package host

import (
	"context"
	"os"
	"testing"

	"github.com/carlosframework/platform/internal/hostguard"
	"github.com/carlosframework/platform/internal/instancectl"
)

func TestPlan14UnitDispatch(t *testing.T) {
	b, in, shape := plan14UnitBindingFixture(t, "console.service", "", "")
	configured := map[string]claimUnitShape{in.Host: shape}
	d := claimUnitDispatch{bindings: b, shapes: func() (map[string]claimUnitShape, error) { return configured, nil }}
	if _, err := d.forStart(t.Context(), in.Host); err == nil {
		t.Fatal("configured unit without retained binding fell through")
	}
	if _, err := b.establish(t.Context(), in.Host); err != nil {
		t.Fatal(err)
	}
	unit, group, err := d.Placement(in.Host)
	if err != nil || unit != shape.Unit || group != instancectl.BoundClaimUnitControlGroup(in.Host, shape.Unit) {
		t.Fatal(unit, group, err)
	}
	unit, group, err = d.Placement("sibling.example")
	if err != nil || unit != instancectl.UnitName(instancectl.RoleRun, "sibling.example") || group != instancectl.ClaimUnitControlGroup("sibling.example") {
		t.Fatal(unit, group, err)
	}
	delete(configured, in.Host)
	if _, err := d.forStart(t.Context(), in.Host); err == nil {
		t.Fatal("removed configuration allowed start")
	}
	unit, _, err = d.Placement(in.Host)
	if err != nil || unit != shape.Unit {
		t.Fatal("cleanup lost retained placement", unit, err)
	}
	configured[in.Host] = shape
	changed := in
	changed.Stamp++
	b.installation = func(context.Context, string) (hostguard.RootInstallation, error) { return changed, nil }
	if _, err := d.forStart(t.Context(), in.Host); err == nil {
		t.Fatal("successor inherited placement")
	}
	b.state.Write(in.Host+".json", []byte("broken"))
	if _, _, err := d.Placement(in.Host); err == nil {
		t.Fatal("corruption fell through")
	}
	d.shapes = func() (map[string]claimUnitShape, error) { return nil, os.ErrPermission }
	if _, _, err := d.Placement("sibling.example"); err != nil {
		t.Fatal("unreadable named configuration blocked ordinary cleanup", err)
	}
}

func TestPlan14BackingUnitRegistryShape(t *testing.T) {
	b, in, s := plan14UnitBindingFixture(t, "carlos-app@shop.example.service", "unit", "")
	if _, err := b.establish(t.Context(), in.Host); err != nil {
		t.Fatal(err)
	}
	r := s.route()
	if r.Unit != "" {
		t.Fatal("canonical backing route invents a named unit", r.Unit)
	}
	if _, err := b.check(t.Context(), in.Host, &r); err != nil {
		t.Fatal(err)
	}
	r.Unit = s.Unit
	if _, err := b.check(t.Context(), in.Host, &r); err == nil {
		t.Fatal("accepted backing-to-named shape change")
	}
}

func TestPlan14UnitBindingRetainedOwnership(t *testing.T) {
	b, in, shape := plan14UnitBindingFixture(t, "console.service", "", "")
	if _, err := b.establish(t.Context(), in.Host); err != nil {
		t.Fatal(err)
	}
	other := in
	other.Host, other.Record = "sibling.example", "apps/bab/shop/instances/sibling.example.json"
	shape.Host = other.Host
	b.installation = func(context.Context, string) (hostguard.RootInstallation, error) { return other, nil }
	b.canonical = func(context.Context, string) (claimUnitShape, error) { return shape, nil }
	if _, err := b.establish(t.Context(), other.Host); err == nil {
		t.Fatal("root config reassigned a retained unit to a sibling")
	}
	if _, err := b.read(other.Host); !os.IsNotExist(err) {
		t.Fatal("created conflicting owner", err)
	}
}