refactor: push commands in to cmd and ev to root as library

pkg/service/service.go

@@ -0,0 +1,169 @@
+package service
+
+import (
+	"context"
+	"log"
+	"net/http"
+	"runtime/debug"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/sour-is/ev/internal/lg"
+	"github.com/sour-is/ev/pkg/cron"
+	"go.opentelemetry.io/otel/attribute"
+	"go.uber.org/multierr"
+	"golang.org/x/sync/errgroup"
+)
+
+type crontab interface {
+	NewCron(expr string, task func(context.Context, time.Time) error)
+	RunOnce(ctx context.Context, once func(context.Context, time.Time) error)
+}
+type Harness struct {
+	crontab
+
+	Services []any
+
+	onStart []func(context.Context) error
+	onStop  []func(context.Context) error
+}
+
+func (s *Harness) Setup(ctx context.Context, apps ...application) error {
+	ctx, span := lg.Span(ctx)
+	defer span.End()
+
+	// setup crontab
+	c := cron.New(cron.DefaultGranularity)
+	s.OnStart(c.Run)
+	s.crontab = c
+
+	var err error
+	for _, app := range apps {
+		err = multierr.Append(err, app(ctx, s))
+	}
+
+	span.RecordError(err)
+	return err
+}
+func (s *Harness) OnStart(fn func(context.Context) error) {
+	s.onStart = append(s.onStart, fn)
+}
+func (s *Harness) OnStop(fn func(context.Context) error) {
+	s.onStop = append(s.onStop, fn)
+}
+func (s *Harness) Add(svcs ...any) {
+	s.Services = append(s.Services, svcs...)
+}
+func (s *Harness) stop(ctx context.Context) error {
+	g, _ := errgroup.WithContext(ctx)
+	for i := range s.onStop {
+		fn := s.onStop[i]
+		g.Go(func() error {
+			if err := fn(ctx); err != nil && err != http.ErrServerClosed {
+				return err
+			}
+			return nil
+		})
+	}
+	return g.Wait()
+}
+func (s *Harness) Run(ctx context.Context, appName, version string) error {
+	{
+		ctx, span := lg.Span(ctx)
+
+		log.Println(appName, version)
+		span.SetAttributes(
+			attribute.String("app", appName),
+			attribute.String("version", version),
+		)
+
+		Mup, err := lg.Meter(ctx).SyncInt64().UpDownCounter("up")
+		if err != nil {
+			return err
+		}
+		Mup.Add(ctx, 1)
+
+		span.End()
+	}
+
+	g, _ := errgroup.WithContext(ctx)
+	g.Go(func() error {
+		<-ctx.Done()
+		// shutdown jobs
+		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+
+		return s.stop(ctx)
+	})
+
+	for i := range s.onStart {
+		fn := s.onStart[i]
+		g.Go(func() error { return fn(ctx) })
+	}
+
+	return g.Wait()
+}
+
+type application func(context.Context, *Harness) error // Len is the number of elements in the collection.
+
+type appscore struct {
+	score int
+	application
+}
+type Apps []appscore
+
+func (a *Apps) Apps() []application {
+	sort.Sort(a)
+	lis := make([]application, len(*a))
+	for i, app := range *a {
+		lis[i] = app.application
+	}
+	return lis
+}
+
+// Len is the number of elements in the collection.
+func (a *Apps) Len() int {
+	if a == nil {
+		return 0
+	}
+	return len(*a)
+}
+
+// Less reports whether the element with index i
+func (a *Apps) Less(i int, j int) bool {
+	if a == nil {
+		return false
+	}
+
+	return (*a)[i].score < (*a)[j].score
+}
+
+// Swap swaps the elements with indexes i and j.
+func (a *Apps) Swap(i int, j int) {
+	if a == nil {
+		return
+	}
+
+	(*a)[i], (*a)[j] = (*a)[j], (*a)[i]
+}
+
+func (a *Apps) Register(score int, app application) (none struct{}) {
+	if a == nil {
+		return
+	}
+
+	*a = append(*a, appscore{score, app})
+	return
+}
+
+func AppName() (string, string) {
+	if info, ok := debug.ReadBuildInfo(); ok {
+		_, name, _ := strings.Cut(info.Main.Path, "/")
+		name = strings.Replace(name, "-", ".", -1)
+		name = strings.Replace(name, "/", "-", -1)
+		return name, info.Main.Version
+	}
+
+	return "sour.is-app", "(devel)"
+}