feat：新增数据导出器

cmd/weatherstation/main.go

@@ -38,8 +38,11 @@ func main() {
 	server.SetupLogger()
 
 	// 初始化数据库连接
-	_ = database.GetDB() // 确保数据库连接已初始化
+	_ = database.GetDB() // 确保PostgreSQL连接已初始化
 	defer database.Close()
+	// 初始化MySQL连接（如果配置存在）
+	_ = database.GetMySQL()
+	defer database.CloseMySQL()
 
 	// 启动前自检
 	if !*noSelftest {
@@ -115,21 +118,42 @@ func main() {
 	}
 
 	// 根据命令行参数启动服务
+	startExporterBackground := func(wg *sync.WaitGroup) {
+		if wg != nil {
+			wg.Add(1)
+		}
+		go func() {
+			defer func() {
+				if wg != nil {
+					wg.Done()
+				}
+			}()
+			log.Println("启动数据导出器（10分钟）...")
+			ctx := context.Background()
+			exporter := tools.NewExporter()
+			if err := exporter.Start(ctx); err != nil {
+				log.Printf("导出器退出: %v", err)
+			}
+		}()
+	}
+
 	if *webOnly {
-		// 只启动Web服务器
+		// 只启动Web服务器 + 导出器
+		startExporterBackground(nil)
 		log.Println("启动Web服务器模式...")
 		if err := server.StartGinServer(); err != nil {
 			log.Fatalf("启动Web服务器失败: %v", err)
 		}
 	} else if *udpOnly {
-		// 只启动UDP服务器
+		// 只启动UDP服务器 + 导出器
+		startExporterBackground(nil)
 		log.Println("启动UDP服务器模式...")
 		if err := server.StartUDPServer(); err != nil {
 			log.Fatalf("启动UDP服务器失败: %v", err)
 		}
 	} else {
-		// 同时启动UDP和Web服务器
+		// 同时启动UDP和Web服务器 + 导出器
-		log.Println("启动完整模式：UDP + Web服务器...")
+		log.Println("启动完整模式：UDP + Web服务器 + 导出器...")
 
 		var wg sync.WaitGroup
 		wg.Add(2)
@@ -152,6 +176,7 @@ func main() {
 			}
 		}()
 
+		startExporterBackground(&wg)
 		wg.Wait()
 	}
 }

config.yaml

@@ -11,3 +11,11 @@ database:
 
 forecast:
   caiyun_token: "ZAcZq49qzibr10F0"
+
+mysql:
+  host: "127.0.0.1"
+  port: 3306
+  user: "remote"
+  password: "your_password"
+  dbname: "rtk_data"
+  params: "parseTime=true&loc=Asia%2FShanghai"

go.mod

@@ -6,11 +6,13 @@ toolchain go1.24.5
 
 require (
 	github.com/gin-gonic/gin v1.10.1
+	github.com/go-sql-driver/mysql v1.8.1
 	github.com/lib/pq v1.10.9
 	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
+	filippo.io/edwards25519 v1.1.0 // indirect
 	github.com/bytedance/sonic v1.11.6 // indirect
 	github.com/bytedance/sonic/loader v0.1.1 // indirect
 	github.com/cloudwego/base64x v0.1.4 // indirect
@@ -36,4 +38,4 @@ require (
 	golang.org/x/sys v0.20.0 // indirect
 	golang.org/x/text v0.15.0 // indirect
 	google.golang.org/protobuf v1.34.1 // indirect
-)
+)

