package cache

import "time"

// TTLTier represents a cache TTL tier with a name and duration.
type TTLTier struct {
	Name     string
	Duration time.Duration
}

// defaultTiers maps engine names to their default TTL tiers.
var defaultTiers = map[string]TTLTier{
	// Static knowledge engines — rarely change
	"wikipedia":     {Name: "static", Duration: 24 * time.Hour},
	"wikidata":      {Name: "static", Duration: 24 * time.Hour},
	"arxiv":         {Name: "static", Duration: 24 * time.Hour},
	"crossref":      {Name: "static", Duration: 24 * time.Hour},
	"stackoverflow": {Name: "static", Duration: 24 * time.Hour},
	"github":        {Name: "static", Duration: 24 * time.Hour},

	// API-based general search — fresher data
	"braveapi": {Name: "api_general", Duration: 1 * time.Hour},
	"youtube":  {Name: "api_general", Duration: 1 * time.Hour},

	// Scraped general search — moderately stable
	"google":     {Name: "scraped_general", Duration: 2 * time.Hour},
	"bing":       {Name: "scraped_general", Duration: 2 * time.Hour},
	"duckduckgo": {Name: "scraped_general", Duration: 2 * time.Hour},
	"qwant":      {Name: "scraped_general", Duration: 2 * time.Hour},
	"brave":      {Name: "scraped_general", Duration: 2 * time.Hour},

	// News/social — changes frequently
	"reddit": {Name: "news_social", Duration: 30 * time.Minute},

	// Image search
	"bing_images":  {Name: "images", Duration: 1 * time.Hour},
	"ddg_images":   {Name: "images", Duration: 1 * time.Hour},
	"qwant_images": {Name: "images", Duration: 1 * time.Hour},
}

// EngineTier returns the TTL tier for an engine, applying overrides if provided.
// If the engine has no defined tier, returns a default of 1 hour.
func EngineTier(engineName string, overrides map[string]time.Duration) TTLTier {
	// Check override first — override tier name is just the engine name
	if override, ok := overrides[engineName]; ok && override > 0 {
		return TTLTier{Name: engineName, Duration: override}
	}

	// Fall back to default tier
	if tier, ok := defaultTiers[engineName]; ok {
		return tier
	}

	// Unknown engines get a sensible default
	return TTLTier{Name: "unknown", Duration: 1 * time.Hour}
}