package hostops

import (
	"context"
	"errors"
	"testing"

	"github.com/carlosframework/platform/internal/release"
)

func TestMutationBoundaryRefusesEveryWriteWithoutAuthority(t *testing.T) {
	ctx := t.Context()
	raw := release.NewDirStore(t.TempDir())
	key := "apps/bab/demo/deleted.json"
	tag, err := raw.Put(ctx, key, []byte("old"), "")
	if err != nil {
		t.Fatal(err)
	}
	calls := 0
	guarded, err := NewMutationBoundary(true, raw, func(context.Context, MutationTarget) error { calls++; return ErrPending })
	if err != nil {
		t.Fatal(err)
	}
	if _, err = guarded.Put(ctx, key, []byte("new"), tag); !errors.Is(err, ErrPending) {
		t.Fatal(err)
	}
	if err = guarded.Delete(ctx, key); !errors.Is(err, ErrPending) {
		t.Fatal(err)
	}
	if err = release.DeleteIfMatch(ctx, guarded, key, tag); !errors.Is(err, ErrPending) {
		t.Fatal(err)
	}
	if err = guarded.Delete(ctx, "apps/bab/demo/absent.json"); !errors.Is(err, ErrPending) {
		t.Fatal(err)
	}
	if calls != 4 {
		t.Fatalf("only %d writes reached the boundary", calls)
	}
	body, after, err := raw.Get(ctx, key)
	if err != nil || string(body) != "old" || after != tag {
		t.Fatalf("refused write changed storage: %q %q %v", body, after, err)
	}
}
func TestMutationBoundaryDeleteCannotEraseSuccessor(t *testing.T) {
	ctx := t.Context()
	raw := release.NewDirStore(t.TempDir())
	key := "domains/one.example.json"
	tag, err := raw.Put(ctx, key, []byte("old"), "")
	if err != nil {
		t.Fatal(err)
	}
	guarded, err := NewMutationBoundary(true, raw, func(_ context.Context, m MutationTarget) error {
		if string(m.Before) != "old" || m.ETag != tag {
			t.Fatal("not the inspected incarnation")
		}
		_, e := raw.Put(ctx, key, []byte("successor"), tag)
		return e
	})
	if err != nil {
		t.Fatal(err)
	}
	if err = guarded.Delete(ctx, key); !errors.Is(err, release.ErrCASConflict) {
		t.Fatalf("successor delete: %v", err)
	}
	body, _, err := raw.Get(ctx, key)
	if err != nil || string(body) != "successor" {
		t.Fatalf("successor: %q %v", body, err)
	}
}
func TestMutationBoundaryDisabledIsOriginalHandle(t *testing.T) {
	raw := release.NewDirStore(t.TempDir())
	s, err := NewMutationBoundary(false, raw, func(context.Context, MutationTarget) error { t.Fatal("flag-off check"); return nil })
	if err != nil || s != raw {
		t.Fatal("flag-off was wrapped")
	}
	if _, err = NewMutationBoundary(true, raw, nil); !errors.Is(err, ErrContract) {
		t.Fatal("enabled without production authority")
	}
}

func TestBoundaryForwardsReadExtensions(t *testing.T) {
	ctx := t.Context()
	raw := release.NewDirStore(t.TempDir())
	const key = "apps/bab/demo/a.json"
	if _, err := raw.Put(ctx, key, []byte("a"), ""); err != nil {
		t.Fatal(err)
	}
	// The production chain: boundary over the record store over the bucket.
	records, err := NewConditionalRecordStore(raw, make([]byte, 32))
	if err != nil {
		t.Fatal(err)
	}
	guarded, err := NewMutationBoundary(true, records, func(context.Context, MutationTarget) error { return nil })
	if err != nil {
		t.Fatal(err)
	}
	cg, ok := guarded.(release.ConditionalGetter)
	if !ok {
		t.Fatal("boundary hides ConditionalGetter")
	}
	el, ok := guarded.(release.ETagLister)
	if !ok {
		t.Fatal("boundary hides ETagLister")
	}
	body, e, changed, err := cg.GetIfChanged(ctx, key, "")
	if err != nil || !changed || string(body) != "a" {
		t.Fatalf("GetIfChanged: %q %v %v", body, changed, err)
	}
	if _, _, changed, err = cg.GetIfChanged(ctx, key, e); err != nil || changed {
		t.Fatalf("unchanged: %v %v", changed, err)
	}
	got, err := el.ListETags(ctx, "apps/")
	if err != nil || len(got) != 1 || got[0].Key != key || got[0].ETag != e {
		t.Fatalf("ListETags: %v %v", got, err)
	}
}

// bareStore has none of the optional extensions.
type bareStore struct{ release.Store }

func TestBoundaryWithoutReadExtensionsIsContractError(t *testing.T) {
	ctx := t.Context()
	guarded, err := NewMutationBoundary(true, bareStore{release.NewDirStore(t.TempDir())}, func(context.Context, MutationTarget) error { return nil })
	if err != nil {
		t.Fatal(err)
	}
	if _, _, _, err = guarded.(release.ConditionalGetter).GetIfChanged(ctx, "apps/bab/demo/a.json", ""); !errors.Is(err, ErrContract) {
		t.Fatalf("GetIfChanged: %v", err)
	}
	if _, err = guarded.(release.ETagLister).ListETags(ctx, "apps/"); !errors.Is(err, ErrContract) {
		t.Fatalf("ListETags: %v", err)
	}
}

func TestRecordStoreWithoutReadExtensionsIsContractError(t *testing.T) {
	ctx := t.Context()
	records, err := NewConditionalRecordStore(bareStore{release.NewDirStore(t.TempDir())}, make([]byte, 32))
	if err != nil {
		t.Fatal(err)
	}
	if _, _, _, err = records.(release.ConditionalGetter).GetIfChanged(ctx, "apps/bab/demo/a.json", ""); !errors.Is(err, ErrContract) {
		t.Fatalf("GetIfChanged: %v", err)
	}
	if _, err = records.(release.ETagLister).ListETags(ctx, "apps/"); !errors.Is(err, ErrContract) {
		t.Fatalf("ListETags: %v", err)
	}
}