go.sum

@@ -1,3 +1,5 @@
+filippo.io/edwards25519 v1.1.0 h1:FNf4tywRC1HmFuKW5xopWpigGjJKiJSV0Cqo0cJWDaA=
+filippo.io/edwards25519 v1.1.0/go.mod h1:BxyFTGdWcka3PhytdK4V28tE5sGfRvvvRV7EaN4VDT4=
 github.com/bytedance/sonic v1.11.6 h1:oUp34TzMlL+OY1OUWxHqsdkgC/Zfc85zGqw9siXjrc0=
 github.com/bytedance/sonic v1.11.6/go.mod h1:LysEHSvpvDySVdC2f87zGWf6CIKJcAvqab1ZaiQtds4=
 github.com/bytedance/sonic/loader v0.1.1 h1:c+e5Pt1k/cy5wMveRDyk2X4B9hF4g7an8N3zCYjJFNM=
@@ -7,6 +9,7 @@ github.com/cloudwego/base64x v0.1.4/go.mod h1:0zlkT4Wn5C6NdauXdJRhSKRlJvmclQ1hhJ
 github.com/cloudwego/iasm v0.2.0 h1:1KNIy1I1H9hNNFEEH3DVnI4UujN+1zjpuk6gwHLTssg=
 github.com/cloudwego/iasm v0.2.0/go.mod h1:8rXZaNYT2n95jn+zTI1sDr+IgcD2GVs0nlbbQPiEFhY=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/gabriel-vasile/mimetype v1.4.3 h1:in2uUcidCuFcDKtdcBxlR0rJ1+fsokWf+uqxgUFjbI0=
 github.com/gabriel-vasile/mimetype v1.4.3/go.mod h1:d8uq/6HKRL6CGdk+aubisF/M5GcPfT7nKyLpA0lbSSk=
@@ -14,14 +17,20 @@ github.com/gin-contrib/sse v0.1.0 h1:Y/yl/+YNO8GZSjAhjMsSuLt29uWRFHdHYUb5lYOV9qE
 github.com/gin-contrib/sse v0.1.0/go.mod h1:RHrZQHXnP2xjPF+u1gW/2HnVO7nvIa9PG3Gm+fLHvGI=
 github.com/gin-gonic/gin v1.10.1 h1:T0ujvqyCSqRopADpgPgiTT63DUQVSfojyME59Ei63pQ=
 github.com/gin-gonic/gin v1.10.1/go.mod h1:4PMNQiOhvDRa013RKVbsiNwoyezlm2rm0uX/T7kzp5Y=
+github.com/go-playground/assert/v2 v2.2.0 h1:JvknZsQTYeFEAhQwI4qEt9cyV5ONwRHC+lYKSsYSR8s=
+github.com/go-playground/assert/v2 v2.2.0/go.mod h1:VDjEfimB/XKnb+ZQfWdccd7VUvScMdVu0Titje2rxJ4=
 github.com/go-playground/locales v0.14.1 h1:EWaQ/wswjilfKLTECiXz7Rh+3BjFhfDFKv/oXslEjJA=
 github.com/go-playground/locales v0.14.1/go.mod h1:hxrqLVvrK65+Rwrd5Fc6F2O76J/NuW9t0sjnWqG1slY=
 github.com/go-playground/universal-translator v0.18.1 h1:Bcnm0ZwsGyWbCzImXv+pAJnYK9S473LQFuzCbDbfSFY=
 github.com/go-playground/universal-translator v0.18.1/go.mod h1:xekY+UJKNuX9WP91TpwSH2VMlDf28Uj24BCp08ZFTUY=
 github.com/go-playground/validator/v10 v10.20.0 h1:K9ISHbSaI0lyB2eWMPJo+kOS/FBExVwjEviJTixqxL8=
 github.com/go-playground/validator/v10 v10.20.0/go.mod h1:dbuPbCMFw/DrkbEynArYaCwl3amGuJotoKCe95atGMM=
+github.com/go-sql-driver/mysql v1.8.1 h1:LedoTUt/eveggdHS9qUFC1EFSa8bU2+1pZjSRpvNJ1Y=
+github.com/go-sql-driver/mysql v1.8.1/go.mod h1:wEBSXgmK//2ZFJyE+qWnIsVGmvmEKlqwuVSjsCm7DZg=
 github.com/goccy/go-json v0.10.2 h1:CrxCmQqYDkv1z7lO7Wbh2HN93uovUHgrECaO5ZrCXAU=
 github.com/goccy/go-json v0.10.2/go.mod h1:6MelG93GURQebXPDq3khkgXZkazVtN9CRI+MGFi0w8I=
+github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
+github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
 github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
@@ -42,6 +51,7 @@ github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9G
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
 github.com/pelletier/go-toml/v2 v2.2.2 h1:aYUidT7k73Pcl9nb2gScu7NSrKCSHIDE89b3+6Wq+LM=
 github.com/pelletier/go-toml/v2 v2.2.2/go.mod h1:1t835xjRzz80PqgE6HHgN2JOsmgYu/h4qDAS4n929Rs=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
@@ -53,6 +63,7 @@ github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/twitchyliquid64/golang-asm v0.15.1 h1:SU5vSMR7hnwNxj24w34ZyCi/FmDZTkS4MhqMhdFk5YI=
 github.com/twitchyliquid64/golang-asm v0.15.1/go.mod h1:a1lVb/DtPvCB8fslRZhAngC2+aY1QWCk3Cedj/Gdt08=
@@ -71,6 +82,8 @@ golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
 golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.15.0 h1:h1V/4gjBv8v9cjcR6+AR5+/cIYK5N/WAgiv4xlsEtAk=
 golang.org/x/text v0.15.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/protobuf v1.34.1 h1:9ddQBjfCyZPOHPUiPxpYESBLc+T8P3E+Vo4IbKZgFWg=
 google.golang.org/protobuf v1.34.1/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=

