package musicbrainz

import (
	"fmt"
	"time"

	"naviwatcher/internal/database"
)

// CacheStats holds the result of a cache lookup for a given artist.
type CacheStats struct {
	// CachedRGIDs is the list of RGIDs that are currently cached (within TTL).
	CachedRGIDs []string
	// CacheHitCount is the number of entries found in cache.
	CacheHitCount int
}

// IsCached returns true if the given RGID is in the cached set.
func (cs *CacheStats) IsCached(rgid string) bool {
	for _, id := range cs.CachedRGIDs {
		if id == rgid {
			return true
		}
	}
	return false
}

// GetCachedReleases queries the external_releases table for entries
// belonging to the given artist that were cached within the specified TTL.
// It returns a CacheStats with the list of valid RGIDs already in cache.
func GetCachedReleases(db *database.DB, artistID string, ttl time.Duration) (*CacheStats, error) {
	releases, err := database.GetExternalReleasesByArtistWithCache(db, artistID, ttl)
	if err != nil {
		return nil, fmt.Errorf("get cached releases: %w", err)
	}

	stats := &CacheStats{}
	for _, r := range releases {
		stats.CachedRGIDs = append(stats.CachedRGIDs, r.RGID)
		stats.CacheHitCount++
	}
	return stats, nil
}

// IsArtistCacheValid checks whether the cache for an artist is still valid.
// Returns true if any entries exist within the TTL for this artist.
func IsArtistCacheValid(db *database.DB, artistID string, ttl time.Duration) (bool, error) {
	stats, err := GetCachedReleases(db, artistID, ttl)
	if err != nil {
		return false, err
	}
	return stats.CacheHitCount > 0, nil
}