export function formatCurrency(amount: number): string {
  return new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' }).format(amount);
}

export function formatBidAmount(amount: number): string {
  return amount > 0 ? formatCurrency(amount) : 'Not priced';
}

export function formatDate(iso: string): string {
  return new Date(iso).toLocaleDateString('en-US', { month: 'short', day: 'numeric', year: 'numeric' });
}

export function formatDateTime(iso: string | null): string {
  if (!iso) return '-';
  return new Date(iso).toLocaleString('en-US', {
    month: 'short',
    day: 'numeric',
    year: 'numeric',
    hour: 'numeric',
    minute: '2-digit',
  });
}

export function formatAge(iso: string): string {
  const diffMs = Date.now() - new Date(iso).getTime();
  const diffMinutes = Math.floor(diffMs / 60000);
  const diffHours = Math.floor(diffMs / 3600000);
  const diffDays = Math.floor(diffMs / 86400000);
  const diffWeeks = Math.floor(diffDays / 7);

  if (diffHours < 1) return `${Math.max(diffMinutes, 0)}m`;
  if (diffDays < 1) return `${diffHours}h`;
  if (diffDays < 7) return `${diffDays}d`;
  return `${diffWeeks}w`;
}

export function getAgeColor(iso: string): string | undefined {
  const diffDays = (Date.now() - new Date(iso).getTime()) / 86400000;
  if (diffDays > 5) return '#d32f2f';
  if (diffDays > 2) return '#ed6c02';
  return undefined;
}

export interface GroupedProposal<T extends { proposalNumber: string }> {
  latest: T;
  revisions: T[];
  hasRevisions: boolean;
  baseNumber: string;
}

export function groupRevisions<T extends { proposalNumber: string }>(rows: T[]): GroupedProposal<T>[] {
  const groups = new Map<string, T[]>();
  for (const row of rows) {
    const base = row.proposalNumber.replace(/-R\d+$/, '');
    const existing = groups.get(base);
    if (existing) {
      existing.push(row);
    } else {
      groups.set(base, [row]);
    }
  }

  const result: GroupedProposal<T>[] = [];
  for (const [baseNumber, items] of groups) {
    items.sort((a, b) => {
      const revA = extractRevision(a.proposalNumber);
      const revB = extractRevision(b.proposalNumber);
      return revB - revA;
    });
    result.push({
      latest: items[0]!,
      revisions: items.slice(1),
      hasRevisions: items.length > 1,
      baseNumber,
    });
  }
  return result;
}

function extractRevision(proposalNumber: string): number {
  const match = proposalNumber.match(/-R(\d+)$/);
  return match ? parseInt(match[1]!, 10) : 0;
}