package main

import (
	"context"
	"database/sql"
	"errors"
	"log"
	"net"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	_ "github.com/go-sql-driver/mysql"
	"google.golang.org/grpc"
	"google.golang.org/grpc/reflection"

	"git.5iot.com/iotlcm-public/iotlcm-sms/api/pb"
	"git.5iot.com/iotlcm-public/iotlcm-sms/internal/grpcapi"
	"git.5iot.com/iotlcm-public/iotlcm-sms/internal/httpapi"
	"git.5iot.com/iotlcm-public/iotlcm-sms/internal/sms"
	"git.5iot.com/iotlcm-public/iotlcm-sms/internal/sms/aliyun"
	"git.5iot.com/iotlcm-public/iotlcm-sms/internal/sms/tencent"
)

// 构建时通过 -ldflags 注入。
var (
	BuildVersion = "0.0"
	BuildTime    = ""
	CommitID     = ""
)

func main() {
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()

	log.Printf("iotlcm-sms starting, version=%s buildTime=%s commit=%s", BuildVersion, BuildTime, CommitID)

	// 默认全局配置：config.yaml 提供默认值，SMS_* 环境变量可覆盖。
	defaultConfig, source, err := sms.LoadDefaultConfig()
	if err != nil {
		log.Fatalf("load sms default config: %v", err)
	}
	log.Printf("sms default config loaded: %s", source.Describe())

	// 场景模板配置来自数据库（表 t_sms_template_config）：改库即生效，无需改代码或重启。
	// 连接参数与凭证同源于 config.yaml（SMS_DB_DSN 等环境变量可覆盖）；DSN 为空时能力关闭。
	var scenes sms.SceneProvider
	var sceneStore *sms.SceneStore
	sceneDb, sceneDbSrc, err := sms.LoadSceneDbConfig()
	if err != nil {
		log.Printf("load scene db config: %v（场景模板能力关闭）", err)
	} else if sceneDb.DSN == "" {
		log.Printf("scene db DSN not set, scene-based template config disabled")
	} else {
		db, err := sql.Open("mysql", sceneDb.DSN)
		if err != nil {
			log.Fatalf("open sms config database: %v", err)
		}
		db.SetMaxOpenConns(4)
		db.SetMaxIdleConns(2)
		db.SetConnMaxLifetime(time.Hour)
		ttl := sceneDb.TTL()
		sceneStore = sms.NewSceneStore(db, ttl)
		defer func() { _ = sceneStore.Close() }()
		scenes = sceneStore
		log.Printf("sms scene config store enabled (source: %s), cache ttl=%s", sceneDbSrc.Describe(), ttl)
	}

	providers := sms.NewRegistryWithDefault(defaultConfig, scenes)
	providers.Register(sms.ServiceAliyun, aliyun.New())
	providers.Register(sms.ServiceTencent, tencent.New())

	httpAddr := envOrDefault("HTTP_ADDR", ":8080")
	httpServer := &http.Server{
		Addr:              httpAddr,
		Handler:           httpapi.NewHandler(providers),
		ReadHeaderTimeout: 5 * time.Second,
		ReadTimeout:       10 * time.Second,
		WriteTimeout:      30 * time.Second,
		IdleTimeout:       60 * time.Second,
	}

	grpcAddr := envOrDefault("GRPC_ADDR", ":11200")
	grpcListener, err := net.Listen("tcp", grpcAddr)
	if err != nil {
		log.Fatalf("listen on gRPC address %s: %v", grpcAddr, err)
	}
	grpcServer := grpc.NewServer()
	pb.RegisterNoticeServer(grpcServer, grpcapi.NewServer(providers))
	reflection.Register(grpcServer)

	errCh := make(chan error, 2)
	go func() {
		log.Printf("sms http server listening on %s", httpAddr)
		if err := httpServer.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
			errCh <- err
		}
	}()
	go func() {
		log.Printf("sms gRPC server listening on %s", grpcAddr)
		if err := grpcServer.Serve(grpcListener); err != nil {
			errCh <- err
		}
	}()

	select {
	case err := <-errCh:
		log.Printf("server stopped unexpectedly: %v", err)
		stop()
	case <-ctx.Done():
	}

	shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	if err := httpServer.Shutdown(shutdownCtx); err != nil {
		log.Printf("shutdown HTTP server: %v", err)
	}
	grpcServer.GracefulStop()
}

func envOrDefault(name, fallback string) string {
	if value := os.Getenv(name); value != "" {
		return value
	}
	return fallback
}