# frozen_string_literal: true

# The central model object within this domain. Represents a Data Management
# Plan for a research project.
#
# == Schema Information
#
# Table name: plans
#
#  id                                :integer          not null, primary key
#  complete                          :boolean          default(FALSE)
#  data_contact                      :string
#  data_contact_email                :string
#  data_contact_phone                :string
#  description                       :text
#  feedback_requested                :boolean          default(FALSE)
#  funder_name                       :string
#  grant_number                      :string
#  identifier                        :string
#  principal_investigator            :string
#  principal_investigator_email      :string
#  principal_investigator_identifier :string
#  principal_investigator_phone      :string
#  title                             :string
#  visibility                        :integer          default(3), not null
#  created_at                        :datetime
#  updated_at                        :datetime
#  template_id                       :integer
#
# Indexes
#
#  index_plans_on_template_id  (template_id)
#
# Foreign Keys
#
#  fk_rails_...  (template_id => templates.id)
#

class Plan < ActiveRecord::Base

  include ConditionalUserMailer
  include ExportablePlan
  include ValidationMessages
  include ValidationValues

  # =============
  # = Constants =
  # =============


  # Returns visibility message given a Symbol type visibility passed, otherwise
  # nil
  VISIBILITY_MESSAGE = {
    organisationally_visible: _("organisational"),
    publicly_visible: _("public"),
    is_test: _("test"),
    privately_visible: _("private")
  }

  # ==============
  # = Attributes =
  # ==============

  # public is a Ruby keyword so using publicly
  enum visibility: %i[organisationally_visible publicly_visible
                      is_test privately_visible]


  alias_attribute :name, :title


  # ================
  # = Associations =
  # ================

  belongs_to :template

  has_many :phases, through: :template

  has_many :sections, through: :phases

  has_many :questions, through: :sections

  has_many :themes, through: :questions

  has_many :guidances, through: :themes

  has_many :guidance_group_options, -> { uniq.published.reorder("id") },
           through: :guidances,
           source: :guidance_group,
           class_name: "GuidanceGroup"

  has_many :answers, dependent: :destroy

  has_many :notes, through: :answers

  has_many :roles, dependent: :destroy

  has_many :users, through: :roles

  has_and_belongs_to_many :guidance_groups, join_table: :plans_guidance_groups

  has_many :exported_plans

  has_many :roles


  # =====================
  # = Nested Attributes =
  # =====================

  accepts_nested_attributes_for :template

  accepts_nested_attributes_for :roles


  # ===============
  # = Validations =
  # ===============

  validates :title, presence: { message: PRESENCE_MESSAGE }

  validates :template, presence: { message: PRESENCE_MESSAGE }

  validates :feedback_requested, inclusion: { in: BOOLEAN_VALUES }

  validates :complete, inclusion: { in: BOOLEAN_VALUES }


  # =============
  # = Callbacks =
  # =============

  before_validation :set_creation_defaults


  # ==========
  # = Scopes =
  # ==========

  # Retrieves any plan in which the user has an active role and
  # is not a reviewer
  scope :active, lambda { |user|
    plan_ids = Role.where(active: true, user_id: user.id)
                   .not_reviewer.pluck(:plan_id)

    includes(:template, :roles)
    .where(id: plan_ids)
  }

  # Retrieves any plan organisationally or publicly visible for a given org id
  scope :organisationally_or_publicly_visible, -> (user) {
    plan_ids = user.org.plans.where(complete: true).pluck(:id)

    includes(:template, roles: :user)
    .where(id: plan_ids, visibility: [
      visibilities[:organisationally_visible],
      visibilities[:publicly_visible]
    ])
    .where(
      "NOT EXISTS (SELECT 1 FROM roles WHERE plan_id = plans.id AND user_id = ?)",
      user.id
    )
  }

  scope :search, lambda { |term|
    search_pattern = "%#{term}%"
    joins(:template)
    .where("lower(plans.title) LIKE lower(?) OR lower(templates.title) LIKE lower(?)",
            search_pattern, search_pattern)
  }

  # Retrieves plan, template, org, phases, sections and questions
  scope :overview, lambda { |id|
    includes(:phases, :sections, :questions, template: [:org]).find(id)
  }

  ##
  # Settings for the template
  has_settings :export, class_name: "Settings::Template" do |s|
    s.key :export, defaults: Settings::Template::DEFAULT_SETTINGS
  end
  alias super_settings settings


  # =================
  # = Class methods =
  # =================

  # Pre-fetched a plan phase together with its sections and questions
  # associated. It also pre-fetches the answers and notes associated to the plan
  def self.load_for_phase(plan_id, phase_id)
    # Preserves the default order defined in the model relationships
    plan = Plan.joins(template: { phases: { sections: :questions } })
               .preload(template: { phases: { sections: :questions } })
               .where(id: plan_id, phases: { id: phase_id })
               .merge(Plan.includes(answers: :notes)).first
    phase = plan.template.phases.find { |p| p.id == phase_id.to_i }

