/**
 * Internal Link Configuration for SEO Tool
 * Defines rules for internal link optimization and analysis
 */

import { PageInfo } from './seo-utils';

/**
 * Priority link configuration
 * These links will be prioritized when optimizing internal links
 */
export interface PriorityLink {
  targetRoute: string;
  keywords: string[];
  maxLinks: number;
  anchorTexts: string[];
  priority: number; // 1-10, where 10 is highest priority
}

/**
 * Keyword to page mapping
 * Auto-magically link specific keywords to target pages
 */
export interface KeywordMapping {
  keyword: string;
  targetRoute: string;
  variations?: string[];
  useNaturalAnchorText?: boolean;
}

/**
 * Page-specific configuration
 */
export interface PageConfig {
  excludeSections?: string[];
  maxLinksPerPage?: number;
  minWordsBetweenLinks?: number;
  preferredAnchorText?: string;
}

/**
 * Link density configuration
 */
export interface LinkDensityConfig {
  maxLinksPerPage: number;
  minWordsBetweenLinks: number;
  maxLinksPerParagraph: number;
  maxPercentagePerPage: number;
}

/**
 * SEO scoring weights
 */
export interface ScoringWeights {
  title: number;
  description: number;
  internalLinks: number;
  contentLength: number;
  keywordOptimization: number;
  structure: number;
  imageOptimization: number;
}

/**
 * Master configuration
 */
export interface InternalLinkConfig {
  // General settings
  businessName: string;
  websiteUrl: string;
  
  // Priority links
  priorityLinks: PriorityLink[];
  
  // Keyword mappings
  keywordMappings: KeywordMapping[];
  
  // Page-specific configurations
  pageConfigs: Record<string, PageConfig>;
  
  // Link density settings
  linkDensity: LinkDensityConfig;
  
  // SEO scoring weights
  scoringWeights: ScoringWeights;
  
  // Excluded pages
  excludedPages: string[];
  
  // Excluded sections within pages
  excludedSections: string[];
  
  // Anchor text preferences
  anchorTextPreferences: {
    preferPageTitle: boolean;
    useNaturalLanguage: boolean;
    avoidGenericText: string[];
  };
}

/**
 * Default configuration
 */
export const defaultConfig: InternalLinkConfig = {
  businessName: "Rocky Mountain Vending",
  websiteUrl: "https://rockymountainvending.com",
  
  priorityLinks: [
    {
      targetRoute: "services/repairs",
      keywords: ["repair", "repairs", "fix", "broken", "maintenance", "service", "fixing"],
      maxLinks: 3,
      anchorTexts: ["vending machine repairs", "repair services", "vending machine repair", "fixing"],
      priority: 10
    },
    {
      targetRoute: "vending-machines/machines-for-sale",
      keywords: ["buy", "purchase", "sale", "for sale", "machine", "equipment", "acquire"],
      maxLinks: 2,
      anchorTexts: ["vending machines for sale", "buy vending machines", "vending machine sales", "purchase"],
      priority: 9
    },
    {
      targetRoute: "vending-machines/machines-we-use",
      keywords: ["machine", "equipment", "vending", "use", "utilize", "employ"],
      maxLinks: 2,
      anchorTexts: ["vending machines we use", "our machines", "vending equipment", "vending systems"],
      priority: 8
    },
    {
      targetRoute: "about-us",
      keywords: ["about", "company", "us", "we", "our", "team", "business"],
      maxLinks: 1,
      anchorTexts: ["about us", "about Rocky Mountain Vending", "our company"],
      priority: 7
    },
    {
      targetRoute: "contact-us",
      keywords: ["contact", "reach", "call", "phone", "email", "get in touch", "reach out"],
      maxLinks: 2,
      anchorTexts: ["contact us", "get in touch", "reach out", "call us"],
      priority: 8
    },
    {
      targetRoute: "food-and-beverage/healthy-options",
      keywords: ["healthy", "wellness", "nutrition", "snack", "beverage", "options"],
      maxLinks: 2,
      anchorTexts: ["healthy vending", "healthy options", "wellness vending", "healthy snacks"],
      priority: 7
    },
    {
      targetRoute: "food-and-beverage/traditional-options",
      keywords: ["traditional", "classic", "standard", "conventional", "regular"],
      maxLinks: 2,
      anchorTexts: ["traditional vending", "classic vending", "standard options"],
      priority: 6
    },
    {
      targetRoute: "services/parts",
      keywords: ["parts", "component", "replacement", "spare", "accessories", "supplies"],
      maxLinks: 2,
      anchorTexts: ["vending machine parts", "parts and support", "replacement parts", "spare parts"],
      priority: 7
    }
  ],
  
