implement reporter

also introduce gomock and tests

README.md

@@ -1,6 +1,9 @@
 # broker2anexoj
 
-This tool converts the statements from brokers into a format compatible with the Portuguese IRS form: [Mod_3_anexo_j](https://info.portaldasfinancas.gov.pt/pt/apoio_contribuinte/modelos_formularios/irs/Documents/Mod_3_anexo_J.pdf)
+This tool converts the statements from brokers and exchanges into a format compatible with the Portuguese IRS form: [Mod_3_anexo_j](https://info.portaldasfinancas.gov.pt/pt/apoio_contribuinte/modelos_formularios/irs/Documents/Mod_3_anexo_J.pdf)
+
+> [!WARNING]
+> Although I made significant efforts to ensure the correctness of the calculations you should verify any outputs produced by this tool on your own or with a certified accountant.
 
 > [!NOTE]
 > This tool is in early stages of development. Use at your own risk!

go.mod

@@ -1,3 +1,5 @@
 module git.naterciomoniz.net/applications/broker2anexoj
 
 go 1.25.3
+
+require go.uber.org/mock v0.6.0

go.sum

@@ -0,0 +1,2 @@
+go.uber.org/mock v0.6.0 h1:hyF9dfmbgIX5EfOdasqLsWD6xqpNZlXblLB/Dbnwv3Y=
+go.uber.org/mock v0.6.0/go.mod h1:KiVJ4BqZJaMj4svdfmHM0AUx4NJYO8ZNpPnZn1Z+BBU=

internal/generate.go

@@ -0,0 +1,3 @@
+package internal
+
+//go:generate mockgen -destination=mocks/mocks_gen.go -package=mocks -typed . RecordReader,Record

