using System;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Web;
using System.Web.Http;

public class ImageController : ApiController {
    private readonly string _baseStoragePath = HttpContext.Current.Server.MapPath("~/StaticStorage");
    private readonly string[] _allowedExtensions = { ".jpg", ".jpeg", ".png", ".gif", ".bmp" };

    // 上传图片接口
    [HttpPost]
    [Route("api/image/upload")]
    public HttpResponseMessage UploadImage() {
        try {
            if (!Request.Content.IsMimeMultipartContent()) {
                return Request.CreateErrorResponse(HttpStatusCode.UnsupportedMediaType, "请求必须包含多部分内容");
            }

            var provider = new MultipartFormDataStreamProvider(Path.GetTempPath());
            var result = Request.Content.ReadAsMultipartAsync(provider).Result;

            if (result.FileData.Count == 0) {
                return Request.CreateErrorResponse(HttpStatusCode.BadRequest, "未接收到文件");
            }

            var fileData = result.FileData[0];
            var fileName = fileData.Headers.ContentDisposition.FileName.Trim('"');
            var fileExt = Path.GetExtension(fileName).ToLower();

            if (Array.IndexOf(_allowedExtensions, fileExt) == -1) {
                return Request.CreateErrorResponse(HttpStatusCode.BadRequest, "不支持的文件类型");
            }

            // 生成日期路径
            var now = DateTime.Now;
            var year = now.ToString("yyyy");
            var month = now.ToString("MM");
            var day = now.ToString("dd");

            // 生成唯一文件名
            var newFileName = $"{now:yyyy-MM-dd-HHmmssfff}{fileExt}";

            // 目标路径
            var targetPath = Path.Combine(_baseStoragePath, "image", year, month, day);

            // 确保目录存在
            Directory.CreateDirectory(targetPath);

            // 完整文件路径
            var fullPath = Path.Combine(targetPath, newFileName);

            // 移动文件到目标位置
            File.Move(fileData.LocalFileName, fullPath);

            // 返回访问URL
            var url = $"{Request.RequestUri.Scheme}://{Request.RequestUri.Authority}/static/image/{year}/{month}/{day}/{newFileName}";

            return Request.CreateResponse(HttpStatusCode.OK, new { Url = url });
        }
        catch (Exception ex) {
            return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, ex.Message);
        }
    }

    // 获取图片接口 - 实际由静态文件处理，这里只是示例
    [HttpGet]
    [Route("static/image/{year}/{month}/{day}/{filename}")]
    public HttpResponseMessage GetImage(string year, string month, string day, string filename) {
        try {
            var filePath = Path.Combine(_baseStoragePath, "image", year, month, day, filename);

            if (!File.Exists(filePath)) {
                return Request.CreateErrorResponse(HttpStatusCode.NotFound, "文件不存在");
            }

            var response = new HttpResponseMessage(HttpStatusCode.OK);
            var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
            response.Content = new StreamContent(stream);

            // 根据文件扩展名设置ContentType
            var ext = Path.GetExtension(filename).ToLower();
            switch (ext) {
                case ".jpg":
                case ".jpeg":
                    response.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("image/jpeg");
                    break;
                case ".png":
                    response.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("image/png");
                    break;
                case ".gif":
                    response.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("image/gif");
                    break;
                case ".bmp":
                    response.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("image/bmp");
                    break;
                default:
                    response.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/octet-stream");
                    break;
            }

            return response;
        }
        catch (Exception ex) {
            return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, ex.Message);
        }
    }
}