/*
 *  author: Yagnik Poshiya
 *  organization: Webbrains Technologies Private Limited
 */

import { NextResponse } from 'next/server';

import { getPublicRagHistory } from '@/lib/public-rag/public-rag-history';
import { verifyPublicRagAccess } from '@/lib/public-rag/verify-public-rag-access';
import { isSupabaseServiceRoleConfigured } from '@/lib/supabase/service-role';

const JSON_HEADERS = { 'content-type': 'application/json' } as const;

function corsReflectOrigin(request: Request): HeadersInit {
  const origin = request.headers.get('origin');
  if (!origin) return {};
  return {
    'Access-Control-Allow-Origin': origin,
    Vary: 'Origin',
    'Access-Control-Allow-Methods': 'POST, OPTIONS',
    'Access-Control-Allow-Headers': 'content-type, x-api-key, x-ae-preview-token, authorization',
  };
}

export async function OPTIONS(request: Request) {
  const origin = request.headers.get('origin');
  if (!origin) return new NextResponse(null, { status: 204 });
  return new NextResponse(null, {
    status: 204,
    headers: {
      'Access-Control-Allow-Origin': origin,
      'Access-Control-Allow-Methods': 'POST, OPTIONS',
      'Access-Control-Allow-Headers': 'content-type, x-api-key, x-ae-preview-token, authorization',
      'Access-Control-Max-Age': '86400',
      Vary: 'Origin',
    },
  });
}

export async function POST(request: Request) {
  if (!isSupabaseServiceRoleConfigured()) {
    return NextResponse.json(
      { ok: false, message: 'Server is not configured.' },
      { status: 500, headers: { ...JSON_HEADERS, ...corsReflectOrigin(request) } },
    );
  }

  let body: Record<string, unknown>;
  try {
    body = (await request.json()) as Record<string, unknown>;
  } catch {
    return NextResponse.json(
      { ok: false, message: 'Invalid JSON body.' },
      { status: 400, headers: { ...JSON_HEADERS, ...corsReflectOrigin(request) } },
    );
  }

  const projectAgentId = String(body.projectAgentId ?? '');
  const apiKey = request.headers.get('x-api-key');
  const origin = request.headers.get('origin');
  const previewToken = request.headers.get('x-ae-preview-token');
  const v = await verifyPublicRagAccess({
    apiKey,
    origin,
    previewToken,
    projectAgentId,
  });
  if (!v.ok) {
    return NextResponse.json(
      { ok: false, message: v.message },
      { status: v.status, headers: { ...JSON_HEADERS, ...corsReflectOrigin(request) } },
    );
  }

  const result = await getPublicRagHistory({
    conversationId: String(body.conversationId ?? ''),
    visitorId: String(body.visitorId ?? ''),
    projectId: v.projectId,
    projectAgentId,
  });

  const cors = corsReflectOrigin(request);

  if (!result.ok) {
    return NextResponse.json(
      { ok: false, message: result.message },
      { status: 400, headers: { ...JSON_HEADERS, ...cors } },
    );
  }

  return NextResponse.json(
    { ok: true, messages: result.messages, projectName: result.projectName, greeting: result.greeting },
    { status: 200, headers: { ...JSON_HEADERS, ...cors } },
  );
}