Initial MVP commit

cmd/weatherapi/main.go

@@ -0,0 +1,102 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"net/http"
+
+	"gitea.maximumdirect.net/ejr/weatherapi/internal/adapters/httpapi"
+	adapterpg "gitea.maximumdirect.net/ejr/weatherapi/internal/adapters/postgres"
+	"gitea.maximumdirect.net/ejr/weatherapi/internal/application/alerts"
+	"gitea.maximumdirect.net/ejr/weatherapi/internal/application/forecasts"
+	"gitea.maximumdirect.net/ejr/weatherapi/internal/application/observations"
+	"gitea.maximumdirect.net/ejr/weatherapi/internal/application/units"
+	"gitea.maximumdirect.net/ejr/weatherapi/internal/platform/config"
+	"gitea.maximumdirect.net/ejr/weatherapi/internal/platform/constants"
+	"gitea.maximumdirect.net/ejr/weatherapi/internal/platform/datasource"
+	dspostgres "gitea.maximumdirect.net/ejr/weatherapi/internal/platform/datasource/postgres"
+)
+
+func main() {
+	cfgPath := flag.String("config", "config.yml", "path to YAML config")
+	addr := flag.String("addr", constants.DefaultHTTPAddr, "HTTP listen address")
+	dbName := flag.String("db-name", "", "optional configured database name to use")
+	flag.Parse()
+
+	cfg, err := config.Load(*cfgPath)
+	if err != nil {
+		log.Fatalf("load config: %v", err)
+	}
+
+	dbCfg, err := chooseDatabase(cfg, *dbName)
+	if err != nil {
+		log.Fatalf("select database: %v", err)
+	}
+
+	registry := datasource.NewRegistry()
+	if err := registry.Register(dspostgres.Factory{}); err != nil {
+		log.Fatalf("register datasource factories: %v", err)
+	}
+
+	ds, err := registry.Open(context.Background(), dbCfg)
+	if err != nil {
+		log.Fatalf("open datasource %q: %v", dbCfg.Name, err)
+	}
+	defer ds.Close()
+
+	pgDataSource, ok := ds.(*dspostgres.DataSource)
+	if !ok {
+		log.Fatalf("unsupported datasource type %T for driver %q", ds, dbCfg.Driver)
+	}
+
+	converter, err := newDefaultConverter()
+	if err != nil {
+		log.Fatalf("configure units: %v", err)
+	}
+
+	obsRepo := adapterpg.NewObservationRepository(pgDataSource.Pool())
+	fcRepo := adapterpg.NewForecastRepository(pgDataSource.Pool())
+	alertRepo := adapterpg.NewAlertRepository(pgDataSource.Pool())
+
+	obsSvc := observations.NewService(obsRepo, converter, constants.ObservationWindow)
+	fcSvc := forecasts.NewService(fcRepo, converter, constants.ForecastQueryLimit)
+	alertsSvc := alerts.NewService(alertRepo)
+
+	server := httpapi.NewServer(obsSvc, fcSvc, alertsSvc)
+
+	httpServer := &http.Server{
+		Addr:    *addr,
+		Handler: server.Handler(),
+	}
+
+	log.Printf("weatherapi listening on %s (db=%s driver=%s units=%s)", *addr, dbCfg.Name, dbCfg.Driver, constants.DefaultOutputUnitSystem)
+	if err := httpServer.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+		log.Fatalf("http server: %v", err)
+	}
+}
+
+func chooseDatabase(cfg *config.Config, name string) (config.DatabaseConfig, error) {
+	if cfg == nil {
+		return config.DatabaseConfig{}, fmt.Errorf("config is nil")
+	}
+	if name == "" {
+		return cfg.Databases[0], nil
+	}
+
+	db, ok := cfg.FindDatabase(name)
+	if !ok {
+		return config.DatabaseConfig{}, fmt.Errorf("database %q not found in config", name)
+	}
+	return db, nil
+}
+
+func newDefaultConverter() (units.Converter, error) {
+	switch constants.DefaultOutputUnitSystem {
+	case "us":
+		return units.USConverter{}, nil
+	default:
+		return nil, fmt.Errorf("unsupported default output unit system %q", constants.DefaultOutputUnitSystem)
+	}
+}