package handlers

import (
	"crypto/tls"
	"encoding/base64"
	"encoding/json"
	"net/http"
	"time"

	"ezops/internal/models"

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

// PromDSHandler Prometheus 数据源管理 handler // Logan.Li
type PromDSHandler struct {
	db *gorm.DB
}

// NewPromDSHandler 创建 Prometheus 数据源 handler
func NewPromDSHandler(db *gorm.DB) *PromDSHandler {
	return &PromDSHandler{db: db}
}

// ============================================
// CRUD
// ============================================

// List 数据源列表
// GET /api/v1/prometheus-datasources
func (h *PromDSHandler) List(c *gin.Context) {
	var sources []models.PrometheusDataSource
	if err := h.db.Order("is_default DESC, id ASC").Find(&sources).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{Code: 500, Message: "查询失败: " + err.Error()})
		return
	}
	if sources == nil {
		sources = []models.PrometheusDataSource{}
	}
	c.JSON(http.StatusOK, models.Response{Code: 200, Data: sources})
}

// Get 获取单个数据源
// GET /api/v1/prometheus-datasources/:id
func (h *PromDSHandler) Get(c *gin.Context) {
	id := c.Param("id")
	var ds models.PrometheusDataSource
	if err := h.db.First(&ds, id).Error; err != nil {
		c.JSON(http.StatusNotFound, models.Response{Code: 404, Message: "数据源不存在"})
		return
	}
	c.JSON(http.StatusOK, models.Response{Code: 200, Data: ds})
}

// Create 创建数据源
// POST /api/v1/prometheus-datasources
func (h *PromDSHandler) Create(c *gin.Context) {
	var req models.CreatePromDSReq
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, models.Response{Code: 400, Message: "参数错误: " + err.Error()})
		return
	}

	// 如果设为默认，先清除其他默认
	if req.IsDefault {
		h.db.Model(&models.PrometheusDataSource{}).Where("is_default = ?", true).Update("is_default", false)
	}

	// 默认值
	if req.Access == "" {
		req.Access = "server"
	}
	if req.HTTPMethod == "" {
		req.HTTPMethod = "POST"
	}
	if req.ScrapeInterval <= 0 {
		req.ScrapeInterval = 15
	}
	if req.QueryTimeout <= 0 {
		req.QueryTimeout = 60
	}
	enableAlerting := true
	if req.EnableAlerting != nil {
		enableAlerting = *req.EnableAlerting
	}

	ds := models.PrometheusDataSource{
		Name:                 req.Name,
		URL:                  req.URL,
		Access:               req.Access,
		BasicAuth:            req.BasicAuth,
		BasicAuthUser:        req.BasicAuthUser,
		BasicAuthPass:        req.BasicAuthPass,
		WithCredentials:      req.WithCredentials,
		TLSClientAuth:        req.TLSClientAuth,
		WithCACert:           req.WithCACert,
		CACert:               req.CACert,
		SkipTLSVerify:        req.SkipTLSVerify,
		CustomHeaders:        req.CustomHeaders,
		EnableAlerting:       enableAlerting,
		AlertmanagerDS:       req.AlertmanagerDS,
		ScrapeInterval:       req.ScrapeInterval,
		QueryTimeout:         req.QueryTimeout,
		HTTPMethod:           req.HTTPMethod,
		DisableMetricsLookup: req.DisableMetricsLookup,
		CustomQueryParams:    req.CustomQueryParams,
		IsDefault:            req.IsDefault,
		Status:               1,
	}

	if err := h.db.Create(&ds).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{Code: 500, Message: "创建失败: " + err.Error()})
		return
	}
	h.recordAudit(c, "create", "prometheus_datasource", ds.Name)
	c.JSON(http.StatusOK, models.Response{Code: 200, Message: "创建成功", Data: ds})
}

// Update 更新数据源
// PUT /api/v1/prometheus-datasources/:id
func (h *PromDSHandler) Update(c *gin.Context) {
	id := c.Param("id")
	var ds models.PrometheusDataSource
	if err := h.db.First(&ds, id).Error; err != nil {
		c.JSON(http.StatusNotFound, models.Response{Code: 404, Message: "数据源不存在"})
		return
	}

	var req models.UpdatePromDSReq
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, models.Response{Code: 400, Message: "参数错误: " + err.Error()})
		return
	}

	updates := map[string]interface{}{}
	if req.Name != nil {
		updates["name"] = *req.Name
	}
	if req.URL != nil {
		updates["url"] = *req.URL
	}
	if req.Access != nil {
		updates["access"] = *req.Access
	}
	if req.BasicAuth != nil {
		updates["basic_auth"] = *req.BasicAuth
	}
	if req.BasicAuthUser != nil {
		updates["basic_auth_user"] = *req.BasicAuthUser
	}
	if req.BasicAuthPass != nil {
		updates["basic_auth_pass"] = *req.BasicAuthPass
	}
	if req.WithCredentials != nil {
		updates["with_credentials"] = *req.WithCredentials
	}
	if req.TLSClientAuth != nil {
		updates["tls_client_auth"] = *req.TLSClientAuth
	}
	if req.WithCACert != nil {
		updates["with_ca_cert"] = *req.WithCACert
	}
	if req.CACert != nil {
		updates["ca_cert"] = *req.CACert
	}
	if req.SkipTLSVerify != nil {
		updates["skip_tls_verify"] = *req.SkipTLSVerify
	}
	if req.CustomHeaders != nil {
		updates["custom_headers"] = *req.CustomHeaders
	}
	if req.EnableAlerting != nil {
		updates["enable_alerting"] = *req.EnableAlerting
	}
	if req.AlertmanagerDS != nil {
		updates["alertmanager_ds"] = *req.AlertmanagerDS
	}
	if req.ScrapeInterval != nil {
		updates["scrape_interval"] = *req.ScrapeInterval
	}
	if req.QueryTimeout != nil {
		updates["query_timeout"] = *req.QueryTimeout
	}
	if req.HTTPMethod != nil {
		updates["http_method"] = *req.HTTPMethod
	}
	if req.DisableMetricsLookup != nil {
		updates["disable_metrics_lookup"] = *req.DisableMetricsLookup
	}
	if req.CustomQueryParams != nil {
		updates["custom_query_params"] = *req.CustomQueryParams
	}
	if req.IsDefault != nil {
		// 如果设为默认，先清除其他默认
		if *req.IsDefault {
			h.db.Model(&models.PrometheusDataSource{}).Where("is_default = ?", true).Update("is_default", false)
		}
		updates["is_default"] = *req.IsDefault
	}
	if req.Status != nil {
		updates["status"] = *req.Status
	}

