Implement CSV import and conversion to contestants

app/controllers/contestants_controller.rb

@@ -45,15 +45,48 @@ class ContestantsController < ApplicationController
   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
+    @csv_import = CsvImport.new
+  end
+
+  def upload_csv
+    authorize @contest
+
+    @csv_import = CsvImport.new(params.require(:csv_import).permit(:file, :separator))
+    if @csv_import.save
+      redirect_to "/contests/#{@contest.id}/import/#{@csv_import.id}"
     else
-      @csv_import = CsvImport.new
+      render :import, status: :unprocessable_entity
+    end
+  end
+
+  def convert_csv
+    authorize @contest
+
+    @csv_import = CsvImport.find(params[:id])
+    @content = JSON.parse(@csv_import.content)
+    @form = Forms::CsvConversionForm.new
+  end
+
+  def finalize_import
+    authorize @contest
+
+    @csv_import = CsvImport.find(params[:id])
+    @content = JSON.parse(@csv_import.content)
+    all_params = params.require(:forms_csv_conversion_form)
+    @form = Forms::CsvConversionForm.new(params.require(:forms_csv_conversion_form).permit(:email_column, :name_column))
+    if @form.valid?
+      @content.each_with_index do |row, i|
+        if all_params["row_#{i}".to_sym] == "1"
+          if @form.email_column == -1
+            Contestant.create(name: row[@form.name_column], contest: @contest)
+          else
+            Contestant.create(name: row[@form.name_column], email: row[@form.email_column], contest: @contest)
+          end
+        end
+      end
+      redirect_to contest_path(@contest)
+    else
+      render :convert_csv, status: :unprocessable_entity
     end
   end
 

app/lib/forms.rb

@@ -0,0 +1,14 @@
+module Forms
+  class CsvConversionForm
+    include ActiveModel::Model
+    include ActiveModel::Attributes
+    include ActiveModel::Validations::Callbacks
+    include ActiveRecord::Transactions
+
+    attribute :name_column, :integer
+    attribute :email_column, :integer
+
+    validates :name_column, presence: true
+    validates_numericality_of :name_column, greater_than: -1
+  end
+end

app/models/csv_import.rb

@@ -3,23 +3,26 @@
 # Table name: csv_imports
 #
 #  id         :integer          not null, primary key
-#  separator  :integer          not null
+#  content    :string           not null
+#  separator  :string           not null
 #  created_at :datetime         not null
 #  updated_at :datetime         not null
 #
 class CsvImport < ApplicationRecord
-  enum :separator, { comma: ",", semicolon: ";" }, default: :comma
+  enum :separator, { comma: ",", semicolon: ";" }, suffix: true, default: :comma
 
   has_one_attached :file
 
   validates :file, presence: true
   validate :acceptable_csv, on: :create
 
+  before_save :read_csv
+
   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")
+    if file.blob.byte_size > 5 * 1024 * 1024
+      errors.add(:file, "this csv file is too large, it must be under 5MB")
       return
     end
 
@@ -31,14 +34,16 @@ class CsvImport < ApplicationRecord
     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 read_csv
+    self.content = JSON.dump(CSV.read(attachment_changes["file"].attachable.path, col_sep: separator_for_database))
+  end
+
   def options_for_separator
     keys = self.class.separators.keys
     keys.map(&:humanize).zip(keys).to_h

app/policies/contest_policy.rb

@@ -19,10 +19,18 @@ class ContestPolicy < ApplicationPolicy
     record.user.id == user.id || user.admin?
   end
 
+  def convert_csv?
+    record.user.id == user.id || user.admin?
+  end
+
   def edit?
     record.user.id == user.id || user.admin?
   end
 
+  def finalize_import?
+    record.user.id == user.id || user.admin?
+  end
+
   def update?
     record.user.id == user.id || user.admin?
   end
@@ -38,4 +46,8 @@ class ContestPolicy < ApplicationPolicy
   def scoreboard?
     true
   end
+
+  def upload_csv?
+    record.user.id == user.id || user.admin?
+  end
 end

app/views/contestants/convert_csv.html.slim

@@ -0,0 +1,40 @@
+= form_with model: @form, url: "/contests/#{@contest.id}/import/#{@csv_import.id}" do |form|
+
+  .row.mb-3
+    .col
+      .form-floating
+        = form.select :name_column, [[t("helpers.none"), -1]] + Array.new(@content[0].count) {|i| [t("helpers.field") + "_#{i}", i] }, {}, class: "form-select"
+        = form.label :name_column
+          = t("contestants.import.name_column")
+
+  .row.mb-3
+    .col
+      .form-floating
+        = form.select :email_column, [[t("helpers.none"), -1]] + Array.new(@content[0].count) {|i| [t("helpers.field") + "_#{i}", i] }, {}, class: "form-select"
+        = form.label :email_column
+          = t("contestants.import.email_column")
+
+  .row.g-3
+    .col
+      table.table.table-striped.table-hover
+        thead
+          tr
+            - @content[0].each_with_index do |_, i|
+              th scope="col"
+                = t("helpers.field") + "_#{i}"
+            th scope="col"
+              = t("contestants.import.import_column")
+        tbody
+          - @content.each_with_index do |row, i|
+            tr scope="row"
+              - row.each do |value|
+                td
+                  = value
+              td
+                .form-check.form-switch
+                  = form.check_box "row_#{i}".to_sym, class: "form-check-input", checked: true
+
+  .row.g-3
+    .col
+      = form.submit t("helpers.buttons.confirm"), class: "btn btn-primary"
+