refactor: disambiguate lines vs detailed lines

Author: turip

openmeter/app/stripe/entity/app/invoice.go

@@ -205,12 +205,12 @@ func (a App) createInvoice(ctx context.Context, invoice billing.Invoice) (*billi
 	// Add lines to the Stripe invoice
 	var stripeLineAdd []*stripe.InvoiceItemParams
 
-	leafLines := invoice.GetLeafLinesWithConsolidatedTaxBehavior()
+	leafLines := invoice.GetDetailedLinesWithConsolidatedTaxBehavior()
 
 	// Iterate over the leaf lines
 	for _, line := range leafLines {
 		// Add discounts for line if any
-		for _, discount := range line.Discounts.Amount {
+		for _, discount := range line.AmountDiscounts {
 			stripeLineAdd = append(stripeLineAdd, getDiscountStripeAddInvoiceItemParams(calculator, line, discount, stripeCustomerData.StripeCustomerID))
 		}
 
@@ -304,7 +304,7 @@ func (a App) updateInvoice(ctx context.Context, invoice billing.Invoice) (*billi
 		stripeLinesRemove []string
 	)
 
-	leafLines := invoice.GetLeafLinesWithConsolidatedTaxBehavior()
+	leafLines := invoice.GetDetailedLinesWithConsolidatedTaxBehavior()
 
 	// Helper to get a Stripe line item by ID
 	stripeLinesByID := make(map[string]*stripe.InvoiceLineItem)
@@ -319,7 +319,7 @@ func (a App) updateInvoice(ctx context.Context, invoice billing.Invoice) (*billi
 
 	// Iterate over the leaf lines
 	for _, line := range leafLines {
-		amountDiscountsById, err := line.Discounts.Amount.GetByID()
+		amountDiscountsById, err := line.AmountDiscounts.GetByID()
 		if err != nil {
 			return nil, fmt.Errorf("failed to get amount discounts by ID: %w", err)
 		}
@@ -452,7 +452,7 @@ func sortInvoiceLines[K StripeInvoiceLineOperationParams](stripeLineAdd []*K) {
 // getDiscountStripeUpdateInvoiceItemParams returns the Stripe line item for a discount
 func getDiscountStripeUpdateInvoiceItemParams(
 	calculator StripeCalculator,
-	line *billing.Line,
+	line billing.DetailedLine,
 	discount billing.AmountLineDiscountManaged,
 	stripeLine *stripe.InvoiceLineItem,
 ) *stripeclient.StripeInvoiceItemWithID {
@@ -463,7 +463,7 @@ func getDiscountStripeUpdateInvoiceItemParams(
 }
 
 // getDiscountStripeInvoiceItemParams returns the Stripe line item for a discount
-func getDiscountStripeInvoiceItemParams(calculator StripeCalculator, line *billing.Line, discount billing.AmountLineDiscountManaged) *stripe.InvoiceItemParams {
+func getDiscountStripeInvoiceItemParams(calculator StripeCalculator, line billing.DetailedLine, discount billing.AmountLineDiscountManaged) *stripe.InvoiceItemParams {
 	name := getDiscountLineName(line, discount)
 	period := getPeriod(line)
 
@@ -480,14 +480,14 @@ func getDiscountStripeInvoiceItemParams(calculator StripeCalculator, line *billi
 	return applyTaxSettingsToInvoiceItem(addParams, line)
 }
 
-func getDiscountStripeAddInvoiceItemParams(calculator StripeCalculator, line *billing.Line, discount billing.AmountLineDiscountManaged, stripeCustomerID string) *stripe.InvoiceItemParams {
+func getDiscountStripeAddInvoiceItemParams(calculator StripeCalculator, line billing.DetailedLine, discount billing.AmountLineDiscountManaged, stripeCustomerID string) *stripe.InvoiceItemParams {
 	params := getDiscountStripeInvoiceItemParams(calculator, line, discount)
 	// Customer is required for adds
 	params.Customer = stripe.String(stripeCustomerID)
 	return params
 }
 
-func applyTaxSettingsToInvoiceItem(add *stripe.InvoiceItemParams, line *billing.Line) *stripe.InvoiceItemParams {
+func applyTaxSettingsToInvoiceItem(add *stripe.InvoiceItemParams, line billing.DetailedLine) *stripe.InvoiceItemParams {
 	if line.TaxConfig != nil && !lo.IsEmpty(line.TaxConfig) {
 		if line.TaxConfig.Behavior != nil {
 			add.TaxBehavior = getStripeTaxBehavior(line.TaxConfig.Behavior)
@@ -504,7 +504,7 @@ func applyTaxSettingsToInvoiceItem(add *stripe.InvoiceItemParams, line *billing.
 // getStripeUpdateInvoiceItemParams returns the Stripe update line params
 func getStripeUpdateInvoiceItemParams(
 	calculator StripeCalculator,
-	line *billing.Line,
+	line billing.DetailedLine,
 	stripeLine *stripe.InvoiceLineItem,
 ) *stripeclient.StripeInvoiceItemWithID {
 	return &stripeclient.StripeInvoiceItemWithID{
@@ -514,7 +514,7 @@ func getStripeUpdateInvoiceItemParams(
 }
 
