import bcrypt from 'bcryptjs'
import jwt from 'jsonwebtoken'
import { prisma } from '@/lib/db'

export async function createUser(email: string, password: string, name?: string) {
  const passwordHash = await bcrypt.hash(password, 10)
  return prisma.user.create({
    data: { email, passwordHash, name }
  })
}

export async function validateUser(email: string, password: string) {
  const user = await prisma.user.findUnique({ where: { email } })
  if (!user) return null

  const isValid = await bcrypt.compare(password, user.passwordHash)
  return isValid ? user : null
}

export function generateToken(userId: string): string {
  return jwt.sign({ userId }, process.env.JWT_SECRET!, { expiresIn: '7d' })
}

export async function verifyToken(token: string) {
  try {
    const payload = jwt.verify(token, process.env.JWT_SECRET!) as { userId: string }
    return payload
  } catch (error) {
    throw new Error('Invalid token')
  }
}

export async function getUserFromToken(token: string) {
  try {
    const payload = await verifyToken(token)
    const user = await prisma.user.findUnique({
      where: { id: payload.userId },
      select: { id: true, email: true, name: true, theme: true, fontSize: true }
    })
    return user
  } catch (error) {
    return null
  }
}