import type { AlbyInvoice } from '@/types/alby'
import { storageService } from './storage/indexedDB'

interface StoredArticleData {
  content: string
  authorPubkey: string
  articleId: string
  invoice: {
    invoice: string
    paymentHash: string
    amount: number
    expiresAt: number
  } | null
  createdAt: number
}

// Default expiration: 30 days in milliseconds
const DEFAULT_EXPIRATION = 30 * 24 * 60 * 60 * 1000
const MASTER_KEY_STORAGE_KEY = 'article_storage_master_key'

function getOrCreateMasterKey(): string {
  if (typeof window === 'undefined') {
    throw new Error('Storage encryption requires browser environment')
  }
  const existing = localStorage.getItem(MASTER_KEY_STORAGE_KEY)
  if (existing) {
    return existing
  }
  const keyBytes = crypto.getRandomValues(new Uint8Array(32))
  let binary = ''
  keyBytes.forEach((b) => {
    binary += String.fromCharCode(b)
  })
  const key = btoa(binary)
  localStorage.setItem(MASTER_KEY_STORAGE_KEY, key)
  return key
}

function deriveSecret(articleId: string): string {
  const masterKey = getOrCreateMasterKey()
  return `${masterKey}:${articleId}`
}

/**
 * Store private content temporarily until payment is confirmed
 * Also stores the invoice if provided
 * Uses IndexedDB exclusively
 * Content expires after 30 days by default
 */
export async function storePrivateContent(
  articleId: string,
  content: string,
  authorPubkey: string,
  invoice?: AlbyInvoice
): Promise<void> {
  try {
    const key = `article_private_content_${articleId}`
    const secret = deriveSecret(articleId)
    const data: StoredArticleData = {
      content,
      authorPubkey,
      articleId,
      invoice: invoice
        ? {
            invoice: invoice.invoice,
            paymentHash: invoice.paymentHash,
            amount: invoice.amount,
            expiresAt: invoice.expiresAt,
          }
        : null,
      createdAt: Date.now(),
    }

    // Store with expiration (30 days)
    await storageService.set(key, data, secret, DEFAULT_EXPIRATION)
  } catch (error) {
    console.error('Error storing private content:', error)
  }
}

/**
 * Get stored private content for an article
 * Returns null if not found or expired
 */
export async function getStoredPrivateContent(articleId: string): Promise<{
  content: string
  authorPubkey: string
  invoice?: AlbyInvoice
} | null> {
  try {
    const key = `article_private_content_${articleId}`
    const secret = deriveSecret(articleId)
    const data = await storageService.get<StoredArticleData>(key, secret)

    if (!data) {
      return null
    }

    return {
      content: data.content,
      authorPubkey: data.authorPubkey,
      ...(data.invoice
        ? {
            invoice: {
              invoice: data.invoice.invoice,
              paymentHash: data.invoice.paymentHash,
              amount: data.invoice.amount,
              expiresAt: data.invoice.expiresAt,
            } as AlbyInvoice,
          }
        : {}),
    }
  } catch (error) {
    console.error('Error retrieving private content:', error)
    return null
  }
}

/**
 * Get stored invoice for an article
 */
export async function getStoredInvoice(articleId: string): Promise<AlbyInvoice | null> {
  const stored = await getStoredPrivateContent(articleId)
  return stored?.invoice ?? null
}

/**
 * Remove stored private content (after successful send or expiry)
 */
export async function removeStoredPrivateContent(articleId: string): Promise<void> {
  try {
    const key = `article_private_content_${articleId}`
    await storageService.delete(key)
  } catch (error) {
    console.error('Error removing private content:', error)
  }
}