 // getStripeAddLinesLineParams returns the Stripe line item
-func getStripeInvoiceItemParams(line *billing.Line, calculator StripeCalculator) *stripe.InvoiceItemParams {
+func getStripeInvoiceItemParams(line billing.DetailedLine, calculator StripeCalculator) *stripe.InvoiceItemParams {
 	description := getLineName(line)
 	period := getPeriod(line)
 	amount := line.Totals.Amount
@@ -551,22 +551,22 @@ func getStripeInvoiceItemParams(line *billing.Line, calculator StripeCalculator)
 }
 
 // getStripeAddInvoiceItemParams returns the Stripe line item
-func getStripeAddInvoiceItemParams(line *billing.Line, calculator StripeCalculator, stripeCustomerID string) *stripe.InvoiceItemParams {
+func getStripeAddInvoiceItemParams(line billing.DetailedLine, calculator StripeCalculator, stripeCustomerID string) *stripe.InvoiceItemParams {
 	params := getStripeInvoiceItemParams(line, calculator)
 	params.Customer = stripe.String(stripeCustomerID)
 	return params
 }
 
 // getPeriod returns the period
-func getPeriod(line *billing.Line) *stripe.InvoiceItemPeriodParams {
+func getPeriod(line billing.DetailedLine) *stripe.InvoiceItemPeriodParams {
 	return &stripe.InvoiceItemPeriodParams{
 		Start: lo.ToPtr(line.Period.Start.Unix()),
 		End:   lo.ToPtr(line.Period.End.Unix()),
 	}
 }
 
 // getDiscountLineName returns the line name
-func getDiscountLineName(line *billing.Line, discount billing.AmountLineDiscountManaged) string {
+func getDiscountLineName(line billing.DetailedLine, discount billing.AmountLineDiscountManaged) string {
 	name := line.Name
 	if discount.Description != nil {
 		name = fmt.Sprintf("%s (%s)", name, *discount.Description)
@@ -576,7 +576,7 @@ func getDiscountLineName(line *billing.Line, discount billing.AmountLineDiscount
 }
 
 // getLineName returns the line name
-func getLineName(line *billing.Line) string {
+func getLineName(line billing.DetailedLine) string {
 	name := line.Name
 	if line.Description != nil {
 		name = fmt.Sprintf("%s (%s)", name, *line.Description)

openmeter/billing/adapter/invoicelines.go

@@ -80,9 +80,9 @@ func (a *adapter) UpsertInvoiceLines(ctx context.Context, inputIn billing.Upsert
 					SetNillableSplitLineGroupID(line.SplitLineGroupID).
 					SetNillableDeletedAt(line.DeletedAt).
 					SetInvoiceAt(line.InvoiceAt.In(time.UTC)).
-					SetStatus(line.Status).
+					SetStatus(billing.InvoiceLineStatusValid).
 					SetManagedBy(line.ManagedBy).
-					SetType(line.Type).
+					SetType(billing.InvoiceLineTypeUsageBased).
 					SetName(line.Name).
 					SetNillableDescription(line.Description).
 					SetCurrency(line.Currency).
@@ -288,9 +288,9 @@ func (a *adapter) UpsertInvoiceLines(ctx context.Context, inputIn billing.Upsert
 	})
 }
 
-func (a *adapter) upsertFeeLineConfig(ctx context.Context, in diff[*billing.Line]) error {
-	return upsertWithOptions(ctx, a.db, in, upsertInput[*billing.Line, *db.BillingInvoiceFlatFeeLineConfigCreate]{
-		Create: func(tx *db.Client, line *billing.Line) (*db.BillingInvoiceFlatFeeLineConfigCreate, error) {
+func (a *adapter) upsertFeeLineConfig(ctx context.Context, in diff[*billing.DetailedLine]) error {
+	return upsertWithOptions(ctx, a.db, in, upsertInput[*billing.DetailedLine, *db.BillingInvoiceFlatFeeLineConfigCreate]{
+		Create: func(tx *db.Client, line *billing.DetailedLine) (*db.BillingInvoiceFlatFeeLineConfigCreate, error) {
 			if line.FlatFee.ConfigID == "" {
 				line.FlatFee.ConfigID = ulid.Make().String()
 			}
@@ -302,10 +302,7 @@ func (a *adapter) upsertFeeLineConfig(ctx context.Context, in diff[*billing.Line
 				SetPaymentTerm(line.FlatFee.PaymentTerm).
 				SetID(line.FlatFee.ConfigID)
 
