package handler

import (
	"fmt"
	"net/http"
	"strings"
	"time"

	"github.com/gin-gonic/gin"
	"golang.org/x/crypto/bcrypt"
	"kefu-sys/server/internal/middleware"
	"kefu-sys/server/internal/model"
	"kefu-sys/server/internal/storage"
)

type AdminHandler struct {
	store storage.ObjectStorage
}

func NewAdminHandler(store storage.ObjectStorage) *AdminHandler {
	return &AdminHandler{store: store}
}

func (h *AdminHandler) Stats(c *gin.Context) {
	var tenantTotal, activeTotal, suspendedTotal, expiringTotal, newThisMonth int64

	model.DB.Model(&model.Tenant{}).Count(&tenantTotal)
	model.DB.Model(&model.Tenant{}).Where("status = ?", "normal").Count(&activeTotal)
	model.DB.Model(&model.Tenant{}).Where("status = ?", "suspended").Count(&suspendedTotal)
	model.DB.Model(&model.Tenant{}).Where("status = ?", "expiring").Count(&expiringTotal)

	now := time.Now()
	monthStart := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
	model.DB.Model(&model.Tenant{}).Where("created_at >= ?", monthStart).Count(&newThisMonth)

	// 估算月收入：正常/即将到期租户 × 套餐月费
	type planCount struct {
		PlanID uint
		Count  int64
	}
	var incomeCounts []planCount
	model.DB.Model(&model.Tenant{}).
		Select("plan_id, count(*) as count").
		Where("status IN ? AND plan_id IS NOT NULL", []string{"normal", "expiring"}).
		Group("plan_id").
		Scan(&incomeCounts)
	var monthlyIncome int64
	for _, item := range incomeCounts {
		var plan model.Plan
		if err := model.DB.First(&plan, item.PlanID).Error; err != nil {
			continue
		}
		monthlyIncome += int64(plan.PriceMonthly) * item.Count
	}

	// 套餐分布：全部已绑定套餐的租户
	var distCounts []planCount
	model.DB.Model(&model.Tenant{}).
		Select("plan_id, count(*) as count").
		Where("plan_id IS NOT NULL").
		Group("plan_id").
		Scan(&distCounts)
	planDist := make([]gin.H, 0, len(distCounts))
	for _, item := range distCounts {
		var plan model.Plan
		if err := model.DB.First(&plan, item.PlanID).Error; err != nil {
			continue
		}
		planDist = append(planDist, gin.H{
			"plan_id": plan.ID,
			"name":    plan.Name,
			"count":   item.Count,
		})
	}

	// 近 6 个月租户增长
	growth := make([]gin.H, 0, 6)
	for offset := 5; offset >= 0; offset-- {
		mStart := time.Date(now.Year(), now.Month()-time.Month(offset), 1, 0, 0, 0, 0, now.Location())
		mEnd := mStart.AddDate(0, 1, 0)
		var newCnt, totalCnt int64
		model.DB.Model(&model.Tenant{}).Where("created_at >= ? AND created_at < ?", mStart, mEnd).Count(&newCnt)
		model.DB.Model(&model.Tenant{}).Where("created_at < ?", mEnd).Count(&totalCnt)
		growth = append(growth, gin.H{
			"month":      mStart.Format("1月"),
			"month_key":  mStart.Format("2006-01"),
			"new_count":  newCnt,
			"total_count": totalCnt,
		})
	}

	var recentLogs []model.OperationLog
	model.DB.Order("created_at desc").Limit(12).Find(&recentLogs)

	middleware.JSON(c, gin.H{
		"tenant_total":       tenantTotal,
		"active_tenant":      activeTotal,
		"suspended_tenant":   suspendedTotal,
		"expiring_tenant":    expiringTotal,
		"new_tenants_month":  newThisMonth,
		"monthly_income":     monthlyIncome,
		"system_uptime":      "99.95%",
		"plan_distribution":  planDist,
		"tenant_growth":      growth,
		"recent_logs":        recentLogs,
	})
}

func (h *AdminHandler) ListTenants(c *gin.Context) {
	page, pageSize := middleware.GetPageParams(c)
	search := c.Query("search")
	status := c.Query("status")
	plan := c.Query("plan")

