diff --git a/app/models/Usuario.rb b/app/models/Usuario.rb
deleted file mode 100644
index 5746bc5f8b..0000000000
--- a/app/models/Usuario.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-class Usuario < ApplicationRecord
-  #mais codigo acima assumindo que Usuario ja exista
-  has_many :matricula_turmas
-  has_many :turmas, through: :matricula_turmas
-end
diff --git a/app/models/user.rb b/app/models/user.rb
new file mode 100644
index 0000000000..2e47818df0
--- /dev/null
+++ b/app/models/user.rb
@@ -0,0 +1,14 @@
+class User < ApplicationRecord
+  has_secure_password
+  has_many :sessions, dependent: :destroy
+  has_many :matricula_turmas
+  has_many :turmas, through: :matricula_turmas
+
+  validates :email_address, presence: true, uniqueness: true
+  validates :login, presence: true, uniqueness: true
+  validates :matricula, presence: true, uniqueness: true
+  validates :nome, presence: true
+
+  normalizes :email_address, with: ->(e) { e.strip.downcase }
+  normalizes :login, with: ->(l) { l.strip.downcase }
+end
diff --git a/app/models/usuario.rb b/app/models/usuario.rb
deleted file mode 100644
index 095adc1d9b..0000000000
--- a/app/models/usuario.rb
+++ /dev/null
@@ -1,7 +0,0 @@
-class Usuario < ApplicationRecord
-  has_secure_password
-
-  validates :login, presence: true, uniqueness: true
-  validates :email, presence: true, uniqueness: true
-  validates :matricula, presence: true, uniqueness: true
-end
diff --git a/app/services/sigaa_import_service.rb b/app/services/sigaa_import_service.rb
new file mode 100644
index 0000000000..ad82709c80
--- /dev/null
+++ b/app/services/sigaa_import_service.rb
@@ -0,0 +1,142 @@
+require 'json'
+require 'csv'
+
+class SigaaImportService
+  def initialize(file_path)
+    @file_path = file_path
+    @results = {
+      turmas_created: 0,
+      turmas_updated: 0,
+      usuarios_created: 0,
+      usuarios_updated: 0,
+      errors: []
+    }
+  end
+
+  def process
+    unless File.exist?(@file_path)
+      @results[:errors] << "Arquivo não encontrado: #{@file_path}"
+      return @results
+    end
+
+    begin
+      ActiveRecord::Base.transaction do
+        case File.extname(@file_path).downcase
+        when '.json'
+          process_json
+        when '.csv'
+          process_csv
+        else
+          @results[:errors] << "Formato de arquivo não suportado: #{File.extname(@file_path)}"
+        end
+
+        if @results[:errors].any?
+          raise ActiveRecord::Rollback
+        end
+      end
+    rescue JSON::ParserError
+      @results[:errors] << "Arquivo JSON inválido"
+    rescue ActiveRecord::StatementInvalid => e
+      @results[:errors] << "Erro de conexão com o banco de dados: #{e.message}"
+    rescue StandardError => e
+      @results[:errors] << "Erro inesperado: #{e.message}"
+    end
+
+    @results
+  end
+
+  private
+
+  def process_json
+    file_content = File.read(@file_path)
+    data = JSON.parse(file_content)
+    data.each do |turma_data|
+      process_turma(turma_data)
+    end
+  end
+
+  def process_csv
+    CSV.foreach(@file_path, headers: true, col_sep: ',') do |row|
+      # Assumindo estrutura do CSV
+      turma_data = {
+        'codigo' => row['codigo_turma'],
+        'nome' => row['nome_turma'],
+        'semestre' => row['semestre']
+      }
+      
+      turma = process_turma_record(turma_data)
+      
+      if turma&.persisted?
+        user_data = {
+          'nome' => row['nome_usuario'],
+          'email' => row['email'],
+          'matricula' => row['matricula'],
+          'papel' => row['papel']
+        }
+        process_participante_single(turma, user_data)
+      end
+    end
+  end
+
+  def process_turma(data)
+    turma = process_turma_record(data)
+    if turma&.persisted?