internal/mocks/mocks_gen.go

@@ -0,0 +1,296 @@
+// Code generated by MockGen. DO NOT EDIT.
+// Source: git.naterciomoniz.net/applications/broker2anexoj/internal (interfaces: RecordReader,Record)
+//
+// Generated by this command:
+//
+//	mockgen -destination=mocks/mocks_gen.go -package=mocks -typed . RecordReader,Record
+//
+
+// Package mocks is a generated GoMock package.
+package mocks
+
+import (
+	big "math/big"
+	reflect "reflect"
+	time "time"
+
+	internal "git.naterciomoniz.net/applications/broker2anexoj/internal"
+	gomock "go.uber.org/mock/gomock"
+)
+
+// MockRecordReader is a mock of RecordReader interface.
+type MockRecordReader struct {
+	ctrl     *gomock.Controller
+	recorder *MockRecordReaderMockRecorder
+	isgomock struct{}
+}
+
+// MockRecordReaderMockRecorder is the mock recorder for MockRecordReader.
+type MockRecordReaderMockRecorder struct {
+	mock *MockRecordReader
+}
+
+// NewMockRecordReader creates a new mock instance.
+func NewMockRecordReader(ctrl *gomock.Controller) *MockRecordReader {
+	mock := &MockRecordReader{ctrl: ctrl}
+	mock.recorder = &MockRecordReaderMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use.
+func (m *MockRecordReader) EXPECT() *MockRecordReaderMockRecorder {
+	return m.recorder
+}
+
+// ReadRecord mocks base method.
+func (m *MockRecordReader) ReadRecord() (internal.Record, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "ReadRecord")
+	ret0, _ := ret[0].(internal.Record)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// ReadRecord indicates an expected call of ReadRecord.
+func (mr *MockRecordReaderMockRecorder) ReadRecord() *MockRecordReaderReadRecordCall {
+	mr.mock.ctrl.T.Helper()
+	call := mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ReadRecord", reflect.TypeOf((*MockRecordReader)(nil).ReadRecord))
+	return &MockRecordReaderReadRecordCall{Call: call}
+}
+
+// MockRecordReaderReadRecordCall wrap *gomock.Call
+type MockRecordReaderReadRecordCall struct {
+	*gomock.Call
+}
+
+// Return rewrite *gomock.Call.Return
+func (c *MockRecordReaderReadRecordCall) Return(arg0 internal.Record, arg1 error) *MockRecordReaderReadRecordCall {
+	c.Call = c.Call.Return(arg0, arg1)
+	return c
+}
+
+// Do rewrite *gomock.Call.Do
+func (c *MockRecordReaderReadRecordCall) Do(f func() (internal.Record, error)) *MockRecordReaderReadRecordCall {
+	c.Call = c.Call.Do(f)
+	return c
+}
+
+// DoAndReturn rewrite *gomock.Call.DoAndReturn
+func (c *MockRecordReaderReadRecordCall) DoAndReturn(f func() (internal.Record, error)) *MockRecordReaderReadRecordCall {
+	c.Call = c.Call.DoAndReturn(f)
+	return c
+}
+
+// MockRecord is a mock of Record interface.
+type MockRecord struct {
+	ctrl     *gomock.Controller
+	recorder *MockRecordMockRecorder
+	isgomock struct{}
+}
+
+// MockRecordMockRecorder is the mock recorder for MockRecord.
+type MockRecordMockRecorder struct {
+	mock *MockRecord
+}
+
+// NewMockRecord creates a new mock instance.
+func NewMockRecord(ctrl *gomock.Controller) *MockRecord {
+	mock := &MockRecord{ctrl: ctrl}
+	mock.recorder = &MockRecordMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use.
+func (m *MockRecord) EXPECT() *MockRecordMockRecorder {
+	return m.recorder
+}
+
+// Price mocks base method.
+func (m *MockRecord) Price() *big.Float {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Price")
+	ret0, _ := ret[0].(*big.Float)
+	return ret0
+}
+
+// Price indicates an expected call of Price.
+func (mr *MockRecordMockRecorder) Price() *MockRecordPriceCall {
+	mr.mock.ctrl.T.Helper()
+	call := mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Price", reflect.TypeOf((*MockRecord)(nil).Price))
+	return &MockRecordPriceCall{Call: call}
+}
+
+// MockRecordPriceCall wrap *gomock.Call
+type MockRecordPriceCall struct {
+	*gomock.Call
+}
+
+// Return rewrite *gomock.Call.Return
+func (c *MockRecordPriceCall) Return(arg0 *big.Float) *MockRecordPriceCall {
+	c.Call = c.Call.Return(arg0)
+	return c
+}
+
+// Do rewrite *gomock.Call.Do
+func (c *MockRecordPriceCall) Do(f func() *big.Float) *MockRecordPriceCall {
+	c.Call = c.Call.Do(f)
+	return c
+}
+
+// DoAndReturn rewrite *gomock.Call.DoAndReturn
+func (c *MockRecordPriceCall) DoAndReturn(f func() *big.Float) *MockRecordPriceCall {
+	c.Call = c.Call.DoAndReturn(f)
+	return c
+}
+
+// Quantity mocks base method.
