// utils/getMissingFields.js

// Treat 0 / "0" as present; only null/undefined/"" are missing.
export const hasValue = (v) => {
  if (v === null || v === undefined) return false;
  if (typeof v === 'string') return v.trim().length > 0;
  return true; // numbers, booleans, objects…
};

// helper: pass if any of these have a value
const any = (...vals) => vals.some(hasValue);

// Human‑readable labels for the banner
export const MISSING_LABELS = {
  start_date: 'Start date',
  retirement_start_date: 'Planned retirement date',
  current_salary: 'Current salary',
  monthly_expenses: 'Monthly expenses (or scenario override)',
  monthly_debt_payments: 'Monthly debt payments (or scenario override)',
  savings_plan: 'Savings plan (either contributions or surplus %)',
  tuition: 'Yearly tuition (can be 0)',
  interest_rate: 'Loan interest rate',
  loan_term: 'Loan term',
  expected_graduation: 'Expected graduation date',
  program_type: 'Program type',
  academic_calendar: 'Academic calendar'
};

/**
 * Return a list of *blocking* missing fields.
 * Keep this minimal so the yellow banner only appears when
 * the projection truly cannot run.
 */
export default function getMissingFields(
  { scenario = {}, financial = {}, college = {} },
  { requireCollegeData = false } = {}
) {
  const missing = [];

  // ── Scenario (only what the simulator truly needs)
  if (!hasValue(scenario.start_date))            missing.push('start_date');
  if (!hasValue(scenario.retirement_start_date)) missing.push('retirement_start_date');

  // ── Financial base
  if (!hasValue(financial.current_salary)) missing.push('current_salary');

  if (!any(scenario.planned_monthly_expenses, financial.monthly_expenses)) {
    missing.push('monthly_expenses');
  }
  if (!any(scenario.planned_monthly_debt_payments, financial.monthly_debt_payments)) {
    missing.push('monthly_debt_payments');
  }

  // ── Savings plan: need at least one way to save
  const hasRetirementPlan = any(
    scenario.planned_monthly_retirement_contribution,
    financial.retirement_contribution,
    scenario.planned_surplus_retirement_pct
  );
  const hasEmergencyPlan = any(
    scenario.planned_monthly_emergency_contribution,
    financial.emergency_contribution,
    scenario.planned_surplus_emergency_pct
  );
  if (!(hasRetirementPlan || hasEmergencyPlan)) {
    missing.push('savings_plan');
  }

  // ── College – only if they’re enrolled / prospective
  if (requireCollegeData) {
    if (!hasValue(college.tuition)) missing.push('tuition');

    const plansToBorrow =
      (Number(college.existing_college_debt) || 0) > 0 ||
      (Number(college.tuition) || 0) > (Number(college.annual_financial_aid) || 0);

    if (plansToBorrow) {
      if (!hasValue(college.interest_rate)) missing.push('interest_rate');
      if (!hasValue(college.loan_term))     missing.push('loan_term');

      if (college.loan_deferral_until_graduation && !hasValue(college.expected_graduation)) {
        missing.push('expected_graduation');
      }
    }

    // Only insist on these if they’ve actually chosen a school/program
    const hasSchoolOrProgram = any(college.selected_school, college.selected_program);
    if (hasSchoolOrProgram) {
      if (!hasValue(college.program_type))      missing.push('program_type');
      if (!hasValue(college.academic_calendar)) missing.push('academic_calendar');
    }
  }

  return missing;
}