chore: initial commit

internal/svc/order/controller/kafka.go

@@ -0,0 +1,179 @@
+// Copyright (C) 2024 Declan Teevan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package controller
+
+import (
+	"context"
+
+	"github.com/rs/zerolog/log"
+	"github.com/twmb/franz-go/pkg/kgo"
+	"google.golang.org/protobuf/proto"
+
+	"github.com/hexolan/stocklet/internal/pkg/messaging"
+	eventpb "github.com/hexolan/stocklet/internal/pkg/protogen/events/v1"
+	pb "github.com/hexolan/stocklet/internal/pkg/protogen/order/v1"
+	"github.com/hexolan/stocklet/internal/svc/order"
+)
+
+type kafkaController struct {
+	cl *kgo.Client
+
+	svc pb.OrderServiceServer
+
+	ctx       context.Context
+	ctxCancel context.CancelFunc
+}
+
+func NewKafkaController(cl *kgo.Client) order.ConsumerController {
+	// Create a cancellable context for the consumer
+	ctx, ctxCancel := context.WithCancel(context.Background())
+
+	// Ensure the required Kafka topics exist
+	err := messaging.EnsureKafkaTopics(
+		cl,
+
+		messaging.Order_State_Created_Topic,
+		messaging.Order_State_Pending_Topic,
+		messaging.Order_State_Rejected_Topic,
+		messaging.Order_State_Approved_Topic,
+
+		messaging.Warehouse_Reservation_Failed_Topic,
+		messaging.Shipping_Shipment_Allocation_Topic,
+		messaging.Payment_Processing_Topic,
+	)
+	if err != nil {
+		log.Warn().Err(err).Msg("kafka: raised attempting to ensure svc topics")
+	}
+
+	// Add the consumption topics
+	cl.AddConsumeTopics(
+		messaging.Product_PriceQuotation_Topic,
+		messaging.Warehouse_Reservation_Failed_Topic,
+		messaging.Shipping_Shipment_Allocation_Topic,
+		messaging.Payment_Processing_Topic,
+	)
+
+	return &kafkaController{cl: cl, ctx: ctx, ctxCancel: ctxCancel}
+}
+
+func (c *kafkaController) Attach(svc pb.OrderServiceServer) {
+	c.svc = svc
+}
+
+func (c *kafkaController) Start() {
+	if c.svc == nil {
+		log.Panic().Msg("consumer: no service interface attached")
+	}
+
+	for {
+		fetches := c.cl.PollFetches(c.ctx)
+		if errs := fetches.Errors(); len(errs) > 0 {
+			log.Panic().Any("kafka-errs", errs).Msg("consumer: unrecoverable kafka errors")
+		}
+
+		fetches.EachTopic(func(ft kgo.FetchTopic) {
+			switch ft.Topic {
+			case messaging.Product_PriceQuotation_Topic:
+				c.consumeProductPriceQuoteEventTopic(ft)
+			case messaging.Warehouse_Reservation_Failed_Topic:
+				c.consumeStockReservationEventTopic(ft)
+			case messaging.Shipping_Shipment_Allocation_Topic:
+				c.consumeShipmentAllocationEventTopic(ft)
+			case messaging.Payment_Processing_Topic:
+				c.consumePaymentProcessedEventTopic(ft)
+			default:
+				log.Warn().Str("topic", ft.Topic).Msg("consumer: recieved records from unexpected topic")
+			}
+		})
+	}
+}
+
+func (c *kafkaController) Stop() {
+	// Cancel the consumer context
+	c.ctxCancel()
+}
+
+func (c *kafkaController) consumeProductPriceQuoteEventTopic(ft kgo.FetchTopic) {
+	log.Info().Str("topic", ft.Topic).Msg("consumer: recieved records from topic")
+
+	// Process each message from the topic
+	ft.EachRecord(func(record *kgo.Record) {
+		// Unmarshal the event
+		var event eventpb.ProductPriceQuoteEvent
+		err := proto.Unmarshal(record.Value, &event)
