/**
 * Notification detector - scans IndexedDB for new events and creates notifications
 * Runs in a service worker or main thread
 */

import { objectCache } from './objectCache'
import { notificationService, type NotificationType } from './notificationService'
import type { CachedObject } from './objectCache'

const USER_OBJECT_NOTIFICATION_TYPES: Array<{ type: string; notificationType: NotificationType }> = [
  { type: 'purchase', notificationType: 'purchase' },
  { type: 'review', notificationType: 'review' },
  { type: 'sponsoring', notificationType: 'sponsoring' },
  { type: 'review_tip', notificationType: 'review_tip' },
  { type: 'payment_note', notificationType: 'payment_note' },
]

interface ObjectChange {
  objectType: string
  objectId: string
  eventId: string
  oldPublished: false | string[]
  newPublished: false | string[]
}

class NotificationDetector {
  private lastScanTime: number = 0
  private scanInterval: number | null = null
  private isScanning = false
  private userPubkey: string | null = null

  /**
   * Start scanning for notifications
   */
  start(userPubkey: string): void {
    if (this.scanInterval) {
      return // Already started
    }

    this.userPubkey = userPubkey
    this.lastScanTime = Date.now()

    // Scan immediately
    void this.scan()

    // Then scan periodically (every 30 seconds)
    this.scanInterval = window.setInterval(() => {
      void this.scan()
    }, 30000)
  }

  /**
   * Stop scanning
   */
  stop(): void {
    if (this.scanInterval) {
      clearInterval(this.scanInterval)
      this.scanInterval = null
    }
    this.userPubkey = null
  }

  /**
   * Scan IndexedDB for new events that should trigger notifications
   */
  async scan(): Promise<void> {
    if (this.isScanning || !this.userPubkey) {
      return
    }

    this.isScanning = true

    try {
      // Scan for user-related objects
      await this.scanUserObjects()

      // Scan for published status changes
      await this.scanPublishedStatusChanges()

      this.lastScanTime = Date.now()
    } catch (error) {
      console.error('[NotificationDetector] Error scanning:', error)
    } finally {
      this.isScanning = false
    }
  }

  /**
   * Scan for user-related objects (purchases, reviews, sponsoring, review_tips, payment_notes)
   */
  private async scanUserObjects(): Promise<void> {
    if (!this.userPubkey) {
      return
    }

    for (const cfg of USER_OBJECT_NOTIFICATION_TYPES) {
      await this.scanUserObjectsOfType(cfg)
    }
  }

  private async scanUserObjectsOfType(params: { type: string; notificationType: NotificationType }): Promise<void> {
    try {
      const {userPubkey} = this
      if (!userPubkey) {
        return
      }
      const allObjects = await objectCache.getAll(params.type as Parameters<typeof objectCache.getAll>[0])
      const userObjects = filterUserRelatedObjects({ type: params.type, allObjects: allObjects as CachedObject[], userPubkey })
      await this.createNotificationsForNewObjects({ type: params.type, notificationType: params.notificationType, objects: userObjects })
    } catch (error) {
      console.error(`[NotificationDetector] Error scanning ${params.type}:`, error)
    }
  }

  private async createNotificationsForNewObjects(params: {
    type: string
    notificationType: NotificationType
    objects: CachedObject[]
  }): Promise<void> {
    for (const obj of params.objects) {
      if (obj.createdAt * 1000 > this.lastScanTime) {
        const eventId = obj.id.split(':')[1] ?? obj.id
        await notificationService.createNotification({
          type: params.notificationType,
          objectType: params.type,
          objectId: obj.id,
          eventId,
          data: { object: obj },
        })
      }
    }
  }

  /**
   * Scan for published status changes (published: false -> list of relays)
   */
  private async scanPublishedStatusChanges(): Promise<void> {
    if (!this.userPubkey) {
      return
    }

    try {
      // Get all object types that can be published
      const objectTypes = ['author', 'series', 'publication', 'review', 'purchase', 'sponsoring', 'review_tip', 'payment_note']
      const oneHourAgo = Date.now() - 60 * 60 * 1000

      for (const objectType of objectTypes) {
        try {
          const allObjects = await objectCache.getAll(objectType as Parameters<typeof objectCache.getAll>[0])
          const userObjects = (allObjects as CachedObject[]).filter((obj: CachedObject) => {
            // Check if object belongs to user - need to check parsed object for pubkey
            const parsed = obj.parsed as { pubkey?: string } | undefined
            return parsed?.pubkey === this.userPubkey
          })

          for (const obj of userObjects) {
            await this.maybeCreatePublishedNotification({
              obj,
              objectType,
              oneHourAgo,
            })
          }
        } catch (error) {
          console.error(`[NotificationDetector] Error scanning published status for ${objectType}:`, error)
        }
      }
    } catch (error) {
      console.error('[NotificationDetector] Error scanning published status changes:', error)
    }
  }

  private async maybeCreatePublishedNotification(params: {
    obj: CachedObject
    objectType: string
    oneHourAgo: number
  }): Promise<void> {
    if (!Array.isArray(params.obj.published) || params.obj.published.length === 0) {
      return
    }

    if (params.obj.createdAt * 1000 <= params.oneHourAgo) {
      return
    }

    const eventId = params.obj.id.split(':')[1] ?? params.obj.id
    const existing = await notificationService.getNotificationByEventId(eventId)
    if (existing?.type === 'published') {
      return
    }

    const relays = params.obj.published
    await notificationService.createNotification({
      type: 'published',
      objectType: params.objectType,
      objectId: params.obj.id,
      eventId,
      data: {
        relays,
        object: params.obj,
        title: 'Publication réussie',
        message: `Votre contenu a été publié sur ${relays.length} relais`,
      },
    })
  }

  /**
   * Manually check for a specific object change
   */
  async checkObjectChange(change: ObjectChange): Promise<void> {
    if (!this.userPubkey) {
      return
    }

    try {
      // Check if published status changed from false to array
      if (change.oldPublished === false && Array.isArray(change.newPublished) && change.newPublished.length > 0) {
        // Get the object to check if it belongs to user
        const obj = await objectCache.get(change.objectType as Parameters<typeof objectCache.get>[0], change.objectId)
        if (obj) {
          const cachedObj = obj as CachedObject
          const parsed = cachedObj.parsed as { pubkey?: string } | undefined
          if (parsed?.pubkey === this.userPubkey) {
            const relays = change.newPublished
            await notificationService.createNotification({
              type: 'published',
              objectType: change.objectType,
              objectId: change.objectId,
              eventId: change.eventId,
              data: {
                relays,
                object: obj,
                title: 'Publication réussie',
                message: `Votre contenu a été publié sur ${relays.length} relais`,
              },
            })
          }
        }
      }
    } catch (error) {
      console.error('[NotificationDetector] Error checking object change:', error)
    }
  }

}

function filterUserRelatedObjects(params: { type: string; allObjects: CachedObject[]; userPubkey: string }): CachedObject[] {
  return params.allObjects.filter((obj: CachedObject) => {
    if (params.type === 'purchase' || params.type === 'sponsoring' || params.type === 'payment_note') {
      return (obj as { targetPubkey?: string }).targetPubkey === params.userPubkey
    }
    if (params.type === 'review' || params.type === 'review_tip') {
      return true
    }
    return false
  })
}

export const notificationDetector = new NotificationDetector()