package controller

import (
	"io"
	"net/http"
	"strings"

	"github.com/gin-gonic/gin"
	"github.com/topfans/backend/gateway/config"
	"github.com/topfans/backend/gateway/pkg/response"
	"github.com/topfans/backend/gateway/service"
	"github.com/topfans/backend/pkg/logger"
	"go.uber.org/zap"
)

// SegmentController 人像抠图代理（密钥仅在服务端，客户端走 multipart 上传）
type SegmentController struct {
	svc *service.SegmentService
}

func NewSegmentController() *SegmentController {
	cfg := config.Load()
	return &SegmentController{svc: service.NewSegmentService(cfg)}
}

// Portrait POST /api/v1/segment — scene=portrait（客户端 multipart 上传）
func (ctrl *SegmentController) Portrait(c *gin.Context) {
	scene := strings.TrimSpace(c.DefaultPostForm("scene", "portrait"))
	if scene != "portrait" {
		response.Error(c, http.StatusBadRequest, "本期仅支持 scene=portrait")
		return
	}

	userID, ok := c.Get("user_id")
	if !ok {
		response.Unauthorized(c, "未登录")
		return
	}
	starID, ok := c.Get("star_id")
	if !ok {
		response.Unauthorized(c, "缺少 star_id")
		return
	}

	file, header, err := c.Request.FormFile("image")
	if err != nil {
		response.Error(c, http.StatusBadRequest, "请上传 image 字段")
		return
	}
	defer file.Close()

	limit := int64(service.MaxSegmentImageBytes()) + 1
	data, err := io.ReadAll(io.LimitReader(file, limit))
	if err != nil {
		response.Error(c, http.StatusBadRequest, "读取图片失败")
		return
	}
	if len(data) > service.MaxSegmentImageBytes() {
		response.Error(c, http.StatusBadRequest, "图片超过 5MB")
		return
	}

	contentType := header.Header.Get("Content-Type")
	result, err := ctrl.svc.Portrait(c.Request.Context(), userID.(int64), starID.(int64), data, contentType)
	if err != nil {
		logger.Logger.Error("segment portrait", zap.Error(err))
		response.Error(c, http.StatusInternalServerError, "抠图服务异常")
		return
	}

	// 失败返回 200 + success:false；前端须中断 thinking，不做降级
	response.Success(c, result)
}

// segmentJSONReq Dify 工作流调用的 JSON 请求体
type segmentJSONReq struct {
	ImageURL string `json:"image_url"`
	Scene    string `json:"scene"`
}

// PortraitByURL POST /api/v1/segment/json — Dify 工作流调用
// 接收 JSON body { "image_url": "...", "scene": "portrait" }
// 无需 JWT 鉴权（仅限内网 Dify→Gateway），使用默认 star_id/user_id 写入 OSS
func (ctrl *SegmentController) PortraitByURL(c *gin.Context) {
	var req segmentJSONReq
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "参数错误: "+err.Error())
		return
	}

	scene := strings.TrimSpace(req.Scene)
	if scene == "" {
		scene = "portrait"
	}
	if scene != "portrait" {
		response.Error(c, http.StatusBadRequest, "本期仅支持 scene=portrait")
		return
	}

	imageURL := strings.TrimSpace(req.ImageURL)
	if imageURL == "" {
		response.BadRequest(c, "image_url 不能为空")
		return
	}

	logger.Logger.Info("segment json: downloading image", zap.String("url", imageURL[:min(len(imageURL), 80)]))

	result, err := ctrl.svc.PortraitFromURL(c.Request.Context(), imageURL)
	if err != nil {
		logger.Logger.Error("segment json failed", zap.Error(err))
		response.Error(c, http.StatusInternalServerError, "抠图服务异常: "+err.Error())
		return
	}

	response.Success(c, result)
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}