+		if err != nil {
+			log.Panic().Err(err).Msg("consumer: failed to unmarshal event")
+		}
+
+		// Process the event
+		ctx := context.Background()
+		c.svc.ProcessProductPriceQuoteEvent(ctx, &event)
+	})
+}
+
+func (c *kafkaController) consumeStockReservationEventTopic(ft kgo.FetchTopic) {
+	log.Info().Str("topic", ft.Topic).Msg("consumer: recieved records from topic")
+
+	// Process each message from the topic
+	ft.EachRecord(func(record *kgo.Record) {
+		// Unmarshal the event
+		var event eventpb.StockReservationEvent
+		err := proto.Unmarshal(record.Value, &event)
+		if err != nil {
+			log.Panic().Err(err).Msg("consumer: failed to unmarshal event")
+		}
+
+		// Process the event
+		ctx := context.Background()
+		c.svc.ProcessStockReservationEvent(ctx, &event)
+	})
+}
+
+func (c *kafkaController) consumeShipmentAllocationEventTopic(ft kgo.FetchTopic) {
+	log.Info().Str("topic", ft.Topic).Msg("consumer: recieved records from topic")
+
+	// Process each message from the topic
+	ft.EachRecord(func(record *kgo.Record) {
+		// Unmarshal the event
+		var event eventpb.ShipmentAllocationEvent
+		err := proto.Unmarshal(record.Value, &event)
+		if err != nil {
+			log.Panic().Err(err).Msg("consumer: failed to unmarshal event")
+		}
+
+		// Process the event
+		ctx := context.Background()
+		c.svc.ProcessShipmentAllocationEvent(ctx, &event)
+	})
+}
+
+func (c *kafkaController) consumePaymentProcessedEventTopic(ft kgo.FetchTopic) {
+	log.Info().Str("topic", ft.Topic).Msg("consumer: recieved records from topic")
+
+	// Process each message from the topic
+	ft.EachRecord(func(record *kgo.Record) {
+		// Unmarshal the event
+		var event eventpb.PaymentProcessedEvent
+		err := proto.Unmarshal(record.Value, &event)
+		if err != nil {
+			log.Panic().Err(err).Msg("consumer: failed to unmarshal event")
+		}
+
+		// Process the event
+		ctx := context.Background()
+		c.svc.ProcessPaymentProcessedEvent(ctx, &event)
+	})
+}

internal/svc/order/controller/postgres.go

@@ -0,0 +1,458 @@
+// Copyright (C) 2024 Declan Teevan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package controller
+
+import (
+	"context"
+	"time"
+
+	"github.com/doug-martin/goqu/v9"
+	_ "github.com/doug-martin/goqu/v9/dialect/postgres"
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgtype"
+	"github.com/jackc/pgx/v5/pgxpool"
+
+	"github.com/hexolan/stocklet/internal/pkg/errors"
+	pb "github.com/hexolan/stocklet/internal/pkg/protogen/order/v1"
+	"github.com/hexolan/stocklet/internal/svc/order"
+)
+
+const (
+	pgOrderBaseQuery      string = "SELECT id, status, customer_id, shipping_id, transaction_id, created_at, updated_at FROM orders"
+	pgOrderItemsBaseQuery string = "SELECT product_id, quantity FROM order_items"
+)
+
+// The postgres controller is responsible for implementing the StorageController interface
+// to store and retrieve the requested items from the Postgres database.
+//
+// Other controllers can be implemented to interface with different database systems.
+type postgresController struct {
+	cl *pgxpool.Pool
+}
+
+// Creates a new postgresController that implements the StorageController interface.
