#-- encoding: UTF-8

#-- copyright
# OpenProject is a project management system.
# Copyright (C) 2012-2018 the OpenProject Foundation (OPF)
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License version 3.
#
# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
# Copyright (C) 2006-2017 Jean-Philippe Lang
# Copyright (C) 2010-2013 the ChiliProject Team
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
# See docs/COPYRIGHT.rdoc for more details.
#++

class WorkPackages::SetAttributesService
  include Concerns::Contracted

  attr_accessor :user,
                :work_package,
                :contract

  def initialize(user:, work_package:, contract:)
    self.user = user
    self.work_package = work_package

    self.contract = contract.new(work_package, user)
  end

  def call(attributes)
    set_attributes(attributes)

    validate_and_result
  end

  private

  def validate_and_result
    success, errors = validate(work_package)

    ServiceResult.new(success: success,
                      errors: errors,
                      result: work_package)
  end

  def set_attributes(attributes)
    if attributes.key?(:attachment_ids)
      work_package.attachments_replacements = Attachment.where(id: attributes[:attachment_ids])
    end

    set_static_attributes(attributes)
    set_default_attributes
    unify_dates
    update_project_dependent_attributes
    set_custom_attributes(attributes)
    update_dates
    reset_custom_values
    reassign_invalid_status_if_type_changed
  end

  def set_static_attributes(attributes)
    assignable_attributes = attributes.except(:attachment_ids).select do |key, _|
      !CustomField.custom_field_attribute?(key) && work_package.respond_to?(key)
    end

    work_package.attributes = assignable_attributes
  end

  def set_default_attributes
    return unless work_package.new_record?

    work_package.priority ||= IssuePriority.active.default
    work_package.author ||= user
    work_package.status ||= Status.default
  end

  def set_custom_attributes(attributes)
    assignable_attributes = attributes.select do |key, _|
      CustomField.custom_field_attribute?(key) && work_package.respond_to?(key)
    end

    work_package.attributes = assignable_attributes
  end

  def unify_dates
    return unless work_package_now_milestone?

    unified_date = work_package.due_date || work_package.start_date
    work_package.start_date = work_package.due_date = unified_date
  end

  def custom_field_context_changed?
    work_package.type_id_changed? || work_package.project_id_changed?
  end

  def work_package_now_milestone?
    work_package.type_id_changed? && work_package.milestone?
  end

  def update_project_dependent_attributes
    return unless work_package.project_id_changed? && work_package.project_id

    set_fixed_version_to_nil
    reassign_category

    reassign_type unless work_package.type_id_changed?
  end

  def update_dates
    min_start = new_start_date

    if min_start
      work_package.due_date = min_start + work_package.duration - 1
      work_package.start_date = min_start
    end
  end

  def set_fixed_version_to_nil
    unless work_package.fixed_version &&
           work_package.project.shared_versions.include?(work_package.fixed_version)
      work_package.fixed_version = nil
    end
  end

  def reassign_category
    # work_package is moved to another project
    # reassign to the category with same name if any
    if work_package.category.present?
      category = work_package.project.categories.find_by(name: work_package.category.name)

      work_package.category = category
    end
  end

  def reassign_type
    available_types = work_package.project.types.order(:position)

    return if available_types.include?(work_package.type) && work_package.type

    work_package.type = available_types.detect(&:is_default) || available_types.first

    reassign_status work_package.new_statuses_allowed_to(user, true)
  end

  def reassign_status(available_statuses)
    return if available_statuses.include? work_package.status

    new_status = available_statuses.detect(&:is_default) || available_statuses.first
    work_package.status = new_status if new_status.present?
  end

  def reassign_invalid_status_if_type_changed
    # Checks that the issue can not be moved to a type with the status unchanged
    # and the target type does not have this status
    if work_package.type_id_changed? && !work_package.status_id_changed?
      reassign_status work_package.type.statuses(include_default: true)
    end
  end

  def reset_custom_values
    # Take over any default custom values
    # for new custom fields
    work_package.set_default_values! if custom_field_context_changed?
  end

  def new_start_date
    current_start_date = work_package.start_date || work_package.due_date

    return unless work_package.parent_id_changed? &&
                  work_package.parent_id &&
                  current_start_date

    min_start = work_package.parent.soonest_start

    if min_start && (min_start > current_start_date)
      min_start
    end
  end
end