service backend

api/ledger/internal/service/ledger/posting.go

@@ -0,0 +1,239 @@
+package ledger
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	ledgerv1 "github.com/tech/sendico/ledger/internal/generated/service/ledger/v1"
+	"github.com/tech/sendico/ledger/storage"
+	"github.com/tech/sendico/ledger/storage/model"
+	storageMongo "github.com/tech/sendico/ledger/storage/mongo"
+	"github.com/tech/sendico/pkg/api/routers/gsresponse"
+	"github.com/tech/sendico/pkg/merrors"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+	"go.uber.org/zap"
+)
+
+const ledgerOutboxSubject = "ledger.entry.posted"
+
+// postCreditResponder implements credit posting with charges
+func (s *Service) postCreditResponder(_ context.Context, req *ledgerv1.PostCreditRequest) gsresponse.Responder[ledgerv1.PostResponse] {
+	return func(ctx context.Context) (*ledgerv1.PostResponse, error) {
+		if req.IdempotencyKey == "" {
+			return nil, merrors.InvalidArgument("idempotency_key is required")
+		}
+		if req.OrganizationRef == "" {
+			return nil, merrors.InvalidArgument("organization_ref is required")
+		}
+		if req.LedgerAccountRef == "" {
+			return nil, merrors.InvalidArgument("ledger_account_ref is required")
+		}
+		if err := validateMoney(req.Money, "money"); err != nil {
+			return nil, err
+		}
+
+		orgRef, err := parseObjectID(req.OrganizationRef)
+		if err != nil {
+			return nil, err
+		}
+		accountRef, err := parseObjectID(req.LedgerAccountRef)
+		if err != nil {
+			return nil, err
+		}
+
+		existingEntry, err := s.storage.JournalEntries().GetByIdempotencyKey(ctx, orgRef, req.IdempotencyKey)
+		if err == nil && existingEntry != nil {
+			recordDuplicateRequest("credit")
+			s.logger.Info("duplicate credit request (idempotency)",
+				zap.String("idempotencyKey", req.IdempotencyKey),
+				zap.String("existingEntryID", existingEntry.GetID().Hex()))
+			return &ledgerv1.PostResponse{
+				JournalEntryRef: existingEntry.GetID().Hex(),
+				Version:         existingEntry.Version,
+				EntryType:       ledgerv1.EntryType_ENTRY_CREDIT,
+			}, nil
+		}
+		if err != nil && err != storage.ErrJournalEntryNotFound {
+			recordJournalEntryError("credit", "idempotency_check_failed")
+			s.logger.Warn("failed to check idempotency", zap.Error(err))
+			return nil, merrors.Internal("failed to check idempotency")
+		}
+
+		account, err := s.storage.Accounts().Get(ctx, accountRef)
+		if err != nil {
+			if err == storage.ErrAccountNotFound {
+				recordJournalEntryError("credit", "account_not_found")
+				return nil, merrors.NoData("account not found")
+			}
+			recordJournalEntryError("credit", "account_lookup_failed")
+			s.logger.Warn("failed to get account", zap.Error(err))
+			return nil, merrors.Internal("failed to get account")
+		}
+		if err := validateAccountForOrg(account, orgRef, req.Money.Currency); err != nil {
+			recordJournalEntryError("credit", "account_invalid")
+			return nil, err
+		}
+
+		accountsByRef := map[primitive.ObjectID]*model.Account{accountRef: account}
+
+		eventTime := getEventTime(req.EventTime)
+		creditAmount, _ := parseDecimal(req.Money.Amount)
+		entryTotal := creditAmount
+
+		charges := req.Charges
+		if len(charges) == 0 {
+			if computed, err := s.quoteFeesForCredit(ctx, req); err != nil {
+				s.logger.Warn("failed to quote fees", zap.Error(err))
+			} else if len(computed) > 0 {
+				charges = computed
+			}
+		}
+		if err := validatePostingLines(charges); err != nil {
+			return nil, err
+		}
+
+		postingLines := make([]*model.PostingLine, 0, 2+len(charges))
+		mainLine := &model.PostingLine{
+			JournalEntryRef: primitive.NilObjectID,
+			AccountRef:      accountRef,
+			Amount:          creditAmount.String(),
+			Currency:        req.Money.Currency,
+			LineType:        model.LineTypeMain,
+		}
+		mainLine.OrganizationRef = orgRef
+		postingLines = append(postingLines, mainLine)
+
+		for i, charge := range charges {
+			chargeAccountRef, err := parseObjectID(charge.LedgerAccountRef)
+			if err != nil {
+				return nil, err
+			}
+			if charge.Money.Currency != req.Money.Currency {
+				return nil, merrors.InvalidArgument(fmt.Sprintf("charges[%d]: currency mismatch", i))
+			}
+
+			chargeAccount, err := s.getAccount(ctx, accountsByRef, chargeAccountRef)
