package budget

import (
	"context"
	"errors"
	"testing"
	"time"
)

func TestDBBudgetRollingWindow(t *testing.T) {
	ctx := context.Background()
	mem := NewMemory()
	now := time.Now()
	clock := func() time.Time { return now }
	b := NewDBBudget(mem, func() float64 { return 100 }, nil, clock)

	// Under cap: allowed.
	if err := b.Check(ctx, "u"); err != nil {
		t.Fatalf("fresh caller should pass: %v", err)
	}
	b.Commit(ctx, "u", 60)
	if err := b.Check(ctx, "u"); err != nil {
		t.Fatalf("60/100 should pass: %v", err)
	}
	// Over cap: rejected.
	b.Commit(ctx, "u", 50) // 110 total
	if err := b.Check(ctx, "u"); !errors.Is(err, ErrBudgetExceeded) {
		t.Fatalf("110/100 should be ErrBudgetExceeded, got %v", err)
	}
	// Window rolls over after 7 days: allowed again.
	now = now.Add(8 * 24 * time.Hour)
	b.Commit(ctx, "u", 1) // triggers rollover inside Add
	if err := b.Check(ctx, "u"); err != nil {
		t.Fatalf("after window rollover should pass: %v", err)
	}
}

func TestNoOpBudgetAlwaysAllows(t *testing.T) {
	b := NewNoOpBudget()
	if err := b.Check(context.Background(), "anyone"); err != nil {
		t.Fatalf("NoOp must always allow: %v", err)
	}
	b.Commit(context.Background(), "anyone", 1e9) // no-op
}