internal/config/config.go

@@ -28,10 +28,21 @@ type ForecastConfig struct {
 	CaiyunToken string `yaml:"caiyun_token"`
 }
 
+// MySQLConfig MySQL 连接配置（用于 rtk_data）
+type MySQLConfig struct {
+	Host     string `yaml:"host"`
+	Port     int    `yaml:"port"`
+	User     string `yaml:"user"`
+	Password string `yaml:"password"`
+	DBName   string `yaml:"dbname"`
+	Params   string `yaml:"params"` // 例如: parseTime=true&loc=Asia%2FShanghai
+}
+
 type Config struct {
 	Server   ServerConfig   `yaml:"server"`
 	Database DatabaseConfig `yaml:"database"`
 	Forecast ForecastConfig `yaml:"forecast"`
+	MySQL    MySQLConfig    `yaml:"mysql"`
 }
 
 var (
@@ -89,6 +100,9 @@ func (c *Config) validate() error {
 	if c.Database.SSLMode == "" {
 		c.Database.SSLMode = "disable" // 默认禁用SSL
 	}
+	if c.MySQL.Port <= 0 {
+		c.MySQL.Port = 3306
+	}
 	// CaiyunToken 允许为空：表示不启用彩云定时任务
 	return nil
 }

internal/database/db.go

@@ -6,6 +6,7 @@ import (
 	"sync"
 	"weatherstation/internal/config"
 
+	_ "github.com/go-sql-driver/mysql"
 	_ "github.com/lib/pq"
 )
 
@@ -48,3 +49,40 @@ func Close() error {
 	}
 	return nil
 }
+
+// -------------------- MySQL 连接（rtk_data） --------------------
+
+var (
+	mysqlInstance *sql.DB
+	mysqlOnce     sync.Once
+)
+
+// GetMySQL 返回 MySQL 连接单例（rtk_data）
+func GetMySQL() *sql.DB {
+	mysqlOnce.Do(func() {
+		cfg := config.GetConfig().MySQL
+		var dsn string
+		if cfg.Params != "" {
+			dsn = fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?%s", cfg.User, cfg.Password, cfg.Host, cfg.Port, cfg.DBName, cfg.Params)
+		} else {
+			dsn = fmt.Sprintf("%s:%s@tcp(%s:%d)/%s", cfg.User, cfg.Password, cfg.Host, cfg.Port, cfg.DBName)
+		}
+		var err error
+		mysqlInstance, err = sql.Open("mysql", dsn)
+		if err != nil {
+			panic(fmt.Sprintf("无法连接到 MySQL: %v", err))
+		}
+		if err = mysqlInstance.Ping(); err != nil {
+			panic(fmt.Sprintf("MySQL 连接测试失败: %v", err))
+		}
+	})
+	return mysqlInstance
+}
+
+// CloseMySQL 关闭 MySQL 连接
+func CloseMySQL() error {
+	if mysqlInstance != nil {
+		return mysqlInstance.Close()
+	}
+	return nil
+}

