From 1740e0ba66fc1a2e3e63fbad897691c98a76fbdf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Javi=20Mart=C3=ADn?= <javim@elretirao.net>
Date: Tue, 17 Nov 2020 21:32:09 +0100
Subject: [PATCH 1/3] Add SDG::Relation model

---
 app/models/concerns/sdg/relatable.rb          |  7 ++++
 app/models/concerns/sdg/related.rb            |  7 ++++
 app/models/sdg/goal.rb                        |  2 ++
 app/models/sdg/relation.rb                    |  6 ++++
 app/models/sdg/target.rb                      |  1 +
 .../20201117200945_create_sdg_relations.rb    | 12 +++++++
 db/schema.rb                                  | 14 +++++++-
 spec/models/sdg/relation_spec.rb              | 33 +++++++++++++++++++
 8 files changed, 81 insertions(+), 1 deletion(-)
 create mode 100644 app/models/concerns/sdg/relatable.rb
 create mode 100644 app/models/concerns/sdg/related.rb
 create mode 100644 app/models/sdg/relation.rb
 create mode 100644 db/migrate/20201117200945_create_sdg_relations.rb
 create mode 100644 spec/models/sdg/relation_spec.rb

diff --git a/app/models/concerns/sdg/relatable.rb b/app/models/concerns/sdg/relatable.rb
new file mode 100644
index 000000000..e886616fc
--- /dev/null
+++ b/app/models/concerns/sdg/relatable.rb
@@ -0,0 +1,7 @@
+module SDG::Relatable
+  extend ActiveSupport::Concern
+
+  included do
+    has_many :sdg_relations, as: :relatable, dependent: :destroy, class_name: "SDG::Relation"
+  end
+end
diff --git a/app/models/concerns/sdg/related.rb b/app/models/concerns/sdg/related.rb
new file mode 100644
index 000000000..ac96ff325
--- /dev/null
+++ b/app/models/concerns/sdg/related.rb
@@ -0,0 +1,7 @@
+module SDG::Related
+  extend ActiveSupport::Concern
+
+  included do
+    has_many :relations, as: :related_sdg, dependent: :destroy
+  end
+end
diff --git a/app/models/sdg/goal.rb b/app/models/sdg/goal.rb
index 940f7a7d1..bd26438c8 100644
--- a/app/models/sdg/goal.rb
+++ b/app/models/sdg/goal.rb
@@ -1,4 +1,6 @@
 class SDG::Goal < ApplicationRecord
+  include SDG::Related
+
   validates :code, presence: true, uniqueness: true, inclusion: { in: 1..17 }
 
   has_many :targets, dependent: :destroy
diff --git a/app/models/sdg/relation.rb b/app/models/sdg/relation.rb
new file mode 100644
index 000000000..0148bea46
--- /dev/null
+++ b/app/models/sdg/relation.rb
@@ -0,0 +1,6 @@
+class SDG::Relation < ApplicationRecord
+  validates :related_sdg_id, uniqueness: { scope: [:related_sdg_type, :relatable_id, :relatable_type] }
+
+  belongs_to :relatable, polymorphic: true, optional: false
+  belongs_to :related_sdg, polymorphic: true, optional: false
+end
diff --git a/app/models/sdg/target.rb b/app/models/sdg/target.rb
index 72568490d..ad165e280 100644
--- a/app/models/sdg/target.rb
+++ b/app/models/sdg/target.rb
@@ -1,5 +1,6 @@
 class SDG::Target < ApplicationRecord
   include Comparable
+  include SDG::Related
 