    [plan, phase]
  end

  # deep copy the given plan and all of it's associations
  #
  # plan - Plan to be deep copied
  #
  # Returns Plan
  def self.deep_copy(plan)
    plan_copy = plan.dup
    plan_copy.title = "Copy of " + plan.title
    plan_copy.save!
    plan.answers.each do |answer|
      answer_copy = Answer.deep_copy(answer)
      answer_copy.plan_id = plan_copy.id
      answer_copy.save!
    end
    plan.guidance_groups.each do |guidance_group|
      plan_copy.guidance_groups << guidance_group if guidance_group.present?
    end
    plan_copy
  end

  # ===========================
  # = Public instance methods =
  # ===========================

  ##
  # Proxy through to the template settings (or defaults if this plan doesn't
  # have an associated template) if there are no settings stored for this plan.
  #
  # TODO: Update this comment below. AFAIK `key` has nothing to do with Rails.
  # key - Is required by rails-settings, so it's required here, too.
  #
  # Returns Hash
  def settings(key)
    self_settings = super_settings(key)
    return self_settings if self_settings.value?
    template&.settings(key)
  end

  # The most recent answer to the given question id optionally can create an answer if
  # none exists.
  #
  # qid               - The id for the question to find the answer for
  # create_if_missing - If true, will genereate a default answer
  #                     to the question (defaults: true).
  #
  # Returns Answer
  # Returns nil
  def answer(qid, create_if_missing = true)
    answer = answers.where(question_id: qid).order("created_at DESC").first
    question = Question.find(qid)
    if answer.nil? && create_if_missing
      answer             = Answer.new
      answer.plan_id     = id
      answer.question_id = qid
      answer.text        = question.default_value
      default_options    = []
      question.question_options.each do |option|
        default_options << option if option.is_default
      end
      answer.question_options = default_options
    end
    answer
  end

  alias get_guidance_group_options guidance_group_options

  deprecate :get_guidance_group_options,
            deprecator: Cleanup::Deprecators::GetDeprecator.new

  ##
  # Sets up the plan for feedback:
  #  emails confirmation messages to owners
  #  emails org admins and org contact
  #  adds org admins to plan with the 'reviewer' Role
  def request_feedback(user)
    Plan.transaction do
      begin
        self.feedback_requested = true
        # Share the plan with each org admin as the reviewer role
        admins = user.org.org_admins
        admins.each do |admin|
          unless admin == user
            add_user!(admin.id, :reviewer)
          end
        end
        if save!
          # Send an email to the org-admin contact
          if user.org.contact_email.present?
            contact = User.new(email: user.org.contact_email,
                               firstname: user.org.contact_name)
            UserMailer.feedback_notification(contact, self, user).deliver_now
          end
          return true
        else
          return false
        end
      rescue Exception => e
        Rails.logger.error e
        return false
      end
    end
  end

  ##
  # Finalizes the feedback for the plan: Emails confirmation messages to owners
  # sets flag on plans.feedback_requested to false removes org admins from the
  # 'reviewer' Role for the Plan.
  def complete_feedback(org_admin)
    Plan.transaction do
      begin
        self.feedback_requested = false

        # Remove the org admins reviewer role from the plan
        roles.delete(Role.where(plan: self).reviewer)

        if save!
          # Send an email confirmation to the owners and co-owners
          deliver_if(recipients: owner_and_coowners,
                     key: "users.feedback_provided") do |r|
                         UserMailer.feedback_complete(
                           r,
                           self,
                           org_admin).deliver_now
                       end
          true
        else
          false
        end
      rescue ArgumentError => e
        Rails.logger.error e
        false
      end
    end
  end

  ##
  # determines if the plan is editable by the specified user
  #
  # user_id - The id for a user
  #
  # Returns Boolean
  def editable_by?(user_id)
    Role.editor.where(plan_id: id, user_id: user_id, active: true).any?
  end

  ##
  # determines if the plan is readable by the specified user
  #
  # user_id - The Integer id for a user
  #
  # Returns Boolean
  def readable_by?(user_id)
    current_user = User.find(user_id)
    if current_user.present?
      # If the user is a super admin and the config allows for supers to view plans
      if current_user.can_super_admin? &&
          Branding.fetch(:service_configuration, :plans, :super_admins_read_all)
        true
      # If the user is an org admin and the config allows for org admins to view plans
      elsif current_user.can_org_admin? &&
          Branding.fetch(:service_configuration, :plans, :org_admins_read_all)
        true
      else
        commentable_by?(user_id)
      end
    else
      false
    end
  end

  # determines if the plan is readable by the specified user.
  #
  # user_id - The Integer id for a user
  #
  # Returns Boolean
  def commentable_by?(user_id)
    Role.commenter.where(plan_id: id, user_id: user_id, active: true).any?
  end

