Add basic functionality

Gemfile

@@ -48,6 +48,9 @@ gem "bootsnap", require: false
 # Use Active Storage variants [https://guides.rubyonrails.org/active_storage_overview.html#transforming-images]
 # gem "image_processing", "~> 1.2"
 
+gem "slim-rails"
+gem "active_interaction"
+
 group :development, :test do
   # See https://guides.rubyonrails.org/debugging_rails_applications.html#debugging-with-the-debug-gem
   gem "debug", platforms: %i[ mri mingw x64_mingw ]

Gemfile.lock

@@ -46,6 +46,9 @@ GEM
       erubi (~> 1.4)
       rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.1, >= 1.2.0)
+    active_interaction (5.3.0)
+      activemodel (>= 5.2, < 8)
+      activesupport (>= 5.2, < 8)
     activejob (7.0.8)
       activesupport (= 7.0.8)
       globalid (>= 0.3.6)
@@ -157,6 +160,13 @@ GEM
       psych (>= 4.0.0)
     reline (0.3.8)
       io-console (~> 0.5)
+    slim (5.1.1)
+      temple (~> 0.10.0)
+      tilt (>= 2.1.0)
+    slim-rails (3.6.2)
+      actionpack (>= 3.1)
+      railties (>= 3.1)
+      slim (>= 3.0, < 6.0, != 5.0.0)
     sprockets (4.2.1)
       concurrent-ruby (~> 1.0)
       rack (>= 2.2.4, < 4)
@@ -168,7 +178,9 @@ GEM
     stimulus-rails (1.2.2)
       railties (>= 6.0.0)
     stringio (3.0.8)
+    temple (0.10.2)
     thor (1.2.2)
+    tilt (2.3.0)
     timeout (0.4.0)
     turbo-rails (1.4.0)
       actionpack (>= 6.0.0)
@@ -190,12 +202,14 @@ PLATFORMS
   x86_64-linux
 
 DEPENDENCIES
+  active_interaction
   bootsnap
   debug
   importmap-rails
   jbuilder
   puma (~> 5.0)
   rails (~> 7.0.8)
+  slim-rails
   sprockets-rails
   sqlite3 (~> 1.4)
   stimulus-rails

app/controllers/application_controller.rb

@@ -1,2 +1,5 @@
 class ApplicationController < ActionController::Base
+  def resource_class
+    controller_path.classify.constantize
+  end
 end

app/controllers/countries_controller.rb

@@ -0,0 +1,13 @@
+class CountriesController < ApplicationController
+  helper_method %i[countries country]
+
+  def countries
+    resource_class.all
+  end
+
+  def country
+    return resource_class.find(params[:id]) if params[:id].is_a?(Integer)
+    return resource_class.find_by(iso2: params[:id]) if params[:id].length == 2
+    resource_class.find_by(iso3: params[:id])
+  end
+end

app/controllers/people_controller.rb

@@ -0,0 +1,7 @@
+class PeopleController < ApplicationController
+  helper_method :person
+
+  def person
+    resource_class.find(params[:id])
+  end
+end

app/models/admission.rb

@@ -1,4 +1,24 @@
 class Admission < ApplicationRecord
-  belongs_to :country
+  belongs_to :country, inverse_of: :admissions
-  belongs_to :person
+  belongs_to :person, inverse_of: :admissions
+  belongs_to :previous, class_name: name, inverse_of: :next, optional: true
+  has_one :next, class_name: name, foreign_key: :previous_id, inverse_of: :previous
+
+  scope :ordered, -> { order(:arrived_on, :previous_id) }
+  scope :before, -> (date) { where("#{table_name}.arrived_on <= ?", date) }
+  scope :after, -> (date) { where("#{table_name}.arrived_on >= ?", date) }
+  
+  around_create :set_previous
+  before_destroy :update_nexts_previous
+
+  def set_previous
+    self.previous ||= person.admissions.ordered.before(arrived_on).last
+    future_next = previous&.reload_next
+    yield
+    future_next&.update(previous: self)
+  end
+
+  def update_nexts_previous
+    self.next&.update(previous: previous)
+  end
 end