+func (m *MockRecord) Quantity() *big.Float {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Quantity")
+	ret0, _ := ret[0].(*big.Float)
+	return ret0
+}
+
+// Quantity indicates an expected call of Quantity.
+func (mr *MockRecordMockRecorder) Quantity() *MockRecordQuantityCall {
+	mr.mock.ctrl.T.Helper()
+	call := mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Quantity", reflect.TypeOf((*MockRecord)(nil).Quantity))
+	return &MockRecordQuantityCall{Call: call}
+}
+
+// MockRecordQuantityCall wrap *gomock.Call
+type MockRecordQuantityCall struct {
+	*gomock.Call
+}
+
+// Return rewrite *gomock.Call.Return
+func (c *MockRecordQuantityCall) Return(arg0 *big.Float) *MockRecordQuantityCall {
+	c.Call = c.Call.Return(arg0)
+	return c
+}
+
+// Do rewrite *gomock.Call.Do
+func (c *MockRecordQuantityCall) Do(f func() *big.Float) *MockRecordQuantityCall {
+	c.Call = c.Call.Do(f)
+	return c
+}
+
+// DoAndReturn rewrite *gomock.Call.DoAndReturn
+func (c *MockRecordQuantityCall) DoAndReturn(f func() *big.Float) *MockRecordQuantityCall {
+	c.Call = c.Call.DoAndReturn(f)
+	return c
+}
+
+// Side mocks base method.
+func (m *MockRecord) Side() internal.Side {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Side")
+	ret0, _ := ret[0].(internal.Side)
+	return ret0
+}
+
+// Side indicates an expected call of Side.
+func (mr *MockRecordMockRecorder) Side() *MockRecordSideCall {
+	mr.mock.ctrl.T.Helper()
+	call := mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Side", reflect.TypeOf((*MockRecord)(nil).Side))
+	return &MockRecordSideCall{Call: call}
+}
+
+// MockRecordSideCall wrap *gomock.Call
+type MockRecordSideCall struct {
+	*gomock.Call
+}
+
+// Return rewrite *gomock.Call.Return
+func (c *MockRecordSideCall) Return(arg0 internal.Side) *MockRecordSideCall {
+	c.Call = c.Call.Return(arg0)
+	return c
+}
+
+// Do rewrite *gomock.Call.Do
+func (c *MockRecordSideCall) Do(f func() internal.Side) *MockRecordSideCall {
+	c.Call = c.Call.Do(f)
+	return c
+}
+
+// DoAndReturn rewrite *gomock.Call.DoAndReturn
+func (c *MockRecordSideCall) DoAndReturn(f func() internal.Side) *MockRecordSideCall {
+	c.Call = c.Call.DoAndReturn(f)
+	return c
+}
+
+// Symbol mocks base method.
+func (m *MockRecord) Symbol() string {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Symbol")
+	ret0, _ := ret[0].(string)
+	return ret0
+}
+
+// Symbol indicates an expected call of Symbol.
+func (mr *MockRecordMockRecorder) Symbol() *MockRecordSymbolCall {
+	mr.mock.ctrl.T.Helper()
+	call := mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Symbol", reflect.TypeOf((*MockRecord)(nil).Symbol))
+	return &MockRecordSymbolCall{Call: call}
+}
+
+// MockRecordSymbolCall wrap *gomock.Call
+type MockRecordSymbolCall struct {
+	*gomock.Call
+}
+
+// Return rewrite *gomock.Call.Return
+func (c *MockRecordSymbolCall) Return(arg0 string) *MockRecordSymbolCall {
+	c.Call = c.Call.Return(arg0)
+	return c
+}
+
+// Do rewrite *gomock.Call.Do
+func (c *MockRecordSymbolCall) Do(f func() string) *MockRecordSymbolCall {
+	c.Call = c.Call.Do(f)
+	return c
+}
+
+// DoAndReturn rewrite *gomock.Call.DoAndReturn
+func (c *MockRecordSymbolCall) DoAndReturn(f func() string) *MockRecordSymbolCall {
+	c.Call = c.Call.DoAndReturn(f)
+	return c
+}
+
+// Timestamp mocks base method.
+func (m *MockRecord) Timestamp() time.Time {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Timestamp")
+	ret0, _ := ret[0].(time.Time)
+	return ret0
+}
+
+// Timestamp indicates an expected call of Timestamp.
+func (mr *MockRecordMockRecorder) Timestamp() *MockRecordTimestampCall {
+	mr.mock.ctrl.T.Helper()
+	call := mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Timestamp", reflect.TypeOf((*MockRecord)(nil).Timestamp))
+	return &MockRecordTimestampCall{Call: call}
+}
+
+// MockRecordTimestampCall wrap *gomock.Call
+type MockRecordTimestampCall struct {
+	*gomock.Call
+}
+
+// Return rewrite *gomock.Call.Return
+func (c *MockRecordTimestampCall) Return(arg0 time.Time) *MockRecordTimestampCall {
+	c.Call = c.Call.Return(arg0)
+	return c
+}
+
+// Do rewrite *gomock.Call.Do
+func (c *MockRecordTimestampCall) Do(f func() time.Time) *MockRecordTimestampCall {
+	c.Call = c.Call.Do(f)
+	return c
+}
+
+// DoAndReturn rewrite *gomock.Call.DoAndReturn
+func (c *MockRecordTimestampCall) DoAndReturn(f func() time.Time) *MockRecordTimestampCall {
+	c.Call = c.Call.DoAndReturn(f)
+	return c
+}