internal/tools/exporter.go

@@ -0,0 +1,338 @@
+package tools
+
+import (
+	"compress/gzip"
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"math"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+	"weatherstation/internal/database"
+)
+
+// Exporter 负责每10分钟导出 CSV（含ZTD融合）
+type Exporter struct {
+	pg  *sql.DB
+	my  *sql.DB
+	loc *time.Location // Asia/Shanghai
+}
+
+func NewExporter() *Exporter {
+	loc, _ := time.LoadLocation("Asia/Shanghai")
+	if loc == nil {
+		loc = time.FixedZone("CST", 8*3600)
+	}
+	return &Exporter{
+		pg:  database.GetDB(),
+		my:  database.GetMySQL(),
+		loc: loc,
+	}
+}
+
+// Start 启动调度循环（阻塞）
+func (e *Exporter) Start(ctx context.Context) error {
+	for {
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		default:
+		}
+
+		now := time.Now().In(e.loc)
+		next := alignToNextBucketEnd(now, 10).Add(30 * time.Second)
+		log.Printf("exporter: now=%s next_run=%s", now.Format("2006-01-02 15:04:05"), next.Format("2006-01-02 15:04:05"))
+		delay := time.Until(next)
+		if delay > 0 {
+			timer := time.NewTimer(delay)
+			select {
+			case <-ctx.Done():
+				timer.Stop()
+				return ctx.Err()
+			case <-timer.C:
+			}
+		}
+
+		end := time.Now().In(e.loc).Truncate(time.Minute)
+		end = alignToPrevBucketEnd(end, 10)
+		start := end.Add(-10 * time.Minute)
+
+		if err := e.exportBucket(ctx, start, end); err != nil {
+			log.Printf("export bucket %s-%s failed: %v", start.Format("2006-01-02 15:04:05"), end.Format("2006-01-02 15:04:05"), err)
+		}
+	}
+}
+
+// exportBucket 导出一个10分钟桶（CST）
+func (e *Exporter) exportBucket(ctx context.Context, bucketStart, bucketEnd time.Time) error {
+	utcDay := bucketEnd.UTC().Format("2006-01-02")
+	outDir := filepath.Join("export_data")
+	histDir := filepath.Join("export_data", "history")
+	if err := os.MkdirAll(histDir, 0o755); err != nil {
+		return err
+	}
+	activePath := filepath.Join(outDir, fmt.Sprintf("weather_data_%s.csv", utcDay))
+	log.Printf("exporter: begin bucket start=%s end=%s -> %s", bucketStart.Format("2006-01-02 15:04:05"), bucketEnd.Format("2006-01-02 15:04:05"), activePath)
+
+	// 轮转上一 UTC 日的文件（若存在且未压缩）
+	if err := rotatePreviousUTC(outDir, histDir, utcDay); err != nil {
+		log.Printf("rotate previous day failed: %v", err)
+	}
+
+	needHeader := ensureFileWithHeader(activePath)
+
+	rows, err := e.pg.QueryContext(ctx, `
+		SELECT 
+		  s.latitude, 
+		  s.longitude, 
+		  s.device_id,
+		  s.altitude,
+		  r.pressure_hpa_x100, 
+		  r.temp_c_x100, 
+		  r.wind_speed_ms_x1000, 
+		  r.wind_dir_deg, 
+		  r.humidity_pct,
+		  r.bucket_start
+		FROM stations s
+		JOIN rs485_weather_10min r ON r.station_id = s.station_id AND r.bucket_start = $1
+		WHERE s.device_type = 'WH65LP'
+		  AND s.latitude IS NOT NULL AND s.longitude IS NOT NULL
+		  AND s.latitude <> 0 AND s.longitude <> 0
+		ORDER BY s.device_id
+	`, bucketStart)
