package services

import (
	"os"
	"time"

	"lokistack/pkg/metrics"
	"lokistack/repository"
)

// InitMetrics 注册指标并启动业务/存储指标的周期刷新。
//
// HTTP 层与 DB 落盘由 middleware / repository 直接埋点；
// 这里只负责需要"扫 DB 算出来"的指标（记录数、部署/采集器状态分布、DB 大小）。
func InitMetrics(version string) {
	metrics.Register(version)

	go func() {
		ticker := time.NewTicker(30 * time.Second)
		defer ticker.Stop()
		refreshGauges()
		for range ticker.C {
			refreshGauges()
		}
	}()
}

// refreshGauges 刷新需要遍历 DB 才能得出的指标。
func refreshGauges() {
	db := repository.GetDB()
	if db == nil {
		return
	}

	if path := databasePath(); path != "" {
		if fi, err := os.Stat(path); err == nil {
			metrics.DBSizeBytes.Set(float64(fi.Size()))
		}
	}

	db.RLock()
	users := len(db.Users)
	clusters := len(db.Clusters)
	hosts := len(db.Hosts)
	storages := len(db.Storages)
	deployList := db.Deployments
	collectorList := db.Collectors
	alertRules := len(db.AlertRules)
	auditCount := len(db.AuditLogs)
	db.RUnlock()

	metrics.DBRecordsTotal.WithLabelValues("users").Set(float64(users))
	metrics.DBRecordsTotal.WithLabelValues("clusters").Set(float64(clusters))
	metrics.DBRecordsTotal.WithLabelValues("hosts").Set(float64(hosts))
	metrics.DBRecordsTotal.WithLabelValues("storages").Set(float64(storages))
	metrics.DBRecordsTotal.WithLabelValues("deployments").Set(float64(len(deployList)))
	metrics.DBRecordsTotal.WithLabelValues("collectors").Set(float64(len(collectorList)))
	metrics.DBRecordsTotal.WithLabelValues("alertRules").Set(float64(alertRules))
	metrics.DBRecordsTotal.WithLabelValues("auditLogs").Set(float64(auditCount))

	// 状态分布：先 Reset 再重算，避免已删除对象留下僵尸时间序列
	metrics.DeploymentsTotal.Reset()
	for _, d := range deployList {
		status := d.Status
		if status == "" {
			status = "unknown"
		}
		mode := d.Mode
		if mode == "" {
			mode = "unknown"
		}
		metrics.DeploymentsTotal.WithLabelValues(status, mode).Inc()
	}

	metrics.CollectorsTotal.Reset()
	for _, c := range collectorList {
		status := c.Status
		if status == "" {
			status = "unknown"
		}
		runMode := c.RunMode
		if runMode == "" {
			runMode = "unknown"
		}
		metrics.CollectorsTotal.WithLabelValues(status, c.Type, runMode).Inc()
	}
}

func databasePath() string {
	if p := os.Getenv("DATABASE_PATH"); p != "" {
		return p
	}
	if p := os.Getenv("DATA_DIR"); p != "" {
		return p + "/opsxloki.json"
	}
	return "/app/data/opsxloki.json"
}