require 'test/unit'
require 'active_record'
require 'acts_as_tree'

class Test::Unit::TestCase
  def assert_queries(num = 1)
    $query_count = 0
    yield
  ensure
    assert_equal num, $query_count, "#{$query_count} instead of #{num} queries were executed."
  end

  def assert_no_queries(&block)
    assert_queries(0, &block)
  end
end

ActiveRecord::Base.establish_connection adapter: "sqlite3", database: ":memory:"

# AR keeps printing annoying schema statements
$stdout = StringIO.new

def setup_db
  ActiveRecord::Base.logger
  ActiveRecord::Schema.define(version: 1) do
    create_table :mixins do |t|
      t.column :type, :string
      t.column :parent_id, :integer
      t.column :children_count, :integer, default: 0
    end
  end
end

def teardown_db
  ActiveRecord::Base.connection.tables.each do |table|
    ActiveRecord::Base.connection.drop_table(table)
  end
end

class Mixin < ActiveRecord::Base
  include ActsAsTree
end

class TreeMixin < Mixin
  acts_as_tree foreign_key: "parent_id", order: "id"
end

class TreeMixinWithoutOrder < Mixin
  acts_as_tree foreign_key: "parent_id"
end

class TreeMixinNullify < Mixin
  acts_as_tree foreign_key: "parent_id", order: "id", dependent: :nullify
end

class TreeMixinWithCounterCache < Mixin
  acts_as_tree foreign_key: "parent_id", order: "id", counter_cache: :children_count
end

class RecursivelyCascadedTreeMixin < Mixin
  acts_as_tree foreign_key: "parent_id"
  has_one :first_child, class_name: 'RecursivelyCascadedTreeMixin', foreign_key: :parent_id
end

class TreeTest < Test::Unit::TestCase

  def setup
    setup_db
    @root1              = TreeMixin.create!
    @root_child1        = TreeMixin.create! parent_id: @root1.id
    @child1_child       = TreeMixin.create! parent_id: @root_child1.id
    @child1_child_child = TreeMixin.create! parent_id: @child1_child.id
    @root_child2        = TreeMixin.create! parent_id: @root1.id
    @root2              = TreeMixin.create!
    @root3              = TreeMixin.create!
  end

  def teardown
    teardown_db
  end

  def test_children
    assert_equal @root1.children, [@root_child1, @root_child2]
    assert_equal @root_child1.children, [@child1_child]
    assert_equal @child1_child.children, [@child1_child_child]
    assert_equal @child1_child_child.children, []
    assert_equal @root_child2.children, []
  end

  def test_parent
    assert_equal @root_child1.parent, @root1
    assert_equal @root_child1.parent, @root_child2.parent
    assert_nil @root1.parent
  end

  def test_delete
    assert_equal 7, TreeMixin.count
    @root1.destroy
    assert_equal 2, TreeMixin.count
    @root2.destroy
    @root3.destroy
    assert_equal 0, TreeMixin.count
  end

  def test_insert
    @extra = @root1.children.create

    assert @extra

    assert_equal @extra.parent, @root1

    assert_equal 3, @root1.reload.children.count
    assert @root1.children.include?(@extra)
    assert @root1.children.include?(@root_child1)
    assert @root1.children.include?(@root_child2)
  end

  def test_ancestors
    assert_equal [], @root1.ancestors
    assert_equal [@root1], @root_child1.ancestors
    assert_equal [@root_child1, @root1], @child1_child.ancestors
    assert_equal [@root1], @root_child2.ancestors
    assert_equal [], @root2.ancestors
    assert_equal [], @root3.ancestors
  end

  def test_root
    assert_equal @root1, TreeMixin.root
    assert_equal @root1, @root1.root
    assert_equal @root1, @root_child1.root
    assert_equal @root1, @child1_child.root
    assert_equal @root1, @root_child2.root
    assert_equal @root2, @root2.root
    assert_equal @root3, @root3.root
  end

  def test_roots
    assert_equal [@root1, @root2, @root3], TreeMixin.roots
  end

  def test_siblings
    assert_equal [@root2, @root3], @root1.siblings
    assert_equal [@root_child2], @root_child1.siblings
    assert_equal [], @child1_child.siblings
    assert_equal [@root_child1], @root_child2.siblings
    assert_equal [@root1, @root3], @root2.siblings
    assert_equal [@root1, @root2], @root3.siblings
  end

  def test_self_and_siblings
    assert_equal [@root1, @root2, @root3], @root1.self_and_siblings
    assert_equal [@root_child1, @root_child2], @root_child1.self_and_siblings
    assert_equal [@child1_child], @child1_child.self_and_siblings
    assert_equal [@root_child1, @root_child2], @root_child2.self_and_siblings
    assert_equal [@root1, @root2, @root3], @root2.self_and_siblings
    assert_equal [@root1, @root2, @root3], @root3.self_and_siblings
  end

