import { NextRequest, NextResponse } from 'next/server';
import { withDb } from '@/lib/api-handler';
import { db } from '@/lib/db';
import { z } from 'zod';
import { getClientIp } from '@/lib/validation';
import { rateLimit } from '@/lib/rate-limit';

const forgotPasswordSchema = z.object({
  email: z.string().email('Please enter a valid email address'),
});

async function handler(request: NextRequest) {
  try {
    // ── Rate Limit: 3 per 15 minutes ─────────────────────────────────
    const ip = getClientIp(request);
    const { allowed, retryAfterMs } = await rateLimit(`forgot-pw:${ip}`, 3, 15 * 60_000);
    if (!allowed) {
      return NextResponse.json(
        { error: 'Too many reset attempts. Please try again later.' },
        {
          status: 429,
          headers: { 'Retry-After': String(Math.ceil(retryAfterMs / 1000)) },
        }
      );
    }

    // ── Parse & Validate Body ─────────────────────────────────────────
    const body = await request.json();
    const parsed = forgotPasswordSchema.safeParse(body);
    if (!parsed.success) {
      return NextResponse.json(
        { error: parsed.error.issues[0].message },
        { status: 400 }
      );
    }

    const { email } = parsed.data;

    // ── Check if user exists ──────────────────────────────────────────
    const user = await db.user.findUnique({ where: { email } });

    if (user) {
      // Generate a random 6-digit code
      const code = String(Math.floor(100000 + Math.random() * 900000));
      const expiresAt = new Date(Date.now() + 15 * 60 * 1000); // 15 minutes

      // Invalidate any existing tokens for this email
      await db.resetToken.updateMany({
        where: { email, usedAt: null },
        data: { usedAt: new Date() },
      });

      // Create new reset token
      await db.resetToken.create({
        data: {
          email,
          token: code,
          expiresAt,
        },
      });

      return NextResponse.json({
        message: 'If an account exists with this email, a reset code has been generated.',
        code, // Demo: return code so user can use it
      });
    }

    // Return same message regardless to prevent email enumeration
    return NextResponse.json({
      message: 'If an account exists with this email, a reset code has been generated.',
    });
  } catch (error) {
    console.error('[FORGOT_PASSWORD_ERROR]', error);
    return NextResponse.json(
      { error: 'Internal server error' },
      { status: 500 }
    );
  }
}

export const POST = withDb(handler);