-			if line.Status == billing.InvoiceLineStatusDetailed {
-				// TODO[later]: Detailed lines must be a separate entity, so that we don't need these hacks (like line config or type specific sets)
-				create = create.SetNillableIndex(line.FlatFee.Index)
-			}
+			create = create.SetNillableIndex(line.FlatFee.Index)
 
 			return create, nil
 		},

openmeter/billing/app.go

@@ -4,8 +4,10 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"strings"
 	"time"
 
+	"github.com/samber/lo"
 	"github.com/samber/mo"
 
 	"github.com/openmeterio/openmeter/openmeter/app"
@@ -217,44 +219,54 @@ func (r UpsertInvoiceResult) MergeIntoInvoice(invoice *Invoice) error {
 	if invoiceNumber, ok := r.GetInvoiceNumber(); ok {
 		invoice.Number = invoiceNumber
 	}
-
 	if externalID, ok := r.GetExternalID(); ok {
 		invoice.ExternalIDs.Invoicing = externalID
 	}
 
+	if !invoice.Lines.IsPresent() {
+		return errors.New("invoice has no expanded lines")
+	}
+
 	var outErr error
 
 	// Let's merge the line IDs
-	if len(r.GetLineExternalIDs()) > 0 {
-		flattenedLines := invoice.FlattenLinesByID()
-
-		// Merge the line IDs
-		for lineID, externalID := range r.GetLineExternalIDs() {
-			if line, ok := flattenedLines[lineID]; ok {
-				line.ExternalIDs.Invoicing = externalID
-			} else {
-				outErr = errors.Join(outErr, fmt.Errorf("line not found in invoice: %s", lineID))
-			}
+	lineIDToExternalID := r.GetLineExternalIDs()
+	dicountIDToExternalID := r.GetLineDiscountExternalIDs()
+
+	lines := invoice.Lines.OrEmpty()
+
+	for _, line := range lines {
+		if externalID, ok := lineIDToExternalID[line.ID]; ok {
+			line.ExternalIDs.Invoicing = externalID
+			delete(lineIDToExternalID, line.ID)
 		}
 
-		// Let's merge the line discount IDs
-		dicountIDToExternalID := r.GetLineDiscountExternalIDs()
+		foundIDs := line.SetDiscountExternalIDs(dicountIDToExternalID)
+		for _, id := range foundIDs {
+			delete(dicountIDToExternalID, id)
+		}
 
-		for _, line := range flattenedLines {
-			for idx, discount := range line.Discounts.Amount {
-				if externalID, ok := dicountIDToExternalID[discount.ID]; ok {
-					line.Discounts.Amount[idx].ExternalIDs.Invoicing = externalID
-				}
+		for idx, detailedLine := range line.Children {
+			if externalID, ok := lineIDToExternalID[detailedLine.ID]; ok {
+				line.Children[idx].ExternalIDs.Invoicing = externalID
+				delete(lineIDToExternalID, detailedLine.ID)
 			}
 
-			for idx, discount := range line.Discounts.Usage {
-				if externalID, ok := dicountIDToExternalID[discount.ID]; ok {
-					line.Discounts.Usage[idx].ExternalIDs.Invoicing = externalID
-				}
+			foundIDs := line.Children[idx].AmountDiscounts.SetDiscountExternalIDs(dicountIDToExternalID)
+			for _, id := range foundIDs {
+				delete(dicountIDToExternalID, id)
 			}
 		}
 	}
 
+	if len(lineIDToExternalID) > 0 {
+		outErr = errors.Join(outErr, fmt.Errorf("some lines were not found in the invoice: ids=[%s]", strings.Join(lo.Keys(lineIDToExternalID), ", ")))
+	}
+
+	if len(dicountIDToExternalID) > 0 {
+		outErr = errors.Join(outErr, fmt.Errorf("some line discounts were not found in the invoice: ids=[%s]", strings.Join(lo.Keys(dicountIDToExternalID), ", ")))
+	}
+
 	return outErr
 }
 

openmeter/billing/invoice.go

@@ -404,12 +404,10 @@ func (i Invoice) RemoveMetaForCompare() Invoice {
 	return invoice
 }
 
-func (i *Invoice) FlattenLinesByID() map[string]*Line {
-	out := make(map[string]*Line, len(i.Lines.OrEmpty()))
+func (i *Invoice) GetDetailedLinesByID() map[string]DetailedLine {
+	out := make(map[string]DetailedLine, len(i.Lines.OrEmpty()))
 
 	for _, line := range i.Lines.OrEmpty() {
-		out[line.ID] = line
-
 		for _, child := range line.Children {
 			out[child.ID] = child
 		}
@@ -418,31 +416,15 @@ func (i *Invoice) FlattenLinesByID() map[string]*Line {
 	return out
 }
 
