/**
 * Parts lookup utility for frontend
 * 
 * Provides functions to fetch parts data by manual filename
 */

import { ebayClient } from './ebay-api'

interface PartForPage {
  partNumber: string
  description: string
  ebayListings: Array<{
    itemId: string
    title: string
    price: string
    currency: string
    imageUrl?: string
    viewItemUrl: string
    condition?: string
    shippingCost?: string
    affiliateLink: string
  }>
}

interface ManualPartsLookup {
  [manualFilename: string]: PartForPage[]
}

interface ManualPagesParts {
  [manualFilename: string]: {
    [pageNumber: string]: PartForPage[]
  }
}

// Cache for eBay search results
const ebaySearchCache = new Map<string, { results: any[]; timestamp: number }>()
const EBAY_CACHE_TTL = 15 * 60 * 1000 // 15 minutes

let manualPartsCache: ManualPartsLookup | null = null
let manualPagesPartsCache: ManualPagesParts | null = null

/**
 * Load parts lookup data
 */
async function loadPartsData(): Promise<{
  manualParts: ManualPartsLookup
  manualPagesParts: ManualPagesParts
}> {
  if (manualPartsCache && manualPagesPartsCache) {
    return {
      manualParts: manualPartsCache,
      manualPagesParts: manualPagesPartsCache,
    }
  }
  
  try {
    // Try to load from public data directory (relative to public folder)
    const [manualPartsResponse, manualPagesResponse] = await Promise.all([
      fetch('/manual_parts_lookup.json'),
      fetch('/manual_pages_parts.json'),
    ])
    
    if (manualPartsResponse.ok && manualPagesResponse.ok) {
      const [manualParts, manualPagesParts] = await Promise.all([
        manualPartsResponse.json(),
        manualPagesResponse.json(),
      ])
      
      manualPartsCache = manualParts
      manualPagesPartsCache = manualPagesParts
      
      return { manualParts, manualPagesParts }
    }
  } catch (error) {
    console.warn('Could not load parts data:', error)
  }
  
  // Return empty data if loading fails
  return {
    manualParts: {},
    manualPagesParts: {},
  }
}

/**
 * Search eBay for parts with caching
 */
async function searchEBayForParts(partNumber: string, description?: string, manufacturer?: string): Promise<any[]> {
  const cacheKey = `parts:${partNumber}:${description || ''}:${manufacturer || ''}`
  
  // Check cache
  const cached = ebaySearchCache.get(cacheKey)
  if (cached && Date.now() - cached.timestamp < EBAY_CACHE_TTL) {
    return cached.results
  }
  
  try {
    const results = await ebayClient.searchVendingParts(partNumber, description, manufacturer)
    ebaySearchCache.set(cacheKey, { results, timestamp: Date.now() })
    return results
  } catch (error) {
    console.error(`Error searching eBay for part ${partNumber}:`, error)
    // Return empty array if API fails
    return []
  }
}

/**
 * Enhance parts data with real-time eBay listings
 */
async function enhancePartsData(parts: PartForPage[]): Promise<PartForPage[]> {
  if (!ebayClient.isConfigured()) {
    return parts
  }

  const enhancedParts = await Promise.all(parts.map(async (part) => {
    // Only search for parts without existing eBay listings
    if (part.ebayListings.length === 0) {
      const ebayResults = await searchEBayForParts(part.partNumber, part.description)
      part.ebayListings = ebayResults.map(result => ({
        itemId: result.itemId,
        title: result.title,
        price: result.price,
        currency: result.currency,
        imageUrl: result.imageUrl,
        viewItemUrl: result.viewItemUrl,
        condition: result.condition,
        shippingCost: result.shippingCost,
        affiliateLink: result.affiliateLink,
      }))
    }
    return part
  }))
  
  return enhancedParts
}

/**
 * Get all parts for a manual with enhanced eBay data
 */
export async function getPartsForManual(
  manualFilename: string
): Promise<PartForPage[]> {
  const { manualParts } = await loadPartsData()
  
  // Try exact match first
  if (manualParts[manualFilename]) {
    const parts = manualParts[manualFilename]
    return enhancePartsData(parts)
  }
  
