package mail

import (
	"context"
	"errors"
	"sync"
	"testing"

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

// okAdmitter admits nothing and refuses nothing: these tests exercise the gate.
type okAdmitter struct{}

func (okAdmitter) AdmitClaimMailApps(ctx context.Context, _ ClaimMailHold, _ []ClaimMailApp) (ClaimMailAdmission, error) {
	var n int
	var mu sync.Mutex
	return fixtureAdmission{ctx: ctx, released: &n, mu: &mu}, nil
}

func TestClaimMailGateSerializesAndRetainsUncertain(t *testing.T) {
	ctx := t.Context()
	base := release.NewDirStore(t.TempDir())
	gate := &memGate{State: "free"}
	one, err := NewClaimMailStore(base, gate, okAdmitter{}, ClaimMailOwner{Console: "c", Enrollment: "e", Controller: "one"})
	if err != nil {
		t.Fatal(err)
	}
	two, err := NewClaimMailStore(base, gate, okAdmitter{}, ClaimMailOwner{Console: "c", Enrollment: "e", Controller: "two"})
	if err != nil {
		t.Fatal(err)
	}
	calls := 0
	if err := WithClaimMailResource(ctx, one, func(held context.Context) error {
		if err := WithClaimMailResource(ctx, two, func(context.Context) error { calls++; return nil }); !errors.Is(err, ErrClaimMailPending) {
			t.Fatalf("competing gate: %v", err)
		}
		return WithClaimMailResource(held, one, func(context.Context) error { calls++; return nil })
	}); err != nil {
		t.Fatal(err)
	}
	if calls != 1 {
		t.Fatalf("calls=%d", calls)
	}
	uncertain := errors.New("backend outcome unknown")
	if err := WithClaimMailResource(ctx, two, func(held context.Context) error { markClaimMailDirty(held); return uncertain }); !errors.Is(err, uncertain) {
		t.Fatal(err)
	}
	if g := gate.snapshot(); g.State != "held" {
		t.Fatalf("uncertain call released the gate: %+v", &g)
	}
	if err := WithClaimMailResource(ctx, one, func(context.Context) error { t.Fatal("uncertain owner replaced"); return nil }); !errors.Is(err, ErrClaimMailPending) {
		t.Fatal(err)
	}
}
func TestClaimMailGateFlagOffWritesNothing(t *testing.T) {
	ctx := t.Context()
	base := release.NewDirStore(t.TempDir())
	calls := 0
	if err := WithClaimMailResource(ctx, base, func(context.Context) error { calls++; return nil }); err != nil {
		t.Fatal(err)
	}
	keys, err := base.List(ctx, "")
	if err != nil {
		t.Fatal(err)
	}
	if calls != 1 || len(keys) != 0 {
		t.Fatalf("calls=%d keys=%v", calls, keys)
	}
}