/**
 * Worker service for republishing unpublished objects to relays
 * Continuously attempts to publish objects with published === false
 */

import { objectCache, type ObjectType } from './objectCache'
import { relaySessionManager } from './relaySessionManager'
import { publishLog } from './publishLog'
import { writeService } from './writeService'
import { getPublishRelays } from './relaySelection'

const REPUBLISH_INTERVAL_MS = 30000 // 30 seconds
const MAX_RETRIES_PER_OBJECT = 10
const RETRY_DELAY_MS = 5000 // 5 seconds between retries for same object

interface UnpublishedObject {
  objectType: ObjectType
  id: string
  event: import('nostr-tools').Event
  retryCount: number
  lastRetryAt: number
}

class PublishWorkerService {
  private isRunning = false
  private intervalId: ReturnType<typeof setInterval> | null = null
  private unpublishedObjects: Map<string, UnpublishedObject> = new Map()
  private processing = false

  /**
   * Start the publish worker
   * Can use Service Worker if available, otherwise falls back to setInterval
   */
  async start(): Promise<void> {
    if (this.isRunning) {
      return
    }

    this.isRunning = true
    console.warn('[PublishWorker] Starting publish worker')

    // Try to use Service Worker for background processing
    if (typeof window !== 'undefined') {
      try {
        const { swClient } = await import('./swClient')
        const isReady = await swClient.isReady()
        if (isReady) {
          console.warn('[PublishWorker] Using Service Worker for background processing')
          await swClient.startPublishWorker()
          // Still process immediately in main thread
          void this.processUnpublished()
          return
        }
      } catch (error) {
        console.warn('[PublishWorker] Service Worker not available, using setInterval:', error)
      }
    }

    // Fallback to setInterval if Service Worker not available
    // Start processing immediately
    void this.processUnpublished()

    // Then process periodically
    this.intervalId = setInterval(() => {
      void this.processUnpublished()
    }, REPUBLISH_INTERVAL_MS)
  }

  /**
   * Stop the publish worker
   */
  async stop(): Promise<void> {
    if (!this.isRunning) {
      return
    }

    this.isRunning = false

    // Stop Service Worker if active
    if (typeof window !== 'undefined') {
      try {
        const { swClient } = await import('./swClient')
        const isReady = await swClient.isReady()
        if (isReady) {
          await swClient.stopPublishWorker()
        }
      } catch {
        // Ignore errors
      }
    }

    // Stop local interval
    if (this.intervalId) {
      clearInterval(this.intervalId)
      this.intervalId = null
    }
    console.warn('[PublishWorker] Stopped publish worker')
  }

  /**
   * Process all unpublished objects
   * Made public for Service Worker access
   */
  async processUnpublished(): Promise<void> {
    if (this.processing) {
      return
    }

    this.processing = true

    try {
      const objectTypes = getAllPublishableObjectTypes()
      const now = Date.now()
      await this.refreshUnpublishedMap({ objectTypes, now })
      await this.processQueuedObjects()
    } catch (error) {
      console.error('[PublishWorker] Error processing unpublished objects:', error)
    } finally {
      this.processing = false
    }
  }

  private async refreshUnpublishedMap(params: { objectTypes: ObjectType[]; now: number }): Promise<void> {
    for (const objectType of params.objectTypes) {
      const unpublished = await objectCache.getUnpublished(objectType)
      this.upsertUnpublishedObjects({ objectType, unpublished, now: params.now })
    }
  }

  private upsertUnpublishedObjects(params: {
    objectType: ObjectType
    unpublished: Array<{ id: string; event: import('nostr-tools').Event }>
    now: number
  }): void {
    for (const { id, event } of params.unpublished) {
      const key = buildUnpublishedKey(params.objectType, id)
      const existing = this.unpublishedObjects.get(key)

      if (existing && existing.retryCount >= MAX_RETRIES_PER_OBJECT) {
        console.warn(`[PublishWorker] Max retries reached for ${params.objectType}:${id}, skipping`)
      }

      const shouldSkip = Boolean(existing && params.now - existing.lastRetryAt < RETRY_DELAY_MS)
      if (!shouldSkip && (!existing || existing.retryCount < MAX_RETRIES_PER_OBJECT)) {
        this.unpublishedObjects.set(key, {
          objectType: params.objectType,
          id,
          event,
          retryCount: existing?.retryCount ?? 0,
          lastRetryAt: params.now,
        })
      }
    }
  }

  private async processQueuedObjects(): Promise<void> {
    const objectsToProcess = Array.from(this.unpublishedObjects.entries())
    for (const [key, obj] of objectsToProcess) {
      await this.attemptPublish({ key, obj })
    }
  }

