import { NextRequest, NextResponse } from 'next/server'
import { auth } from '@/auth'
import prisma from '@/lib/prisma'

/**
 * GET /api/user/me
 * Returns lightweight user profile including onboardingCompleted flag.
 */
export async function GET() {
  const session = await auth()
  if (!session?.user?.id) {
    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
  }
  const user = await prisma.user.findUnique({
    where: { id: session.user.id },
    select: { id: true, name: true, email: true, onboardingCompleted: true, onboardingStep: true },
  })
  if (!user) return NextResponse.json({ error: 'User not found' }, { status: 404 })
  return NextResponse.json(user)
}

/**
 * PATCH /api/user/me
 * Partial update of user profile. Supported fields: onboardingCompleted, onboardingStep.
 */
export async function PATCH(req: NextRequest) {
  const session = await auth()
  if (!session?.user?.id) {
    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
  }
  let body: Record<string, unknown>
  try {
    body = await req.json()
  } catch {
    return NextResponse.json({ error: 'Invalid JSON' }, { status: 400 })
  }

  const allowedFields = ['onboardingCompleted', 'onboardingStep'] as const
  type AllowedField = typeof allowedFields[number]
  const data: Partial<Record<AllowedField, unknown>> = {}
  if ('onboardingCompleted' in body) {
    data.onboardingCompleted = Boolean(body.onboardingCompleted)
  }
  if ('onboardingStep' in body) {
    const val = parseInt(String(body.onboardingStep), 10)
    if (Number.isInteger(val) && val >= 0 && val <= 10) {
      data.onboardingStep = val
    }
  }

  if (Object.keys(data).length === 0) {
    return NextResponse.json({ error: 'No valid fields to update' }, { status: 400 })
  }

  const updated = await prisma.user.update({
    where: { id: session.user.id },
    data: data as any,
    select: { id: true, onboardingCompleted: true, onboardingStep: true },
  })
  return NextResponse.json(updated)
}