import { source } from "@/app/source";

export interface LinkSuggestion {
  href: string;
  title: string;
  description?: string;
  confidence: number;
}

export interface BrokenLinkInfo {
  originalHref: string;
  suggestions: LinkSuggestion[];
  isExternal: boolean;
}

/**
 * Validates if a link is broken and provides suggestions
 */
export function validateLink(href: string): BrokenLinkInfo {
  const isExternal =
    href.startsWith("http") ||
    href.startsWith("mailto:") ||
    href.startsWith("tel:");

  if (isExternal) {
    return {
      originalHref: href,
      suggestions: [],
      isExternal: true,
    };
  }

  // For internal links, check if the page exists
  const normalizedHref = href.startsWith("/") ? href.slice(1) : href;
  const slug = normalizedHref.split("/").filter(Boolean);

  try {
    const page = source.getPage(slug);
    if (page) {
      return {
        originalHref: href,
        suggestions: [],
        isExternal: false,
      };
    }
  } catch (error) {
    // Page doesn't exist
  }

  // Generate suggestions based on the broken link
  const suggestions = generateSuggestions(href, slug);

  return {
    originalHref: href,
    suggestions,
    isExternal: false,
  };
}

/**
 * Generates suggestions for a broken link
 */
function generateSuggestions(
  originalHref: string,
  slug: string[],
): LinkSuggestion[] {
  const suggestions: LinkSuggestion[] = [];

  // Get all available pages for fuzzy matching
  const allPages = getAllPages();

  if (slug.length === 0) {
    // If it's just a root link, suggest main sections
    suggestions.push(
      {
        href: "/direct-to-llm",
        title: "Direct to LLM",
        description: "Build copilots with any LLM",
        confidence: 0.8,
      },
      {
        href: "/langgraph",
        title: "LangChain",
        description: "Agentic workflows and state machines",
        confidence: 0.8,
      },
      {
        href: "/mastra",
        title: "Mastra",
        description: "Multi-agent orchestration",
        confidence: 0.8,
      },
      {
        href: "/reference",
        title: "API Reference",
        description: "Complete API documentation",
        confidence: 0.8,
      },
    );
    return suggestions;
  }

  // Try to find similar pages
  const lastSegment = slug[slug.length - 1];
  const similarPages = allPages.filter((page) => {
    const pageSlug = page.slugs.join("/");
    return (
      pageSlug.includes(lastSegment) ||
      page.data.title?.toLowerCase().includes(lastSegment.toLowerCase())
    );
  });

  similarPages.slice(0, 3).forEach((page) => {
    suggestions.push({
      href: `/${page.slugs.join("/")}`,
      title: page.data.title || "Untitled",
      description: page.data.description,
      confidence: 0.7,
    });
  });

  // If no similar pages found, suggest main sections
  if (suggestions.length === 0) {
    const firstSegment = slug[0];
    if (firstSegment) {
      suggestions.push(
        {
          href: `/${firstSegment}`,
          title: `${firstSegment} Documentation`,
          confidence: 0.6,
        },
        { href: "/", title: "Home", confidence: 0.5 },
      );
    }
  }

  return suggestions;
}

/**
 * Gets all available pages (this would need to be implemented based on your source structure)
 */
function getAllPages(): Array<{
  slugs: string[];
  data: { title?: string; description?: string };
}> {
  // This is a simplified version - you'd need to implement this based on your source structure
  try {
    // This would need to be implemented to get all pages from your source
    return [];
  } catch (error) {
    return [];
  }
}

/**
 * Creates a link suggestion component
 */
export function createLinkSuggestion(suggestion: LinkSuggestion) {
  return {
    href: suggestion.href,
    title: suggestion.title,
    description: suggestion.description,
    confidence: suggestion.confidence,
  };
}