  /**
   * Attempt to publish an unpublished object
   * Uses websocketService to route events to Service Worker
   */
  private async attemptPublish(params: { key: string; obj: UnpublishedObject }): Promise<void> {
    const { obj } = params
    try {
      const { websocketService } = await import('./websocketService')
      const relays = await getPublishRelays()
      console.warn(`[PublishWorker] Attempting to publish ${obj.objectType}:${obj.id} to ${relays.length} relay(s)`)
      const statuses = await websocketService.publishEvent(obj.event, relays)
      const successfulRelays = this.processPublishStatuses({ obj, relays, statuses })
      await this.finalizePublishAttempt({ key: params.key, obj, successfulRelays })
    } catch (error) {
      console.error(`[PublishWorker] Error publishing ${obj.objectType}:${obj.id}:`, error)
      this.incrementRetryOrRemove({ key: params.key, fallbackObj: params.obj })
    }
  }

  private processPublishStatuses(params: {
    obj: UnpublishedObject
    relays: string[]
    statuses: { success: boolean; error?: string }[]
  }): string[] {
    const successfulRelays: string[] = []
    params.statuses.forEach((status, index) => {
      const relayUrl = params.relays[index]
      if (!relayUrl) {
        return
      }
      if (status.success) {
        successfulRelays.push(relayUrl)
        void publishLog.logPublication({ eventId: params.obj.event.id, relayUrl, success: true, objectType: params.obj.objectType, objectId: params.obj.id })
        return
      }
      const errorMessage = status.error ?? 'Unknown error'
      console.warn(`[PublishWorker] Relay ${relayUrl} failed for ${params.obj.objectType}:${params.obj.id}:`, errorMessage)
      relaySessionManager.markRelayFailed(relayUrl)
      void publishLog.logPublication({ eventId: params.obj.event.id, relayUrl, success: false, error: errorMessage, objectType: params.obj.objectType, objectId: params.obj.id })
    })
    return successfulRelays
  }

  private async finalizePublishAttempt(params: { key: string; obj: UnpublishedObject; successfulRelays: string[] }): Promise<void> {
    if (params.successfulRelays.length > 0) {
      await writeService.updatePublished(params.obj.objectType, params.obj.id, params.successfulRelays)
      console.warn(`[PublishWorker] Successfully published ${params.obj.objectType}:${params.obj.id} to ${params.successfulRelays.length} relay(s)`)
      this.unpublishedObjects.delete(params.key)
      return
    }
    this.incrementRetryOrRemove({ key: params.key, fallbackObj: params.obj })
  }

  private incrementRetryOrRemove(params: { key: string; fallbackObj: UnpublishedObject }): void {
    const current = this.unpublishedObjects.get(params.key)
    const base = current ?? params.fallbackObj
    const next = { ...base, retryCount: base.retryCount + 1, lastRetryAt: Date.now() }
    this.unpublishedObjects.set(params.key, next)
    console.warn(`[PublishWorker] All relays failed for ${next.objectType}:${next.id}, retry count: ${next.retryCount}/${MAX_RETRIES_PER_OBJECT}`)
    if (next.retryCount >= MAX_RETRIES_PER_OBJECT) {
      this.unpublishedObjects.delete(params.key)
    }
  }
}

export const publishWorker = new PublishWorkerService()

function getAllPublishableObjectTypes(): ObjectType[] {
  return ['author', 'series', 'publication', 'review', 'purchase', 'sponsoring', 'review_tip', 'payment_note']
}

function buildUnpublishedKey(objectType: ObjectType, id: string): string {
  return `${objectType}:${id}`
}