import { count, eq } from 'drizzle-orm'
import type { Config } from '../config.ts'
import type { Db } from '../db/client.ts'
import { attachments } from '../db/schema.ts'
import type { FileStorage } from '../storage.ts'
import { detectFileType } from './file-type.ts'
import { fail } from './http.ts'

export const MAX_ATTACHMENTS_PER_INCIDENT = 20

/** Validates and stores one uploaded file against an incident. */
export async function saveAttachment(
  { db, storage, config }: { db: Db; storage: FileStorage; config: Config },
  incidentId: string,
  file: unknown,
  uploadedById: string | null,
) {
  if (!(file instanceof File)) throw fail(400, 'Attach a file in the "file" field')
  if (file.size > config.maxUploadBytes) throw fail(413, `Files can be at most ${Math.round(config.maxUploadBytes / 1024 / 1024)} MB`)
  const [{ existing }] = await db.select({ existing: count() }).from(attachments).where(eq(attachments.incidentId, incidentId))
  if (existing >= MAX_ATTACHMENTS_PER_INCIDENT) throw fail(409, `An incident can have at most ${MAX_ATTACHMENTS_PER_INCIDENT} attachments`)

  const data = new Uint8Array(await file.arrayBuffer())
  const type = detectFileType(data)
  if (!type) throw fail(400, 'Only photos (JPEG, PNG, WebP, GIF, HEIC) and PDFs can be attached')

  const storageKey = await storage.save(data, type.extension)
  const fileName = (file.name || `attachment.${type.extension}`).replace(/[\r\n"\\/]/g, '_').slice(0, 200)
  try {
    const [row] = await db
      .insert(attachments)
      .values({ incidentId, fileName, contentType: type.contentType, sizeBytes: data.byteLength, storageKey, uploadedById })
      .returning()
    return row
  } catch (error) {
    await storage.remove(storageKey)
    throw error
  }
}