+func NewPostgresController(cl *pgxpool.Pool) order.StorageController {
+	return postgresController{cl: cl}
+}
+
+// Internal method - Validation is assumed to have taken place already
+// Gets an order by its specified id from the database
+func (c postgresController) GetOrder(ctx context.Context, orderId string) (*pb.Order, error) {
+	return c.getOrder(ctx, nil, orderId)
+}
+
+func (c postgresController) getOrder(ctx context.Context, tx *pgx.Tx, orderId string) (*pb.Order, error) {
+	// Query order
+	var row pgx.Row
+	if tx == nil {
+		row = c.cl.QueryRow(ctx, pgOrderBaseQuery+" WHERE id=$1", orderId)
+	} else {
+		row = (*tx).QueryRow(ctx, pgOrderBaseQuery+" WHERE id=$1", orderId)
+	}
+
+	// Scan row to protobuf order
+	order, err := scanRowToOrder(row)
+	if err != nil {
+		return nil, err
+	}
+
+	// Append the order items
+	order, err = c.appendItemsToOrderObj(ctx, tx, order)
+	if err != nil {
+		return nil, err
+	}
+
+	return order, nil
+}
+
+// Internal method - Inputs are assumed valid
+// Create a new order in the database
+func (c postgresController) CreateOrder(ctx context.Context, orderObj *pb.Order) (*pb.Order, error) {
+	// Begin a DB transaction
+	tx, err := c.cl.Begin(ctx)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to begin transaction", err)
+	}
+	defer tx.Rollback(ctx)
+
+	// Prepare and perform insert query
+	newOrder := pb.Order{
+		Items:      orderObj.Items,
+		Status:     orderObj.Status,
+		CustomerId: orderObj.CustomerId,
+		CreatedAt:  time.Now().Unix(),
+	}
+	err = tx.QueryRow(
+		ctx,
+		"INSERT INTO orders (status, customer_id) VALUES ($1, $2) RETURNING id",
+		newOrder.Status,
+		newOrder.CustomerId,
+	).Scan(&newOrder.Id)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to create order", err)
+	}
+
+	// Create records for any order items
+	err = c.createOrderItems(ctx, tx, newOrder.Id, newOrder.Items)
+	if err != nil {
+		// The deffered rollback will be called (so the transaction will not be commited)
+		return nil, err
+	}
+
+	// Prepare a created event.
+	//
+	// Then add the event to the outbox table with the transaction
+	// to ensure that the event will be dispatched if
+	// the transaction succeeds.
+	evt, evtTopic, err := order.PrepareOrderCreatedEvent(&newOrder)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeService, "failed to create order event", err)
+	}
+
+	_, err = tx.Exec(ctx, "INSERT INTO event_outbox (aggregateid, aggregatetype, payload) VALUES ($1, $2, $3)", newOrder.Id, evtTopic, evt)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to insert order event", err)
+	}
+
+	// Commit the transaction
+	err = tx.Commit(ctx)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to commit transaction", err)
+	}
+
+	return &newOrder, nil
+}
+
+// Get all orders related to a specified customer.
+// TODO: implement pagination
+func (c postgresController) GetCustomerOrders(ctx context.Context, customerId string) ([]*pb.Order, error) {
+	rows, err := c.cl.Query(ctx, pgOrderBaseQuery+" WHERE customer_id=$1 LIMIT 10", customerId)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeService, "query error whilst fetching customer orders", err)
+	}
+
+	orders := []*pb.Order{}
+	for rows.Next() {
+		orderObj, err := scanRowToOrder(rows)
+		if err != nil {
+			return nil, err
+		}
+
+		// Append the order's items
+		orderObj, err = c.appendItemsToOrderObj(ctx, nil, orderObj)
+		if err != nil {
+			return nil, err
+		}
+
+		orders = append(orders, orderObj)
+	}
+
+	if rows.Err() != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeService, "error whilst scanning order rows", rows.Err())
+	}
+
+	return orders, nil
+}
+
+// Set order status to approved
+// Dispatch OrderApprovedEvent
+func (c postgresController) ApproveOrder(ctx context.Context, orderId string, transactionId string) (*pb.Order, error) {
+	// Begin a DB transaction
+	tx, err := c.cl.Begin(ctx)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to begin transaction", err)
+	}
+	defer tx.Rollback(ctx)
+
+	// Execute update query
+	_, err = tx.Exec(
+		ctx,
+		"UPDATE orders SET status = $1, transaction_id = $2 WHERE id = $3",
+		pb.OrderStatus_ORDER_STATUS_APPROVED,
+		transactionId,
+		orderId,
+	)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to approve order", err)
+	}
+
+	orderObj, err := c.getOrder(ctx, &tx, orderId)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to approve order", err)
+	}
+
+	// Then add the event to the outbox table with the transaction.
