using System;
using System.IO;
using System.Threading.Tasks;
using AI.AgentIntegration;
using GeoSigmaDrawLib;

namespace PcgDrawR.Services
{
    /// <summary>
    /// 负责各种“从文件导入”相关的业务逻辑（井点 / 井曲线等）。
    /// </summary>
    public class ImportService
    {
        private readonly IAppEnvironment env;

        public ImportService(IAppEnvironment env)
        {
            this.env = env ?? throw new ArgumentNullException(nameof(env));
        }

        /// <summary>
        /// 从指定文件导入井点数据。
        /// 要求文件内容为 GeoSigma 井点导入所需的 XML 文本（与界面导入生成的 XML 格式一致）。
        /// </summary>
        public Task<AppActionResult> ImportWellPointsAsync(AppAction action)
        {
            return ImportAsync(action, StreamImportType.Points, "井点");
        }

        /// <summary>
        /// 从指定文件导入井曲线数据。
        /// 要求文件内容为 GeoSigma 曲线导入所需的 XML 文本。
        /// </summary>
        public Task<AppActionResult> ImportWellCurvesAsync(AppAction action)
        {
            return ImportAsync(action, StreamImportType.Curves, "井曲线");
        }

        private Task<AppActionResult> ImportAsync(AppAction action, StreamImportType type, string entityName)
        {
            if (!action.Parameters.TryGetValue("path", out var pathObj))
            {
                return Task.FromResult(AppActionResult.Fail("缺少 'path' 参数"));
            }

            var path = pathObj.ToString();
            if (string.IsNullOrWhiteSpace(path))
            {
                return Task.FromResult(AppActionResult.Fail("参数 'path' 不能为空"));
            }

            if (!File.Exists(path))
            {
                return Task.FromResult(AppActionResult.Fail($"文件不存在: {path}"));
            }

            if (env.ActiveGeo == null)
            {
                return Task.FromResult(AppActionResult.Fail($"当前没有打开任何图件，无法导入{entityName}"));
            }

            try
            {
                ImportFile(path, type);
                return Task.FromResult(AppActionResult.Sucess($"{entityName}导入成功"));
            }
            catch (Exception ex)
            {
                return Task.FromResult(AppActionResult.Fail($"{entityName}导入失败: {ex.Message}"));
            }
        }

        private void ImportFile(string path, StreamImportType type)
        {
            using var stream = new FileStream(path, FileMode.Open, FileAccess.Read);
            using var importer = env.ActiveGeo?.CreateStreamImporter(type);
            if (importer == null)
            {
                return;
            }

            byte[] buffer = new byte[4096];
            int n = 0;

            while ((n = stream.Read(buffer, 0, buffer.Length)) > 0)
            {
                importer.Write(buffer, n);
            }
        }

    }
}