+			if err != nil {
+				if err == storage.ErrAccountNotFound {
+					return nil, merrors.NoData(fmt.Sprintf("charges[%d]: account not found", i))
+				}
+				s.logger.Warn("failed to get charge account", zap.Error(err), zap.String("chargeAccountRef", chargeAccountRef.Hex()))
+				return nil, merrors.Internal("failed to get charge account")
+			}
+			if err := validateAccountForOrg(chargeAccount, orgRef, charge.Money.Currency); err != nil {
+				return nil, merrors.InvalidArgument(fmt.Sprintf("charges[%d]: %s", i, err.Error()))
+			}
+
+			chargeAmount, err := parseDecimal(charge.Money.Amount)
+			if err != nil {
+				return nil, err
+			}
+			entryTotal = entryTotal.Add(chargeAmount)
+
+			chargeLine := &model.PostingLine{
+				JournalEntryRef: primitive.NilObjectID,
+				AccountRef:      chargeAccountRef,
+				Amount:          chargeAmount.String(),
+				Currency:        charge.Money.Currency,
+				LineType:        protoLineTypeToModel(charge.LineType),
+			}
+			chargeLine.OrganizationRef = orgRef
+			postingLines = append(postingLines, chargeLine)
+		}
+
+		contraAccount, err := s.resolveSettlementAccount(ctx, orgRef, req.Money.Currency, req.ContraLedgerAccountRef, accountsByRef)
+		if err != nil {
+			recordJournalEntryError("credit", "contra_resolve_failed")
+			return nil, err
+		}
+		contraAccountID := contraAccount.GetID()
+		if contraAccountID == nil {
+			recordJournalEntryError("credit", "contra_missing_id")
+			return nil, merrors.Internal("contra account missing identifier")
+		}
+
+		contraAmount := entryTotal.Neg()
+		if !contraAmount.IsZero() || len(postingLines) == 1 {
+			contraLine := &model.PostingLine{
+				JournalEntryRef: primitive.NilObjectID,
+				AccountRef:      *contraAccountID,
+				Amount:          contraAmount.String(),
+				Currency:        req.Money.Currency,
+				LineType:        model.LineTypeMain,
+			}
+			contraLine.OrganizationRef = orgRef
+			postingLines = append(postingLines, contraLine)
+			entryTotal = entryTotal.Add(contraAmount)
+		}
+
+		if !entryTotal.IsZero() {
+			recordJournalEntryError("credit", "unbalanced_after_contra")
+			return nil, merrors.Internal("failed to balance journal entry")
+		}
+
+		mongoStore, ok := s.storage.(*storageMongo.Store)
+		if !ok {
+			return nil, merrors.Internal("storage does not support transactions")
+		}
+
+		result, err := mongoStore.TransactionFactory().CreateTransaction().Execute(ctx, func(txCtx context.Context) (any, error) {
+			entry := &model.JournalEntry{
+				IdempotencyKey: req.IdempotencyKey,
+				EventTime:      eventTime,
+				EntryType:      model.EntryTypeCredit,
+				Description:    req.Description,
+				Metadata:       req.Metadata,
+				Version:        time.Now().UnixNano(),
+			}
+			entry.OrganizationRef = orgRef
+
+			if err := s.storage.JournalEntries().Create(txCtx, entry); err != nil {
+				s.logger.Warn("failed to create journal entry", zap.Error(err))
+				return nil, merrors.Internal("failed to create journal entry")
+			}
+
+			entryRef := entry.GetID()
+			if entryRef == nil {
+				return nil, merrors.Internal("journal entry missing identifier")
+			}
+
+			for _, line := range postingLines {
+				line.JournalEntryRef = *entryRef
+			}
+
+			if err := validateBalanced(postingLines); err != nil {
+				return nil, err
+			}
+
+			if err := s.storage.PostingLines().CreateMany(txCtx, postingLines); err != nil {
+				s.logger.Warn("failed to create posting lines", zap.Error(err))
+				return nil, merrors.Internal("failed to create posting lines")
+			}
+
+			if err := s.upsertBalances(txCtx, postingLines, accountsByRef); err != nil {
+				return nil, err
+			}
+
+			if err := s.enqueueOutbox(txCtx, entry, postingLines); err != nil {
+				return nil, err
+			}
+
+			return &ledgerv1.PostResponse{
+				JournalEntryRef: entryRef.Hex(),
+				Version:         entry.Version,
+				EntryType:       ledgerv1.EntryType_ENTRY_CREDIT,
+			}, nil
+		})
+
+		if err != nil {
+			recordJournalEntryError("credit", "transaction_failed")
+			return nil, err
+		}
+
+		amountFloat, _ := creditAmount.Float64()
+		recordTransactionAmount(req.Money.Currency, "credit", amountFloat)
+		recordJournalEntry("credit", "success", 0)
+		return result.(*ledgerv1.PostResponse), nil
+	}
+}