Learn.VideoAnalysis/VideoAnalysisCore/Common/Expand/SimpLetexExpand.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Net.Sockets;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using AlibabaCloud.OpenApiClient.Models;
using AlibabaCloud.SDK.Vod20170321;
using AlibabaCloud.SDK.Vod20170321.Models;
using AlibabaCloud.TeaUtil.Models;
using Azure;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using Newtonsoft.Json;
using VideoAnalysisCore.Job;

namespace VideoAnalysisCore.Common
{


    public class SimpleTexOcrResponseData
    {
        public bool status { get; set; }
        public SimpleTexOcrResponseDataRes res { get; set; }
        public string request_id { get; set; }
    }

    public class SimpleTexOcrResponseDataRes
    {
        public string type { get; set; }
        public SimpleTexOcrResponseDataInfo info { get; set; }
    }

    public class SimpleTexOcrResponseDataInfo
    {
        public string markdown { get; set; }
    }


    /// <summary>
    /// 请求参数
    /// </summary>
    public class SimpleTexOcrRequest
    {
        public SimpleTexOcrRequest(string filePath)
        {
            file = File.OpenRead(filePath);
        }
        /// <summary>
        /// 合法的图片二进制文件信息，包括png/jpg等格式，无法开启批量调用，仅支持一次上传一张图片
        /// </summary>
        public FileStream file { get; set; }
        /// <summary>
        /// 用以指定识别图片的类型，如果使用auto则会自动检测，使用document会返回markdown文档结果，使用formula会返回LaTeX结果
        /// <para>"auto", "document", "formula"</para>
        /// </summary>
        public string rec_mode { get; set; } = "auto";
        /// <summary>
        /// 开启后，模型将基于0°，90°, 180°, 270°自动矫正上传图片的方向，默认不开启
        /// </summary>
        public bool enable_img_rot { get; set; } = false;
        /// <summary>
        /// 用于修改行内公式在markdown中的包裹符号。以Json形式填入，如果格式错误将使用默认的包裹符号
        /// <para>示例:["$","$"]</para>
        /// </summary>
        public string inline_formula_wrapper { get; set; }
        /// <summary>
        /// 用于修改独立行公式在markdown中的包裹符号。以Json形式填入，如果格式错误将使用默认的包裹符号
        /// <para>示例:["$$","$$"]</para>
        /// </summary>
        public string isolated_formula_wrapper { get; set; }
    }
    /// <summary>
    /// ocr响应
    /// </summary>
    public class SimpleTexOcrResponse
    {
        public bool Success { get; set; }
        public SimpleTexOcrResponseData Result { get; set; }
        public string Error { get; set; }
    }


    public class SimpLetexClient
    {
        private readonly IHttpClientFactory _httpClientFactory;
        public SimpLetexClient(
    IHttpClientFactory httpClientFactory)
        {
            _httpClientFactory = httpClientFactory;
        }

        public async Task<SimpleTexOcrResponse> ProcessImageAsync(SimpleTexOcrRequest request)
        {
            var client = _httpClientFactory.CreateClient();
            using var content = new MultipartFormDataContent();
            var parameters = new Dictionary<string, string>();

            // 添加文件内容
            var fileContent = new StreamContent(request.file);
            content.Add(fileContent, nameof(request.file), Path.GetFileName(request.file.Name));

            // 添加并收集其他参数
            if (request.rec_mode != "auto")
            {
                content.Add(new StringContent(request.rec_mode), nameof(request.rec_mode));
                parameters[nameof(request.rec_mode)] = request.rec_mode;
            }

            var enableImgRotStr = request.enable_img_rot.ToString().ToLower();
            content.Add(new StringContent(enableImgRotStr), nameof(request.enable_img_rot));
            parameters[nameof(request.enable_img_rot)] = enableImgRotStr;

            if (request.inline_formula_wrapper != null)
            {
                content.Add(new StringContent(request.inline_formula_wrapper), nameof(request.inline_formula_wrapper));
                parameters[nameof(request.inline_formula_wrapper)] = request.inline_formula_wrapper;
            }

            if (request.isolated_formula_wrapper != null)
            {
                var isolatedWrapper = JsonConvert.SerializeObject(request.isolated_formula_wrapper);
                content.Add(new StringContent(isolatedWrapper), nameof(request.isolated_formula_wrapper));
                parameters[nameof(request.isolated_formula_wrapper)] = isolatedWrapper;
            }

            // 生成鉴权参数
            var randomStr = Guid.NewGuid().ToString("N").Substring(16);
            var timestamp = DateTimeOffset.UtcNow.ToUnixTimeSeconds().ToString();
            var appId = AppCommon.Config.SimpLetex.AppId;

            parameters["timestamp"] = timestamp;
            parameters["random-str"] = randomStr;
            parameters["app-id"] = appId;

            // 生成签名
            var signStr = string.Join("&", parameters
                .OrderBy(p => p.Key)
                .Select(p => $"{p.Key}={Uri.EscapeDataString(p.Value)}"))
                + $"&secret={AppCommon.Config.SimpLetex.AppSecret}";
            var sign = ComputeMD5(signStr);

            // 创建请求并添加Header
            var requestMessage = new HttpRequestMessage(HttpMethod.Post,
                AppCommon.Config.SimpLetex.Host + "simpletex_ocr")
            {
                Content = content
            };

            requestMessage.Headers.Add("random-str", randomStr);
            requestMessage.Headers.Add("timestamp", timestamp);
            requestMessage.Headers.Add("app-id", appId);
            requestMessage.Headers.Add("sign", sign);

            try
            {
                var response = await client.SendAsync(requestMessage);
                var responseContent = await response.Content.ReadFromJsonAsync<SimpleTexOcrResponseData>();

                return new SimpleTexOcrResponse
                {
                    Success = response.IsSuccessStatusCode,
                    Result = responseContent,
                    Error = response.IsSuccessStatusCode ? null : $"HTTP Error: {response.StatusCode}"
                };
            }
            catch (Exception ex)
            {
                return new SimpleTexOcrResponse
                {
                    Success = false,
                    Error = $"Request Failed: {ex.Message}"
                };
            }
        }

        private string GenerateSignatureString(IDictionary<string, string> parameters, string secret)
        {
            var sortedParams = parameters
                .OrderBy(p => p.Key)
                .Select(p => $"{p.Key}={Uri.EscapeDataString(p.Value)}");

            return string.Join("&", sortedParams) + $"&secret={secret}";
        }

        private string ComputeMD5(string input)
        {
            using var md5 = MD5.Create();
            var inputBytes = Encoding.UTF8.GetBytes(input);
            var hashBytes = md5.ComputeHash(inputBytes);
            return BitConverter.ToString(hashBytes).Replace("-", "").ToLower();
        }
    }

    /// <summary>
    /// 服务注册扩展
    /// </summary>
    public static class SSimpLetexExtensions
    {
        public static IServiceCollection AddSimpleTexOcrClient(this IServiceCollection services)
        {
            services.AddSingleton<SimpLetexClient>();
            return services;
        }
    }
}