   validates :code, presence: true, uniqueness: true
   validates :goal, presence: true
diff --git a/db/migrate/20201117200945_create_sdg_relations.rb b/db/migrate/20201117200945_create_sdg_relations.rb
new file mode 100644
index 000000000..55415c78c
--- /dev/null
+++ b/db/migrate/20201117200945_create_sdg_relations.rb
@@ -0,0 +1,12 @@
+class CreateSDGRelations < ActiveRecord::Migration[5.2]
+  def change
+    create_table :sdg_relations do |t|
+      t.references :related_sdg, polymorphic: true
+      t.references :relatable, polymorphic: true
+
+      t.index [:related_sdg_id, :related_sdg_type, :relatable_id, :relatable_type], name: "sdg_relations_unique", unique: true
+
+      t.timestamps
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 5cb3ed956..5b1944278 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2020_11_12_155047) do
+ActiveRecord::Schema.define(version: 2020_11_17_200945) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_trgm"
@@ -1304,6 +1304,18 @@ ActiveRecord::Schema.define(version: 2020_11_12_155047) do
     t.index ["code"], name: "index_sdg_goals_on_code", unique: true
   end
 
+  create_table "sdg_relations", force: :cascade do |t|
+    t.string "related_sdg_type"
+    t.bigint "related_sdg_id"
+    t.string "relatable_type"
+    t.bigint "relatable_id"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["relatable_type", "relatable_id"], name: "index_sdg_relations_on_relatable_type_and_relatable_id"
+    t.index ["related_sdg_id", "related_sdg_type", "relatable_id", "relatable_type"], name: "sdg_relations_unique", unique: true
+    t.index ["related_sdg_type", "related_sdg_id"], name: "index_sdg_relations_on_related_sdg_type_and_related_sdg_id"
+  end
+
   create_table "sdg_targets", force: :cascade do |t|
     t.bigint "goal_id"
     t.string "code", null: false
diff --git a/spec/models/sdg/relation_spec.rb b/spec/models/sdg/relation_spec.rb
new file mode 100644
index 000000000..d2da87fdd
--- /dev/null
+++ b/spec/models/sdg/relation_spec.rb
@@ -0,0 +1,33 @@
+require "rails_helper"
+
+describe SDG::Relation do
+  describe "Validations" do
+    it "is valid with a related SDG and a relatable model" do
+      relation = SDG::Relation.new(related_sdg: SDG::Goal[1], relatable: create(:proposal))
+
+      expect(relation).to be_valid
+    end
+
+    it "is not valid without a related SDG" do
+      relation = SDG::Relation.new(relatable: create(:proposal))
+
+      expect(relation).not_to be_valid
+    end
+
+    it "is not valid without a relatable model" do
+      relation = SDG::Relation.new(related_sdg: SDG::Goal[1])
+
+      expect(relation).not_to be_valid
+    end
+
+    it "is not valid when a relation already exists" do
+      proposal = create(:proposal)
+      goal = SDG::Goal[1]
+
+      SDG::Relation.create!(related_sdg: goal, relatable: proposal)
+      relation = SDG::Relation.new(related_sdg: goal, relatable: proposal)
+
+      expect(relation).not_to be_valid
+    end
+  end
+end

From 42699275a1095ed369c193d8655e04334b61cd05 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Javi=20Mart=C3=ADn?= <javim@elretirao.net>
Date: Wed, 18 Nov 2020 19:35:17 +0100
Subject: [PATCH 2/3] Add relations between relatable models and SDGs

Note we cannot directly get all related SDGs through SQL because they're
spread through different tables.
---
 app/models/budget/investment.rb      |  1 +
 app/models/concerns/sdg/relatable.rb | 11 ++++++
 app/models/debate.rb                 |  1 +
 app/models/legislation/process.rb    |  1 +
 app/models/poll.rb                   |  1 +
 app/models/proposal.rb               |  1 +
 spec/models/sdg/relatable_spec.rb    | 55 ++++++++++++++++++++++++++++
 7 files changed, 71 insertions(+)
 create mode 100644 spec/models/sdg/relatable_spec.rb

diff --git a/app/models/budget/investment.rb b/app/models/budget/investment.rb
index 8258bcc6b..092153eed 100644
--- a/app/models/budget/investment.rb
+++ b/app/models/budget/investment.rb
@@ -13,6 +13,7 @@ class Budget
     include Imageable
     include Mappable
     include Documentable
+    include SDG::Relatable
 
