Yi.Admin/Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain.Shared/Dtos/Gemini/GeminiGenerateContentAcquirer.cs

using System.Text.Json;
using Yi.Framework.AiHub.Domain.Shared.Dtos.OpenAi;
using Yi.Framework.AiHub.Domain.Shared.Extensions;

namespace Yi.Framework.AiHub.Domain.Shared.Dtos.Gemini;

public static class GeminiGenerateContentAcquirer
{
    public static ThorUsageResponse? GetUsage(JsonElement response)
    {
        var usage = response.GetPath("usageMetadata");
        if (!usage.HasValue)
        {
            return null;
        }

        var inputTokens = usage.Value.GetPath("promptTokenCount").GetInt();
        var outputTokens = usage.Value.GetPath("candidatesTokenCount").GetInt()
                           + usage.Value.GetPath("cachedContentTokenCount").GetInt()
                           + usage.Value.GetPath("thoughtsTokenCount").GetInt()
                           + usage.Value.GetPath("toolUsePromptTokenCount").GetInt();


        return new ThorUsageResponse
        {
            PromptTokens = inputTokens,
            InputTokens = inputTokens,
            OutputTokens = outputTokens,
            CompletionTokens = outputTokens,
            TotalTokens = inputTokens + outputTokens,
        };
    }

    /// <summary>
    /// 获取图片url，包含前缀
    /// </summary>
    /// <param name="response"></param>
    /// <returns></returns>
    public static string GetImagePrefixBase64(JsonElement response)
    {
        // 获取 candidates[0].content.parts[0].text
        var text = response.GetPath("candidates", 0, "content", "parts", 0, "text").GetString();
        if (string.IsNullOrEmpty(text))
        {
            return string.Empty;
        }

        // 解析 markdown 图片格式: ![image](data:image/png;base64,xxx)
        // 提取括号内的 data:image/xxx;base64,xxx 部分
        var startMarker = "(data:image/";
        var startIndex = text.IndexOf(startMarker);
        if (startIndex < 0)
        {
            return string.Empty;
        }

        // 从 "data:" 开始
        startIndex += 1; // 跳过 "("
        var endIndex = text.IndexOf(')', startIndex);
        if (endIndex < 0)
        {
            return string.Empty;
        }

        return text.Substring(startIndex, endIndex - startIndex);
    }
}