	var tenants []model.Tenant
	var total int64

	query := model.DB.Model(&model.Tenant{})
	if search != "" {
		query = query.Where("name LIKE ? OR contact_name LIKE ?", "%"+search+"%", "%"+search+"%")
	}
	if status != "" {
		query = query.Where("status = ?", status)
	}
	if plan != "" {
		query = query.Where("plan_id IN (SELECT id FROM plans WHERE name = ?)", plan)
	}

	query.Count(&total)
	query.Order("created_at desc").Offset((page - 1) * pageSize).Limit(pageSize).Find(&tenants)

	middleware.JSONList(c, tenants, total, page, pageSize)
}

func (h *AdminHandler) GetTenant(c *gin.Context) {
	id := c.Param("id")
	var tenant model.Tenant
	if err := model.DB.First(&tenant, id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"code": 404, "message": "租户不存在"})
		return
	}
	middleware.JSON(c, tenant)
}

type createTenantReq struct {
	Name           string `json:"name" binding:"required"`
	ContactName    string `json:"contact_name" binding:"required"`
	ContactPhone   string `json:"contact_phone" binding:"required"`
	ContactEmail   string `json:"contact_email"`
	PlanID         *uint  `json:"plan_id"`
	SeatCount      int    `json:"seat_count"`
	DurationMonths int    `json:"duration_months"`
	AdminUsername  string `json:"admin_username"`
	AdminPassword  string `json:"admin_password"`
}

func (h *AdminHandler) CreateTenant(c *gin.Context) {
	var req createTenantReq
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "参数错误"})
		return
	}
	name := strings.TrimSpace(req.Name)
	if len([]rune(name)) < 2 || len([]rune(name)) > 100 {
		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "公司名称需为 2-100 个字符"})
		return
	}
	var exists int64
	model.DB.Model(&model.Tenant{}).Where("name = ?", name).Count(&exists)
	if exists > 0 {
		c.JSON(http.StatusConflict, gin.H{"code": 409, "message": "租户名称已存在"})
		return
	}
	if req.SeatCount <= 0 {
		req.SeatCount = 2
	}
	if req.DurationMonths <= 0 {
		req.DurationMonths = 12
	}
	if req.DurationMonths > 36 {
		req.DurationMonths = 36
	}
	if req.PlanID != nil {
		var plan model.Plan
		if err := model.DB.First(&plan, *req.PlanID).Error; err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "套餐不存在"})
			return
		}
		if plan.Status != "active" {
			c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "套餐已下架，无法开通"})
			return
		}
		if req.SeatCount < plan.Seats {
			req.SeatCount = plan.Seats
		}
	}

	tenant := model.Tenant{
		Name:         name,
		PlanID:       req.PlanID,
		SeatCount:    req.SeatCount,
		ExpireAt:     time.Now().AddDate(0, req.DurationMonths, 0),
		Status:       "normal",
		ContactName:  strings.TrimSpace(req.ContactName),
		ContactPhone: strings.TrimSpace(req.ContactPhone),
		ContactEmail: strings.TrimSpace(req.ContactEmail),
	}
	if err := model.DB.Create(&tenant).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"code": 500, "message": "创建失败"})
		return
	}

	// 默认租户管理员账号
	adminUser := strings.TrimSpace(req.AdminUsername)
	if adminUser == "" {
		adminUser = fmt.Sprintf("admin_t%d", tenant.ID)
	}
	password := req.AdminPassword
	if password == "" {
		password = "kefu_admin123"
	}
	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"code": 500, "message": "创建管理员账号失败"})
		return
	}
	user := model.User{
		TenantID: tenant.ID, Role: "admin", Username: adminUser,
		PasswordHash: string(hash), Nickname: tenant.ContactName, Status: "online",
	}
	if err := model.DB.Create(&user).Error; err != nil {
		// 回滚租户（尽力）
		model.DB.Delete(&tenant)
		c.JSON(http.StatusConflict, gin.H{"code": 409, "message": "管理员用户名已存在"})
		return
	}

