package api

import (
	"time"

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

	"eai_agentplatform/backend/internal/middleware"
	"eai_agentplatform/backend/internal/model"
	"eai_agentplatform/backend/internal/store"
	"eai_agentplatform/backend/internal/web"
)

// —— 积分规则（游戏化成长值，集中一处便于调整，见 docs/01_System_Overall/变更日志.md 待确认项）——
const (
	ptFirstCompany    = 10 // 首次浏览公司介绍
	ptFirstProduct    = 2  // 首次浏览单个产品
	ptFirstCourse     = 5  // 首次浏览单门课程
	ptSelfTestSubmit  = 5  // 自测提交一次
	ptFormalPass      = 50 // 正式考试通过
	ptMistakeResolved = 3  // 错题标记已掌握
)

// awardPoints 记录积分流水并累加到 user.learning_points（points<=0 直接忽略，避免负分刷分）。
func awardPoints(userID uint, eventType string, points int, refType string, refID uint) {
	if userID == 0 || points <= 0 {
		return
	}
	store.DB.Create(&model.PointEvent{
		UserID:    userID,
		EventType: eventType,
		Points:    points,
		RefType:   refType,
		RefID:     refID,
	})
	store.DB.Model(&model.User{}).Where("id = ?", userID).
		UpdateColumn("learning_points", gorm.Expr("learning_points + ?", points))
}

// awardFirstView 首次浏览公司/产品/课程加分（由 RecordLearningProgress 幂等触发）。
func awardFirstView(userID uint, itemType string, itemID uint) {
	switch itemType {
	case "company":
		awardPoints(userID, "first_company", ptFirstCompany, itemType, itemID)
	case "product":
		awardPoints(userID, "first_product", ptFirstProduct, itemType, itemID)
	case "course":
		awardPoints(userID, "first_course", ptFirstCourse, itemType, itemID)
	}
}

// MyPoints GET /api/points/me —— 我的积分 + 最近积分流水
func MyPoints(c *gin.Context) {
	u := middleware.CurrentUser(c)
	if u == nil {
		web.Fail(c, web.NewAuthError("未登录"))
		return
	}
	var total int
	store.DB.Raw(`SELECT COALESCE(SUM(points), 0) FROM point_event WHERE user_id = ?`, u.ID).Scan(&total)
	var events []model.PointEvent
	store.DB.Where("user_id = ?", u.ID).Order("created_at DESC, id DESC").Limit(50).Find(&events)
	web.OK(c, gin.H{"total": total, "events": events})
}

// Leaderboard GET /api/points/leaderboard —— 学习积分排行榜（全员，含我的名次）
func Leaderboard(c *gin.Context) {
	u := middleware.CurrentUser(c)
	var users []model.User
	store.DB.Where("role = ? AND status = ?", "employee", "active").
		Order("learning_points DESC, id ASC").Find(&users)

	out := make([]gin.H, 0, len(users))
	myRank := 0
	for i, usr := range users {
		out = append(out, gin.H{
			"rank":            i + 1,
			"user_id":         usr.ID,
			"full_name":       usr.FullName,
			"department":      usr.Department,
			"learning_points": usr.LearningPoints,
			"is_me":           u != nil && usr.ID == u.ID,
		})
		if u != nil && usr.ID == u.ID {
			myRank = i + 1
		}
	}
	web.OK(c, gin.H{"items": out, "my_rank": myRank, "total": len(out), "updated_at": time.Now()})
}