
-        if upvote and slide.id in request.session['__wslides_downvote']:
-            request.session['__wslides_downvote'].remove(slide.id)
-            return 0
-        if not upvote and slide.id in request.session['__wslides_upvote']:
-            request.session['__wslides_upvote'].remove(slide.id)
-            return 0
-        if upvote:
-            request.session['__wslides_upvote'].append(slide.id)
-            return 1
-        if not upvote:
-            request.session['__wslides_downvote'].append(slide.id)
-            return -1
-
     def _get_slide_detail(self, slide):
         most_viewed_slides = slide.get_most_viewed_slides(self._slides_per_list)
         related_slides = slide.get_related_slides(self._slides_per_list)
@@ -234,21 +212,19 @@ class WebsiteSlides(http.Controller):
     def slide_like(self, slide_id, upvote):
         if request.website.is_public_user():
             return {'error': 'public_user'}
-        slide = request.env['slide.slide'].browse(int(slide_id))
-        slide.check_access_rights('read')
-        slide.check_access_rule('read')
-        check = self._check_session_slide_vote(slide, upvote=upvote)
-        if check is False:
+        slide_users = request.env['slide.users'].sudo().search([
+            ('slide_id', '=', slide_id),
+            ('user_id', '=', request.env.uid)
+        ])
+        if (upvote and slide_users.vote == 1) or (not upvote and slide_users.vote == -1):
             return {'error': 'vote_done'}
-        if check == 1:
-            slide.sudo().likes += 1
-        elif check == 0 and upvote:
-            slide.sudo().dislikes -= 1
-        elif check == 0 and not upvote:
-            slide.sudo().likes -= 1
+        slide = request.env['slide.slide'].browse(int(slide_id))
+        if upvote:
+            slide.action_like()
         else:
-            slide.sudo().dislikes += 1
-        return {'state': check, 'likes': slide.likes, 'dislikes': slide.dislikes}
+            slide.action_dislike()
+        slide.invalidate_cache()
+        return slide.read(['likes', 'dislikes', 'user_vote'])[0]
 
     @http.route(['/slides/slide/send_share_email'], type='json', auth='user', website=True)
     def slide_send_share_email(self, slide_id, email):
diff --git a/addons/website_slides/models/slide_slide.py b/addons/website_slides/models/slide_slide.py
index 6f1df65d99b..2337e41aab4 100644
--- a/addons/website_slides/models/slide_slide.py
+++ b/addons/website_slides/models/slide_slide.py
@@ -19,6 +19,16 @@ from odoo.http import request
 from odoo.addons.http_routing.models.ir_http import url_for
 
 
+class SlideUsersRelation(models.Model):
+    _name = 'slide.users'
+    _description = 'Slide / Users decorated m2m'
+    _table = 'slide_users'
+
+    slide_id = fields.Many2one('slide.slide', index=True, required=True)
+    user_id = fields.Many2one('res.users', index=True, required=True)
+    vote = fields.Integer('Vote', default=0)
+
+
 class EmbeddedSlide(models.Model):
     """ Embedding in third party websites. Track view count, generate statistics. """
     _name = 'slide.embed'
@@ -93,6 +103,10 @@ class Slide(models.Model):
     image = fields.Binary('Image', attachment=True)
     image_medium = fields.Binary('Medium', compute="_get_image", store=True, attachment=True)
     image_thumb = fields.Binary('Thumbnail', compute="_get_image", store=True, attachment=True)
+    # subscribers
+    user_ids = fields.Many2many('res.users', 'slide_users', 'slide_id', 'user_id',
+                                string='Subscribers', groups='base.group_system')
+    slide_user_ids = fields.One2many('slide.users', 'slide_id', string='Subscribers information', groups='base.group_system')
 
     @api.depends('image')
     def _get_image(self):
@@ -135,8 +149,9 @@ class Slide(models.Model):
     # website
     website_id = fields.Many2one(related='channel_id.website_id', readonly=True)
     date_published = fields.Datetime('Publish Date')
-    likes = fields.Integer('Likes')
-    dislikes = fields.Integer('Dislikes')
+    likes = fields.Integer('Likes', compute='_compute_user_info', store=True)
+    dislikes = fields.Integer('Dislikes', compute='_compute_user_info', store=True)
+    user_vote = fields.Integer('User vote', compute='_compute_user_info')
     # views
     embedcount_ids = fields.One2many('slide.embed', 'slide_id', string="Embed Count")
     slide_views = fields.Integer('# of Website Views')
@@ -148,6 +163,24 @@ class Slide(models.Model):
         for record in self:
             record.total_views = record.slide_views + record.embed_views
 
