/**
 * Application Breadcrumbs
 * Displays navigation breadcrumb trail for application pages
 * Supports dynamic breadcrumb items and project context
 */

'use client';

import { Link } from '@/lib/i18n/routing';
import { usePathname } from '@/lib/i18n/routing';
import { ChevronRight, Home } from 'lucide-react';
import { cn } from '@/lib/utils';

export interface BreadcrumbItem {
  /** Display label */
  label: string;
  /** Navigation href */
  href: string;
  /** If true, this is the current page */
  current?: boolean;
}

interface AppBreadcrumbsProps {
  /** Custom breadcrumb items (overrides auto-generation) */
  items?: BreadcrumbItem[];
  /** Show home icon as first item */
  showHome?: boolean;
  /** Additional className */
  className?: string;
}

/** Path segment to label mappings */
const pathLabels: Record<string, string> = {
  projects: 'Projects',
  issues: 'Issues',
  sprints: 'Sprints',
  agents: 'Agents',
  settings: 'Settings',
  dashboard: 'Dashboard',
  admin: 'Admin',
  'agent-types': 'Agent Types',
  users: 'Users',
  organizations: 'Organizations',
};

/**
 * Generate breadcrumb items from the current pathname
 */
function generateBreadcrumbs(pathname: string): BreadcrumbItem[] {
  const segments = pathname.split('/').filter(Boolean);
  const breadcrumbs: BreadcrumbItem[] = [];

  let currentPath = '';

  segments.forEach((segment, index) => {
    currentPath += `/${segment}`;

    // Skip locale segments (2-letter codes)
    if (segment.length === 2 && /^[a-z]{2}$/i.test(segment)) {
      return;
    }

    // Check if segment is a dynamic ID/slug (not in pathLabels)
    const label = pathLabels[segment] || segment;
    const isLast = index === segments.length - 1;

    breadcrumbs.push({
      label,
      href: currentPath,
      current: isLast,
    });
  });

  return breadcrumbs;
}

export function AppBreadcrumbs({
  items,
  showHome = true,
  className,
}: AppBreadcrumbsProps) {
  const pathname = usePathname();

  // Use provided items or generate from pathname
  const breadcrumbs = items ?? generateBreadcrumbs(pathname);

  // Don't render if no breadcrumbs or only home
  if (breadcrumbs.length === 0) {
    return null;
  }

  return (
    <nav
      aria-label="Breadcrumb"
      className={cn('border-b bg-background px-4 py-3 lg:px-6', className)}
      data-testid="breadcrumbs"
    >
      <ol className="flex flex-wrap items-center gap-1 text-sm">
        {/* Home link */}
        {showHome && (
          <li className="flex items-center">
            <Link
              href="/"
              className="flex items-center text-muted-foreground hover:text-foreground transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 rounded-sm"
              aria-label="Home"
              data-testid="breadcrumb-home"
            >
              <Home className="h-4 w-4" aria-hidden="true" />
            </Link>
          </li>
        )}

        {/* Breadcrumb items */}
        {breadcrumbs.map((breadcrumb, index) => {
          const showSeparator = showHome || index > 0;
          const testId = `breadcrumb-${breadcrumb.label.toLowerCase().replace(/\s+/g, '-')}`;

          return (
            <li key={breadcrumb.href} className="flex items-center">
              {showSeparator && (
                <ChevronRight
                  className="mx-1 h-4 w-4 text-muted-foreground flex-shrink-0"
                  aria-hidden="true"
                />
              )}
              {breadcrumb.current ? (
                <span
                  className="font-medium text-foreground"
                  aria-current="page"
                  data-testid={testId}
                >
                  {breadcrumb.label}
                </span>
              ) : (
                <Link
                  href={breadcrumb.href}
                  className="text-muted-foreground hover:text-foreground transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 rounded-sm"
                  data-testid={testId}
                >
                  {breadcrumb.label}
                </Link>
              )}
            </li>
          );
        })}
      </ol>
    </nav>
  );
}