  keywordMappings: [
    {
      keyword: "warehouse",
      targetRoute: "warehouses",
      variations: ["warehouses"],
      useNaturalAnchorText: true
    },
    {
      keyword: "auto repair",
      targetRoute: "auto-repair",
      variations: ["auto-repair", "automotive repair"],
      useNaturalAnchorText: true
    },
    {
      keyword: "gym",
      targetRoute: "gyms",
      variations: ["gyms", "fitness center"],
      useNaturalAnchorText: true
    },
    {
      keyword: "community center",
      targetRoute: "community-centers",
      variations: ["community centers", "community facility"],
      useNaturalAnchorText: true
    },
    {
      keyword: "dance studio",
      targetRoute: "dance-studios",
      variations: ["dance studios", "dance facility"],
      useNaturalAnchorText: true
    },
    {
      keyword: "car wash",
      targetRoute: "car-washes",
      variations: ["car washes", "car washing"],
      useNaturalAnchorText: true
    },
    {
      keyword: "suppliers",
      targetRoute: "food-and-beverage/suppliers",
      variations: ["supplier", "wholesale", "distributor"],
      useNaturalAnchorText: true
    },
    {
      keyword: "faq",
      targetRoute: "about/faqs",
      variations: ["faqs", "frequently asked", "questions"],
      useNaturalAnchorText: false
    },
    {
      keyword: "manuals",
      targetRoute: "manuals",
      variations: ["manual", "guide", "documentation"],
      useNaturalAnchorText: true
    }
  ],
  
  pageConfigs: {
    "": { // Home page
      maxLinksPerPage: 8,
      minWordsBetweenLinks: 100
    },
    "about-us": {
      maxLinksPerPage: 3,
      minWordsBetweenLinks: 150
    },
    "contact-us": {
      maxLinksPerPage: 2,
      minWordsBetweenLinks: 200
    },
    "services": {
      maxLinksPerPage: 6,
      minWordsBetweenLinks: 80
    },
    "vending-machines": {
      maxLinksPerPage: 5,
      minWordsBetweenLinks: 90
    },
    "manuals": {
      maxLinksPerPage: 4,
      minWordsBetweenLinks: 120
    }
  },
  
  linkDensity: {
    maxLinksPerPage: 10,
    minWordsBetweenLinks: 50,
    maxLinksPerParagraph: 2,
    maxPercentagePerPage: 3
  },
  
  scoringWeights: {
    title: 0.2,
    description: 0.15,
    internalLinks: 0.25,
    contentLength: 0.15,
    keywordOptimization: 0.15,
    structure: 0.05,
    imageOptimization: 0.05
  },
  
  excludedPages: [
    "api",
    "robots",
    "sitemap"
  ],
  
  excludedSections: [
    "header",
    "footer",
    "navigation",
    "sidebar",
    "menu"
  ],
  
  anchorTextPreferences: {
    preferPageTitle: true,
    useNaturalLanguage: true,
    avoidGenericText: ["click here", "read more", "link", "learn more", "visit"]
  }
};

/**
 * Get configuration for a specific page
 */
export function getPageConfig(route: string, config: InternalLinkConfig = defaultConfig): PageConfig {
  // Check exact match first
  if (config.pageConfigs[route]) {
    return config.pageConfigs[route];
  }
  
  // Check partial matches (e.g., services/*)
  for (const [key, pageConfig] of Object.entries(config.pageConfigs)) {
    if (key !== '' && route.startsWith(key)) {
      return pageConfig;
    }
  }
  
  // Return default config
  return {
    maxLinksPerPage: config.linkDensity.maxLinksPerPage,
    minWordsBetweenLinks: config.linkDensity.minWordsBetweenLinks
  };
}

/**
 * Get all keywords that should be linked to a target page
 */
export function getKeywordsForTarget(targetRoute: string, config: InternalLinkConfig = defaultConfig): string[] {
  const keywords: string[] = [];
  