+    @api.depends('slide_user_ids.vote')
+    def _compute_user_info(self):
+        slide_data = dict.fromkeys(self.ids, dict({'likes': 0, 'dislikes': 0, 'user_vote': False}))
+        slide_users = self.env['slide.users'].sudo().search([
+            ('slide_id', 'in', self.ids)
+        ])
+        for slide_user in slide_users:
+            if slide_user.vote == 1:
+                slide_data[slide_user.slide_id.id]['likes'] += 1
+                if slide_user.user_id == self.env.user:
+                    slide_data[slide_user.slide_id.id]['user_vote'] = 1
+            elif slide_user.vote == -1:
+                slide_data[slide_user.slide_id.id]['dislikes'] += 1
+                if slide_user.user_id == self.env.user:
+                    slide_data[slide_user.slide_id.id]['user_vote'] = -1
+        for slide_sudo in self.sudo():
+            slide_sudo.update(slide_data[slide_sudo.id])
+
     embed_code = fields.Text('Embed Code', readonly=True, compute='_get_embed_code')
 
     def _get_embed_code(self):
@@ -305,6 +338,43 @@ class Slide(models.Model):
         base_url = self.env['ir.config_parameter'].sudo().get_param('web.base.url')
         return self.channel_id.share_template_id.with_context(email=email, base_url=base_url).send_mail(self.id, notif_layout='mail.mail_notification_light')
 
+    def action_like(self):
+        self.check_access_rights('read')
+        self.check_access_rule('read')
+        return self._action_vote(upvote=True)
+
+    def action_dislike(self):
+        self.check_access_rights('read')
+        self.check_access_rule('read')
+        return self._action_vote(upvote=False)
+
+    def _action_vote(self, upvote=True):
+        """ Private implementation of voting. It does not check for any real access
+        rights; public methods should grant access before calling this method.
+
+          :param upvote: if True, is a like; if False, is a dislike
+        """
+        self_sudo = self.sudo()
+        SlideUsersSudo = self.env['slide.users'].sudo()
+        slide_users = SlideUsersSudo.search([
+            ('slide_id', 'in', self.ids),
+            ('user_id', '=', self.env.uid)
+        ])
+        new_slides = self_sudo - slide_users.mapped('slide_id')
+
+        for slide_user in slide_users:
+            if upvote:
+                new_vote = 0 if slide_user.vote == -1 else 1
+            else:
+                new_vote = 0 if slide_user.vote == 1 else -1
+            slide_user.vote = new_vote
+
+        for new_slide in new_slides:
+            new_vote = 1 if upvote else -1
+            new_slide.write({
+                'slide_user_ids': [(0, 0, {'vote': new_vote, 'user_id': self.env.uid})]
+            })
+
     # --------------------------------------------------
     # Parsing methods
     # --------------------------------------------------
diff --git a/addons/website_slides/security/ir.model.access.csv b/addons/website_slides/security/ir.model.access.csv
index 07d087f7db9..38588d920d1 100644
--- a/addons/website_slides/security/ir.model.access.csv
+++ b/addons/website_slides/security/ir.model.access.csv
@@ -2,6 +2,8 @@ id,name,model_id:id,group_id:id,perm_read,perm_write,perm_create,perm_unlink
 access_slide_slide_public,slide.slide.public,model_slide_slide,base.group_public,1,0,0,0
 access_slide_slide_portal,slide.slide.portal,model_slide_slide,base.group_portal,1,0,0,0
 access_slide_slide_user,slide.slide.user,model_slide_slide,base.group_user,1,1,1,1
+access_slide_users_all,slide.users.all,model_slide_users,,0,0,0,0
+access_slide_users_system,slide.users.system,model_slide_users,base.group_system,1,1,1,1
 access_slide_tag_public,slide.tag.public,model_slide_tag,base.group_public,1,0,0,0
 access_slide_tag_portal,slide.tag.portal,model_slide_tag,base.group_portal,1,0,0,0
 access_slide_tag_user,slide.tag.user,model_slide_tag,base.group_user,1,1,1,1