Start CSV importer feature

Gemfile

@@ -44,6 +44,7 @@ gem "slim"
 gem "dartsass-rails"
 gem "bootstrap", "~> 5.3.3"
 gem "friendly_id", "~> 5.5.0"
+gem "csv"
 
 group :development, :test do
   # See https://guides.rubyonrails.org/debugging_rails_applications.html#debugging-with-the-debug-gem

Gemfile.lock

@@ -101,6 +101,7 @@ GEM
     concurrent-ruby (1.3.5)
     connection_pool (2.5.3)
     crass (1.0.6)
+    csv (3.3.4)
     dartsass-rails (0.5.1)
       railties (>= 6.0.0)
       sass-embedded (~> 1.63)
@@ -432,6 +433,7 @@ DEPENDENCIES
   bootstrap (~> 5.3.3)
   brakeman
   capybara
+  csv
   dartsass-rails
   debug
   factory_bot_rails

app/controllers/contestants_controller.rb

@@ -42,6 +42,21 @@ class ContestantsController < ApplicationController
     redirect_to contest_path(@contest)
   end
 
+  def import
+    authorize @contest
+
+    if params[:csv_import]
+      @csv_import = CsvImport.new(params.require(:csv_import).permit(:file, :separator))
+      if @csv_import.save
+        @csv_import = CsvImport.new
+      else
+        render :import, status: :unprocessable_entity
+      end
+    else
+      @csv_import = CsvImport.new
+    end
+  end
+
   private
 
   def set_contest

app/models/csv_import.rb

@@ -0,0 +1,46 @@
+# == Schema Information
+#
+# Table name: csv_imports
+#
+#  id         :integer          not null, primary key
+#  separator  :integer          not null
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#
+class CsvImport < ApplicationRecord
+  enum :separator, { comma: ",", semicolon: ";" }, default: :comma
+
+  has_one_attached :file
+
+  validates :file, presence: true
+  validate :acceptable_csv, on: :create
+
+  def acceptable_csv
+    return unless file.attached?
+
+    if file.blob.byte_size > 20
+      errors.add(:file, "this csv file is too large, it must be under 20MB")
+      return
+    end
+
+    if file.content_type != "text/csv"
+      errors.add(:file, :not_a_csv_file)
+      return
+    end
+
+    begin
+      csv = CSV.read(attachment_changes["file"].attachable.path, col_sep: separator)
+
+      logger = Logger.new(STDOUT)
+      logger.info(csv)
+      errors.add(:file, :empty) if csv.count < 1 || (csv.count == 1 && csv[0].count == 1 && csv[0][0] == "")
+    rescue CSV::MalformedCSVError => e
+      errors.add(:file, e.message)
+    end
+  end
+
+  def options_for_separator
+    keys = self.class.separators.keys
+    keys.map(&:humanize).zip(keys).to_h
+  end
+end

app/policies/contest_policy.rb

@@ -31,6 +31,10 @@ class ContestPolicy < ApplicationPolicy
     record.user.id == user.id || user.admin?
   end
 
+  def import?
+    record.user.id == user.id || user.admin?
+  end
+
   def scoreboard?
     true
   end

app/views/contestants/import.html.slim

@@ -0,0 +1,19 @@
+= form_with(model: @csv_import, url: contest_import_path(@contest), html: { novalidate: true }) do |form|
+  .row.g-3
+    .col
+      .mb-3
+        .form-floating
+          = form.file_field :file, class: "form-control", accept: ".csv, text/csv"
+          = form.label :file
+
+  .row.g-3
+    .col
+      .mb-3
+        .form-floating
+          = form.select :separator, @csv_import.options_for_separator, {}, class: "form-select"
+          = form.label :separator
+
+  .row.g-3
+    .col
+      .mb-3
+        = form.submit t("helpers.buttons.import"), class: "btn btn-primary"

app/views/contests/show.html.slim

@@ -76,6 +76,8 @@
           = t("contestants.plural").capitalize
           a.ms-3.btn.btn-primary href=new_contest_contestant_path(@contest) style="margin-top: -3px"
             | + #{t("helpers.buttons.add")}
+          a.ms-3.btn.btn-primary href=contest_import_path(@contest) style="margin-top: -3px"
+            | #{t("helpers.buttons.import")}
     table.table.table-striped.table-hover
       thead
         tr

