import Google from 'next-auth/providers/google';
import Credentials from 'next-auth/providers/credentials';
import { z } from 'zod';
import bcrypt from 'bcryptjs';
import prisma from '@/lib/prisma';
import { rateLimit } from '@/lib/rate-limit';

export function buildAuthProviders() {
  const providers = [];

  if (process.env.AUTH_GOOGLE_ID && process.env.AUTH_GOOGLE_SECRET) {
    const googlePrompt =
      process.env.AUTH_GOOGLE_PROMPT === 'login' ? 'login' : 'select_account';

    providers.push(
      Google({
        clientId: process.env.AUTH_GOOGLE_ID,
        clientSecret: process.env.AUTH_GOOGLE_SECRET,
        authorization: {
          params: {
            prompt: googlePrompt,
            access_type: 'online',
          },
        },
      }),
    );
  }

  providers.push(
    Credentials({
      async authorize(credentials) {
        try {
          const parsedCredentials = z
            .object({ email: z.string().email(), password: z.string().min(6) })
            .safeParse(credentials);

          if (!parsedCredentials.success) {
            return null;
          }

          const { email, password } = parsedCredentials.data;

          const { allowed } = rateLimit(`login:${email.toLowerCase()}`);
          if (!allowed) {
            return null;
          }

          const user = await prisma.user.findUnique({
            where: { email: email.toLowerCase() },
          });

          if (!user || !user.password) {
            return null;
          }

          const passwordsMatch = await bcrypt.compare(password, user.password);

          if (passwordsMatch) {
            return {
              id: user.id,
              email: user.email,
              name: user.name,
              role: user.role,
            };
          }

          return null;
        } catch {
          return null;
        }
      },
    }),
  );

  return providers;
}

export function isGoogleAuthEnabled() {
  return Boolean(process.env.AUTH_GOOGLE_ID && process.env.AUTH_GOOGLE_SECRET);
}