app/models/country.rb

@@ -1,2 +1,4 @@
 class Country < ApplicationRecord
+  has_many :admissions, inverse_of: :country
+  has_many :people, foreign_key: :birth_country_id, inverse_of: :birth_country
 end

app/models/person.rb

@@ -1,2 +1,18 @@
 class Person < ApplicationRecord
+  belongs_to :birth_country, class_name: Country.name
+  has_many :admissions
+
+  def stays
+    stays = []
+    admissions.ordered.includes(:country).all.each_cons(2) do |a, b|
+      stays.push(
+        country: a.country,
+        arrival: a.arrived_on,
+        departure: b.arrived_on,
+        duration: (b.arrived_on - a.arrived_on).to_i + 1
+      )
+    end
+
+    stays
+  end
 end

app/views/countries/index.html.slim

@@ -0,0 +1,11 @@
+h1 Countries
+table
+  tr
+    th Name
+    th ISO 3166-1 alpha-2 code
+    th ISO 3166-1 alpha-3 code
+  - for country in countries
+    tr
+      td = country.name
+      td = country.iso2
+      td = country.iso3

app/views/countries/show.html.slim

@@ -0,0 +1,9 @@
+h1 = country.name
+b ID &nbsp
+= country.id
+br
+b ISO 3166-1 alpha-2 code &nbsp
+= country.iso2
+br
+b ISO 3166-1 alpha-2 code &nbsp
+= country.iso3

app/views/people/show.html.slim

@@ -0,0 +1,15 @@
+h1= person.name
+table
+  thead
+    tr
+      th Country
+      th Arrival
+      th Departure
+      th Duration (days)
+  tbody
+    - for stay in person.stays
+      tr
+        td = stay[:country].name + " (" + stay[:country].iso2 + ")" 
+        td = stay[:arrival]
+        td = stay[:departure]
+        td = stay[:duration]

config/routes.rb

@@ -1,4 +1,7 @@
 Rails.application.routes.draw do
+  resources :people, only: :show
+  resources :countries, only: %i[index show]
+
   # Define your application routes per the DSL in https://guides.rubyonrails.org/routing.html
 
   # Defines the root path route ("/")

db/migrate/20230924015422_create_people.rb

@@ -2,6 +2,8 @@ class CreatePeople < ActiveRecord::Migration[7.0]
   def change
     create_table :people do |t|
       t.string :name, null: false
+      t.date :birth_day, null: false
+      t.references :birth_country, null: false, foreign_key: { to_table: :countries }
 
       t.timestamps
     end

db/migrate/20230924015803_create_admissions.rb

@@ -3,6 +3,8 @@ class CreateAdmissions < ActiveRecord::Migration[7.0]
     create_table :admissions do |t|
       t.references :country, null: false, foreign_key: true
       t.references :person, null: false, foreign_key: true
+      t.references :previous, null: true, foreign_key: { to_table: :admissions }
+
       t.date :arrived_on, null: false
 
       t.timestamps

db/schema.rb

@@ -14,11 +14,13 @@ ActiveRecord::Schema[7.0].define(version: 2023_09_24_015803) do
   create_table "admissions", force: :cascade do |t|
     t.integer "country_id", null: false
     t.integer "person_id", null: false
+    t.integer "previous_id"
     t.date "arrived_on", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.index ["country_id"], name: "index_admissions_on_country_id"
     t.index ["person_id"], name: "index_admissions_on_person_id"
+    t.index ["previous_id"], name: "index_admissions_on_previous_id"
   end
 
   create_table "countries", force: :cascade do |t|
@@ -34,10 +36,15 @@ ActiveRecord::Schema[7.0].define(version: 2023_09_24_015803) do
 
   create_table "people", force: :cascade do |t|
     t.string "name", null: false
+    t.date "birth_day", null: false
+    t.integer "birth_country_id", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.index ["birth_country_id"], name: "index_people_on_birth_country_id"
   end
 
+  add_foreign_key "admissions", "admissions", column: "previous_id"
   add_foreign_key "admissions", "countries"
   add_foreign_key "admissions", "people"
+  add_foreign_key "people", "countries", column: "birth_country_id"
 end