     acts_as_taggable_on :valuation_tags
     acts_as_votable
diff --git a/app/models/concerns/sdg/relatable.rb b/app/models/concerns/sdg/relatable.rb
index e886616fc..e85e1407c 100644
--- a/app/models/concerns/sdg/relatable.rb
+++ b/app/models/concerns/sdg/relatable.rb
@@ -3,5 +3,16 @@ module SDG::Relatable
 
   included do
     has_many :sdg_relations, as: :relatable, dependent: :destroy, class_name: "SDG::Relation"
+
+    %w[SDG::Goal SDG::Target].each do |sdg_type|
+      has_many sdg_type.constantize.table_name.to_sym,
+               through: :sdg_relations,
+               source: :related_sdg,
+               source_type: sdg_type
+    end
+  end
+
+  def related_sdgs
+    sdg_relations.map(&:related_sdg)
   end
 end
diff --git a/app/models/debate.rb b/app/models/debate.rb
index 22ed568b1..47a78f360 100644
--- a/app/models/debate.rb
+++ b/app/models/debate.rb
@@ -14,6 +14,7 @@ class Debate < ApplicationRecord
   include Relationable
   include Notifiable
   include Randomizable
+  include SDG::Relatable
 
   acts_as_votable
   acts_as_paranoid column: :hidden_at
diff --git a/app/models/legislation/process.rb b/app/models/legislation/process.rb
index 63f819a5d..f1a2e12c1 100644
--- a/app/models/legislation/process.rb
+++ b/app/models/legislation/process.rb
@@ -4,6 +4,7 @@ class Legislation::Process < ApplicationRecord
   include Milestoneable
   include Imageable
   include Documentable
+  include SDG::Relatable
 
   acts_as_paranoid column: :hidden_at
   acts_as_taggable_on :customs
diff --git a/app/models/poll.rb b/app/models/poll.rb
index edef37f06..0289a0fc2 100644
--- a/app/models/poll.rb
+++ b/app/models/poll.rb
@@ -8,6 +8,7 @@ class Poll < ApplicationRecord
   include Sluggable
   include StatsVersionable
   include Reportable
+  include SDG::Relatable
 
   translates :name,        touch: true
   translates :summary,     touch: true
diff --git a/app/models/proposal.rb b/app/models/proposal.rb
index d35da3b75..9fe469915 100644
--- a/app/models/proposal.rb
+++ b/app/models/proposal.rb
@@ -19,6 +19,7 @@ class Proposal < ApplicationRecord
   include Relationable
   include Milestoneable
   include Randomizable
+  include SDG::Relatable
 
   acts_as_votable
   acts_as_paranoid column: :hidden_at
diff --git a/spec/models/sdg/relatable_spec.rb b/spec/models/sdg/relatable_spec.rb
new file mode 100644
index 000000000..4b87971be
--- /dev/null
+++ b/spec/models/sdg/relatable_spec.rb
@@ -0,0 +1,55 @@
+require "rails_helper"
+
+describe SDG::Relatable do
+  let(:goal) { SDG::Goal[1] }
+  let(:target) { SDG::Target["1.2"] }
+  let(:another_goal) { SDG::Goal[2] }
+  let(:another_target) { SDG::Target["2.3"] }
+
+  let(:relatable) { create(:proposal) }
+
+  describe "#sdg_goals" do
+    it "can assign goals to a model" do
+      relatable.sdg_goals = [goal, another_goal]
+
+      expect(SDG::Relation.count).to be 2
+      expect(SDG::Relation.first.relatable).to eq relatable
+      expect(SDG::Relation.last.relatable).to eq relatable
+      expect(SDG::Relation.first.related_sdg).to eq goal
+      expect(SDG::Relation.last.related_sdg).to eq another_goal
+    end
+
+    it "can obtain the list of goals" do
+      relatable.sdg_goals = [goal, another_goal]
+
+      expect(relatable.reload.sdg_goals).to match_array [goal, another_goal]
+    end
+  end
+
+  describe "#sdg_targets" do
+    it "can assign targets to a model" do
+      relatable.sdg_targets = [target, another_target]
+
+      expect(SDG::Relation.count).to be 2
+      expect(SDG::Relation.first.relatable).to eq relatable
+      expect(SDG::Relation.last.relatable).to eq relatable
+      expect(SDG::Relation.first.related_sdg).to eq target
+      expect(SDG::Relation.last.related_sdg).to eq another_target
+    end
+
+    it "can obtain the list of targets" do
+      relatable.sdg_targets = [target, another_target]
+
+      expect(relatable.reload.sdg_targets).to match_array [target, another_target]
+    end
+  end
+
+  describe "#related_sdgs" do
+    it "returns all related goals and targets" do
+      relatable.sdg_goals = [goal, another_goal]
+      relatable.sdg_targets = [target, another_target]
+
+      expect(relatable.reload.related_sdgs).to match_array [goal, another_goal, target, another_target]
+    end
+  end
+end