	// 默认网页渠道
	key, keyErr := newChannelKey("WK")
	if keyErr == nil {
		model.DB.Create(&model.Channel{
			TenantID: tenant.ID, Type: "web", Name: "网页聊天", Status: "enabled",
			ScriptCode: buildWebScript(key),
		})
	}

	model.DB.Create(&model.OperationLog{
		OperatorID: middleware.GetUserID(c),
		Action:     "create_tenant",
		Detail:     fmt.Sprintf("开通新租户: %s（管理员 %s）", tenant.Name, adminUser),
		TargetType: "tenant",
		TargetID:   &tenant.ID,
		IP:         c.ClientIP(),
	})

	middleware.JSON(c, gin.H{
		"tenant":         tenant,
		"admin_username": adminUser,
		"admin_password": password,
	})
}

func (h *AdminHandler) UpdateTenant(c *gin.Context) {
	id := c.Param("id")
	var tenant model.Tenant
	if err := model.DB.First(&tenant, id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"code": 404, "message": "租户不存在"})
		return
	}

	var updates map[string]interface{}
	if err := c.ShouldBindJSON(&updates); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "参数错误"})
		return
	}

	allowed := map[string]bool{
		"contact_name": true, "contact_phone": true, "contact_email": true,
		"seat_count": true, "plan_id": true, "expire_at": true, "status": true, "name": true,
	}
	for key := range updates {
		if !allowed[key] {
			delete(updates, key)
		}
	}
	if len(updates) == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "没有可更新字段"})
		return
	}

	if err := model.DB.Model(&tenant).Updates(updates).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"code": 500, "message": "更新失败"})
		return
	}
	model.DB.First(&tenant, tenant.ID)
	model.DB.Create(&model.OperationLog{
		OperatorID: middleware.GetUserID(c),
		Action:     "update_tenant",
		Detail:     "更新租户: " + tenant.Name,
		TargetType: "tenant",
		TargetID:   &tenant.ID,
		IP:         c.ClientIP(),
	})
	middleware.JSON(c, tenant)
}

func (h *AdminHandler) SuspendTenant(c *gin.Context) {
	id := c.Param("id")
	var tenant model.Tenant
	if err := model.DB.First(&tenant, id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"code": 404, "message": "租户不存在"})
		return
	}
	if err := model.DB.Model(&tenant).Update("status", "suspended").Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"code": 500, "message": "暂停失败"})
		return
	}

	model.DB.Create(&model.OperationLog{
		OperatorID: middleware.GetUserID(c),
		Action:     "suspend_tenant",
		Detail:     "暂停租户: " + tenant.Name,
		TargetType: "tenant",
		TargetID:   &tenant.ID,
		IP:         c.ClientIP(),
	})

	middleware.JSON(c, gin.H{"message": "已暂停"})
}

func (h *AdminHandler) ResumeTenant(c *gin.Context) {
	id := c.Param("id")
	var tenant model.Tenant
	if err := model.DB.First(&tenant, id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"code": 404, "message": "租户不存在"})
		return
	}
	status := "normal"
	if tenant.ExpireAt.Before(time.Now()) {
		status = "expired"
	}
	if err := model.DB.Model(&tenant).Update("status", status).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"code": 500, "message": "恢复失败"})
		return
	}

	model.DB.Create(&model.OperationLog{
		OperatorID: middleware.GetUserID(c),
		Action:     "resume_tenant",
		Detail:     "恢复租户: " + tenant.Name,
		TargetType: "tenant",
		TargetID:   &tenant.ID,
		IP:         c.ClientIP(),
	})

	middleware.JSON(c, gin.H{"message": "已恢复", "status": status})
}

func (h *AdminHandler) ListPlans(c *gin.Context) {
	var plans []model.Plan
	model.DB.Find(&plans)
	middleware.JSON(c, plans)
}

func (h *AdminHandler) CreatePlan(c *gin.Context) {
	var plan model.Plan
	if err := c.ShouldBindJSON(&plan); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "参数错误"})
		return
	}

	model.DB.Create(&plan)
	middleware.JSON(c, plan)
}

func (h *AdminHandler) UpdatePlan(c *gin.Context) {
	id := c.Param("id")
	var plan model.Plan
	if err := model.DB.First(&plan, id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"code": 404, "message": "套餐不存在"})
		return
	}

