/**
 * SEO utilities for Next.js App Router
 * Uses the new Metadata API for better SEO
 */

import { Metadata } from 'next'

export interface SEOConfig {
  title?: string
  description?: string
  keywords?: string[]
  authors?: Array<{ name: string; url?: string }>
  creator?: string
  publisher?: string
  robots?: {
    index?: boolean
    follow?: boolean
    nocache?: boolean
    googleBot?: {
      index?: boolean
      follow?: boolean
      noimageindex?: boolean
      'max-video-preview'?: number
      'max-image-preview'?: 'none' | 'standard' | 'large'
      'max-snippet'?: number
    }
  }
  openGraph?: {
    title?: string
    description?: string
    url?: string
    siteName?: string
    images?: Array<{
      url: string
      width?: number
      height?: number
      alt?: string
    }>
    type?: 'website' | 'article'
    publishedTime?: string
    modifiedTime?: string
    authors?: string[]
    section?: string
    tags?: string[]
  }
  twitter?: {
    card?: 'summary' | 'summary_large_image' | 'app' | 'player'
    title?: string
    description?: string
    siteId?: string
    creator?: string
    creatorId?: string
    images?: string | Array<{ url: string; alt?: string }>
  }
  alternates?: {
    canonical?: string
    languages?: Record<string, string>
  }
  icons?: {
    icon?: string | Array<{ url: string; sizes?: string; type?: string }>
    shortcut?: string
    apple?: string | Array<{ url: string; sizes?: string; type?: string }>
  }
}

const defaultSEOConfig: SEOConfig = {
  title: 'NextJS Boilerplate',
  description:
    'A production-ready NextJS boilerplate with TypeScript, Tailwind CSS, and authentication',
  keywords: ['Next.js', 'React', 'TypeScript', 'Tailwind CSS', 'Authentication', 'Boilerplate'],
  authors: [{ name: 'NextJS Boilerplate Team' }],
  creator: 'NextJS Boilerplate',
  publisher: 'NextJS Boilerplate',
  robots: {
    index: true,
    follow: true,
    googleBot: {
      index: true,
      follow: true,
      'max-video-preview': -1,
      'max-image-preview': 'large',
      'max-snippet': -1,
    },
  },
  openGraph: {
    type: 'website',
    siteName: 'NextJS Boilerplate',
    images: [
      {
        url: '/og-image.png',
        width: 1200,
        height: 630,
        alt: 'NextJS Boilerplate',
      },
    ],
  },
  twitter: {
    card: 'summary_large_image',
    creator: '@nextjs_boilerplate',
  },
  icons: {
    icon: '/favicon.ico',
    shortcut: '/favicon.ico',
    apple: '/apple-touch-icon.png',
  },
}

/**
 * Generate metadata for pages
 */
export function generateMetadata(config: SEOConfig = {}): Metadata {
  const mergedConfig = {
    ...defaultSEOConfig,
    ...config,
    openGraph: {
      ...defaultSEOConfig.openGraph,
      ...config.openGraph,
    },
    twitter: {
      ...defaultSEOConfig.twitter,
      ...config.twitter,
    },
    robots: {
      ...defaultSEOConfig.robots,
      ...config.robots,
    },
  }

  return {
    title: mergedConfig.title,
    description: mergedConfig.description,
    keywords: mergedConfig.keywords,
    authors: mergedConfig.authors,
    creator: mergedConfig.creator,
    publisher: mergedConfig.publisher,
    robots: mergedConfig.robots,
    openGraph: mergedConfig.openGraph,
    twitter: mergedConfig.twitter,
    alternates: config.alternates,
    icons: mergedConfig.icons,
  }
}

/**
 * Generate metadata for article pages
 */
export function generateArticleMetadata(
  title: string,
  description: string,
  config: {
    publishedTime?: string
    modifiedTime?: string
    authors?: string[]
    section?: string
    tags?: string[]
    image?: string
    url?: string
  } = {}
): Metadata {
  return generateMetadata({
    title,
    description,
    openGraph: {
      type: 'article',
      title,
      description,
      publishedTime: config.publishedTime,
      modifiedTime: config.modifiedTime,
      authors: config.authors,
      section: config.section,
      tags: config.tags,
      url: config.url,
      images: config.image
        ? [
            {
              url: config.image,
              width: 1200,
              height: 630,
              alt: title,
            },
          ]
        : undefined,
    },
    twitter: {
      card: 'summary_large_image',
      title,
      description,
      images: config.image ? [{ url: config.image, alt: title }] : undefined,
    },
  })
}

/**
 * Generate structured data (JSON-LD)
 */
export function generateStructuredData(type: string, data: Record<string, any>) {
  const structuredData = {
    '@context': 'https://schema.org',
    '@type': type,
    ...data,
  }

  return {
    __html: JSON.stringify(structuredData),
  }
}

/**
 * Website structured data
 */
export function generateWebsiteStructuredData(
  name: string,
  url: string,
  description?: string,
  logo?: string
) {
  return generateStructuredData('WebSite', {
    name,
    url,
    description,
    logo,
    potentialAction: {
      '@type': 'SearchAction',
      target: {
        '@type': 'EntryPoint',
        urlTemplate: `${url}/search?q={search_term_string}`,
      },
      'query-input': 'required name=search_term_string',
    },
  })
}

/**
 * Organization structured data
 */
export function generateOrganizationStructuredData(
  name: string,
  url: string,
  logo?: string,
  contactPoint?: {
    telephone?: string
    contactType?: string
    email?: string
  }
) {
  return generateStructuredData('Organization', {
    name,
    url,
    logo,
    contactPoint: contactPoint
      ? {
          '@type': 'ContactPoint',
          ...contactPoint,
        }
      : undefined,
  })
}

/**
 * Article structured data
 */
export function generateArticleStructuredData(
  headline: string,
  description: string,
  author: string,
  publishedDate: string,
  modifiedDate?: string,
  image?: string,
  url?: string
) {
  return generateStructuredData('Article', {
    headline,
    description,
    author: {
      '@type': 'Person',
      name: author,
    },
    datePublished: publishedDate,
    dateModified: modifiedDate || publishedDate,
    image,
    url,
    publisher: {
      '@type': 'Organization',
      name: 'NextJS Boilerplate',
      logo: {
        '@type': 'ImageObject',
        url: '/logo.png',
      },
    },
  })
}

/**
 * Breadcrumb structured data
 */
export function generateBreadcrumbStructuredData(items: Array<{ name: string; url: string }>) {
  return generateStructuredData('BreadcrumbList', {
    itemListElement: items.map((item, index) => ({
      '@type': 'ListItem',
      position: index + 1,
      name: item.name,
      item: item.url,
    })),
  })
}

/**
 * FAQ structured data
 */
export function generateFAQStructuredData(faqs: Array<{ question: string; answer: string }>) {
  return generateStructuredData('FAQPage', {
    mainEntity: faqs.map((faq) => ({
      '@type': 'Question',
      name: faq.question,
      acceptedAnswer: {
        '@type': 'Answer',
        text: faq.answer,
      },
    })),
  })
}