import type { Event, Filter } from 'nostr-tools'
import type { SimplePoolWithSub } from '@/types/nostr-tools-extended'
import { nostrService } from '../nostr'
import { MIN_EVENT_DATE, PLATFORM_SERVICE } from '../platformConfig'
import { cachePlatformEvent } from './cacheEvent'
import { SYNC_INTERVAL_MS, SYNC_TIMEOUT_MS } from './constants'
import { collectEventsFromRelays, type RelaySessionManager, type SyncProgressManager } from './relayCollection'

export class PlatformSyncService {
  private syncInProgress = false
  private syncSubscription: { unsub: () => void } | null = null
  private lastSyncTime = 0

  /**
   * Start background sync
   * Scans all notes with service='zapwall.fr' and caches them
   * Does not require pubkey - syncs all public notes with service='zapwall.fr'
   */
  public async startSync(): Promise<void> {
    if (this.syncInProgress) {
      return
    }

    const pool = nostrService.getPool()
    if (!pool) {
      console.warn('Pool not initialized, cannot start platform sync')
      return
    }

    this.syncInProgress = true

    const { relaySessionManager, syncProgressManager, activeRelays } = await this.loadSyncManagers()
    const initialRelay = activeRelays[0] ?? 'Connecting...'
    const totalRelays = activeRelays.length ?? 1
    syncProgressManager.setProgress({ currentStep: 0, totalSteps: totalRelays, completed: false, currentRelay: initialRelay })

    try {
      await this.performSync({ pool: pool as unknown as SimplePoolWithSub, relaySessionManager, syncProgressManager, activeRelays })
      const finalRelay = activeRelays[activeRelays.length - 1] ?? initialRelay
      syncProgressManager.setProgress({ currentStep: totalRelays, totalSteps: totalRelays, completed: true, currentRelay: finalRelay })
    } catch (error) {
      console.error('Error in platform sync:', error)
      syncProgressManager.setProgress(null)
    } finally {
      this.syncInProgress = false
      setTimeout(() => {
        syncProgressManager.setProgress(null)
      }, 500)
    }
  }

  /**
   * Start continuous sync (runs periodically)
   * Can use Service Worker if available, otherwise falls back to setInterval
   */
  public async startContinuousSync(): Promise<void> {
    if (typeof window !== 'undefined') {
      const usedSw = await this.tryStartServiceWorkerSync()
      if (usedSw) {
        void this.startSync()
        return
      }
    }

    void this.startSync()
    setInterval(() => {
      if (!this.syncInProgress) {
        void this.startSync()
      }
    }, SYNC_INTERVAL_MS)
  }

  /**
   * Stop sync
   */
  public async stopSync(): Promise<void> {
    if (typeof window !== 'undefined') {
      await this.tryStopServiceWorkerSync()
    }

    if (this.syncSubscription) {
      this.syncSubscription.unsub()
      this.syncSubscription = null
    }
    this.syncInProgress = false
  }

  /**
   * Check if sync is in progress
   */
  public isSyncing(): boolean {
    return this.syncInProgress
  }

  /**
   * Get last sync time
   */
  public getLastSyncTime(): number {
    return this.lastSyncTime
  }

  /**
   * Perform a sync operation
   * Scans all notes with service='zapwall.fr' tag from ALL active relays
   * Starts from January 5, 2026 00:00:00 UTC
   */
  private async performSync(params: {
    pool: SimplePoolWithSub
    relaySessionManager: RelaySessionManager
    syncProgressManager: SyncProgressManager
    activeRelays: string[]
  }): Promise<void> {
    const filters = buildSyncFilters()
    logSyncStart(filters)

    if (params.activeRelays.length === 0) {
      throw new Error('No active relays available')
    }

    const allEvents = await collectEventsFromRelays({
      pool: params.pool,
      activeRelays: params.activeRelays,
      filters,
      relaySessionManager: params.relaySessionManager,
      syncProgressManager: params.syncProgressManager,
      syncTimeoutMs: SYNC_TIMEOUT_MS,
      setSyncSubscription: (sub): void => {
        this.syncSubscription = sub
      },
    })

    await processAndCacheEvents(allEvents)
    console.warn(`[PlatformSync] Total events collected from all relays: ${allEvents.length}`)
    this.lastSyncTime = Date.now()
  }

  private async loadSyncManagers(): Promise<{
    relaySessionManager: RelaySessionManager & { getActiveRelays: () => Promise<string[]> }
    syncProgressManager: SyncProgressManager
    activeRelays: string[]
  }> {
    const { syncProgressManager } = await import('../syncProgressManager')
    const { relaySessionManager } = await import('../relaySessionManager')
    const activeRelays = await relaySessionManager.getActiveRelays()
    return { relaySessionManager, syncProgressManager, activeRelays }
  }

  private async tryStartServiceWorkerSync(): Promise<boolean> {
    try {
      const { swClient } = await import('../swClient')
      const isReady = await swClient.isReady()
      if (!isReady) {
        return false
      }
      console.warn('[PlatformSync] Using Service Worker for background sync')
      await swClient.startPlatformSync()
      return true
    } catch (error) {
      console.warn('[PlatformSync] Service Worker not available, using setInterval:', error)
      return false
    }
  }

  private async tryStopServiceWorkerSync(): Promise<void> {
    try {
      const { swClient } = await import('../swClient')
      const isReady = await swClient.isReady()
      if (isReady) {
        await swClient.stopPlatformSync()
      }
    } catch {
      // Ignore errors
    }
  }
}

function buildSyncFilters(): Filter[] {
  return [{ kinds: [1], since: MIN_EVENT_DATE, limit: 1000 }]
}

function logSyncStart(filters: Filter[]): void {
  console.warn(
    `[PlatformSync] Starting sync with filter (no #service filter on relay side):`,
    JSON.stringify(filters, null, 2)
  )
  console.warn(`[PlatformSync] MIN_EVENT_DATE: ${MIN_EVENT_DATE} (${new Date(MIN_EVENT_DATE * 1000).toISOString()})`)
  console.warn(`[PlatformSync] Will filter by service='${PLATFORM_SERVICE}' client-side after receiving events`)
}

async function processAndCacheEvents(events: Event[]): Promise<void> {
  for (const event of events) {
    try {
      await cachePlatformEvent(event)
    } catch (error) {
      console.error('Error processing event:', error, event.id)
    }
  }
}