import { NextRequest, NextResponse } from 'next/server';
import { z } from 'zod';
import { getSession } from '@/lib/auth';
import { getGHLClientForUser } from '@/lib/ghl/helpers';

const sendSMSSchema = z.object({
  type: z.literal('SMS'),
  contactId: z.string(),
  message: z.string().min(1),
});

const sendEmailSchema = z.object({
  type: z.literal('EMAIL'),
  contactId: z.string(),
  subject: z.string().min(1),
  htmlBody: z.string().min(1),
  fromName: z.string().optional(),
  replyTo: z.string().email().optional(),
});

const sendMessageSchema = z.discriminatedUnion('type', [sendSMSSchema, sendEmailSchema]);

export async function POST(request: NextRequest) {
  const session = await getSession();
  if (!session) {
    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
  }

  const ghl = await getGHLClientForUser(session.user.id);
  if (!ghl) {
    return NextResponse.json({ error: 'GHL not configured' }, { status: 400 });
  }

  try {
    const body = await request.json();
    const validated = sendMessageSchema.parse(body);

    let message;
    if (validated.type === 'SMS') {
      message = await ghl.conversations.sendSMS({
        contactId: validated.contactId,
        message: validated.message,
      });
    } else {
      message = await ghl.conversations.sendEmail({
        contactId: validated.contactId,
        subject: validated.subject,
        htmlBody: validated.htmlBody,
        fromName: validated.fromName,
        replyTo: validated.replyTo,
      });
    }

    return NextResponse.json(message, { status: 201 });
  } catch (error) {
    if (error instanceof z.ZodError) {
      return NextResponse.json({ error: 'Validation failed', details: error.issues }, { status: 400 });
    }
    console.error('Failed to send message:', error);
    return NextResponse.json({ error: 'Failed to send message' }, { status: 500 });
  }
}