  # determines if the plan is administerable by the specified user
  #
  # user_id - The Integer id for the user
  #
  # Returns Boolean
  def administerable_by?(user_id)
    Role.administrator.where(plan_id: id, user_id: user_id, active: true).any?
  end

  # determines if the plan is reviewable by the specified user
  #
  # user_id - The Integer id for the user
  #
  # Returns Boolean
  def reviewable_by?(user_id)
    Role.reviewer.where(plan_id: id, user_id: user_id, active: true).any?
  end

  # the datetime for the latest update of this plan
  #
  # Returns DateTime
  def latest_update
    (phases.pluck(:updated_at) + [updated_at]).max
  end

  # The owner (aka :creator) of the project
  #
  # Returns User
  # Returns nil
  def owner
    usr_ids = Role.where(plan_id: id, active: true)
                  .administrator
                  .order(:created_at)
                  .pluck(:user_id).uniq
    User.where(id: usr_ids).first
  end

  # Creates a role for the specified user (will update the user's
  # existing role if it already exists)
  #
  # Expects a User.id and access_type from the following list:
  #  :creator, :administrator, :editor, :commenter
  #
  # Returns Boolean
  def add_user!(user_id, access_type = :commenter)
    user = User.where(id: user_id).first
    if user.present?
      role = Role.find_or_initialize_by(user_id: user_id, plan_id: self.id)

      # Access is cumulative, so set the appropriate flags
      # (e.g. an administrator can also edit and comment)
      case access_type
      when :creator
        role.creator = true
        role.administrator = true
        role.editor = true
      when :administrator
        role.administrator = true
        role.editor = true
      when :editor
        role.editor = true
      when :reviewer
        role.reviewer = true
      end
      role.commenter = true
      role.save
    else
      false
    end
  end

  ##
  # Whether or not the plan is associated with users other than the creator
  #
  # Returns Boolean
  def shared?
    roles.where(Role.not_creator_condition).any?
  end

  alias shared shared?

  deprecate :shared, deprecator: Cleanup::Deprecators::PredicateDeprecator.new

  # The owner and co-owners (aka :creator and :administrator) of the project
  #
  # Returns ActiveRecord::Relation
  def owner_and_coowners
    # We only need to search for :administrator in the bitflag
    # since :creator includes :administrator rights
    usr_ids = Role.where(plan_id: id, active: true)
                  .administrator
                  .pluck(:user_id).uniq
    User.where(id: usr_ids)
  end

  # The creator, administrator and editors
  #
  # Returns ActiveRecord::Relation
  def authors
    # We only need to search for :editor in the bitflag
    # since :creator and :administrator include :editor rights
    usr_ids = Role.where(plan_id: id, active: true)
                  .editor
                  .pluck(:user_id).uniq
    User.where(id: usr_ids)
  end

  # The number of answered questions from the entire plan
  #
  # Returns Integer
  def num_answered_questions
    Answer.where(id: answers.map(&:id))
          .includes(:question_options, question: :question_format)
          .to_a
          .sum { |answer| answer.is_valid? ? 1 : 0 }
  end

  # The number of questions for a plan.
  #
  # Returns Integer
  def num_questions
    questions.count
  end

  # Determines whether or not visibility changes are permitted according to the
  # percentage of the plan answered in respect to a threshold defined at
  # application.config
  #
  # Returns Boolean
  def visibility_allowed?
    !is_test? && phases.select { |phase| phase.visibility_allowed?(self) }.any?
  end

  # Determines whether or not a question (given its id) exists for the self plan
  #
  # Returns Boolean
  def question_exists?(question_id)
    Plan.joins(:questions).exists?(id: id, "questions.id": question_id)
  end

  # Checks whether or not the number of questions matches the number of valid
  # answers
  #
  # Returns Boolean
  def no_questions_matches_no_answers?
    num_questions = question_ids.length
    pre_fetched_answers = Answer.includes(:question_options,
                                          question: :question_format)
                                .where(id: answer_ids)
    num_answers = pre_fetched_answers.reduce(0) do |m, a|
      m += 1 if a.is_valid?
      m
    end
    num_questions == num_answers
  end

  # Deactivates the plan (sets all roles to inactive and visibility to :private)
  #
  # Returns Boolean
  def deactivate!
    # If no other :creator, :administrator or :editor is attached
    # to the plan, then also deactivate all other active roles
    # and set the plan's visibility to :private
    if authors.size == 0
      roles.where(active: true).update_all(active: false)
      self.visibility = Plan.visibilities[:privately_visible]
      save!
    else
      false
    end
  end


  private

  # Initialize the title for new templates
  #
  # Returns nil
  # Returns String
  def set_creation_defaults
    # Only run this before_validation because rails fires this before
    # save/create
    return if id?
    self.title = "My plan (#{template.title})" if title.nil? && !template.nil?
  end

end