package controller

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

	"ezops/model"

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

const (
	defaultNotifyTitleTemplate  = "[{{severity_label}}] {{rule_name}} — {{hostname}} ({{metric}})"
	defaultNotifyFooterTemplate = "{{time}} ｜ {{platform}}"
	defaultNotifyPlatformName   = "AIOps 智能运维平台"
)

// ensureNotifySettings 确保全局消息模版存在 // Logan.Li
func ensureNotifySettings(db *gorm.DB) model.AlertNotifySettings {
	var s model.AlertNotifySettings
	if err := db.First(&s).Error; err != nil {
		s = model.AlertNotifySettings{
			TitleTemplate:  defaultNotifyTitleTemplate,
			FooterTemplate: defaultNotifyFooterTemplate,
			PlatformName:   defaultNotifyPlatformName,
		}
		db.Create(&s)
	}
	if s.PlatformName == "" {
		s.PlatformName = defaultNotifyPlatformName
	}
	return s
}

// GetNotifyMessageSettings GET /alerts/notify-message-settings // Logan.Li
func (h *AlertHandler) GetNotifyMessageSettings(c *gin.Context) {
	s := ensureNotifySettings(h.db)
	c.JSON(http.StatusOK, model.Response{Code: 200, Data: s})
}

// SaveNotifyMessageSettings PUT /alerts/notify-message-settings // Logan.Li
func (h *AlertHandler) SaveNotifyMessageSettings(c *gin.Context) {
	var req struct {
		TitleTemplate  string `json:"title_template"`
		FooterTemplate string `json:"footer_template"`
		PlatformName   string `json:"platform_name"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, model.Response{Code: 400, Message: "请求参数错误: " + err.Error()})
		return
	}
	s := ensureNotifySettings(h.db)
	updates := map[string]interface{}{
		"title_template":  strings.TrimSpace(req.TitleTemplate),
		"footer_template": strings.TrimSpace(req.FooterTemplate),
		"platform_name":   strings.TrimSpace(req.PlatformName),
	}
	if updates["platform_name"] == "" {
		updates["platform_name"] = defaultNotifyPlatformName
	}
	h.db.Model(&s).Updates(updates)
	h.db.First(&s, s.ID)
	c.JSON(http.StatusOK, model.Response{Code: 200, Data: s, Message: "消息模版已保存"})
}

// notifyTemplateVars 告警通知模版变量 // Logan.Li
func notifyTemplateVars(ruleName, hostname, metric, severity, message string, value, threshold float64, platform string) map[string]string {
	sevLabel := "严重告警"
	switch severity {
	case "warning":
		sevLabel = "警告"
	case "info":
		sevLabel = "信息"
	}
	if platform == "" {
		platform = defaultNotifyPlatformName
	}
	return map[string]string{
		"time":            time.Now().Format("2006-01-02 15:04:05"),
		"platform":        platform,
		"rule_name":       ruleName,
		"hostname":        hostname,
		"metric":          metric,
		"severity":        severity,
		"severity_label":  sevLabel,
		"message":         message,
		"value":           fmt.Sprintf("%.2f", value),
		"threshold":       fmt.Sprintf("%.2f", threshold),
	}
}

// renderNotifyTemplate 简单变量替换 {{key}} // Logan.Li
func renderNotifyTemplate(tpl string, vars map[string]string) string {
	out := tpl
	for k, v := range vars {
		out = strings.ReplaceAll(out, "{{"+k+"}}", v)
	}
	return out
}

// buildNotifyTitle 按全局模版生成通知标题 // Logan.Li
func buildNotifyTitle(db *gorm.DB, ruleName, hostname, metric, severity string) string {
	s := ensureNotifySettings(db)
	tpl := s.TitleTemplate
	if tpl == "" {
		tpl = defaultNotifyTitleTemplate
	}
	return renderNotifyTemplate(tpl, notifyTemplateVars(ruleName, hostname, metric, severity, "", 0, 0, s.PlatformName))
}

// buildNotifyFooter 按全局模版生成卡片底部 // Logan.Li
func buildNotifyFooter(db *gorm.DB) string {
	s := ensureNotifySettings(db)
	tpl := s.FooterTemplate
	if tpl == "" {
		tpl = defaultNotifyFooterTemplate
	}
	vars := map[string]string{
		"time":     time.Now().Format("2006-01-02 15:04:05"),
		"platform": s.PlatformName,
	}
	if vars["platform"] == "" {
		vars["platform"] = defaultNotifyPlatformName
	}
	return renderNotifyTemplate(tpl, vars)
}

// buildAlertContent 生成告警正文（字段列表，供飞书卡片解析） // Logan.Li
func buildAlertContent(ruleName, hostname, metric, severity, message string, value, threshold float64) string {
	return fmt.Sprintf(
		"**规则名称：** %s\\n**目标主机：** %s\\n**指标类型：** %s\\n**告警级别：** %s\\n**当前值：** %.2f\\n**阈值：** %.2f\\n**详细信息：** %s\\n**触发时间：** %s",
		ruleName, hostname, metric, severity, value, threshold, message, time.Now().Format("2006-01-02 15:04:05"),
	)
}