class Dorsale::BillingMachine::Quotation < ::Dorsale::ApplicationRecord
  self.table_name = "dorsale_billing_machine_quotations"

  STATES = %w(draft pending accepted refused canceled)

  belongs_to :customer, polymorphic: true
  belongs_to :payment_term

  has_many :lines,
    :inverse_of => :quotation,
    :dependent  => :destroy,
    :class_name => "Dorsale::BillingMachine::QuotationLine"

  has_many :attachments,
    :as         => :attachable,
    :dependent  => :destroy,
    :class_name => "Dorsale::Alexandrie::Attachment"

  accepts_nested_attributes_for :lines, allow_destroy: true

  polymorphic_id_for :customer

  mount_uploader :pdf_file, ::Dorsale::PdfUploader

  validates :date,  presence: true
  validates :state, presence: true, inclusion: {in: proc { STATES }}

  default_scope -> {
    order(unique_index: :desc)
  }

  def document_type
    :quotation
  end

  before_save :update_totals
  before_create :assign_unique_index
  before_create :assign_tracking_id

  def assign_unique_index
    if unique_index.nil?
      self.unique_index = self.class.all.pluck(:unique_index).max.to_i.next
    end
  end

  def assign_tracking_id
    self.tracking_id = date.year.to_s + "-" + unique_index.to_s.rjust(2, "0")
  end

  def assign_default_values
    assign_default :state,                  STATES.first
    assign_default :date,                   Date.current
    assign_default :expires_at,             date + 1.month
    assign_default :commercial_discount,    0
    assign_default :vat_amount,             0
    assign_default :total_excluding_taxes,  0
  end

  def update_totals
    assign_default_values
    lines.each(&:update_total)
    apply_vat_rate_to_lines

    lines_sum = lines.sum(&:total)

    self.total_excluding_taxes = lines_sum - commercial_discount

    if commercial_discount.nonzero? && lines_sum.nonzero?
      discount_rate = commercial_discount / lines_sum
    else
      discount_rate = 0.0
    end

    self.vat_amount = 0.0

    lines.each do |line|
      line_total = line.total - (line.total * discount_rate)
      line_vat = (line_total * line.vat_rate / 100.0)
      line_vat = line_vat.round(2) if Dorsale::BillingMachine.vat_round_by_line
      self.vat_amount += line_vat
    end

    self.vat_amount = vat_amount.round(2)

    self.total_including_taxes = total_excluding_taxes + vat_amount
  end

  # rubocop:disable Style/SingleLineMethods
  private def total_excluding_taxes=(*); super; end
  private def vat_amount=(*);            super; end
  private def total_including_taxes=(*); super; end
  # rubocop:enable Style/SingleLineMethods

  def balance
    total_including_taxes
  end

  def vat_rate
    if ::Dorsale::BillingMachine.vat_mode == :multiple
      raise "Quotation#vat_rate is not available in multiple vat mode"
    end

    return @vat_rate if @vat_rate

    vat_rates = lines.map(&:vat_rate).uniq

    if vat_rates.length > 1
      raise "Quotation has multiple vat rates"
    end

    vat_rates.first || ::Dorsale::BillingMachine.default_vat_rate
  end

  attr_writer :vat_rate

  def apply_vat_rate_to_lines
    return if ::Dorsale::BillingMachine.vat_mode == :multiple

    lines.each do |line|
      line.vat_rate = vat_rate
    end
  end

  def on_attachment_action(_attachment, _action)
    Dorsale::BillingMachine::PdfFileGenerator.(self)
  end
end