Issue #7 - add availability model and select only available participa…

…nts in matchmaking job

app/jobs/establish_matches_for_grouping_job.rb

@@ -13,7 +13,7 @@ def perform(grouping:)
 
     matches = @matches_participants.call(
       grouping: grouping,
-      participant_ids: @loads_slack_channel_members.call(channel: channel.id)
+      participant_ids: members_for_channel(channel, selected_by: Matchmaking::SelectsAvailableParticipants.new(grouping: grouping))
     )
     matches.each do |match|
       @notifies_grouping_members.call(
@@ -30,6 +30,12 @@ def perform(grouping:)
 
   private
 
+  def members_for_channel(channel, selected_by:)
+    participant_ids = @loads_slack_channel_members.call(channel: channel.id)
+
+    selected_by.call(participant_ids)
+  end
+
   def channel_for_grouping(grouping)
     grouping_sym = grouping.intern
 

app/lib/matchmaking/selects_available_participants.rb

@@ -0,0 +1,17 @@
+module Matchmaking
+  class SelectsAvailableParticipants
+    def initialize(grouping:)
+      @grouping = grouping
+    end
+
+    def call(participant_ids)
+      participant_ids - unavailable_participants_for_grouping(@grouping)
+    end
+
+    private
+
+    def unavailable_participants_for_grouping(grouping)
+      GroupingMemberAvailability.unavailable.where(grouping: grouping).pluck(:member_id)
+    end
+  end
+end

app/models/grouping_member_availability.rb

@@ -0,0 +1,8 @@
+class GroupingMemberAvailability < ApplicationRecord
+  enum availability: {
+    available: 0,
+    unavailable: 1
+  }
+
+  validates :grouping, :member_id, presence: true
+end

db/migrate/20220120164553_create_grouping_member_availabilities.rb

@@ -0,0 +1,13 @@
+class CreateGroupingMemberAvailabilities < ActiveRecord::Migration[6.1]
+  def change
+    create_table :grouping_member_availabilities do |t|
+      t.string :grouping
+      t.string :member_id
+      t.integer :availability, default: 0
+
+      t.timestamps
+    end
+
+    add_index :grouping_member_availabilities, [:grouping, :availability], name: "grouping_availability"
+  end
+end

db/schema.rb

@@ -10,11 +10,20 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_10_21_003356) do
+ActiveRecord::Schema.define(version: 2022_01_20_164553) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
+  create_table "grouping_member_availabilities", force: :cascade do |t|
+    t.string "grouping"
+    t.string "member_id"
+    t.integer "availability", default: 0
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+    t.index ["grouping", "availability"], name: "grouping_availability"
+  end
+
   create_table "historical_matches", force: :cascade do |t|
     t.string "members", default: [], array: true
     t.string "grouping"

spec/lib/matchmaking/selects_available_participants_spec.rb

@@ -0,0 +1,51 @@
+require "rails_helper"
+
+RSpec.describe Matchmaking::SelectsAvailableParticipants, type: :matchmaking do
+  let(:grouping) { "coffee_time" }
+
+  subject { Matchmaking::SelectsAvailableParticipants.new(grouping: grouping) }
+
+  it "returns empty list for no participants" do
+    result = subject.call([])
+
+    expect(result).to eq([])
+  end
+
+  context "when there are no unavailabilities" do
+    it "returns all participants" do
+      participant_ids = ["USER_1", "USER_2", "USER_3"]
+
+      result = subject.call(participant_ids)
+
+      expect(result).to eq(participant_ids)
+    end
+  end
+
+  context "when there are unavailabilities for the grouping" do
+    before do
+      create_grouping_member_availability(grouping: grouping, member_id: "USER_3", availability: :unavailable)
+    end
+
+    it "selects only available participants" do
+      participant_ids = ["USER_1", "USER_2", "USER_3"]
+
+      result = subject.call(participant_ids)
+
+      expect(result).to eq(["USER_1", "USER_2"])
+    end
+  end
+
+  context "when there are unavailabilities for a different grouping" do
+    before do
+      create_grouping_member_availability(grouping: "rotating_brunch", member_id: "USER_3", availability: :unavailable)
+    end
+
+    it "should not effect participants of an unrelated grouping" do
+      participant_ids = ["USER_1", "USER_2", "USER_3"]
+
+      result = subject.call(participant_ids)
+
+      expect(result).to eq(participant_ids)
+    end
+  end
+end

spec/models/grouping_member_availability_spec.rb

@@ -0,0 +1,38 @@
+require "rails_helper"
+
+RSpec.describe GroupingMemberAvailability, type: :model do
+  it "requires grouping attribute" do
+    availability = GroupingMemberAvailability.create
+
+    expect(availability.valid?).to be false
+    expect(availability.errors[:grouping].first).to eq("can't be blank")
+  end
+
+  it "requires member_id attribute" do
+    availability = GroupingMemberAvailability.create
+
+    expect(availability.valid?).to be false
+    expect(availability.errors[:member_id].first).to eq("can't be blank")
+  end
+
+  it "must be created with valid availability" do
+    expect {
+      GroupingMemberAvailability.create(
+        grouping: "test",
+        member_id: "USER_1",
+        availability: :bogus
+      )
+    }.to raise_error(ArgumentError)
+  end
+
+  it "creates successfully" do
+    availability = GroupingMemberAvailability.create(
+      grouping: "test",
+      member_id: "USER_ID_1",
+      availability: :unavailable
+    )
+
+    expect(availability.valid?).to be true
+    expect(availability.errors).to be_empty
+  end
+end

spec/support/database_helpers.rb

@@ -2,4 +2,12 @@ module DatabaseHelpers
   def create_historical_match(grouping:, members:)
     HistoricalMatch.create(grouping: grouping, members: members, matched_on: Date.today)
   end
+
+  def create_grouping_member_availability(grouping:, member_id:, availability:)
+    GroupingMemberAvailability.create(
+      grouping: grouping,
+      member_id: member_id,
+      availability: availability
+    )
+  end
 end