package services

import (
	"context"

	"github.com/treytartt/honeydue-api/internal/models"
	"github.com/treytartt/honeydue-api/internal/repositories"
)

// cachedSubscriptionSettings fetches the singleton settings row, going
// through Redis (30-min TTL) before falling back to Postgres.
//
// Hot read — touched on every CheckLimit, every GetSubscriptionStatus,
// and every Stripe webhook. The row is admin-toggleable but writes are
// rare; the cache cuts the per-request cost from ~250ms (transatlantic
// Postgres roundtrip) to ~1ms (cluster-internal Redis).
//
// On a nil cache (tests, Redis-down), falls through to the repo directly
// so the caller never sees a hard failure from caching.
//
// Admin writes invalidate via cache.InvalidateSubscriptionSettings.
func cachedSubscriptionSettings(
	ctx context.Context,
	cache *CacheService,
	subRepo *repositories.SubscriptionRepository,
) (*models.SubscriptionSettings, error) {
	if cache != nil {
		var settings models.SubscriptionSettings
		if err := cache.GetCachedSubscriptionSettings(ctx, &settings); err == nil {
			return &settings, nil
		}
	}

	settings, err := subRepo.WithContext(ctx).GetSettings()
	if err != nil {
		return nil, err
	}

	if cache != nil {
		_ = cache.CacheSubscriptionSettings(ctx, settings)
	}
	return settings, nil
}