package article

import (
	"net/http"
	"time"
	"toutoukan/init/databaseInit"

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

// 投票请求结构体，同时支持单选(optionId)和多选(optionIds)
type VoteArticleRequest struct {
	Uid       string  `json:"uid" binding:"required,min=1,max=50"`      // 用户ID
	ArticleID int64   `json:"articleId" binding:"required,min=1"`       // 文章ID
	OptionID  int64   `json:"optionId" binding:"omitempty,min=1"`       // 单个选项ID（单选时使用）
	OptionIDs []int64 `json:"optionIds" binding:"omitempty,dive,min=1"` // 多个选项ID（多选时使用）
}

// 用户投票记录表结构
type UserVote struct {
	UserID        string    `gorm:"column:user_id"`
	VoteArticleID int64     `gorm:"column:vote_article_id"`
	OptionID      int64     `gorm:"column:option_id"`
	VoteTime      time.Time `gorm:"column:vote_time"`
}

func VoteArticle(c *gin.Context) {
	var req VoteArticleRequest

	// 1. 解析并验证请求参数
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{
			"error":  "参数解析失败",
			"detail": err.Error(),
		})
		return
	}

	// 2. 开启数据库事务确保数据一致性
	tx := databaseInit.UserDB.Begin()
	if tx.Error != nil {
		c.JSON(http.StatusInternalServerError, gin.H{
			"error": "开启事务失败: " + tx.Error.Error(),
		})
		return
	}
	defer func() {
		if r := recover(); r != nil {
			tx.Rollback()
		}
	}()

	// 3. 检查文章状态和投票类型
	var articleStatus struct {
		IsEnded  bool      `gorm:"column:is_ended"`
		EndTime  time.Time `gorm:"column:end_time"`
		VoteType string    `gorm:"column:vote_type"` // 投票类型：single-单选，multiple-多选
	}
	if err := tx.Table("article_list").
		Where("articleId = ?", req.ArticleID).
		First(&articleStatus).Error; err != nil {
		tx.Rollback()
		if err == gorm.ErrRecordNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "文评不存在"})
		} else {
			c.JSON(http.StatusInternalServerError, gin.H{"error": "查询文评失败: " + err.Error()})
		}
		return
	}

	// 3.1 检查投票是否已结束
	now := time.Now()
	if articleStatus.IsEnded || articleStatus.EndTime.Before(now) {
		tx.Rollback()
		c.JSON(http.StatusForbidden, gin.H{"error": "该文评投票已结束或已过截止时间，无法投票"})
		return
	}

	// 4. 处理投票选项，统一转换为选项ID列表
	var selectedOptions []int64
	if articleStatus.VoteType == "single" {
		if req.OptionID == 0 || len(req.OptionIDs) > 0 {
			tx.Rollback()
			c.JSON(http.StatusForbidden, gin.H{
				"error": "该文评为单选投票，请使用optionId提交单个选项",
			})
			return
		}
		selectedOptions = []int64{req.OptionID}
	} else {
		if len(req.OptionIDs) == 0 || req.OptionID != 0 {
			tx.Rollback()
			c.JSON(http.StatusForbidden, gin.H{
				"error": "该文评为多选投票，请使用optionIds提交多个选项",
			})
			return
		}
		selectedOptions = req.OptionIDs
	}

	// 5. 检查用户是否已投票
	var voteCount int64
	if err := tx.Table("user_votes").
		Where("user_id = ? AND vote_article_id = ?", req.Uid, req.ArticleID).
		Count(&voteCount).Error; err != nil {
		tx.Rollback()
		c.JSON(http.StatusInternalServerError, gin.H{"error": "检查投票记录失败: " + err.Error()})
		return
	}
	if voteCount > 0 {
		tx.Rollback()
		c.JSON(http.StatusForbidden, gin.H{"error": "您已对该文评投过票，无法重复投票"})
		return
	}

	// 6. 批量检查所有选项是否属于该文评
	var existingOptionsCount int64
	if err := tx.Table("article_options").
		Where("vote_article_id = ? AND id IN ?", req.ArticleID, selectedOptions).
		Count(&existingOptionsCount).Error; err != nil {
		tx.Rollback()
		c.JSON(http.StatusInternalServerError, gin.H{"error": "查询选项失败: " + err.Error()})
		return
	}
	if existingOptionsCount != int64(len(selectedOptions)) {
		tx.Rollback()
		c.JSON(http.StatusNotFound, gin.H{"error": "部分选项ID不存在或不属于该文评"})
		return
	}

	// 7. 执行批量投票事务
	voteTime := time.Now()

	// 7.1 批量插入用户投票记录
	userVotes := make([]UserVote, len(selectedOptions))
	for i, optionID := range selectedOptions {
		userVotes[i] = UserVote{
			UserID:        req.Uid,
			VoteArticleID: req.ArticleID,
			OptionID:      optionID,
			VoteTime:      voteTime,
		}
	}
	if err := tx.Table("user_votes").Create(&userVotes).Error; err != nil {
		tx.Rollback()
		c.JSON(http.StatusInternalServerError, gin.H{"error": "批量记录投票失败: " + err.Error()})
		return
	}

	// 7.2 批量更新选项票数
	if err := tx.Table("article_options").
		Where("id IN ?", selectedOptions).
		Update("option_votes_num", gorm.Expr("option_votes_num + 1")).Error; err != nil {
		tx.Rollback()
		c.JSON(http.StatusInternalServerError, gin.H{"error": "批量更新选项票数失败: " + err.Error()})
		return
	}

	// 7.3 更新文评总投票人数
	if err := tx.Table("article_list").
		Where("articleId = ?", req.ArticleID).
		Update("total_voters_num", gorm.Expr("total_voters_num + 1")).Error; err != nil {
		tx.Rollback()
		c.JSON(http.StatusInternalServerError, gin.H{"error": "更新总投票人数失败: " + err.Error()})
		return
	}

	// 8. 提交事务
	if err := tx.Commit().Error; err != nil {
		tx.Rollback()
		c.JSON(http.StatusInternalServerError, gin.H{"error": "提交投票失败: " + err.Error()})
		return
	}

	// 9. 返回成功响应
	responseData := gin.H{
		"articleId": req.ArticleID,
		"voteTime":  voteTime.Format("2006-01-02 15:04:05"),
	}
	if articleStatus.VoteType == "single" {
		responseData["optionId"] = req.OptionID
	} else {
		responseData["optionIds"] = req.OptionIDs
	}

	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": "投票成功",
		"data":    responseData,
	})
}