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	f, err := os.OpenFile(activePath, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0o644)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	if needHeader {
+		if _, err := f.WriteString(headerLine() + "\n"); err != nil {
+			return err
+		}
+	}
+
+	var total, ztdHit, ztdMiss int
+
+	for rows.Next() {
+		var (
+			lat, lon, elev sql.NullFloat64
+			deviceID       string
+			pX100, tX100   sql.NullInt64
+			wsX1000        sql.NullInt64
+			wdDeg          sql.NullInt64
+			rh             sql.NullInt64
+			bucketStartTS  time.Time
+		)
+		if err := rows.Scan(&lat, &lon, &deviceID, &elev, &pX100, &tX100, &wsX1000, &wdDeg, &rh, &bucketStartTS); err != nil {
+			log.Printf("scan row failed: %v", err)
+			continue
+		}
+
+		// date_time 使用 Go 端按 CST 格式化
+		dateTimeStr := bucketStartTS.In(e.loc).Format("2006-01-02 15:04:05")
+
+		var pressureStr, tempStr, wsStr, wdStr, rhStr string
+		if pX100.Valid {
+			pressureStr = fmtFloat(float64(pX100.Int64)/100.0, 2)
+		}
+		if tX100.Valid {
+			tempStr = fmtFloat(float64(tX100.Int64)/100.0, 2)
+		}
+		if wsX1000.Valid {
+			wsStr = fmtFloat(float64(wsX1000.Int64)/1000.0, 3)
+		}
+		if wdDeg.Valid {
+			wdStr = fmtFloat(float64(wdDeg.Int64), 0)
+		}
+		if rh.Valid {
+			rhStr = fmtFloat(float64(rh.Int64), 0)
+		}
+
+		ztdStr := e.lookupZTD(ctx, deviceID, bucketEnd)
+		if ztdStr != "" {
+			ztdHit++
+		} else {
+			ztdMiss++
+		}
+
+		var b strings.Builder
+		b.WriteString(fmtNullFloat(lat))
+		b.WriteByte(',')
+		b.WriteString(fmtNullFloat(lon))
+		b.WriteByte(',')
+		b.WriteString(deviceID)
+		b.WriteByte(',')
+		b.WriteByte(',') // station_name 留空
+		b.WriteString(dateTimeStr)
+		b.WriteByte(',')
+		b.WriteString(fmtNullFloat(elev))
+		b.WriteByte(',')
+		b.WriteString(pressureStr)
+		b.WriteByte(',')
+		b.WriteString(tempStr)
+		b.WriteByte(',')
+		b.WriteByte(',') // dewpoint 留空
+		b.WriteString(wsStr)
+		b.WriteByte(',')
+		b.WriteString(wdStr)
+		b.WriteByte(',')
+		b.WriteString(rhStr)
+		b.WriteByte(',')
+		b.WriteString(ztdStr)
+		b.WriteByte(',') // pwv 留空
+
+		if _, err := f.WriteString(b.String() + "\n"); err != nil {
+			log.Printf("write csv failed: %v", err)
+		}
+		total++
+	}
+	if err := rows.Err(); err != nil {
+		return err
+	}
+	log.Printf("exporter: done bucket start=%s end=%s, rows=%d, ztd_hit=%d, ztd_miss=%d", bucketStart.Format("2006-01-02 15:04:05"), bucketEnd.Format("2006-01-02 15:04:05"), total, ztdHit, ztdMiss)
+	return nil
+}
+
+func (e *Exporter) lookupZTD(ctx context.Context, deviceID string, bucketEnd time.Time) string {
+	if e.my == nil {
+		return ""
+	}
+	var ztd sql.NullFloat64
+	var ts time.Time
+	err := e.my.QueryRowContext(ctx, `
+		SELECT ztd, timestamp FROM rtk_data
+		WHERE station_id = ?
+		  AND ABS(TIMESTAMPDIFF(MINUTE, timestamp, ?)) <= 5
+		LIMIT 1
+	`, deviceID, bucketEnd).Scan(&ztd, &ts)
+	if err != nil {