+      process_participantes(turma, data['participantes']) if data['participantes']
+    end
+  end
+
+  def process_turma_record(data)
+    turma = Turma.find_or_initialize_by(codigo: data['codigo'], semestre: data['semestre'])
+    
+    is_new_record = turma.new_record?
+    turma.nome = data['nome']
+    
+    if turma.save
+      if is_new_record
+        @results[:turmas_created] += 1
+      else
+        @results[:turmas_updated] += 1
+      end
+      turma
+    else
+      @results[:errors] << "Erro ao salvar turma #{data['codigo']}: #{turma.errors.full_messages.join(', ')}"
+      nil
+    end
+  end
+
+  def process_participantes(turma, participantes_data)
+    participantes_data.each do |p_data|
+      process_participante_single(turma, p_data)
+    end
+  end
+
+  def process_participante_single(turma, p_data)
+    # Usuario identificado pela matrícula
+    user = User.find_or_initialize_by(matricula: p_data['matricula'])
+    
+    is_new_user = user.new_record?
+    user.nome = p_data['nome']
+    user.email = p_data['email']
+
+    generated_password = nil
+    if is_new_user
+      generated_password = SecureRandom.hex(8)
+      user.password = generated_password
+    end
+
+    if user.save
+      if is_new_user
+        @results[:usuarios_created] += 1
+        UserMailer.cadastro_email(user, generated_password).deliver_now
+      else
+        @results[:usuarios_updated] += 1
+      end
+      
+      matricula = MatriculaTurma.find_or_initialize_by(turma: turma, user: user)
+      matricula.papel = p_data['papel']
+      matricula.save!
+    else
+      @results[:errors] << "Erro ao salvar usuário #{p_data['matricula']}: #{user.errors.full_messages.join(', ')}"
+    end
+  end
+end
diff --git a/test/services/sigaa_import_service_test.rb b/test/services/sigaa_import_service_test.rb
new file mode 100644
index 0000000000..dd83ccecea
--- /dev/null
+++ b/test/services/sigaa_import_service_test.rb
@@ -0,0 +1,65 @@
+require 'test_helper'
+
+class SigaaImportServiceTest < ActiveSupport::TestCase
+  def setup
+    @file_path = Rails.root.join('tmp', 'sigaa_data.json')
+    @data = [
+      {
+        "codigo" => "TURMA123",
+        "nome" => "Engenharia de Software",
+        "semestre" => "2023.2",
+        "participantes" => [
+          {
+            "nome" => "João Silva",
+            "email" => "joao@example.com",
+            "matricula" => "2023001",
+            "papel" => "discente"
+          }
+        ]
+      }
+    ]
+    File.write(@file_path, @data.to_json)
+  end
+
+  def teardown
+    File.delete(@file_path) if File.exist?(@file_path)
+  end
+
+  test "importa turmas e usuarios com sucesso" do
+    assert_difference 'ActionMailer::Base.deliveries.size', 1 do
+      service = SigaaImportService.new(@file_path)
+      result = service.process
+
+      assert_empty result[:errors]
+      assert_equal 1, result[:turmas_created]
+      assert_equal 1, result[:usuarios_created]
+    end
+
+    turma = Turma.find_by(codigo: "TURMA123")
+    assert_not_nil turma
+    assert_equal "Engenharia de Software", turma.nome
+
+    user = User.find_by(matricula: "2023001")
+    assert_not_nil user
+    assert_equal "João Silva", user.nome
+    assert user.authenticate(user.password) if user.respond_to?(:authenticate) # Optional verification if has_secure_password
+    
+    matricula = MatriculaTurma.find_by(turma: turma, user: user)
+    assert_not_nil matricula
+    assert_equal "discente", matricula.papel
+  end
+
+  test "reverte em caso de erro de validação" do
+    # Criar dados inválidos (semestre faltando para Turma)
+    invalid_data = @data.dup
+    invalid_data[0]["semestre"] = nil
+    File.write(@file_path, invalid_data.to_json)
+
+    service = SigaaImportService.new(@file_path)
+    result = service.process
+
+    assert_not_empty result[:errors]
+    assert_equal 0, Turma.count
+    assert_equal 0, User.count
+  end
+end