+	evt, evtTopic, err := order.PrepareOrderApprovedEvent(orderObj)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeService, "failed to create event", err)
+	}
+
+	_, err = tx.Exec(ctx, "INSERT INTO event_outbox (aggregateid, aggregatetype, payload) VALUES ($1, $2, $3)", orderObj.Id, evtTopic, evt)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to insert event", err)
+	}
+
+	// Commit the transaction
+	err = tx.Commit(ctx)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to commit transaction", err)
+	}
+
+	return orderObj, nil
+}
+
+// Set order status to processing
+// Dispatch OrderProcessingEvent
+func (c postgresController) ProcessOrder(ctx context.Context, orderId string, itemsPrice float32) (*pb.Order, error) {
+	// Begin a DB transaction
+	tx, err := c.cl.Begin(ctx)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to begin transaction", err)
+	}
+	defer tx.Rollback(ctx)
+
+	// Execute update query
+	_, err = tx.Exec(
+		ctx,
+		"UPDATE orders SET status = $1, items_price = $2, total_price = $3 WHERE id = $4",
+		pb.OrderStatus_ORDER_STATUS_PROCESSING,
+		itemsPrice,
+		itemsPrice,
+		orderId,
+	)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to update order", err)
+	}
+
+	orderObj, err := c.getOrder(ctx, &tx, orderId)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to update order", err)
+	}
+
+	// Then add the event to the outbox table with the transaction.
+	// todo: fix name discrepency (mixed up processing and pending in my wording)
+	evt, evtTopic, err := order.PrepareOrderPendingEvent(orderObj)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeService, "failed to create event", err)
+	}
+
+	_, err = tx.Exec(ctx, "INSERT INTO event_outbox (aggregateid, aggregatetype, payload) VALUES ($1, $2, $3)", orderObj.Id, evtTopic, evt)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to insert event", err)
+	}
+
+	// Commit the transaction
+	err = tx.Commit(ctx)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to commit transaction", err)
+	}
+
+	return orderObj, nil
+}
+
+// Set order status to rejected (from processing)
+// Dispatch OrderRejectedEvent
+func (c postgresController) RejectOrder(ctx context.Context, orderId string) (*pb.Order, error) {
+	// Begin a DB transaction
+	tx, err := c.cl.Begin(ctx)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to begin transaction", err)
+	}
+	defer tx.Rollback(ctx)
+
+	// Execute update query
+	_, err = tx.Exec(
+		ctx,
+		"UPDATE orders SET status = $1 WHERE id = $2",
+		pb.OrderStatus_ORDER_STATUS_REJECTED,
+		orderId,
+	)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to approve order", err)
+	}
+
+	orderObj, err := c.getOrder(ctx, &tx, orderId)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to approve order", err)
+	}
+
+	// Then add the event to the outbox table with the transaction.
+	evt, evtTopic, err := order.PrepareOrderRejectedEvent(orderObj)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeService, "failed to create event", err)
+	}
+
+	_, err = tx.Exec(ctx, "INSERT INTO event_outbox (aggregateid, aggregatetype, payload) VALUES ($1, $2, $3)", orderObj.Id, evtTopic, evt)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to insert event", err)
+	}
+
+	// Commit the transaction
+	err = tx.Commit(ctx)
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeExtService, "failed to commit transaction", err)
+	}
+
+	return orderObj, nil
+}
+
+// Append shipment id to order
+func (c postgresController) SetOrderShipmentId(ctx context.Context, orderId string, shippingId string) error {
+	// Execute update query
+	_, err := c.cl.Exec(
+		ctx,
+		"UPDATE orders SET shipment_id = $1 WHERE id = $2",
+		shippingId,
+		orderId,
+	)
+	if err != nil {
+		return errors.WrapServiceError(errors.ErrCodeExtService, "failed to approve order", err)
+	}
+
+	return nil
+}
+
+// Build and exec an insert statement for a map of order items
+func (c postgresController) createOrderItems(ctx context.Context, tx pgx.Tx, orderId string, items map[string]int32) error {
+	// check there are items to add
+	if len(items) > 1 {
+		vals := [][]interface{}{}
+		for productId, quantity := range items {
+			vals = append(
+				vals,
+				goqu.Vals{orderId, productId, quantity},
+			)
+		}
+
+		statement, args, err := goqu.Dialect("postgres").From(
+			"order_items",
+		).Insert().Cols(
+			"order_id",
+			"product_id",
+			"quantity",
+		).Vals(
+			vals...,
+		).Prepared(
+			true,
+		).ToSQL()
+		if err != nil {
+			return errors.WrapServiceError(errors.ErrCodeService, "failed to build SQL statement", err)
+		}
+
+		// Execute the statement on the transaction
+		_, err = tx.Exec(ctx, statement, args...)