+		if !errors.Is(err, sql.ErrNoRows) {
+			log.Printf("mysql query ztd failed: %v", err)
+		}
+		return ""
+	}
+	if !ztd.Valid {
+		return ""
+	}
+	return fmtFloat(ztd.Float64*1000.0, -1)
+}
+
+func ensureFileWithHeader(path string) bool {
+	if _, err := os.Stat(path); err == nil {
+		return false
+	}
+	dir := filepath.Dir(path)
+	_ = os.MkdirAll(dir, 0o755)
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY, 0o644)
+	if err != nil {
+		log.Printf("create csv failed: %v", err)
+		return false
+	}
+	_ = f.Close()
+	return true
+}
+
+func headerLine() string {
+	return "latitude,longitude,station_id,station_name,date_time,elevation,pressure,temperature,dewpoint,wind_speed,wind_direction,relative_humidity,ztd,pwv"
+}
+
+func alignToNextBucketEnd(t time.Time, minutes int) time.Time {
+	m := t.Minute()
+	next := (m/minutes + 1) * minutes
+	dt := time.Duration(next-m) * time.Minute
+	return t.Truncate(time.Minute).Add(dt).Truncate(time.Minute)
+}
+
+func alignToPrevBucketEnd(t time.Time, minutes int) time.Time {
+	m := t.Minute()
+	prev := (m / minutes) * minutes
+	return t.Truncate(time.Minute).Add(time.Duration(prev-m) * time.Minute).Add(time.Duration(minutes) * time.Minute)
+}
+
+func fmtNullFloat(v sql.NullFloat64) string {
+	if v.Valid {
+		return fmtFloat(v.Float64, -1)
+	}
+	return ""
+}
+
+// fmtFloat: prec < 0 表示用不固定小数（去除无意义零），否则保留指定小数位
+func fmtFloat(fv float64, prec int) string {
+	if prec >= 0 {
+		return fmt.Sprintf("%.*f", prec, fv)
+	}
+	s := fmt.Sprintf("%.10f", fv)
+	s = strings.TrimRight(s, "0")
+	s = strings.TrimRight(s, ".")
+	if s == "-0" {
+		s = "0"
+	}
+	if s == "" || s == "-" || s == "+" || s == "." {
+		return "0"
+	}
+	if math.Abs(fv) < 1e-9 {
+		return "0"
+	}
+	return s
+}
+
+// rotatePreviousUTC 将上一UTC日的活跃CSV压缩到history目录
+func rotatePreviousUTC(outDir, histDir, currentUTC string) error {
+	// 计算昨日 UTC 日期
+	curDay, err := time.Parse("2006-01-02", currentUTC)
+	if err != nil {
+		return nil
+	}
+	yesterday := curDay.Add(-24 * time.Hour).Format("2006-01-02")
+	prevPath := filepath.Join(outDir, fmt.Sprintf("weather_data_%s.csv", yesterday))
+	gzPath := filepath.Join(histDir, fmt.Sprintf("weather_data_%s.csv.gz", yesterday))
+
+	if _, err := os.Stat(prevPath); err != nil {
+		return nil
+	}
+	if _, err := os.Stat(gzPath); err == nil {
+		// 已压缩
+		return nil
+	}
+	return gzipFile(prevPath, gzPath)
+}
+
+func gzipFile(src, dst string) error {
+	srcF, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer srcF.Close()
+
+	if err := os.MkdirAll(filepath.Dir(dst), 0o755); err != nil {
+		return err
+	}
+	dstF, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		_ = dstF.Close()
+	}()
+
+	gw := gzip.NewWriter(dstF)
+	gw.Name = filepath.Base(src)
+	gw.ModTime = time.Now()
+	defer func() { _ = gw.Close() }()
+
+	if _, err := io.Copy(gw, srcF); err != nil {
+		return err
+	}
+	// 压缩成功后删除原文件
+	return os.Remove(src)
+}