module Validations::Sales::FinancialValidations
  # Validations methods need to be called 'validate_<page_name>' to run on model save
  # or 'validate_' to run on submit as well

  def validate_income1(record)
    return unless record.income1 && record.la && record.shared_ownership_scheme?

    relevant_fields = %i[income1 ownershipsch uprn la postcode_full]
    if record.london_property? && !record.income1.between?(0, 90_000)
      relevant_fields.each { |field| record.errors.add field, :outside_london_income_range, message: I18n.t("validations.financial.income.outside_london_income_range") }
    elsif record.property_not_in_london? && !record.income1.between?(0, 80_000)
      relevant_fields.each { |field| record.errors.add field, :outside_non_london_income_range, message: I18n.t("validations.financial.income.outside_non_london_income_range") }
    end
  end

  def validate_income2(record)
    return unless record.income2 && record.la && record.shared_ownership_scheme?

    relevant_fields = %i[income2 ownershipsch uprn la postcode_full]
    if record.london_property? && !record.income2.between?(0, 90_000)
      relevant_fields.each { |field| record.errors.add field, :outside_london_income_range, message: I18n.t("validations.financial.income.outside_london_income_range") }
    elsif record.property_not_in_london? && !record.income2.between?(0, 80_000)
      relevant_fields.each { |field| record.errors.add field, :outside_non_london_income_range, message: I18n.t("validations.financial.income.outside_non_london_income_range") }
    end
  end

  def validate_combined_income(record)
    return unless record.income1 && record.income2 && record.la && record.shared_ownership_scheme?

    combined_income = record.income1 + record.income2
    relevant_fields = %i[income1 income2 ownershipsch uprn la postcode_full]
    if record.london_property? && combined_income > 90_000
      relevant_fields.each { |field| record.errors.add field, :over_combined_hard_max_for_london, message: I18n.t("validations.financial.income.combined_over_hard_max_for_london") }
    elsif record.property_not_in_london? && combined_income > 80_000
      relevant_fields.each { |field| record.errors.add field, :over_combined_hard_max_for_outside_london, message: I18n.t("validations.financial.income.combined_over_hard_max_for_outside_london") }
    end
  end

  def validate_mortgage(record)
    record.errors.add :mortgage, :cannot_be_0, message: I18n.t("validations.financial.mortgage") if record.mortgage_used? && record.mortgage&.zero?
  end

  def validate_monthly_leasehold_charges(record)
    record.errors.add :mscharge, I18n.t("validations.financial.monthly_leasehold_charges.not_zero") if record.mscharge&.zero?
  end

  def validate_percentage_bought_not_greater_than_percentage_owned(record)
    return unless record.stairbought && record.stairowned

    if record.stairbought > record.stairowned
      record.errors.add :stairowned, I18n.t("validations.financial.staircasing.percentage_bought_must_be_greater_than_percentage_owned", buyer_now_owns: record.joint_purchase? ? "buyers now own" : "buyer now owns")
    end
  end

  def validate_percentage_bought_not_equal_percentage_owned(record)
    return unless record.stairbought && record.stairowned
    return unless record.saledate && record.form.start_year_after_2024?

    if record.stairbought == record.stairowned
      record.errors.add :stairbought, I18n.t("validations.financial.staircasing.percentage_bought_equal_percentage_owned", stairbought: sprintf("%g", record.stairbought), stairowned: sprintf("%g", record.stairowned))
      record.errors.add :stairowned, I18n.t("validations.financial.staircasing.percentage_bought_equal_percentage_owned", stairbought: sprintf("%g", record.stairbought), stairowned: sprintf("%g", record.stairowned))
    end
  end

  def validate_percentage_bought_at_least_threshold(record)
    return unless record.stairbought && record.type

    threshold = if [2, 16, 18, 24].include? record.type
                  10
                else
                  1
                end

    if threshold && record.stairbought < threshold
      record.errors.add :stairbought, I18n.t("validations.financial.staircasing.percentage_bought_must_be_at_least_threshold", threshold:)
      record.errors.add :type, I18n.t("validations.setup.type.percentage_bought_must_be_at_least_threshold", threshold:)
    end
  end

  def validate_child_income(record)
    return unless record.income2 && record.ecstat2

    if record.income2.positive? && is_economic_status_child?(record.ecstat2) && record.form.start_date.year >= 2023
      record.errors.add :ecstat2, I18n.t("validations.financial.income.child_has_income")
      record.errors.add :income2, I18n.t("validations.financial.income.child_has_income")
    end
  end

  def validate_equity_in_range_for_year_and_type(record)
    return unless record.type && record.equity && record.collection_start_year

    ranges = EQUITY_RANGES_BY_YEAR.fetch(record.collection_start_year, DEFAULT_EQUITY_RANGES)

    return unless (range = ranges[record.type])

    if record.equity < range.min
      record.errors.add :type, I18n.t("validations.financial.equity.under_min", min_equity: range.min)
      record.errors.add :equity, :under_min, message: I18n.t("validations.financial.equity.under_min", min_equity: range.min)
    elsif record.equity > range.max
      record.errors.add :type, I18n.t("validations.financial.equity.over_max", max_equity: range.max)
      record.errors.add :equity, :over_max, message: I18n.t("validations.financial.equity.over_max", max_equity: range.max)
    end
  end

  def validate_equity_less_than_staircase_difference(record)
    return unless record.equity && record.stairbought && record.stairowned
    return unless record.saledate && record.form.start_year_after_2024?

    if record.equity > record.stairowned - record.stairbought
      formatted_equity = sprintf("%g", record.equity)
      record.errors.add :equity, I18n.t("validations.financial.equity.over_stairowned_minus_stairbought", equity: formatted_equity, staircase_difference: record.stairowned - record.stairbought, buyer_owns: record.joint_purchase? ? "buyers own" : "buyer owns")
      record.errors.add :stairowned, I18n.t("validations.financial.equity.over_stairowned_minus_stairbought", equity: formatted_equity, staircase_difference: record.stairowned - record.stairbought, buyer_owns: record.joint_purchase? ? "buyers own" : "buyer owns")
      record.errors.add :stairbought, I18n.t("validations.financial.equity.over_stairowned_minus_stairbought", equity: formatted_equity, staircase_difference: record.stairowned - record.stairbought, buyer_owns: record.joint_purchase? ? "buyers own" : "buyer owns")
    end
  end

private

  def is_relationship_child?(relationship)
    relationship == "C"
  end

  def is_economic_status_child?(economic_status)
    economic_status == 9
  end

  EQUITY_RANGES_BY_YEAR = {
    2022 => {
      2 => 25..75,
      30 => 10..75,
      18 => 25..75,
      16 => 10..75,
      24 => 25..75,
      31 => 0..75,
    },
  }.freeze

  DEFAULT_EQUITY_RANGES = {
    2 => 25..75,
    30 => 10..75,
    18 => 25..75,
    16 => 10..75,
    24 => 25..75,
    31 => 0..75,
    32 => 0..75,
  }.freeze
end