From c0edd1b227820e063066bd73b621464f5f295638 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Javi=20Mart=C3=ADn?= <javim@elretirao.net>
Date: Fri, 20 Nov 2020 12:14:17 +0100
Subject: [PATCH 3/3] Allow SDGs to get all their related contents

Note we cannot directly get all related contents through SQL because
related contents are spread through different tables.
---
 app/models/concerns/sdg/related.rb | 19 ++++++++++++++++
 spec/models/sdg/related_spec.rb    | 36 ++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+)
 create mode 100644 spec/models/sdg/related_spec.rb

diff --git a/app/models/concerns/sdg/related.rb b/app/models/concerns/sdg/related.rb
index ac96ff325..1820b3ae3 100644
--- a/app/models/concerns/sdg/related.rb
+++ b/app/models/concerns/sdg/related.rb
@@ -1,7 +1,26 @@
 module SDG::Related
   extend ActiveSupport::Concern
 
+  RELATABLE_TYPES = %w[
+    Budget::Investment
+    Debate
+    Legislation::Process
+    Poll
+    Proposal
+  ].freeze
+
   included do
     has_many :relations, as: :related_sdg, dependent: :destroy
+
+    RELATABLE_TYPES.each do |relatable_type|
+      has_many relatable_type.constantize.table_name.to_sym,
+               through: :relations,
+               source: :relatable,
+               source_type: relatable_type
+    end
+  end
+
+  def relatables
+    relations.map(&:relatable)
   end
 end
diff --git a/spec/models/sdg/related_spec.rb b/spec/models/sdg/related_spec.rb
new file mode 100644
index 000000000..fb19c3732
--- /dev/null
+++ b/spec/models/sdg/related_spec.rb
@@ -0,0 +1,36 @@
+require "rails_helper"
+
+describe SDG::Related do
+  let(:proposal) { create(:proposal) }
+  let(:another_proposal) { create(:proposal) }
+  let(:related_sdg) { SDG::Goal[1] }
+
+  describe "#proposals" do
+    it "can assign proposals to a model" do
+      related_sdg.proposals = [proposal, another_proposal]
+
+      expect(SDG::Relation.count).to be 2
+      expect(SDG::Relation.first.related_sdg).to eq related_sdg
+      expect(SDG::Relation.last.related_sdg).to eq related_sdg
+      expect(SDG::Relation.first.relatable).to eq proposal
+      expect(SDG::Relation.last.relatable).to eq another_proposal
+    end
+
+    it "can obtain the list of proposals" do
+      related_sdg.proposals = [proposal, another_proposal]
+
+      expect(related_sdg.reload.proposals).to match_array [proposal, another_proposal]
+    end
+  end
+
+  describe "#relatables" do
+    let(:investment) { create(:budget_investment) }
+
+    it "returns all related content" do
+      related_sdg.proposals = [proposal, another_proposal]
+      related_sdg.budget_investments = [investment]
+
+      expect(related_sdg.reload.relatables).to match_array [proposal, another_proposal, investment]
+    end
+  end
+end