	var updates map[string]interface{}
	if err := c.ShouldBindJSON(&updates); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "参数错误"})
		return
	}

	allowed := map[string]bool{
		"name": true, "price_monthly": true, "seats": true, "storage_days": true,
		"kb_limit": true, "features": true, "status": true,
	}
	for key := range updates {
		if !allowed[key] {
			delete(updates, key)
		}
	}
	if status, ok := updates["status"].(string); ok && status != "active" && status != "inactive" {
		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "套餐状态仅支持 active/inactive"})
		return
	}
	if len(updates) == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "没有可更新字段"})
		return
	}
	if err := model.DB.Model(&plan).Updates(updates).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"code": 500, "message": "更新失败"})
		return
	}
	model.DB.First(&plan, plan.ID)
	model.DB.Create(&model.OperationLog{
		OperatorID: middleware.GetUserID(c),
		Action:     "update_plan",
		Detail:     "更新套餐: " + plan.Name,
		TargetType: "plan",
		TargetID:   &plan.ID,
		IP:         c.ClientIP(),
	})
	middleware.JSON(c, plan)
}

func (h *AdminHandler) ListLogs(c *gin.Context) {
	page, pageSize := middleware.GetPageParams(c)

	var logs []model.OperationLog
	var total int64

	model.DB.Model(&model.OperationLog{}).Count(&total)
	model.DB.Order("created_at desc").Offset((page - 1) * pageSize).Limit(pageSize).Find(&logs)

	middleware.JSONList(c, logs, total, page, pageSize)
}

func (h *AdminHandler) ListAnnouncements(c *gin.Context) {
	var announcements []model.Announcement
	model.DB.Order("created_at desc").Find(&announcements)
	middleware.JSON(c, announcements)
}

func (h *AdminHandler) CreateAnnouncement(c *gin.Context) {
	var ann model.Announcement
	if err := c.ShouldBindJSON(&ann); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "参数错误"})
		return
	}
	ann.Title = strings.TrimSpace(ann.Title)
	if ann.Title == "" {
		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "公告标题不能为空"})
		return
	}
	if ann.Status == "" {
		ann.Status = "draft"
	}
	if ann.Status != "draft" && ann.Status != "published" {
		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "状态仅支持 draft/published"})
		return
	}
	if err := model.DB.Create(&ann).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"code": 500, "message": "创建失败"})
		return
	}
	model.DB.Create(&model.OperationLog{
		OperatorID: middleware.GetUserID(c),
		Action:     "create_announcement",
		Detail:     "创建公告: " + ann.Title,
		TargetType: "announcement",
		TargetID:   &ann.ID,
		IP:         c.ClientIP(),
	})
	middleware.JSON(c, ann)
}

func (h *AdminHandler) UpdateAnnouncement(c *gin.Context) {
	id := c.Param("id")
	var ann model.Announcement
	if err := model.DB.First(&ann, id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"code": 404, "message": "公告不存在"})
		return
	}

	var updates map[string]interface{}
	if err := c.ShouldBindJSON(&updates); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "参数错误"})
		return
	}

	allowed := map[string]bool{"title": true, "content": true, "status": true}
	for key := range updates {
		if !allowed[key] {
			delete(updates, key)
		}
	}
	if len(updates) == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "没有可更新字段"})
		return
	}
	if err := model.DB.Model(&ann).Updates(updates).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"code": 500, "message": "更新失败"})
		return
	}
	model.DB.First(&ann, ann.ID)
	middleware.JSON(c, ann)
}

func (h *AdminHandler) DeleteAnnouncement(c *gin.Context) {
	id := c.Param("id")
	var ann model.Announcement
	if err := model.DB.First(&ann, id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"code": 404, "message": "公告不存在"})
		return
	}
	if err := model.DB.Delete(&ann).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"code": 500, "message": "删除失败"})
		return
	}
	model.DB.Create(&model.OperationLog{
		OperatorID: middleware.GetUserID(c),
		Action:     "delete_announcement",
		Detail:     "删除公告: " + ann.Title,
		TargetType: "announcement",
		TargetID:   &ann.ID,
		IP:         c.ClientIP(),
	})
	middleware.JSON(c, gin.H{"message": "已删除"})
}