  // Add priority link keywords
  const priorityLink = config.priorityLinks.find(pl => pl.targetRoute === targetRoute);
  if (priorityLink) {
    keywords.push(...priorityLink.keywords);
  }
  
  // Add keyword mapping keywords
  for (const mapping of config.keywordMappings) {
    if (mapping.targetRoute === targetRoute) {
      keywords.push(mapping.keyword);
      if (mapping.variations) {
        keywords.push(...mapping.variations);
      }
    }
  }
  
  // Remove duplicates
  return [...new Set(keywords)];
}

/**
 * Get anchor text options for a target page
 */
export function getAnchorTexts(targetRoute: string, config: InternalLinkConfig = defaultConfig): string[] {
  // Get from priority links
  const priorityLink = config.priorityLinks.find(pl => pl.targetRoute === targetRoute);
  if (priorityLink && priorityLink.anchorTexts.length > 0) {
    return priorityLink.anchorTexts;
  }
  
  // Default to page title
  return [targetRoute.split('/').pop() || targetRoute];
}

/**
 * Check if a route should be excluded from linking
 */
export function isExcludedRoute(route: string, config: InternalLinkConfig = defaultConfig): boolean {
  return config.excludedPages.some(excluded => 
    route === excluded || route.startsWith(excluded + '/')
  );
}

/**
 * Calculate maximum links allowed for a page
 */
export function getMaxLinksForPage(route: string, config: InternalLinkConfig = defaultConfig): number {
  const pageConfig = getPageConfig(route, config);
  return pageConfig.maxLinksPerPage || config.linkDensity.maxLinksPerPage;
}

/**
 * Calculate minimum words between links
 */
export function getMinWordsBetweenLinks(route: string, config: InternalLinkConfig = defaultConfig): number {
  const pageConfig = getPageConfig(route, config);
  return pageConfig.minWordsBetweenLinks || config.linkDensity.minWordsBetweenLinks;
}

/**
 * SEO scoring function
 */
export function calculatePageScore(
  route: string,
  content: string,
  internalLinks: { to: string; text: string }[],
  config: InternalLinkConfig = defaultConfig
): number {
  const weights = config.scoringWeights;
  let score = 0;
  
  // Title score (20%)
  const hasTitle = content.match(/title:/i) || content.match(/Head>/i);
  score += hasTitle ? weights.title : 0;
  
  // Description score (15%)
  const hasDescription = content.match(/description:/i) || content.match(/Head>/i);
  score += hasDescription ? weights.description : 0;
  
  // Internal links score (25%)
  const maxLinks = getMaxLinksForPage(route, config);
  const linkScore = Math.min(internalLinks.length / maxLinks, 1) * weights.internalLinks;
  score += linkScore;
  
  // Content length score (15%)
  const wordCount = content.split(/\s+/).length;
  const contentScore = Math.min(wordCount / 500, 1) * weights.contentLength;
  score += contentScore;
  
  // Keyword optimization score (15%)
  const keywordsFound = findKeywordsInContent(content, config).length;
  const keywordScore = Math.min(keywordsFound / 10, 1) * weights.keywordOptimization;
  score += keywordScore;
  
  // Structure score (5%)
  const hasGoodStructure = content.match(/<h[1-6]>/i) && content.match(/<p>/i);
  score += hasGoodStructure ? weights.structure : 0;
  
  // Image optimization score (5%)
  const imageCount = (content.match(/<img[^>]*>/gi) || []).length;
  const imageScore = Math.min(imageCount / 3, 1) * weights.imageOptimization;
  score += imageScore;
  
  return Math.round(score * 100) / 100;
}

/**
 * Find keywords in content for SEO analysis
 */
export function findKeywordsInContent(content: string, config: InternalLinkConfig = defaultConfig): string[] {
  const keywords: string[] = [];
  const allKeywords = [
    ...config.priorityLinks.flatMap(pl => pl.keywords),
    ...config.keywordMappings.map(km => km.keyword),
    ...config.keywordMappings.flatMap(km => km.variations || [])
  ];
  
  const contentLower = content.toLowerCase();
  
  for (const keyword of allKeywords) {
    if (contentLower.includes(keyword.toLowerCase())) {
      keywords.push(keyword);
    }
  }
  
  return [...new Set(keywords)];
}