package controller

import (
	"ezops/model"
	"net/http"
	"strconv"
	"sync"

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

// SNMPHandler SNMP 设备管理 + 采集 handler // Logan.Li
type SNMPHandler struct {
	db     *gorm.DB
	stopCh chan struct{}
	wg     sync.WaitGroup
}

// NewSNMPHandler 创建 SNMP handler
func NewSNMPHandler(db *gorm.DB) *SNMPHandler {
	return &SNMPHandler{db: db, stopCh: make(chan struct{})}
}

// ========== SNMP Device CRUD ==========

// ListDevices 列出 SNMP 设备
// GET /api/v1/snmp/devices?page=1&page_size=20&keyword=
func (h *SNMPHandler) ListDevices(c *gin.Context) {
	var devices []model.SNMPDevice
	q := h.db.Model(&model.SNMPDevice{})

	if kw := c.Query("keyword"); kw != "" {
		q = q.Where("name LIKE ? OR ip LIKE ?", "%"+kw+"%", "%"+kw+"%")
	}

	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
	var total int64
	q.Count(&total)
	q.Offset((page - 1) * pageSize).Limit(pageSize).Order("name ASC").Find(&devices)

	if devices == nil {
		devices = []model.SNMPDevice{}
	}
	c.JSON(http.StatusOK, model.Response{Code: 200, Data: gin.H{"list": devices, "total": total}})
}

// CreateDevice 创建 SNMP 设备
// POST /api/v1/snmp/devices
func (h *SNMPHandler) CreateDevice(c *gin.Context) {
	var req struct {
		Name         string `json:"name" binding:"required"`
		IP           string `json:"ip" binding:"required"`
		Port         int    `json:"port"`
		SnmpVersion  string `json:"snmp_version"`
		Version      string `json:"version"`
		Community    string `json:"community"`
		TemplateID   uint   `json:"template_id"`
		DeviceType   string `json:"device_type"`
		Vendor       string `json:"vendor"`
		Description  string `json:"description"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, model.Response{Code: 400, Message: err.Error()})
		return
	}
	ver := req.SnmpVersion
	if ver == "" {
		ver = req.Version
	}
	if ver == "" {
		ver = "v2c"
	}
	device := model.SNMPDevice{
		Name: req.Name, IP: req.IP, Port: req.Port,
		Version: model.SNMPVersion(ver), Community: req.Community,
		TemplateID: req.TemplateID, DeviceType: req.DeviceType,
		Vendor: req.Vendor, Description: req.Description,
		Status: model.SNMPDeviceOffline,
	}
	if device.Port == 0 {
		device.Port = 161
	}
	if device.Community == "" {
		device.Community = "public"
	}
	if err := h.db.Create(&device).Error; err != nil {
		c.JSON(http.StatusInternalServerError, model.Response{Code: 500, Message: err.Error()})
		return
	}
	c.JSON(http.StatusOK, model.Response{Code: 200, Data: device, Message: "创建成功"})
}

// UpdateDevice 更新 SNMP 设备
// PUT /api/v1/snmp/devices/:id
func (h *SNMPHandler) UpdateDevice(c *gin.Context) {
	id := c.Param("id")
	var device model.SNMPDevice
	if err := h.db.First(&device, id).Error; err != nil {
		c.JSON(http.StatusNotFound, model.Response{Code: 404, Message: "设备不存在"})
		return
	}
	if err := c.ShouldBindJSON(&device); err != nil {
		c.JSON(http.StatusBadRequest, model.Response{Code: 400, Message: err.Error()})
		return
	}
	h.db.Save(&device)
	c.JSON(http.StatusOK, model.Response{Code: 200, Data: device, Message: "更新成功"})
}

// DeleteDevice 删除 SNMP 设备
// DELETE /api/v1/snmp/devices/:id
func (h *SNMPHandler) DeleteDevice(c *gin.Context) {
	id := c.Param("id")
	if err := h.db.Delete(&model.SNMPDevice{}, id).Error; err != nil {
		c.JSON(http.StatusInternalServerError, model.Response{Code: 500, Message: err.Error()})
		return
	}
	c.JSON(http.StatusOK, model.Response{Code: 200, Message: "删除成功"})
}

// BatchDeleteDevices 批量删除
// DELETE /api/v1/snmp/devices/batch-delete
func (h *SNMPHandler) BatchDeleteDevices(c *gin.Context) {
	var req model.IDsRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, model.Response{Code: 400, Message: err.Error()})
		return
	}
	h.db.Where("id IN ?", req.IDs).Delete(&model.SNMPDevice{})
	c.JSON(http.StatusOK, model.Response{Code: 200, Message: "批量删除成功"})
}

// ========== SNMP Template CRUD ==========

// ListTemplates 列出 OID 模板（含 OID 条目）// Logan.Li
// GET /api/v1/snmp/templates
func (h *SNMPHandler) ListTemplates(c *gin.Context) {
	var templates []model.SNMPTemplate
	h.db.Preload("OIDs", func(db *gorm.DB) *gorm.DB {
		return db.Order("sort_order ASC")
	}).Order("name ASC").Find(&templates)
	if templates == nil {
		templates = []model.SNMPTemplate{}
	}
	c.JSON(http.StatusOK, model.Response{Code: 200, Data: gin.H{"list": templates, "total": len(templates)}})
}

// CreateTemplate 创建 OID 模板
// POST /api/v1/snmp/templates
func (h *SNMPHandler) CreateTemplate(c *gin.Context) {
	var template model.SNMPTemplate
	if err := c.ShouldBindJSON(&template); err != nil {
		c.JSON(http.StatusBadRequest, model.Response{Code: 400, Message: err.Error()})
		return
	}
	if err := h.db.Create(&template).Error; err != nil {
		c.JSON(http.StatusInternalServerError, model.Response{Code: 500, Message: err.Error()})
		return
	}
	c.JSON(http.StatusOK, model.Response{Code: 200, Data: template, Message: "创建成功"})
}

// ========== SNMP Statistics ==========

// GetSNMPStats 获取 SNMP 概览统计
// GET /api/v1/snmp/stats
func (h *SNMPHandler) GetSNMPStats(c *gin.Context) {
	var total, online int64
	h.db.Model(&model.SNMPDevice{}).Count(&total)
	h.db.Model(&model.SNMPDevice{}).Where("status = ?", "online").Count(&online)

	c.JSON(http.StatusOK, model.Response{Code: 200, Data: gin.H{
		"total":  total,
		"online": online,
		"abnormal": total - online,
	}})
}