package controller

import (
	"bytes"
	"image"
	"image/jpeg"
	"image/png"
	"io"
	"net/http"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"metazone.cc/metalab/internal/common"

	"github.com/gin-gonic/gin"
)

// UploadImage 上传评论图片 POST /api/comments/upload-image
// 需要 LV4+（Exp ≥ 1500），复用帖子图片上传的 WebP 转码逻辑
func (ctrl *CommentController) UploadImage(c *gin.Context) {
	uid, _, ok := common.GetGinUser(c)
	if !ok {
		common.Error(c, http.StatusUnauthorized, "请先登录")
		return
	}

	// LV4+ 检查（Exp ≥ 1500）
	expVal, exists := c.Get("exp")
	if !exists {
		common.Error(c, http.StatusForbidden, "无法获取经验值")
		return
	}
	exp := expVal.(int)
	if exp < 1500 {
		common.Error(c, http.StatusForbidden, "需 Lv4 以上才能上传评论图片")
		return
	}

	file, header, err := c.Request.FormFile("file")
	if err != nil {
		common.Error(c, http.StatusBadRequest, "请选择文件")
		return
	}
	defer file.Close()

	// 检查扩展名
	ext := strings.ToLower(filepath.Ext(header.Filename))
	allowedExt := map[string]bool{".jpg": true, ".jpeg": true, ".png": true, ".gif": true, ".webp": true}
	if !allowedExt[ext] {
		common.Error(c, http.StatusBadRequest, "仅支持 jpg/jpeg/png/gif/webp 格式")
		return
	}

	// 限制 5MB
	if header.Size > 5<<20 {
		common.Error(c, http.StatusBadRequest, "图片大小不能超过 5MB")
		return
	}

	data, err := io.ReadAll(file)
	if err != nil {
		common.Error(c, http.StatusInternalServerError, "读取文件失败")
		return
	}

	storageDir := "storage/uploads/posts"
	if err := os.MkdirAll(storageDir, 0755); err != nil {
		common.Error(c, http.StatusInternalServerError, "存储初始化失败")
		return
	}

	ts := time.Now().UnixMilli()
	isJPEGPNG := ext == ".jpg" || ext == ".jpeg" || ext == ".png"

	var savePath, url string

	// JPEG/PNG 转 WebP
	if isJPEGPNG {
		img, _, err := image.Decode(bytes.NewReader(data))
		if err != nil {
			common.Error(c, http.StatusBadRequest, "图片格式无效")
			return
		}
		webpData := encodeWebPBinary(img, len(data))
		if webpData != nil && len(webpData) < len(data) {
			filename := strconv.FormatUint(uint64(uid), 10) + "_" + strconv.FormatInt(ts, 10) + ".webp"
			savePath = filepath.Join(storageDir, filename)
			os.WriteFile(savePath, webpData, 0644)
			url = "/uploads/posts/" + filename
		}
	}

	// 回退存储
	if savePath == "" {
		dataOut := data
		if isJPEGPNG {
			decImg, _, decErr := image.Decode(bytes.NewReader(data))
			if decErr == nil {
				var buf bytes.Buffer
				if ext == ".png" {
					png.Encode(&buf, decImg)
				} else {
					jpeg.Encode(&buf, decImg, &jpeg.Options{Quality: 92})
				}
				dataOut = buf.Bytes()
			}
		}
		filename := strconv.FormatUint(uint64(uid), 10) + "_" + strconv.FormatInt(ts, 10) + ext
		savePath = filepath.Join(storageDir, filename)
		os.WriteFile(savePath, dataOut, 0644)
		url = "/uploads/posts/" + filename
	}

	// 返回标准 JSON（前端将 URL 插入评论文本）
	common.Ok(c, gin.H{"url": url})
}
