package cache

import (
	"iter"
	"time"
)

// RecordStore handles record persistence operations.
// Iterator methods use iter.Seq2 for iteration, with keys and values
// cloned to memory to avoid holding read locks during iteration.
type RecordStore interface {
	// SaveRecords stores records for a given DID.
	SaveRecords(did string, records map[string][]byte) error

	// IterateUnpublished iterates over unpublished records.
	// The iterator yields (key, record) pairs.
	// If reverse is true, iterates in reverse order using Cursor.Last/Cursor.Prev.
	IterateUnpublished(did string, reverse bool) iter.Seq2[string, []byte]

	// IteratePublished iterates over published records.
	// The iterator yields (key, record) pairs.
	// If reverse is true, iterates in reverse order using Cursor.Last/Cursor.Prev.
	IteratePublished(did string, reverse bool) iter.Seq2[string, []byte]

	// IterateFailed iterates over failed records.
	// Returns a function that yields (key, record, errorMessage) triples.
	IterateFailed(did string) func(yield func(key string, rec []byte, errMsg string) bool)

	MarkPublished(did string, keys ...string) error
	MarkFailed(did string, keys []string, err string) error
	RemoveFailed(did string, keys ...string) error
	GetPublished(did string) (map[string]bool, error)

	Clear(did string) error
	Close() error
}

// QuotaStore handles rate limit quota tracking.
type QuotaStore interface {
	GetMulti(keys []string) (map[string]int, error)
	IncrByMulti(counts map[string]int) error
}

// Storage combines RecordStore and QuotaStore interfaces.
// Provided for backwards compatibility.
type Storage interface {
	RecordStore
	QuotaStore

	IsValid(did string) bool
	Timestamp(did string) (time.Time, error)

	ClearAll() error

	// Stats returns database statistics
	Stats() (DBStats, error)
}

type DBStats struct {
	TotalRecords     int            `json:"totalRecords"`
	MarkedPublished  int            `json:"markedPublished"`
	FailedCount      int            `json:"failedCount"`
	UnpublishedCount int            `json:"unpublishedCount"`
	UserStats        map[string]any `json:"userStats"`
}