/**
 * Object modification and deletion utilities
 * Only the author (pubkey) who published the original note can modify or delete it
 *
 * Access rules:
 * - Modification: Only the author (event.pubkey === userPubkey) can modify
 * - Deletion: Only the author (event.pubkey === userPubkey) can delete
 * - Read access: All users can read previews, paid content requires payment verification
 */

import type { Event } from 'nostr-tools'
import { extractTagsFromEvent } from './nostrTagSystem'
import { canModifyObject, getNextVersion } from './versionManager'

/**
 * Check if user can modify an object
 * Only the author (pubkey) who published the original note can modify it
 */
export function canUserModifyObject(event: Event, userPubkey: string): boolean {
  return canModifyObject(event, userPubkey)
}

/**
 * Build an update event (new version)
 * Increments version and keeps the same hash ID
 */
export async function buildUpdateEvent(
  originalEvent: Event,
  updatedData: Record<string, unknown>,
  userPubkey: string
): Promise<Event | null> {
  // Check if user can modify
  if (!canUserModifyObject(originalEvent, userPubkey)) {
    throw new Error('Only the author can modify this object')
  }

  const tags = extractTagsFromEvent(originalEvent)
  const nextVersion = getNextVersion([originalEvent])

  // Build new event with incremented version
  // The hash ID stays the same, only version changes
  const newTags = originalEvent.tags.map((tag) => {
    if (tag[0] === 'version') {
      return ['version', nextVersion.toString()]
    }
    return tag
  })

  // Remove hidden tag if present (object is being updated, not deleted)
  const filteredTags = newTags.filter((tag) => !(tag[0] === 'hidden' && tag[1] === 'true'))

  return {
    ...originalEvent,
    tags: filteredTags,
    created_at: Math.floor(Date.now() / 1000),
    // Content and other fields should be updated by the caller
  } as Event
}

/**
 * Build a delete event (hide object)
 * Sets hidden=true and increments version
 */
export async function buildDeleteEvent(
  originalEvent: Event,
  userPubkey: string
): Promise<Event | null> {
  // Check if user can modify
  if (!canUserModifyObject(originalEvent, userPubkey)) {
    throw new Error('Only the author can delete this object')
  }

  const tags = extractTagsFromEvent(originalEvent)
  const nextVersion = getNextVersion([originalEvent])

  // Build new event with hidden=true and incremented version
  const newTags = originalEvent.tags.map((tag) => {
    if (tag[0] === 'version') {
      return ['version', nextVersion.toString()]
    }
    if (tag[0] === 'hidden') {
      return ['hidden', 'true']
    }
    return tag
  })

  // Add hidden tag if not present
  if (!newTags.some((tag) => tag[0] === 'hidden')) {
    newTags.push(['hidden', 'true'])
  }

  return {
    ...originalEvent,
    tags: newTags,
    created_at: Math.floor(Date.now() / 1000),
  } as Event
}