// Package handlers_v2 provides thin HTTP handlers that delegate to service layer.
// This is the refactored version — handlers contain ONLY HTTP concerns:
// parse request → call service → return HTTP response.
package controller

import (
	"net/http"
	"strconv"

	"ezops/dto"
	"ezops/model"
	"ezops/service"
	"ezops/utils"

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

// ━━━ Server Handler (v2 thin) ━━━━━━━━━━━━━━━━━━━━━━━━━━

// ServerHandlerV2 服务器处理器 — thin handler，委托给 ServerService
type ServerHandlerV2 struct {
	svc *service.ServerService
	db  *gorm.DB // retained for audit logging until audit is extracted
}

func NewServerHandlerV2(svc *service.ServerService, db *gorm.DB) *ServerHandlerV2 {
	return &ServerHandlerV2{svc: svc, db: db}
}

func (h *ServerHandlerV2) recordAudit(c *gin.Context, action, resource, resourceID string, status int, errMsg string) {
	userID, _ := c.Get("userID")
	username, _ := c.Get("username")
	uid, _ := userID.(uint)
	uname, _ := username.(string)

	h.db.Create(&model.AuditLog{
		UserID:     &uid,
		Username:   uname,
		IP:         c.ClientIP(),
		UserAgent:  c.Request.UserAgent(),
		Module:     "server",
		Action:     action,
		Resource:   resource,
		ResourceID: resourceID,
		Status:     status,
		Error:      errMsg,
	})
}

func (h *ServerHandlerV2) ListServers(c *gin.Context) {
	var query model.PageQuery
	if err := c.ShouldBindQuery(&query); err != nil {
		utils.BadRequest(c, "请求参数错误")
		return
	}
	status := c.Query("status")
	regionID := c.Query("region_id")

	list, total, err := h.svc.ListServers(query.Keyword, status, regionID, query.Page, query.PageSize)
	if err != nil {
		utils.InternalError(c, "查询失败")
		return
	}
	utils.ListResponse(c, list, total)
}

func (h *ServerHandlerV2) GetServer(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))
	server, err := h.svc.GetServer(uint(id))
	if err != nil {
		utils.NotFound(c, "服务器不存在")
		return
	}
	utils.OK(c, server)
}

func (h *ServerHandlerV2) CreateServer(c *gin.Context) {
	var req dto.CreateServerRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		utils.BadRequest(c, "请求参数错误: "+err.Error())
		return
	}

	server, err := h.svc.CreateServer(&req)
	if err != nil {
		utils.InternalError(c, "创建失败: "+err.Error())
		return
	}

	h.recordAudit(c, "create", server.Hostname+" ("+server.IP+")", strconv.Itoa(int(server.ID)), 1, "")
	utils.OK(c, server)
}

func (h *ServerHandlerV2) UpdateServer(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	var req dto.UpdateServerRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		utils.BadRequest(c, "请求参数错误: "+err.Error())
		return
	}

	if err := h.svc.UpdateServer(uint(id), &req); err != nil {
		utils.InternalError(c, "更新失败: "+err.Error())
		return
	}

	server, _ := h.svc.GetServer(uint(id))
	h.recordAudit(c, "update", server.Hostname+" ("+server.IP+")", strconv.Itoa(int(server.ID)), 1, "")
	utils.OK(c, server)
}

func (h *ServerHandlerV2) DeleteServer(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	server, err := h.svc.GetServer(uint(id))
	if err != nil {
		utils.NotFound(c, "服务器不存在")
		return
	}

	// 清理关联数据
	h.db.Unscoped().Where("hostname = ?", server.Hostname).Delete(&model.AgentReport{})
	h.db.Unscoped().Where("hostname = ?", server.Hostname).Delete(&model.MetricsAggregate{})

	if err := h.svc.DeleteServer(uint(id)); err != nil {
		utils.InternalError(c, "删除失败")
		return
	}

	h.recordAudit(c, "delete", server.Hostname+" ("+server.IP+")", strconv.Itoa(int(server.ID)), 1, "")
	c.JSON(http.StatusOK, model.Response{Code: 200, Message: "服务器已彻底删除"})
}

func (h *ServerHandlerV2) GetServerStats(c *gin.Context) {
	stats, err := h.svc.GetDashboardStats()
	if err != nil {
		utils.InternalError(c, "获取统计失败")
		return
	}
	utils.OK(c, stats.ServerStats)
}

// BatchCreateServers / BatchDeleteServers — 暂时保留原始逻辑（复杂批量操作待后续迁移）
func (h *ServerHandlerV2) BatchCreateServers(c *gin.Context) {
	// 暂时委托给原始 handler 逻辑（从 server.go 复制）
	var servers []model.Server
	if err := c.ShouldBindJSON(&servers); err != nil {
		utils.BadRequest(c, "请求参数错误")
		return
	}
	for i := range servers {
		if servers[i].Port == 0 {
			servers[i].Port = 22
		}
		if servers[i].Username == "" {
			servers[i].Username = "root"
		}
		if servers[i].Status == "" {
			servers[i].Status = "stopped"
		}
	}
	if err := h.db.Create(&servers).Error; err != nil {
		utils.InternalError(c, "批量创建失败")
		return
	}
	utils.OK(c, servers)
}

func (h *ServerHandlerV2) BatchDeleteServers(c *gin.Context) {
	var ids []uint
	if err := c.ShouldBindJSON(&ids); err != nil {
		utils.BadRequest(c, "请求参数错误")
		return
	}
	// 清理关联数据
	for _, id := range ids {
		var s model.Server
		if err := h.db.First(&s, id).Error; err == nil {
			h.db.Unscoped().Where("hostname = ?", s.Hostname).Delete(&model.AgentReport{})
			h.db.Unscoped().Where("hostname = ?", s.Hostname).Delete(&model.MetricsAggregate{})
		}
	}
	h.db.Unscoped().Delete(&model.Server{}, ids)
	utils.OK(c, gin.H{"deleted": len(ids)})
}