import { BibleHighlight } from '@/types'

const DB_NAME = 'BiblicalGuide'
const DB_VERSION = 2 // Increment version if schema changes
const HIGHLIGHTS_STORE = 'highlights'

let db: IDBDatabase | null = null

export async function initHighlightsDatabase(): Promise<IDBDatabase> {
  if (db) return db

  return new Promise((resolve, reject) => {
    const request = indexedDB.open(DB_NAME, DB_VERSION)

    request.onerror = () => reject(new Error('Failed to open IndexedDB'))

    request.onsuccess = () => {
      db = request.result
      resolve(db)
    }

    request.onupgradeneeded = (event) => {
      const database = (event.target as IDBOpenDBRequest).result

      // Create highlights store if it doesn't exist
      if (!database.objectStoreNames.contains(HIGHLIGHTS_STORE)) {
        const store = database.createObjectStore(HIGHLIGHTS_STORE, { keyPath: 'id' })
        // Index for finding highlights by syncStatus for batch operations
        store.createIndex('syncStatus', 'syncStatus', { unique: false })
        // Index for finding highlights by verse
        store.createIndex('verseId', 'verseId', { unique: false })
      }
    }
  })
}

export async function addHighlight(highlight: BibleHighlight): Promise<string> {
  const db = await initHighlightsDatabase()
  return new Promise((resolve, reject) => {
    const tx = db.transaction(HIGHLIGHTS_STORE, 'readwrite')
    const store = tx.objectStore(HIGHLIGHTS_STORE)
    const request = store.add(highlight)

    request.onsuccess = () => resolve(request.result as string)
    request.onerror = () => reject(new Error('Failed to add highlight'))
  })
}

export async function updateHighlight(highlight: BibleHighlight): Promise<void> {
  const db = await initHighlightsDatabase()
  return new Promise((resolve, reject) => {
    const tx = db.transaction(HIGHLIGHTS_STORE, 'readwrite')
    const store = tx.objectStore(HIGHLIGHTS_STORE)
    const request = store.put(highlight)

    request.onsuccess = () => resolve()
    request.onerror = () => reject(new Error('Failed to update highlight'))
  })
}

export async function getHighlight(id: string): Promise<BibleHighlight | null> {
  const db = await initHighlightsDatabase()
  return new Promise((resolve, reject) => {
    const tx = db.transaction(HIGHLIGHTS_STORE, 'readonly')
    const store = tx.objectStore(HIGHLIGHTS_STORE)
    const request = store.get(id)

    request.onsuccess = () => resolve(request.result || null)
    request.onerror = () => reject(new Error('Failed to get highlight'))
  })
}

export async function getHighlightsByVerse(verseId: string): Promise<BibleHighlight[]> {
  const db = await initHighlightsDatabase()
  return new Promise((resolve, reject) => {
    const tx = db.transaction(HIGHLIGHTS_STORE, 'readonly')
    const store = tx.objectStore(HIGHLIGHTS_STORE)
    const index = store.index('verseId')
    const request = index.getAll(verseId)

    request.onsuccess = () => resolve(request.result || [])
    request.onerror = () => reject(new Error('Failed to get highlights by verse'))
  })
}

export async function getAllHighlights(): Promise<BibleHighlight[]> {
  const db = await initHighlightsDatabase()
  return new Promise((resolve, reject) => {
    const tx = db.transaction(HIGHLIGHTS_STORE, 'readonly')
    const store = tx.objectStore(HIGHLIGHTS_STORE)
    const request = store.getAll()

    request.onsuccess = () => resolve(request.result || [])
    request.onerror = () => reject(new Error('Failed to get all highlights'))
  })
}

export async function getPendingHighlights(): Promise<BibleHighlight[]> {
  const db = await initHighlightsDatabase()
  return new Promise((resolve, reject) => {
    const tx = db.transaction(HIGHLIGHTS_STORE, 'readonly')
    const store = tx.objectStore(HIGHLIGHTS_STORE)
    const index = store.index('syncStatus')
    const request = index.getAll(IDBKeyRange.only('pending'))

    request.onsuccess = () => resolve(request.result || [])
    request.onerror = () => reject(new Error('Failed to get pending highlights'))
  })
}

export async function deleteHighlight(id: string): Promise<void> {
  const db = await initHighlightsDatabase()
  return new Promise((resolve, reject) => {
    const tx = db.transaction(HIGHLIGHTS_STORE, 'readwrite')
    const store = tx.objectStore(HIGHLIGHTS_STORE)
    const request = store.delete(id)

    request.onsuccess = () => resolve()
    request.onerror = () => reject(new Error('Failed to delete highlight'))
  })
}

export async function clearAllHighlights(): Promise<void> {
  const db = await initHighlightsDatabase()
  return new Promise((resolve, reject) => {
    const tx = db.transaction(HIGHLIGHTS_STORE, 'readwrite')
    const store = tx.objectStore(HIGHLIGHTS_STORE)
    const request = store.clear()

    request.onsuccess = () => resolve()
    request.onerror = () => reject(new Error('Failed to clear highlights'))
  })
}