  def test_self_and_children
    assert_equal [@root1, @root_child1, @root_child2], @root1.self_and_children
    assert_equal [@root2], @root2.self_and_children
  end

  def test_nullify
    root4       = TreeMixinNullify.create!
    root4_child = TreeMixinNullify.create! parent_id: root4.id

    assert_equal 2, TreeMixinNullify.count
    assert_equal root4.id, root4_child.parent_id

    root4.destroy

    assert_equal 1, TreeMixinNullify.count
    assert_nil root4_child.reload.parent_id
  end

end

class TreeTestWithEagerLoading < Test::Unit::TestCase

  def setup
    teardown_db
    setup_db
    @root1        = TreeMixin.create!
    @root_child1  = TreeMixin.create! parent_id: @root1.id
    @child1_child = TreeMixin.create! parent_id: @root_child1.id
    @root_child2  = TreeMixin.create! parent_id: @root1.id
    @root2        = TreeMixin.create!
    @root3        = TreeMixin.create!

    @rc1 = RecursivelyCascadedTreeMixin.create!
    @rc2 = RecursivelyCascadedTreeMixin.create! parent_id: @rc1.id
    @rc3 = RecursivelyCascadedTreeMixin.create! parent_id: @rc2.id
    @rc4 = RecursivelyCascadedTreeMixin.create! parent_id: @rc3.id
  end

  def teardown
    teardown_db
  end

  def test_eager_association_loading
    roots = TreeMixin.find :all, include: :children,
                                 conditions: "mixins.parent_id IS NULL",
                                 order: "mixins.id"

    assert_equal [@root1, @root2, @root3], roots

    assert_no_queries do
      assert_equal 2, roots[0].children.count
      assert_equal 0, roots[1].children.count
      assert_equal 0, roots[2].children.count
    end
  end

  def test_eager_association_loading_with_recursive_cascading_three_levels_has_many
    root_node = RecursivelyCascadedTreeMixin.find :first,
                                                  include: {children: {children: :children}},
                                                  order:   'mixins.id'

    assert_equal @rc4, assert_no_queries { root_node.children.first.children.first.children.first }
  end

  def test_eager_association_loading_with_recursive_cascading_three_levels_has_one
    root_node = RecursivelyCascadedTreeMixin.find :first,
                                                  include: {first_child: {first_child: :first_child}},
                                                  order:   'mixins.id'

    assert_equal @rc4, assert_no_queries { root_node.first_child.first_child.first_child }
  end

  def test_eager_association_loading_with_recursive_cascading_three_levels_belongs_to
    leaf_node = RecursivelyCascadedTreeMixin.find :first,
                                                  include: {parent: {parent: :parent}},
                                                  order:   'mixins.id DESC'

    assert_equal @rc1, assert_no_queries { leaf_node.parent.parent.parent }
  end
end

class TreeTestWithoutOrder < Test::Unit::TestCase

  def setup
    setup_db
    @root1 = TreeMixinWithoutOrder.create!
    @root2 = TreeMixinWithoutOrder.create!
  end

  def teardown
    teardown_db
  end

  def test_root
    assert [@root1, @root2].include? TreeMixinWithoutOrder.root
  end

  def test_roots
    assert_equal [], [@root1, @root2] - TreeMixinWithoutOrder.roots
  end
end

class UnsavedTreeTest < Test::Unit::TestCase
  def setup
    setup_db
    @root       = TreeMixin.new
    @root_child = @root.children.build
  end

  def teardown
    teardown_db
  end

  def test_inverse_of
    # We want children to be aware of their parent before saving either
    assert_equal @root, @root_child.parent
  end
end


class TreeTestWithCounterCache < Test::Unit::TestCase
  def setup
    teardown_db
    setup_db
    @root          = TreeMixinWithCounterCache.create!
    @child1        = TreeMixinWithCounterCache.create! parent_id: @root.id
    @child1_child1 = TreeMixinWithCounterCache.create! parent_id: @child1.id
    @child2        = TreeMixinWithCounterCache.create! parent_id: @root.id
  end

  def teardown
    teardown_db
  end

  def test_counter_cache
    assert_equal 2, @root.reload.children_count
    assert_equal 1, @child1.reload.children_count
  end

  def test_update_parents_counter_cache
    @child1_child1.update_attributes(:parent_id => @root.id)
    assert_equal 3, @root.reload.children_count
    assert_equal 0, @child1.reload.children_count
  end

end