import type { APIRoute } from 'astro';
import crypto from 'crypto';

const POCKETBASE_URL = import.meta.env.POCKETBASE_URL || 'http://127.0.0.1:8090';

const POCKETBASE_ID_REGEX = /^[a-z0-9]{15}$/;

function getClientIp(request: Request): string {
  const forwarded = request.headers.get('x-forwarded-for');
  if (forwarded) {
    return forwarded.split(',')[0].trim();
  }
  return request.headers.get('x-real-ip') || 'unknown';
}

function generateVisitorHash(ip: string, userAgent: string): string {
  return crypto.createHash('sha256').update(ip + userAgent).digest('hex').slice(0, 32);
}

export const POST: APIRoute = async ({ request, url }) => {
  try {
    const postId = url.searchParams.get('postId');

    if (!postId || !POCKETBASE_ID_REGEX.test(postId)) {
      return new Response(
        JSON.stringify({ error: 'Некорректный postId' }),
        { status: 400, headers: { 'Content-Type': 'application/json' } }
      );
    }

    const postRes = await fetch(
      `${POCKETBASE_URL}/api/collections/posts/records/${postId}`,
    );

    if (!postRes.ok) {
      return new Response(
        JSON.stringify({ error: 'Пост не найден' }),
        { status: 404, headers: { 'Content-Type': 'application/json' } }
      );
    }

    const post = await postRes.json();

    const ip = getClientIp(request);
    const userAgent = request.headers.get('user-agent') || 'unknown';
    const visitorHash = generateVisitorHash(ip, userAgent);

    const now = new Date();
    const yesterday = new Date(now.getTime() - 24 * 60 * 60 * 1000);
    const yesterdayStr = yesterday.toISOString();

    const existingViewRes = await fetch(
      `${POCKETBASE_URL}/api/collections/post_views/records?` +
      new URLSearchParams({
        filter: `post="${postId}" && visitor_hash="${visitorHash}" && created >= "${yesterdayStr}"`,
      })
    );

    let isNewView = false;

    if (existingViewRes.ok) {
      const existingData = await existingViewRes.json();
      if (existingData.items?.length === 0) {
        isNewView = true;

        await fetch(
          `${POCKETBASE_URL}/api/collections/post_views/records`,
          {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({
              post: postId,
              visitor_hash: visitorHash,
              ip: ip,
              user_agent: userAgent,
            }),
          }
        );
      }
    }

    let totalViews = post.views || 0;
    
    if (isNewView) {
      totalViews += 1;
      
      await fetch(
        `${POCKETBASE_URL}/api/collections/posts/records/${postId}`,
        {
          method: 'PATCH',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({ views: totalViews }),
        }
      );
    }

    return new Response(
      JSON.stringify({ views: totalViews, isNewView }),
      { status: 200, headers: { 'Content-Type': 'application/json' } }
    );

  } catch (error) {
    console.error('[Increment Views API] Error:', error);
    return new Response(
      JSON.stringify({ error: 'Внутренняя ошибка сервера' }),
      { status: 500, headers: { 'Content-Type': 'application/json' } }
    );
  }
};