	if len(updates) == 0 {
		c.JSON(http.StatusBadRequest, models.Response{Code: 400, Message: "无更新字段"})
		return
	}

	if err := h.db.Model(&ds).Updates(updates).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{Code: 500, Message: "更新失败: " + err.Error()})
		return
	}

	// 重新查询返回
	h.db.First(&ds, id)
	h.recordAudit(c, "update", "prometheus_datasource", ds.Name)
	c.JSON(http.StatusOK, models.Response{Code: 200, Message: "更新成功", Data: ds})
}

// Delete 删除数据源
// DELETE /api/v1/prometheus-datasources/:id
func (h *PromDSHandler) Delete(c *gin.Context) {
	id := c.Param("id")
	var ds models.PrometheusDataSource
	if err := h.db.First(&ds, id).Error; err != nil {
		c.JSON(http.StatusNotFound, models.Response{Code: 404, Message: "数据源不存在"})
		return
	}
	if err := h.db.Delete(&ds).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{Code: 500, Message: "删除失败: " + err.Error()})
		return
	}
	h.recordAudit(c, "delete", "prometheus_datasource", ds.Name)
	c.JSON(http.StatusOK, models.Response{Code: 200, Message: "删除成功"})
}

// SetDefault 设为默认数据源
// POST /api/v1/prometheus-datasources/:id/default
func (h *PromDSHandler) SetDefault(c *gin.Context) {
	id := c.Param("id")
	var ds models.PrometheusDataSource
	if err := h.db.First(&ds, id).Error; err != nil {
		c.JSON(http.StatusNotFound, models.Response{Code: 404, Message: "数据源不存在"})
		return
	}

	// 清除所有默认
	h.db.Model(&models.PrometheusDataSource{}).Where("is_default = ?", true).Update("is_default", false)
	// 设置当前为默认
	h.db.Model(&ds).Update("is_default", true)

	c.JSON(http.StatusOK, models.Response{Code: 200, Message: "已设为默认"})
}

// ============================================
// Test Connection
// ============================================

// TestConnection 测试数据源连接
// POST /api/v1/prometheus-datasources/test
func (h *PromDSHandler) TestConnection(c *gin.Context) {
	var req models.TestPromDSReq
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, models.Response{Code: 400, Message: "参数错误: " + err.Error()})
		return
	}

	client := &http.Client{Timeout: 15 * time.Second}

	// TLS 配置
	if req.SkipTLSVerify {
		client.Transport = &http.Transport{
			TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
		}
	}

	// 构造请求
	apiURL := req.URL + "/api/v1/query?query=up&time=" + time.Now().UTC().Format(time.RFC3339)
	httpReq, err := http.NewRequest("GET", apiURL, nil)
	if err != nil {
		c.JSON(http.StatusOK, models.Response{Code: 400, Data: gin.H{
			"success": false, "message": "URL 格式错误: " + err.Error(),
		}})
		return
	}

	// Basic Auth
	if req.BasicAuth {
		auth := base64.StdEncoding.EncodeToString([]byte(req.BasicAuthUser + ":" + req.BasicAuthPass))
		httpReq.Header.Set("Authorization", "Basic "+auth)
	}

	resp, err := client.Do(httpReq)
	if err != nil {
		c.JSON(http.StatusOK, models.Response{Code: 200, Data: gin.H{
			"success": false, "message": "连接失败: " + err.Error(),
		}})
		return
	}
	defer resp.Body.Close()

	if resp.StatusCode >= 200 && resp.StatusCode < 300 {
		// 尝试解析响应获取 target 数量
		var result struct {
			Data struct {
				Result []interface{} `json:"result"`
			} `json:"data"`
		}
		json.NewDecoder(resp.Body).Decode(&result)
		c.JSON(http.StatusOK, models.Response{Code: 200, Data: gin.H{
			"success":      true,
			"message":      "连接成功",
			"status_code":  resp.StatusCode,
			"target_count": len(result.Data.Result),
		}})
	} else {
		c.JSON(http.StatusOK, models.Response{Code: 200, Data: gin.H{
			"success":     false,
			"message":     "连接返回异常状态码",
			"status_code": resp.StatusCode,
		}})
	}
}

// ============================================
// 审计
// ============================================

func (h *PromDSHandler) recordAudit(c *gin.Context, action, resource, name string) {
	userID, _ := c.Get("userID")
	username, _ := c.Get("username")
	var uid uint
	var uname string
	if v, ok := userID.(uint); ok {
		uid = v
	}
	if v, ok := username.(string); ok {
		uname = v
	}
	h.db.Create(&models.AuditLog{
		UserID:     &uid,
		Username:   uname,
		IP:         c.ClientIP(),
		UserAgent:  c.Request.UserAgent(),
		Module:     "prometheus_datasource",
		Action:     action,
		Resource:   resource,
		ResourceID: name,
		Status:     200,
	})
}