/**
 * Image Cleanup Utility
 * Safely deletes orphaned image files from disk.
 * Checks database references before deleting to avoid breaking shared images.
 */

import { promises as fs } from 'fs'
import path from 'path'
import { prisma } from '@/lib/prisma'

const UPLOADS_DIR = 'public/uploads/notes'

/**
 * Delete an image file from disk only if no other note references it.
 * @param imageUrl - The relative URL path (e.g. "/uploads/notes/abc.jpg")
 * @param excludeNoteId - Note ID to exclude from reference check (the note being deleted)
 */
export async function deleteImageFileSafely(imageUrl: string, excludeNoteId?: string): Promise<void> {
  if (!imageUrl || !imageUrl.startsWith('/uploads/notes/')) return

  try {
    const notes = await prisma.note.findMany({
      where: { images: { contains: imageUrl } },
      select: { id: true },
    })
    const otherRefs = notes.filter(n => n.id !== excludeNoteId)
    if (otherRefs.length > 0) return // File still referenced elsewhere

    const filePath = path.join(process.cwd(), imageUrl)
    await fs.unlink(filePath)
  } catch {
    // File already gone or unreadable -- silently skip
  }
}

/**
 * Delete all image files associated with a note.
 * Checks that each image is not referenced by any other note before deleting.
 */
export async function cleanupNoteImages(noteId: string, imageUrls: string[]): Promise<void> {
  for (const url of imageUrls) {
    await deleteImageFileSafely(url, noteId)
  }
}

/**
 * Parse the images JSON field from a note record.
 */
export function parseImageUrls(imagesJson: string | null): string[] {
  if (!imagesJson) return []
  try {
    const parsed = JSON.parse(imagesJson)
    return Array.isArray(parsed) ? parsed.filter((u: unknown) => typeof u === 'string') : []
  } catch {
    return []
  }
}