import { executeQuery, executeQuerySingle } from '@/lib/clickhouse';
import { Link, LinkQueryParams } from '../types';

/**
 * Find links with filtering options
 */
export async function findLinks({
  limit = 10,
  offset = 0,
  searchTerm = '',
  tagFilter = '',
  isActive = null,
}: LinkQueryParams) {
  // Build WHERE conditions
  const conditions = [];
  
  if (searchTerm) {
    conditions.push(`
      (lower(title) LIKE lower('%${searchTerm}%') OR 
       lower(original_url) LIKE lower('%${searchTerm}%'))
    `);
  }
  
  if (tagFilter) {
    conditions.push(`hasAny(tags, ['${tagFilter}'])`);
  }
  
  if (isActive !== null) {
    conditions.push(`is_active = ${isActive ? 'true' : 'false'}`);
  }
  
  const whereClause = conditions.length > 0 
    ? `WHERE ${conditions.join(' AND ')}` 
    : '';
  
  // Get total count
  const countQuery = `
    SELECT count() as total
    FROM links
    ${whereClause}
  `;
  
  const countData = await executeQuery<{ total: number }>(countQuery);
  const total = countData.length > 0 ? countData[0].total : 0;
  
  // 使用左连接获取链接数据和统计信息
  const linksQuery = `
    SELECT 
      l.link_id, 
      l.original_url, 
      l.created_at, 
      l.created_by, 
      l.title, 
      l.description, 
      l.tags, 
      l.is_active, 
      l.expires_at, 
      l.team_id, 
      l.project_id,
      count(le.event_id) as visits,
      count(DISTINCT le.visitor_id) as unique_visits
    FROM links l
    LEFT JOIN link_events le ON l.link_id = le.link_id
    ${whereClause}
    GROUP BY 
      l.link_id, 
      l.original_url, 
      l.created_at, 
      l.created_by, 
      l.title, 
      l.description, 
      l.tags, 
      l.is_active, 
      l.expires_at, 
      l.team_id, 
      l.project_id
    ORDER BY l.created_at DESC
    LIMIT ${limit}
    OFFSET ${offset}
  `;
  
  const links = await executeQuery<Link>(linksQuery);
  
  return {
    links,
    total,
    limit,
    offset,
    page: Math.floor(offset / limit) + 1,
    totalPages: Math.ceil(total / limit)
  };
}

/**
 * Find a single link by ID
 */
export async function findLinkById(linkId: string): Promise<Link | null> {
  const query = `
    SELECT 
      l.link_id, 
      l.original_url, 
      l.created_at, 
      l.created_by, 
      l.title, 
      l.description, 
      l.tags, 
      l.is_active, 
      l.expires_at, 
      l.team_id, 
      l.project_id,
      count(le.event_id) as visits,
      count(DISTINCT le.visitor_id) as unique_visits
    FROM links l
    LEFT JOIN link_events le ON l.link_id = le.link_id
    WHERE l.link_id = '${linkId}'
    GROUP BY 
      l.link_id, 
      l.original_url, 
      l.created_at, 
      l.created_by, 
      l.title, 
      l.description, 
      l.tags, 
      l.is_active, 
      l.expires_at, 
      l.team_id, 
      l.project_id
    LIMIT 1
  `;
  
  return await executeQuerySingle<Link>(query);
}

/**
 * Find a single link by ID - only basic info without statistics
 */
export async function findLinkDetailsById(linkId: string): Promise<Omit<Link, 'visits' | 'unique_visits'> | null> {
  const query = `
    SELECT 
      link_id, 
      original_url, 
      created_at, 
      created_by, 
      title, 
      description, 
      tags, 
      is_active, 
      expires_at, 
      team_id, 
      project_id
    FROM links
    WHERE link_id = '${linkId}'
    LIMIT 1
  `;
  
  return await executeQuerySingle<Omit<Link, 'visits' | 'unique_visits'>>(query);
}