config/locales/en.yml

@@ -49,6 +49,12 @@ en:
               invalid: "Allowed formats: xx:xx:xx, x:xx:xx, xx:xx, x:xx"
             puzzle_id:
               taken: "This contestant has already completed this puzzle"
+        csv_import:
+          attributes:
+            file:
+              blank: "No file selected"
+              empty: "This file is empty"
+              not_a_csv_file: "it must be a CSV file"
   completions:
     edit:
       title: "Edit completion"
@@ -75,6 +81,8 @@ en:
     edit:
       title: "Participant"
       team_title: "Teams"
+    import:
+      title: "Import participants from a CSV file"
     new:
       title: "New participant"
       team_title: "New team"
@@ -87,6 +95,7 @@ en:
     buttons:
       add: "Add"
       create: "Create"
+      import: "CSV Import"
       save: "Save"
   messages:
     convert:

config/locales/fr.yml

@@ -20,6 +20,12 @@ fr:
               invalid: "Formats autorisés: xx:xx:xx, x:xx:xx, xx:xx, x:xx"
             puzzle_id:
               taken: "Ce.tte participant.e a déjà complété ce puzzle"
+        csv_import:
+          attributes:
+            file:
+              blank: "Aucun fichier sélectionné"
+              empty: "Ce fichier est vide"
+              not_a_csv_file: "Le fichier doit être au format CSV"
   completions:
     edit:
       title: "Modifier la complétion"
@@ -46,6 +52,8 @@ fr:
     edit:
       title: "Participant.e"
       team_title: "Équipe"
+    import:
+      title: "Importer des participant.e.s"
     new:
       title: "Nouveau.elle participant.e"
       team_title: "Nouvelle équipe"
@@ -58,6 +66,7 @@ fr:
     buttons:
       add: "Ajouter"
       create: "Créer"
+      import: "Importer un CSV"
       save: "Modifier"
   messages:
     convert:

config/routes.rb

@@ -15,6 +15,8 @@ Rails.application.routes.draw do
     resources :messages, only: :destroy do
       get "convert", to: "messages#convert"
     end
+    get "import", to: "contestants#import"
+    post "import", to: "contestants#import"
   end
   resources :passwords, param: :token
   resource :session

db/migrate/20250517083830_create_csv_imports.rb

@@ -0,0 +1,9 @@
+class CreateCsvImports < ActiveRecord::Migration[8.0]
+  def change
+    create_table :csv_imports do |t|
+      t.string :separator, null: false
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2025_05_15_062154) do
+ActiveRecord::Schema[8.0].define(version: 2025_05_17_083830) do
   create_table "active_storage_attachments", force: :cascade do |t|
     t.string "name", null: false
     t.string "record_type", null: false
@@ -75,6 +75,12 @@ ActiveRecord::Schema[8.0].define(version: 2025_05_15_062154) do
     t.index ["user_id"], name: "index_contests_on_user_id"
   end
 
+  create_table "csv_imports", force: :cascade do |t|
+    t.string "separator", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
   create_table "friendly_id_slugs", force: :cascade do |t|
     t.string "slug", null: false
     t.integer "sluggable_id", null: false

spec/factories/csv_imports.rb

@@ -0,0 +1,14 @@
+# == Schema Information
+#
+# Table name: csv_imports
+#
+#  id         :integer          not null, primary key
+#  separator  :string           not null
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#
+FactoryBot.define do
+  factory :csv_import do
+    separator { 1 }
+  end
+end

spec/models/csv_import_spec.rb

@@ -0,0 +1,14 @@
+# == Schema Information
+#
+# Table name: csv_imports
+#
+#  id         :integer          not null, primary key
+#  separator  :string           not null
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#
+require 'rails_helper'
+
+RSpec.describe CsvImport, type: :model do
+  pending "add some examples to (or delete) #{__FILE__}"
+end