using YD_Event.Application.Common.Dtos;
using YD_Event.Core.Options;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Options;
using Microsoft.AspNetCore.Mvc;
using YD_Event.Core.Infrastructure.Aliyun.Oss;

namespace YD_Event.Application.Common;

[ApiDescriptionSettings("通用服务")]
public class FileService : IDynamicApiController, ITransient
{
    private readonly IOptionsMonitor<OssConnectionOptions> _ossOptionsMonitor;
    private readonly IHttpContextAccessor _httpContextAccessor;
    private readonly IWebHostEnvironment _webHostEnvironment;
    private readonly IIdGenerator _idGenerator;
    private readonly OssService _ossService;

    public FileService(
        IOptionsMonitor<OssConnectionOptions> ossOptionsMonitor,
        IHttpContextAccessor httpContextAccessor,
        IWebHostEnvironment webHostEnvironment,
        IIdGenerator idGenerator,
        OssService ossService)
    {
        _ossOptionsMonitor = ossOptionsMonitor;
        _httpContextAccessor = httpContextAccessor;
        _webHostEnvironment = webHostEnvironment;
        _idGenerator = idGenerator;
        _ossService = ossService;
    }

    /// <summary>
    /// 上传附件
    /// </summary>
    /// <param name="file">表单文件</param>
    /// <returns>返回上传文件信息</returns>
    [NonUnify]
    public async Task<List<UploadFileOutput>> Upload([Required] IFormFile file)
    {
        if (file is null or { Length: 0 })
        {
            throw Oops.Oh("请上传文件");
        }
        var options = _ossOptionsMonitor.CurrentValue;
        var now = DateTime.Today;
        string name = _idGenerator.Encode(_idGenerator.NewLong());
        string extension = Path.GetExtension(file.FileName);
        if (string.IsNullOrWhiteSpace(extension))
        {
            throw Oops.Bah("无效文件");
        }
        
        string filePath = $"{now.Year}/{now.Month:D2}/{now.Day:D2}/";
        string fileName = $"{filePath}{name}{extension}";

        using var stream = file.OpenReadStream();
        string url = await UploadStreamInternal(fileName, stream, options);

        return new List<UploadFileOutput>()
        {
            new()
            {
                Name = $"{name}{extension}",
                Url = url
            }
        };
    }

    /// <summary>
    /// 上传文件流 (供其他服务调用)
    /// </summary>
    /// <param name="fileName">文件名及路径</param>
    /// <param name="stream">文件流</param>
    /// <returns>返回完整 URL</returns>
    [NonAction]
    public async Task<string> UploadFileStreamAsync(string fileName, Stream stream)
    {
        var options = _ossOptionsMonitor.CurrentValue;
        return await UploadStreamInternal(fileName, stream, options);
    }

    /// <summary>
    /// 内部上传文件流
    /// </summary>
    private async Task<string> UploadStreamInternal(string fileName, Stream stream, OssConnectionOptions options)
    {
        if (!options.Enable)
        {
            // 本地存储
            string basePath = Path.Combine(_webHostEnvironment.WebRootPath, options.Bucket ?? "uploads");
            string fullPath = Path.Combine(basePath, fileName);
            string dir = Path.GetDirectoryName(fullPath);
            if (!Directory.Exists(dir))
            {
                Directory.CreateDirectory(dir);
            }

            using var fileStream = System.IO.File.Create(fullPath);
            await stream.CopyToAsync(fileStream);

            var request = _httpContextAccessor.HttpContext?.Request;
            if (request != null)
            {
                return $"{request.Scheme}://{request.Host.Value}/{(options.Bucket ?? "uploads")}/{fileName}";
            }
            return $"/{(options.Bucket ?? "uploads")}/{fileName}";
        }
        else
        {
            // OSS 上传
            return await _ossService.PutObjectAsync(fileName, stream);
        }
    }

    /// <summary>
    /// 下载文件
    /// </summary>
    /// <param name="url">文件 URL</param>
    /// <returns>文件流结果</returns>
    [HttpGet("download")]
    public IActionResult Download([FromQuery] string url)
    {
        if (string.IsNullOrWhiteSpace(url)) throw Oops.Bah("参数错误");

        var options = _ossOptionsMonitor.CurrentValue;
        
        try
        {
            if (!options.Enable)
            {
                // 本地下载
                var uri = new Uri(url);
                string localPath = Path.Combine(_webHostEnvironment.WebRootPath, uri.AbsolutePath.TrimStart('/'));
                if (!System.IO.File.Exists(localPath)) throw Oops.Bah("文件不存在");

                var stream = System.IO.File.OpenRead(localPath);
                return new FileStreamResult(stream, "application/octet-stream")
                {
                    FileDownloadName = Path.GetFileName(localPath)
                };
            }
            else
            {
                // OSS 下载
                // 解析 objectName (移除 Domain 部分)
                string domainUrl = options.Domain.TrimEnd('/') + "/";
                string objectName = url;
                if (url.StartsWith(domainUrl, StringComparison.OrdinalIgnoreCase))
                {
                    objectName = url.Substring(domainUrl.Length);
                }
                else
                {
                    var uri = new Uri(url);
                    objectName = uri.AbsolutePath.TrimStart('/');
                }

                var contentStream = _ossService.GetObject(objectName);
                return new FileStreamResult(contentStream, "application/octet-stream")
                {
                    FileDownloadName = Path.GetFileName(objectName)
                };
            }
        }
        catch (Exception ex)
        {
            throw Oops.Bah($"下载失败: {ex.Message}");
        }
    }

    /// <summary>
    /// 删除文件
    /// </summary>
    /// <param name="url">文件 URL</param>
    [HttpDelete("delete")]
    public IActionResult Delete([FromQuery] string url)
    {
        if (string.IsNullOrWhiteSpace(url)) throw Oops.Bah("参数错误");

        var options = _ossOptionsMonitor.CurrentValue;

        try
        {
            if (!options.Enable)
            {
                // 本地删除
                var uri = new Uri(url);
                string localPath = Path.Combine(_webHostEnvironment.WebRootPath, uri.AbsolutePath.TrimStart('/'));
                if (System.IO.File.Exists(localPath))
                {
                    System.IO.File.Delete(localPath);
                }
            }
            else
            {
                // OSS 删除
                string domainUrl = options.Domain.TrimEnd('/') + "/";
                string objectName = url;
                if (url.StartsWith(domainUrl, StringComparison.OrdinalIgnoreCase))
                {
                    objectName = url.Substring(domainUrl.Length);
                }
                else
                {
                    var uri = new Uri(url);
                    objectName = uri.AbsolutePath.TrimStart('/');
                }

                _ossService.DeleteObject(objectName);
            }
            
            return new JsonResult(new { success = true, msg = "删除成功" });
        }
        catch (Exception ex)
        {
            throw Oops.Bah($"删除失败: {ex.Message}");
        }
    }
}