import { NextRequest, NextResponse } from 'next/server';
import bcryptjs from 'bcryptjs';
import { eq } from 'drizzle-orm';
import { db } from '@/lib/db';
import { users } from '@/lib/db/schema';

export async function POST(request: NextRequest) {
  let body: unknown;
  try {
    body = await request.json();
  } catch {
    return NextResponse.json({ error: 'Invalid JSON body' }, { status: 400 });
  }

  const { email, password, name } = body as Record<string, unknown>;

  // Validate email
  if (!email || typeof email !== 'string' || email.trim() === '') {
    return NextResponse.json({ error: 'Email is required' }, { status: 400 });
  }

  // Validate password
  if (!password || typeof password !== 'string' || password.length < 8) {
    return NextResponse.json(
      { error: 'Password must be at least 8 characters' },
      { status: 400 }
    );
  }

  const normalizedEmail = email.trim().toLowerCase();

  // Check email uniqueness
  const [existingUser] = await db
    .select({ id: users.id })
    .from(users)
    .where(eq(users.email, normalizedEmail))
    .limit(1);

  if (existingUser) {
    return NextResponse.json(
      { error: 'An account with this email already exists' },
      { status: 409 }
    );
  }

  // Hash password
  const password_hash = await bcryptjs.hash(password, 12);

  // Insert user
  const [newUser] = await db
    .insert(users)
    .values({
      email: normalizedEmail,
      password_hash,
      name: typeof name === 'string' && name.trim() !== '' ? name.trim() : null,
      provider: 'credentials',
    })
    .returning({ id: users.id, email: users.email, name: users.name });

  return NextResponse.json(
    { id: newUser.id, email: newUser.email, name: newUser.name },
    { status: 201 }
  );
}