  // Try case-insensitive match
  const lowerFilename = manualFilename.toLowerCase()
  for (const [filename, parts] of Object.entries(manualParts)) {
    if (filename.toLowerCase() === lowerFilename) {
      return enhancePartsData(parts)
    }
  }
  
  // Try partial match (filename without extension)
  const filenameWithoutExt = manualFilename.replace(/\.pdf$/i, '')
  const lowerWithoutExt = filenameWithoutExt.toLowerCase()
  
  for (const [filename, parts] of Object.entries(manualParts)) {
    const otherWithoutExt = filename.replace(/\.pdf$/i, '').toLowerCase()
    if (otherWithoutExt === lowerWithoutExt || otherWithoutExt.includes(lowerWithoutExt) || lowerWithoutExt.includes(otherWithoutExt)) {
      return enhancePartsData(parts)
    }
  }
  
  return []
}

/**
 * Get parts for a specific page of a manual with enhanced eBay data
 */
export async function getPartsForPage(
  manualFilename: string,
  pageNumber: number
): Promise<PartForPage[]> {
  const { manualPagesParts } = await loadPartsData()
  
  // Try exact match first
  if (manualPagesParts[manualFilename] && manualPagesParts[manualFilename][pageNumber.toString()]) {
    const parts = manualPagesParts[manualFilename][pageNumber.toString()]
    return enhancePartsData(parts)
  }
  
  // Try case-insensitive match
  const lowerFilename = manualFilename.toLowerCase()
  for (const [filename, pages] of Object.entries(manualPagesParts)) {
    if (filename.toLowerCase() === lowerFilename) {
      if (pages[pageNumber.toString()]) {
        const parts = pages[pageNumber.toString()]
        return enhancePartsData(parts)
      }
    }
  }
  
  // Try partial match
  const filenameWithoutExt = manualFilename.replace(/\.pdf$/i, '')
  const lowerWithoutExt = filenameWithoutExt.toLowerCase()
  
  for (const [filename, pages] of Object.entries(manualPagesParts)) {
    const otherWithoutExt = filename.replace(/\.pdf$/i, '').toLowerCase()
    if (otherWithoutExt === lowerWithoutExt || otherWithoutExt.includes(lowerWithoutExt) || lowerWithoutExt.includes(otherWithoutExt)) {
      if (pages[pageNumber.toString()]) {
        const parts = pages[pageNumber.toString()]
        return enhancePartsData(parts)
      }
    }
  }
  
  return []
}

/**
 * Get top N parts for a manual (most relevant) with enhanced eBay data
 */
export async function getTopPartsForManual(
  manualFilename: string,
  limit: number = 5
): Promise<PartForPage[]> {
  const parts = await getPartsForManual(manualFilename)
  
  // Sort by number of eBay listings (more listings = more relevant)
  const sorted = parts.sort((a, b) => b.ebayListings.length - a.ebayListings.length)
  
  return sorted.slice(0, limit)
}

/**
 * Check if a manual has parts available
 */
export async function hasPartsForManual(manualFilename: string): Promise<boolean> {
  const parts = await getPartsForManual(manualFilename)
  return parts.length > 0 && parts.some(part => part.ebayListings.length > 0)
}

/**
 * Get a set of all manual filenames that have parts available
 * Useful for filtering
 */
export async function getManualsWithParts(): Promise<Set<string>> {
  const { manualParts } = await loadPartsData()
  const manualsWithParts = new Set<string>()
  
  for (const [filename, parts] of Object.entries(manualParts)) {
    if (parts.length > 0 && parts.some(part => part.ebayListings.length > 0)) {
      manualsWithParts.add(filename)
      // Also add variations for matching
      manualsWithParts.add(filename.toLowerCase())
      manualsWithParts.add(filename.replace(/\.pdf$/i, ''))
      manualsWithParts.add(filename.replace(/\.pdf$/i, '').toLowerCase())
    }
  }
  
  return manualsWithParts
}

/**
 * Clear cache (useful for development)
 */
export function clearPartsCache(): void {
  manualPartsCache = null
  manualPagesPartsCache = null
}