import { readFile, writeFile } from "fs/promises";
import { existsSync } from "fs";
import { getFilePath } from "./storage";
import { encryptBuffer, decryptBuffer } from "./filecrypto";
import { prisma } from "./prisma";

// Chiffrement/déchiffrement explicite d'un fichier (action groupée "chiffrer/déchiffrer").
// Format auto-porté géré par filecrypto. Le flag File.isEncrypted indique l'état sur disque.

export async function encryptFile(fileId: string): Promise<boolean> {
  const file = await prisma.file.findUnique({ where: { id: fileId } });
  if (!file || file.isEncrypted) return false;

  const filePath = getFilePath(file.storagePath);
  if (!existsSync(filePath)) return false;

  const plain = await readFile(filePath);
  await writeFile(filePath, encryptBuffer(plain));
  await prisma.file.update({
    where: { id: fileId },
    data: { isEncrypted: true, encryptionIV: "v2" },
  });
  return true;
}

export async function decryptFile(fileId: string): Promise<Buffer | null> {
  const file = await prisma.file.findUnique({ where: { id: fileId } });
  if (!file) return null;

  const filePath = getFilePath(file.storagePath);
  if (!existsSync(filePath)) return null;

  const raw = await readFile(filePath);
  return file.isEncrypted ? decryptBuffer(raw) : raw;
}

export async function removeEncryption(fileId: string): Promise<boolean> {
  const file = await prisma.file.findUnique({ where: { id: fileId } });
  if (!file || !file.isEncrypted) return false;

  const filePath = getFilePath(file.storagePath);
  if (!existsSync(filePath)) return false;

  const raw = await readFile(filePath);
  await writeFile(filePath, decryptBuffer(raw));
  await prisma.file.update({
    where: { id: fileId },
    data: { isEncrypted: false, encryptionIV: null },
  });
  return true;
}