-// getLeafLines returns the leaf lines
-func (i *Invoice) getLeafLines() []*Line {
-	var leafLines []*Line
-
-	for _, line := range i.FlattenLinesByID() {
-		// Skip non leaf nodes
-		if line.Type != InvoiceLineTypeFee {
-			continue
-		}
-
-		leafLines = append(leafLines, line)
-	}
-
-	return leafLines
-}
-
-// GetLeafLinesWithConsolidatedTaxBehavior returns the leaf lines with the tax behavior set to the invoice's tax behavior
+// GetDetailedLinesWithConsolidatedTaxBehavior returns the detailed lines with the tax behavior set to the invoice's tax behavior
 // unless the line already has a tax behavior set.
-func (i *Invoice) GetLeafLinesWithConsolidatedTaxBehavior() []*Line {
-	leafLines := i.getLeafLines()
+func (i *Invoice) GetDetailedLinesWithConsolidatedTaxBehavior() []DetailedLine {
+	leafLines := lo.Values(i.GetDetailedLinesByID())
 	if i.Workflow.Config.Invoicing.DefaultTaxConfig == nil {
 		return leafLines
 	}
 
-	return lo.Map(leafLines, func(line *Line, _ int) *Line {
+	return lo.Map(leafLines, func(line DetailedLine, _ int) DetailedLine {
 		line.TaxConfig = productcatalog.MergeTaxConfigs(i.Workflow.Config.Invoicing.DefaultTaxConfig, line.TaxConfig)
 		return line
 	})
@@ -469,55 +451,7 @@ func (i Invoice) RemoveCircularReferences() Invoice {
 }
 
 func (i *Invoice) SortLines() {
-	if !i.Lines.IsPresent() {
-		return
-	}
-
-	lines := i.Lines.OrEmpty()
-
-	sortLines(lines)
-
-	i.Lines = NewInvoiceLines(lines)
-}
-
-func sortLines(lines []*Line) {
-	sort.Slice(lines, func(a, b int) bool {
-		lineA := lines[a]
-		lineB := lines[b]
-
-		// If both lines are flat fee lines, we sort them by index if possible
-		if lineA.Type == InvoiceLineTypeFee && lineB.Type == InvoiceLineTypeFee {
-			if lineA.FlatFee.Index != nil && lineB.FlatFee.Index != nil {
-				return *lineA.FlatFee.Index < *lineB.FlatFee.Index
-			}
-
-			if lineA.FlatFee.Index != nil {
-				return true
-			}
-
-			if lineB.FlatFee.Index != nil {
-				return false
-			}
-		}
-
-		if nameOrder := strings.Compare(lineA.Name, lineB.Name); nameOrder != 0 {
-			return nameOrder < 0
-		}
-
-		if !lineA.Period.Start.Equal(lineB.Period.Start) {
-			return lineA.Period.Start.Before(lineB.Period.Start)
-		}
-
-		return strings.Compare(lineA.ID, lineB.ID) < 0
-	})
-
-	for idx, line := range lines {
-		if line.Type == InvoiceLineTypeUsageBased {
-			sortLines(line.Children)
-		}
-
-		lines[idx] = line
-	}
+	i.Lines.Sort()
 }
 
 type InvoiceLines struct {
@@ -586,10 +520,39 @@ func (c *InvoiceLines) ReplaceByID(id string, newLine *Line) bool {
 	return false
 }
 
+func (c *InvoiceLines) Sort() {
+	if c.IsAbsent() {
+		return
+	}
+
+	lines := c.OrEmpty()
+
+	sort.Slice(lines, func(a, b int) bool {
+		lineA := lines[a]
+		lineB := lines[b]
+
+		if nameOrder := strings.Compare(lineA.Name, lineB.Name); nameOrder != 0 {
+			return nameOrder < 0
+		}
+
+		if !lineA.Period.Start.Equal(lineB.Period.Start) {
+			return lineA.Period.Start.Before(lineB.Period.Start)
+		}
+
+		return strings.Compare(lineA.ID, lineB.ID) < 0
+	})
+
+	for _, line := range lines {
+		line.SortDetailedLines()
+	}
+
+	c.Option = mo.Some(lines)
+}
+
 // NonDeletedLineCount returns the number of lines that are not deleted and have a valid status (e.g. we are ignoring split lines)
 func (c InvoiceLines) NonDeletedLineCount() int {
 	return lo.CountBy(c.OrEmpty(), func(l *Line) bool {
-		return l.DeletedAt == nil && l.Status == InvoiceLineStatusValid
+		return l.DeletedAt == nil
 	})
 }