internal/record.go

@@ -36,7 +36,7 @@ func (rq *RecordQueue) Push(r Record) {
 	rq.l.PushBack(r)
 }
 
-// Pop removes and returns the first element of the list as the first return value. If the list is
+// Pop removes and returns the first Record of the list as the first return value. If the list is
 // empty returns falso on the 2nd return value, true otherwise.
 func (rq *RecordQueue) Pop() (Record, bool) {
 	if rq == nil || rq.l == nil {

internal/reporter.go

@@ -0,0 +1,130 @@
+package internal
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"log/slog"
+	"math/big"
+	"sync"
+)
+
+type RecordReader interface {
+	// ReadRecord should return Records until an error is found.
+	ReadRecord() (Record, error)
+}
+
+// Reporter consumes each record to produce ReportItem.
+type Reporter struct {
+	reader RecordReader
+}
+
+func NewReporter(rr RecordReader) *Reporter {
+	return &Reporter{
+		reader: rr,
+	}
+}
+
+func (r *Reporter) Run() error {
+	forewarders := make(map[string]chan Record)
+
+	aggregator := make(chan processResult)
+	defer close(aggregator)
+
+	go func() {
+		for result := range aggregator {
+			fmt.Printf("%v\n", result)
+		}
+	}()
+
+	wg := sync.WaitGroup{}
+	defer func() {
+		wg.Wait()
+	}()
+
+	for {
+		rec, err := r.reader.ReadRecord()
+		if err != nil {
+			if errors.Is(err, io.EOF) {
+				return nil
+			}
+			return err
+		}
+
+		router, ok := forewarders[rec.Symbol()]
+		if !ok {
+			router = make(chan Record, 1)
+			defer close(router)
+
+			wg.Go(func() {
+				processRecords(router, aggregator)
+			})
+
+			forewarders[rec.Symbol()] = router
+		}
+
+		router <- rec
+	}
+}
+
+func processRecords(records <-chan Record, results chan<- processResult) {
+	var q RecordQueue
+
+	for rec := range records {
+		switch rec.Side() {
+		case SideBuy:
+			q.Push(rec)
+
+		case SideSell:
+			unmatchedQty := new(big.Float).Copy(rec.Quantity())
+			zero := new(big.Float)
+
+			for unmatchedQty.Cmp(zero) > 0 {
+				buy, ok := q.Pop()
+				if !ok {
+					results <- processResult{
+						err: ErrSellWithoutBuy,
+					}
+					return
+				}
+
+				var matchedQty *big.Float
+				if buy.Quantity().Cmp(unmatchedQty) > 0 {
+					matchedQty = unmatchedQty
+					buy.Quantity().Sub(buy.Quantity(), unmatchedQty)
+				} else {
+					matchedQty = buy.Quantity()
+				}
+
+				unmatchedQty.Sub(unmatchedQty, matchedQty)
+
+				sellValue := new(big.Float).Mul(matchedQty, rec.Price())
+				buyValue := new(big.Float).Mul(matchedQty, buy.Price())
+				realisedPnL := new(big.Float).Sub(sellValue, buyValue)
+				slog.Info("Realised PnL",
+					slog.Any("Symbol", rec.Symbol()),
+					slog.Any("PnL", realisedPnL),
+					slog.Any("Timestamp", rec.Timestamp()))
+
+				results <- processResult{
+					item: ReportItem{},
+				}
+			}
+
+		default:
+			results <- processResult{
+				err: fmt.Errorf("unknown side: %v", rec.Side()),
+			}
+			return
+		}
+	}
+}
+
+type processResult struct {
+	item ReportItem
+	err  error
+}
+
+type ReportItem struct{}
+
+var ErrSellWithoutBuy = fmt.Errorf("found sell without bought volume")

internal/reporter_test.go

@@ -0,0 +1,42 @@
+package internal_test
+
+import (
+	"io"
+	"math/big"
+	"testing"
+
+	"git.naterciomoniz.net/applications/broker2anexoj/internal"
+	"git.naterciomoniz.net/applications/broker2anexoj/internal/mocks"
+	"go.uber.org/mock/gomock"
+)
+
+func TestReporter_Run(t *testing.T) {
+	ctrl := gomock.NewController(t)
+
+	rec := mocks.NewMockRecord(ctrl)
+	rec.EXPECT().Price().Return(big.NewFloat(1.25)).AnyTimes()
+	rec.EXPECT().Quantity().Return(big.NewFloat(10)).AnyTimes()
+	rec.EXPECT().Side().Return(internal.SideBuy).AnyTimes()
+	rec.EXPECT().Symbol().Return("TEST").AnyTimes()
+
+	reader := mocks.NewMockRecordReader(ctrl)
+	records := []internal.Record{
+		rec,
+		rec,
+	}
+	reader.EXPECT().ReadRecord().DoAndReturn(func() (internal.Record, error) {
+		if len(records) > 0 {
+			r := records[0]
+			records = records[1:]
+			return r, nil
+		} else {
+			return nil, io.EOF
+		}
+	}).AnyTimes()
+
+	reporter := internal.NewReporter(reader)
+	gotErr := reporter.Run()
+	if gotErr != nil {
+		t.Fatalf("got unexpected err: %v", gotErr)
+	}
+}

internal/trading212/record.go

@@ -56,7 +56,7 @@ const (
 	LimitSell  = "limit sell"
 )
 
-func (rr RecordReader) ReadRecord() (Record, error) {
+func (rr RecordReader) ReadRecord() (internal.Record, error) {
 	for {
 		raw, err := rr.reader.Read()
 		if err != nil {

internal/trading212/record_test.go

@@ -111,24 +111,24 @@ func TestRecordReader_ReadRecord(t *testing.T) {
 				t.Fatalf("ReadRecord() expected an error")
 			}
 
