# frozen_string_literal: true

# Provides the routine to export the accounting data to an external accounting software
class AccountingExportService
  attr_reader :file, :encoding, :format, :separator, :log_code, :date_format

  def initialize(file, columns, encoding = 'UTF-8', format = 'CSV', separator = ';')
    @file = file
    @encoding = encoding
    @format = format
    @separator = separator
    @log_code = Setting.find_by(name: 'accounting-export_log-code').value
    @date_format = Setting.find_by(name: 'accounting-export_date-format').value
    @columns = columns
  end

  def export(start_date, end_date)
    # build CVS content
    content = ''
    invoices = Invoice.where('created_at >= ? AND created_at <= ?', start_date, end_date).order('created_at ASC')
    invoices.each do |i|
      content << generate_rows(i)
    end

    # write content to file
    File.open(file, "w:#{encoding}+b") { |f| f.puts content }
  end

  private

  def generate_rows(invoice)
    client_row(invoice) << "\n" <<
      items_rows(invoice) << "\n" <<
      vat_row(invoice) << "\n"
  end

  # Generate the "subscription" and "reservation" rows associated with the provided invoice
  def items_rows(invoice)
    rows = invoice.subscription_invoice? ? subscription_row(invoice) << "\n" : ''
    invoice.invoice_items.each do |item|
      rows << reservation_row(invoice, item) << "\n"
    end
  end

  # Generate the "client" row, which contains the debit to the client account, all taxes included
  def client_row(invoice)
    row = ''
    columns.each do |column|
      case column
      when :log_code
        row << log_code
      when :date
        row << invoice.created_at.strftime(date_format)
      when :account_code
        row << account(invoice, :client)
      when :account_label
        row << account(invoice, :client, :label)
      when :piece
        row << invoice.reference
      when :line_label
        row << invoice.invoicing_profile.full_name
      when :debit_origin
        row << invoice.total / 100.0
      when :credit_origin
        row << 0
      when :debit_euro
        row << invoice.total / 100.0
      when :credit_euro
        row << 0
      else
        puts "Unsupported column: #{column}"
      end
      row << separator
    end
  end

  # Generate the "reservation" row, which contains the credit to the reservation account, all taxes excluded
  def reservation_row(invoice, item)
    vat_rate = Setting.find_by(name: 'invoice_VAT-rate').value.to_f
    wo_taxes = item.amount / (vat_rate / 100 + 1)
    row = ''
    columns.each do |column|
      case column
      when :log_code
        row << log_code
      when :date
        row << invoice.created_at.strftime(date_format)
      when :account_code
        row << account(invoice, :reservation)
      when :account_label
        row << account(invoice, :reservation, :label)
      when :piece
        row << invoice.reference
      when :line_label
        row << item.description
      when :debit_origin
        row << 0
      when :credit_origin
        row << wo_taxes
      when :debit_euro
        row << 0
      when :credit_euro
        row << wo_taxes
      else
        puts "Unsupported column: #{column}"
      end
      row << separator
    end
  end

  # Generate the "subscription" row, which contains the credit to the subscription account, all taxes excluded
  def subscription_row(invoice)
    subscription_item = invoice.invoice_items.select(&:subscription).first
    vat_rate = Setting.find_by(name: 'invoice_VAT-rate').value.to_f
    wo_taxes = subscription_item.amount / (vat_rate / 100 + 1)
    row = ''
    columns.each do |column|
      case column
      when :log_code
        row << log_code
      when :date
        row << invoice.created_at.strftime(date_format)
      when :account_code
        row << account(invoice, :subscription)
      when :account_label
        row << account(invoice, :subscription, :label)
      when :piece
        row << invoice.reference
      when :line_label
        row << subscription_item.description
      when :debit_origin
        row << 0
      when :credit_origin
        row << wo_taxes
      when :debit_euro
        row << 0
      when :credit_euro
        row << wo_taxes
      else
        puts "Unsupported column: #{column}"
      end
      row << separator
    end
  end
  # Generate the "VAT" row, which contains the credit to the VAT account, with VAT amount only
  def vat_row(invoice)
    # first compute the VAT amount
    vat_rate = Setting.find_by(name: 'invoice_VAT-rate').value.to_f
    vat = invoice.total - (invoice.total / (vat_rate / 100 + 1))
    # now feed the row
    row = ''
    columns.each do |column|
      case column
      when :log_code
        row << log_code
      when :date
        row << invoice.created_at.strftime(date_format)
      when :account_code
        row << account(invoice, :vat)
      when :account_label
        row << account(invoice, :vat, :label)
      when :piece
        row << invoice.reference
      when :line_label
        row << I18n.t('accounting_export.VAT')
      when :debit_origin
        row << vat
      when :credit_origin
        row << 0
      when :debit_euro
        row << vat
      when :credit_euro
        row << 0
      else
        puts "Unsupported column: #{column}"
      end
      row << separator
    end
  end

  # Get the account code (or label) for the given invoice and the specified line type (client, vat, subscription or reservation)
  def account(invoice, account, type = :code)
    case account
    when :client
      Setting.find_by(name: "accounting-export_client-account-#{type.to_s}").value
    when :vat
      Setting.find_by(name: "accounting-export_VAT-account-#{type.to_s}").value
    when :subscription
      return if invoice.invoiced_type != 'Subscription'

      Setting.find_by(name: "accounting-export_subscription-account-#{type.to_s}").value
    when :reservation
      return if invoice.invoiced_type != 'Reservation'

      Setting.find_by(name: "accounting-export_#{invoice.invoiced.reservable_type}-account-#{type.to_s}").value
    else
      puts "Unsupported account #{account}"
    end
  end
end