+		if err != nil {
+			return errors.WrapServiceError(errors.ErrCodeExtService, "failed to add items to order", err)
+		}
+	}
+
+	return nil
+}
+
+func (c postgresController) getOrderItems(ctx context.Context, tx *pgx.Tx, orderId string) (*map[string]int32, error) {
+	// Determine if transaction is being used.
+	var rows pgx.Rows
+	var err error
+	if tx == nil {
+		rows, err = c.cl.Query(ctx, pgOrderItemsBaseQuery+" WHERE order_id=$1", orderId)
+	} else {
+		rows, err = (*tx).Query(ctx, pgOrderItemsBaseQuery+" WHERE order_id=$1", orderId)
+	}
+
+	if err != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeService, "query error whilst fetching order items", err)
+	}
+
+	items := make(map[string]int32)
+	for rows.Next() {
+		var (
+			itemId   string
+			quantity int32
+		)
+		err := rows.Scan(
+			&itemId,
+			&quantity,
+		)
+		if err != nil {
+			return nil, errors.WrapServiceError(errors.ErrCodeService, "failed to scan an order item", err)
+		}
+
+		items[itemId] = quantity
+	}
+
+	if rows.Err() != nil {
+		return nil, errors.WrapServiceError(errors.ErrCodeService, "error whilst scanning order item rows", rows.Err())
+	}
+
+	return &items, nil
+}
+
+// Appends order items to an order object.
+func (c postgresController) appendItemsToOrderObj(ctx context.Context, tx *pgx.Tx, orderObj *pb.Order) (*pb.Order, error) {
+	// Load the order items
+	orderItems, err := c.getOrderItems(ctx, tx, orderObj.Id)
+	if err != nil {
+		return nil, err
+	}
+
+	// Add the order items to the order protobuf
+	orderObj.Items = *orderItems
+
+	// Return the order
+	return orderObj, nil
+}
+
+// Scan a postgres row to a protobuf order object.
+func scanRowToOrder(row pgx.Row) (*pb.Order, error) {
+	var order pb.Order
+
+	// Temporary variables that require conversion
+	var tmpCreatedAt pgtype.Timestamp
+	var tmpUpdatedAt pgtype.Timestamp
+
+	err := row.Scan(
+		&order.Id,
+		&order.Status,
+		&order.CustomerId,
+		&order.ShippingId,
+		&order.TransactionId,
+		&tmpCreatedAt,
+		&tmpUpdatedAt,
+	)
+	if err != nil {
+		if err == pgx.ErrNoRows {
+			return nil, errors.WrapServiceError(errors.ErrCodeNotFound, "order not found", err)
+		} else {
+			return nil, errors.WrapServiceError(errors.ErrCodeExtService, "something went wrong scanning order", err)
+		}
+	}
+
+	// Convert the temporary variables
+	//
+	// This includes converting postgres timestamps to unix format
+	if tmpCreatedAt.Valid {
+		order.CreatedAt = tmpCreatedAt.Time.Unix()
+	} else {
+		return nil, errors.NewServiceError(errors.ErrCodeUnknown, "failed to convert order (created_at) timestamp")
+	}
+
+	if tmpUpdatedAt.Valid {
+		unixUpdated := tmpUpdatedAt.Time.Unix()
+		order.UpdatedAt = &unixUpdated
+	}
+
+	return &order, nil
+}