-			if got.symbol != tt.want.symbol {
-				t.Fatalf("want symbol %v but got %v", tt.want.symbol, got.symbol)
+			if got.Symbol() != tt.want.symbol {
+				t.Fatalf("want symbol %v but got %v", tt.want.symbol, got.Symbol())
 			}
 
-			if got.side != tt.want.side {
-				t.Fatalf("want side %v but got %v", tt.want.side, got.side)
+			if got.Side() != tt.want.side {
+				t.Fatalf("want side %v but got %v", tt.want.side, got.Side())
 			}
 
-			if got.price.Cmp(tt.want.price) != 0 {
-				t.Fatalf("want price %v but got %v", tt.want.price, got.price)
+			if got.Price().Cmp(tt.want.price) != 0 {
+				t.Fatalf("want price %v but got %v", tt.want.price, got.Price())
 			}
 
-			if got.quantity.Cmp(tt.want.quantity) != 0 {
-				t.Fatalf("want quantity %v but got %v", tt.want.quantity, got.quantity)
+			if got.Quantity().Cmp(tt.want.quantity) != 0 {
+				t.Fatalf("want quantity %v but got %v", tt.want.quantity, got.Quantity())
 			}
 
-			if !got.timestamp.Equal(tt.want.timestamp) {
-				t.Fatalf("want timestamp %v but got %v", tt.want.timestamp, got.timestamp)
+			if !got.Timestamp().Equal(tt.want.timestamp) {
+				t.Fatalf("want timestamp %v but got %v", tt.want.timestamp, got.Timestamp())
 			}
 		})
 	}

main.go

@@ -1,12 +1,8 @@
 package main
 
 import (
-	"container/list"
-	"errors"
 	"fmt"
-	"io"
 	"log/slog"
-	"math/big"
 	"os"
 
 	"git.naterciomoniz.net/applications/broker2anexoj/internal"
@@ -26,72 +22,16 @@ func run() error {
 		return fmt.Errorf("open statement: %w", err)
 	}
 
-	r := trading212.NewRecordReader(f)
+	reader := trading212.NewRecordReader(f)
 
-	assets := make(map[string]*list.List)
-	for {
-		record, err := r.ReadRecord()
+	reporter := internal.NewReporter(reader)
+
+	err = reporter.Run()
 	if err != nil {
-			if errors.Is(err, io.EOF) {
-				break
-			}
-			return fmt.Errorf("read statement record: %w", err)
+		return err
 	}
 
-		switch record.Side() {
-		case internal.SideBuy:
-			lst, ok := assets[record.Symbol()]
-			if !ok {
-				lst = list.New()
-				assets[record.Symbol()] = lst
-			}
-			lst.PushBack(record)
-
-		case internal.SideSell:
-			lst, ok := assets[record.Symbol()]
-			if !ok {
-				return ErrSellWithoutBuy
-			}
-
-			unmatchedQty := new(big.Float).Copy(record.Quantity())
-			zero := new(big.Float)
-
-			for unmatchedQty.Cmp(zero) > 0 {
-				front := lst.Front()
-				if front == nil {
-					return ErrSellWithoutBuy
-				}
-
-				next, ok := front.Value.(internal.Record)
-				if !ok {
-					return fmt.Errorf("unexpected record type: %T", front)
-				}
-
-				var matchedQty *big.Float
-				if next.Quantity().Cmp(unmatchedQty) > 0 {
-					matchedQty = unmatchedQty
-					next.Quantity().Sub(next.Quantity(), unmatchedQty)
-				} else {
-					matchedQty = next.Quantity()
-					lst.Remove(front)
-				}
-
-				unmatchedQty.Sub(unmatchedQty, matchedQty)
-
-				sellValue := new(big.Float).Mul(matchedQty, record.Price())
-				buyValue := new(big.Float).Mul(matchedQty, next.Price())
-				realisedPnL := new(big.Float).Sub(sellValue, buyValue)
-				slog.Info("Realised PnL",
-					slog.Any("Symbol", record.Symbol()),
-					slog.Any("PnL", realisedPnL))
-			}
-
-		default:
-			return fmt.Errorf("unknown side: %s", record.Side())
-		}
-	}
-
-	slog.Info("Finish processing statement", slog.Any("assets_count", len(assets)))
+	slog.Info("Finish processing statement")
 
 	return nil
 }