using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Threading.Tasks;
using Newtonsoft.Json;

namespace BaiduSearchApp
{
    public class BaiduSearchApi
    {
        private readonly string _apiKey;
        private readonly HttpClient _httpClient;
        private const string ApiUrl = "https://qianfan.baidubce.com/v2/ai_search/web_search";

        public BaiduSearchApi(string apiKey)
        {
            _apiKey = apiKey;
            _httpClient = new HttpClient();
            _httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", _apiKey);
            _httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
        }

        public async Task<SearchResponse> SearchAsync(string query, int pageSize = 50)
        {
            if (string.IsNullOrEmpty(query))
                throw new ArgumentException("搜索内容不能为空", nameof(query));

            var requestBody = new SearchRequest
            {
                Messages = new List<Message>
                {
                    new Message { Content = query, Role = "user" }
                },
                SearchSource = "baidu_search_v2",
                ResourceTypeFilter = new List<SearchResource>
                {
                    new SearchResource { Type = "web", TopK = pageSize }
                },
                SearchRecencyFilter = "year"
            };

            var jsonContent = JsonConvert.SerializeObject(requestBody);
            var content = new StringContent(jsonContent, Encoding.UTF8, "application/json");

            HttpResponseMessage response = await _httpClient.PostAsync(ApiUrl, content);
            response.EnsureSuccessStatusCode();

            string responseContent = await response.Content.ReadAsStringAsync();
            return JsonConvert.DeserializeObject<SearchResponse>(responseContent);
        }
    }

    // 请求相关类
    public class SearchRequest
    {
        [JsonProperty("messages")]
        public List<Message> Messages { get; set; }

        [JsonProperty("search_source")]
        public string SearchSource { get; set; }

        [JsonProperty("resource_type_filter")]
        public List<SearchResource> ResourceTypeFilter { get; set; }

        [JsonProperty("search_recency_filter")]
        public string SearchRecencyFilter { get; set; }

        [JsonProperty("edition")]
        public string Edition { get; set; } = "standard";
    }

    public class Message
    {
        [JsonProperty("content")]
        public string Content { get; set; }

        [JsonProperty("role")]
        public string Role { get; set; }
    }

    public class SearchResource
    {
        [JsonProperty("type")]
        public string Type { get; set; }

        [JsonProperty("top_k")]
        public int TopK { get; set; }
    }

    // 响应相关类
    public class SearchResponse
    {
        [JsonProperty("request_id")]
        public string RequestId { get; set; }

        [JsonProperty("references")]
        public List<Reference> References { get; set; }

        [JsonProperty("code")]
        public string Code { get; set; }

        [JsonProperty("message")]
        public string ErrorMessage { get; set; }
    }

    public class Reference
    {
        [JsonProperty("title")]
        public string Title { get; set; }

        [JsonProperty("url")]
        public string Url { get; set; }

        [JsonProperty("content")]
        public string Content { get; set; }

        [JsonProperty("date")]
        public string Date { get; set; }

        [JsonProperty("type")]
        public string Type { get; set; }

        [JsonProperty("web_anchor")]
        public string WebAnchor { get; set; }

        [JsonProperty("website")]
        public string Website { get; set; }
    }
}