// Package handler provides HTTP handlers for various endpoints.
package handler

import (
	"net/http"

	"modelRT/logger"
	"modelRT/model"
	"modelRT/network"

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

// MeasurementRecommendHandler define measurement recommend API
// @Summary 测量点推荐（搜索框自动补全）
// @Description 根据用户输入的字符串，从 Redis 中查询可能的测量点或结构路径，并提供推荐列表。
// @Tags Measurement Recommend
// @Accept json
// @Produce json
// @Param request body network.MeasurementRecommendRequest true "查询输入参数，例如 'trans' 或 'transformfeeder1_220.'"
// @Success 200 {object} network.SuccessResponse{payload=network.MeasurementRecommendPayload} "返回推荐列表成功"
//
//	@Example 200 {
//	    "code": 200,
//	    "msg": "success",
//	    "payload": {
//	        "input": "transformfeeder1_220.",
//	        "offset": 21,
//	        "recommended_list": [
//	            "I_A_rms",
//	            "I_B_rms",
//	            "I_C_rms",
//	        ]
//	    }
//	}
//
// @Failure 400 {object} network.FailureResponse "返回推荐列表失败"
// @Example 400 {
//     "code": 400,
//     "msg": "failed to get recommend data from redis",
// }
// @Router /measurement/recommend [get]
func MeasurementRecommendHandler(c *gin.Context) {
	var request network.MeasurementRecommendRequest

	if err := c.ShouldBindJSON(&request); err != nil {
		logger.Error(c, "failed to unmarshal measurement recommend request", "error", err)
		c.JSON(http.StatusOK, network.FailureResponse{
			Code: http.StatusBadRequest,
			Msg:  err.Error(),
		})
		return
	}

	recommends, isFuzzy, err := model.RedisSearchRecommend(c, request.Input)
	if err != nil {
		logger.Error(c, "failed to get recommend data from redis", "input", request.Input, "error", err)
		c.JSON(http.StatusOK, network.FailureResponse{
			Code: http.StatusInternalServerError,
			Msg:  err.Error(),
			PayLoad: map[string]any{
				"input": request.Input,
			},
		})
		return
	}

	var finalOffset int
	if isFuzzy {
		var maxOffset int
		for index, recommend := range recommends {
			offset := model.GetLongestCommonPrefixLength(request.Input, recommend)
			if index == 0 || offset > maxOffset {
				maxOffset = offset
			}
		}
		finalOffset = maxOffset
	} else {
		var minOffset int
		for index, recommend := range recommends {
			offset := model.GetLongestCommonPrefixLength(request.Input, recommend)
			if index == 0 || offset < minOffset {
				minOffset = offset
			}
		}
		finalOffset = minOffset
	}

	resultRecommends := make([]string, 0, len(recommends))
	seen := make(map[string]struct{})

	for _, recommend := range recommends {
		recommendTerm := recommend[finalOffset:]
		if len(recommendTerm) != 0 {
			if _, exists := seen[recommendTerm]; !exists {
				seen[recommendTerm] = struct{}{}
				resultRecommends = append(resultRecommends, recommendTerm)
			}
		}
	}

	c.JSON(http.StatusOK, network.SuccessResponse{
		Code: http.StatusOK,
		Msg:  "success",
		// PayLoad: map[string]any{
		// 	"input":            request.Input,
		// 	"offset":           finalOffset,
		// 	"recommended_list": resultRecommends,
		// },
		PayLoad: &network.MeasurementRecommendPayload{
			Input:           request.Input,
			Offset:          finalOffset,
			RecommendedList: resultRecommends,
		},
	})
}