package settlement

import (
	"context"
	"crypto/rand"
	"encoding/hex"
	"fmt"
	"time"

	"gl/domain/ledger"
)

type EnqueueRepository interface {
	Enqueue(context.Context, ledger.Settlement) (ledger.Settlement, bool, error)
	Get(context.Context, string, string) (ledger.Settlement, error)
	RetryByOperator(context.Context, string, string, string, time.Time) (ledger.Settlement, error)
}

func (s *Service) RetryByOperator(ctx context.Context, settlementID, actorID, reason string) (ledger.Settlement, error) {
	if settlementID == "" || actorID == "" || reason == "" {
		return ledger.Settlement{}, fmt.Errorf("settlement id, actor id, and reason are required")
	}
	now := time.Now().UTC()
	if s.now != nil {
		now = s.now().UTC()
	}
	return s.repository.RetryByOperator(ctx, settlementID, actorID, reason, now)
}

type Service struct {
	repository EnqueueRepository
	now        func() time.Time
}

func NewService(repository EnqueueRepository) *Service { return &Service{repository: repository} }

func (s *Service) Enqueue(ctx context.Context, sourceService, sourceTxID, idempotencyKey, network, xdr string) (ledger.Settlement, bool, error) {
	if sourceService == "" || sourceTxID == "" || idempotencyKey == "" || network == "" || xdr == "" {
		return ledger.Settlement{}, false, fmt.Errorf("settlement identity, network, and signed transaction are required")
	}
	id := make([]byte, 16)
	if _, err := rand.Read(id); err != nil {
		return ledger.Settlement{}, false, fmt.Errorf("generate settlement id: %w", err)
	}
	now := time.Now().UTC()
	if s.now != nil {
		now = s.now().UTC()
	}
	encoded := hex.EncodeToString(id)
	record := ledger.Settlement{ID: encoded[0:8] + "-" + encoded[8:12] + "-" + encoded[12:16] + "-" + encoded[16:20] + "-" + encoded[20:], SourceService: sourceService, SourceTxID: sourceTxID, IdempotencyKey: idempotencyKey, Status: ledger.SettlementPending, Network: network, SignedTransactionXDR: xdr, AvailableAt: now}
	if err := record.Validate(); err != nil {
		return ledger.Settlement{}, false, err
	}
	return s.repository.Enqueue(ctx, record)
}

func (s *Service) Get(ctx context.Context, settlementID, idempotencyKey string) (ledger.Settlement, error) {
	if settlementID == "" && idempotencyKey == "" {
		return ledger.Settlement{}, fmt.Errorf("settlement id or idempotency key is required")
	}
	return s.repository.Get(ctx, settlementID, idempotencyKey)
}